Author Topic: How to Build a Rifling Machine.......A to Z  (Read 67317 times)

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Offline GGaskill

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Re: How to Build a Rifling Machine.......A to Z
« Reply #30 on: January 09, 2007, 08:30:16 AM »
Running that hand wheel round and round turns your arm to rubber!

So why is the wheel hand turned instead of electric motor turned?  You need the feel?
GG
“If you're not a liberal at 20, you have no heart; if you're not a conservative at 40, you have no brain.”
--Winston Churchill

Offline CU_Cannon

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Re: How to Build a Rifling Machine.......A to Z
« Reply #31 on: January 09, 2007, 03:49:53 PM »
I have been considered building a rifling machine for some time now.  If for no other reason than for the challenge.  It will be a long time before I attempt on of my own.  I look forward to reading your description. 

I second what Wes said.  There are few out there that really appreciate the amount of time and effort that goes into the quality of work you are producing. 

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #32 on: January 09, 2007, 05:36:05 PM »
     Jeeper1,  you are right on; Green River, UT.

     GGaskill,  in a word, yes, especially during the experimental tube rifling phase of your initial cutting tool and technique development.  Much more on this after we review our experiment notebook.  An important question.

     CU-Cannon,  Thanks for your seconding of Wes's much appreciated comments.  We believe you fellows and probably most who follow these postings realize that this work which we do is way beyond just another job or career for Mike and I.  It is more of a calling.  Back to Cannons - although Mike and I have sent over a ton of concrete downrange over the years out of three smooth bore cannon,  we still don't own anything as nice as those which you have built.  They are REALLY good looking guns.  Someday maybe!  Hope you build a rifling machine eventually; it's a challenge with with tangible results at the end of the tunnel.  When you walk down to your 100 yard target and find your 5 cannon shots went into a group of less than four inches, it's a moment that you will NEVER forget.

Thanks to all.      Mike and Tracy

Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #33 on: January 12, 2007, 10:46:47 AM »
Tracy has been out of action for a couple days.  He is now a Grandpa! His daugters first child a big boy at 9Lbs 7oz.  He will be heplping the new Dad, mom and baby get organized for a couple more days, then we can get back to work and finish up the rifling mach. photos and construction detail. We hope to release step by step instructions around next Wed. Jan. 17th.  Thx for being patient.

Mike
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Cat Whisperer

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Re: How to Build a Rifling Machine.......A to Z
« Reply #34 on: January 12, 2007, 01:12:06 PM »
Tracy has been out of action for a couple days.  He is now a Grandpa!
...
Mike

Mike - That says his priorities are right!

Tim K                 www.GBOCANNONS.COM
Cat Whisperer
Chief of Smoke, Pulaski Coehorn Works & Winery
U.S.Army Retired
N 37.05224  W 80.78133 (front door +/- 15 feet)

Offline gimlet

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Re: How to Build a Rifling Machine.......A to Z
« Reply #35 on: January 17, 2007, 05:09:16 PM »
I'm still with you on this, and hope to be till the end. I found the questions & comments so far on twist rates interesting. I've tinkered with black powder cartdrige rifles some. By far the most accurite is an old Krag I rebarrled to 40 cal. By rights it has way to fast a twist. Sometimes the rules just don't seem to apply.  Butch

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #36 on: January 17, 2007, 08:20:29 PM »
I'm a grandpa! I'm changing diapers again after 20 years. He's a real cute boy and his Mommy and Daddy are very proud of him, and so am I.
     
      Don’t you just hate it when, after finally getting the entire family in the car and driving to the Cineplex without any major sibling fights or traffic hassles and getting them in their seats on-time for a change, you must still sit through 20 minutes of commercials before the Feature Film actually starts?  What ever became of CARTOONS?  Sorry guys, but the first six photos are a shameless commercial for Seacoast Artillery Company.   



 

     These photos show a few of the hundreds of details which Mike and I re-create on the fully-functional, EXACT, 1/6th scale 100 Pdr. Parrott Rifle, Model 1861 that our company produces.   Please click on our banner on this forum for more information.

Rifling Machine Information Starts Here


     We are not selling our rifling machine or any copies of it.  It works very well for our purposes.  With a change of rifling heads we can produce any historically accurate rifling which any seacoast rifled cannon produced during the Civil War era possessed, in a reduced scale, of course.  Now we will tell you what it won’t do and also what it isn’t.  Our very simple, basic, sine bar rifling machine isn’t fast, isn’t automatic, isn’t hydraulic and isn’t  pretty or polished.  It won’t do two barrels at once, won’t do deep-hole drilling or reaming.  It won’t do automatic barrel indexing to cut the next groove.  It does not have a flow-through oil system to lubricate the hook cutter or to flush the shavings out.  You use an acid brush to paint the hook with dark, high-sulfur, thread-cutting oil BEFORE each stroke.  You also clear the shavings from the recess for them in the rifling head immediately in front of the hook with a different acid brush AFTER each stroke. 

     What will Seacoast Artillery’s rifling machine do?   Our rifling machine will transform a “round of rifle barrel steel”, at  a hardness of up to 32 on the Rockwell ‘C’ Scale, which has been gundrilled straight, and reamed smoothly to size, into an accurate, rifled cannon tube.  The machines weight, almost 400 pounds, and the rigidity of the chassis contribute to its ability to cut accurate grooves in hardened steel.  Even more important is the fact that there are no misalignment's which cause binding or vibration  of the components as they move back and forth.  The whirring of the chain drive is the only sound you hear as our machine does it’s work. 

     More good news is that this particular type of machine is fairly easy to build and also relatively inexpensive.  If you really buy your components carefully, we think you could build one for less than $200.  We went to the scrap-yard for our steel and blocks of aluminum.  The most expensive items which we purchased were the two 66” long, 1.500” diameter Thompson ball bushing “ways” for the carriage to ride on.  Used they cost approximately  $100. 

       Step 1.     Determine whether you are willing to sign up for a year or two of build and development and fine-tune time.  Following those efforts you also must consider the large number of field tests necessary to find out if you are reaching your accuracy goal.  You probably want to know if what you have built is actually capable of producing an accurate artillery tube.



On the top left is the 100 yard target shot by our 4th experimental rifled tube which documents the attainment of our main goal which was to create a rifled cannon tube which was capable of a 5 shot, 4 inch or less group at 100 yards.  This 3.25 Inch group, measured center to center, was shot in May of 2004, just about one year after we started to build our rifling machine. 

Photo # Two is a shot of our experimental barrel testing fixture.  Look at that precision landscape timber and that 35 pound chunk of steel straight from the scrap yard.  Don’t laugh; this thing actually works quite well!  It provides a stable platform for testing various rifling configurations without wasting a lot of time with exterior shaping when, as yet, you are not quite sure of your rifling expertise.   We used the same size 4150 steel round at 28 Rc hardness for all of our tests which was 2.5” dia., 18” O.A.L. with a 1.000” bore and a rifled section that was 15.5 inches long and a threaded breech plug 1.300” Long, un-welded.  The one pictured is our first SUCCESSFUL rifled tube which shot the target featured here.  To say we were happy with this result is the “understatement of the century”. 

The other photos show a small part of the whole new world of experimentation which opens up to you after you rifle your very first artillery tube.  The possibilities are endless.  You may want to try solid steel bullets which you create on a lathe or scopes on cannons which looks very bizarre.  How about recoiling landscape logs and lots of range testing which is loads of fun? 





Step 2.     Determine what specific types of rifling that you want to produce.  This decision will affect the width of your machine.  The faster the rate of twist, the wider the machine must be to accommodate the increased angle of the sine bar, even with a smaller pinion gear.  These photos show the various types of seacoast gun rifling that we considered when we designed our particular machine’s rate of twist capability.  For our use, we determined that the Parrott 100 Pdr. had the fastest twist of any gun we had an interest in.  It was one turn in 18 Ft. on the original.  Our gun is 1/6th scale, therefore, 18/6=3.  Our machine will rifle a tube with one turn in 36 inches and it is only 15 ¾” wide.  We do not like extremely small pinion gears.  We can measure backlash between the pinion and the rack and we don’t want to increase this “slop” between the teeth engaged.  If you build a machine similar to ours, just add 6 inches to the width and rifle clear down to 1 turn in 8”, 9”or 10”.   A 1/6th scale 12 Pdr. Whitworth will require a twist of a tiny bit more than 1 turn in 9”, actually 1 turn in 9.167”.  Original is 1 turn in 55”.

   One---100 Pdr. Parrott Rifle in City Park, Denver, Colorado
   Two---7” Brooke at the National Civil War Naval Museum in Columbus, Georgia
   Three---150 Pdr. Armstrong Rifle  at the U.S.M.A. at West Point, New York
   Four---Unbanded Confederate Rifled 32 Pdr. At Fort Gaines, Alabama
For Field Artillery enthusiasts the following unique rifling is presented:
   Five---Ames gun with “James System” rifling at Wilson Creek Battlefield, MO 





Step 3.     Consider the O.A.L. of this type of machine and where it will be used.  Our version, which will rifle tubes of 54” maximum length, is 2 inches shy of 10 Feet long.
It requires approx. 40 square feet of floor space when in use. 


Step4.     If you do not have a spare, unused lathe gathering dust like Cat Whisperer's, which, most likely, would make an excellent foundation for a rifling machine, head for the scrap yard to buy some steel and aluminum.  You can get some useful dimensions off our marker board drawing.  Careful planning will help you prevent any serious “capability” issues later on.  Initial mistakes in your design are a lot easier to correct on paper!!  On Thursday Mike and I will attempt to answer some of your excellent questions and on Friday and Saturday we will get back to posting photos and descriptions of construction details.
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #37 on: January 18, 2007, 08:16:04 PM »
                                                                  Basic Functioning of a Sine-bar Rifling Machine and Q&A

     A machine of this type basically turns the linear motion of the carriage on the the ways into rotary motion thru the interaction of the follower attached to the rack moving along the sine-bar while moving the rack at right angles to the movement of the carriage.  The movement of the rack, in turn, rotates the pinion gear attached to the pinion gear shaft upon the end of which is the firmly attached rifling head.  The simultaneous rotation and linear movement of the rifling head within the tube is what creates the helix or spiral twist of the groove being cut.

     Gimlet asked, "I'm curious about twist rates.  I think they should get slower as the bore gets bigger, but don't really know."  Mike and I have been interested in rates of twist and stabilization since we started to shoot 45-70s in various configurations since 1973.  After all what rifle cartridge throws its bullets through a trajectory most like an artillery round's trajectory?  We did quite a bit of reading on this subject over the years and we believe that your assumption is quite correct.  As proof we offer these facts:  the original 100 Pdr. Parrott Rifle,(6.4"), has a gain twist of zero to one turn in 18 feet.  The 200 Pdr. Parrott Rifle,(8"), has a gain twist of zero to one turn in 23 feet.  The 300 Pdr. Parrott Rifle, (10"), has a gain twist of zero to one turn in 30 feet.

     I posed a situation where the bore size was known, and the bullet wt., hence length, was known, but the twist necessary to stabilize that bullet was not.  A quick response from Cat Whisperer was noted when he wrote, 'Let me guess, would this have something to do with the Greenhill formula?"  He was correct, this formula has been used for years and years to determine the right twist for stabilizing bullets of the 45-70 configuration and most 19th century artillery shells.  It is expressed:  T=(150/L) x D squared       Where:   T=Twist     L=Bullet length
D=Bore diameter      150=a constant

     Will Bison wrote that he has a rifle tube with 16 or 18 grooves and a twist that seemed to be too fast at one turn in about 96".  I agree vigorously with guardsgunner who said the twist is about right for civil war projectiles and he thinks a Read type elongated projectile would be the way to go.  Another option would be a milled-base Brooke type projectile which can be turned from a single piece of malleable steel such as 12L14. 

     Don Krag asked, "What's the optimum(if any) number of lands and grooves for rifling for the different bores (.750-3" range)?  How deep do they need to be cut?
We don't know of any optimum number, Don or any formula to determine this.  We will say that "nothing succeeds like success", though, and we achieved real success by duplicating historic designs and reducing their scale by direct proportion.  Although we had good results with four groove rifling in the 1.0" bore test barrel, we had great results by going with the historic 9 groove rifling in the 1/6th scale 100 Pounder Parrott with a tiny bit larger bore, 1.067".  "How deep do they need to be cut?"  Once again, we duplicated the original in a smaller scale with excellent results in the accuracy department.  The original 100 Pdr. Parrott rifling is .100" deep. We cut ours to 1/6th of that which is .0167" deep.  A rough "rule of thumb" seems to be that the more grooves you have in the same size bore, the shallower they can be.  The tendency in more modern artillery is for more grooves which are less deep.  A look down the maw of a 16 inch naval rifle produced in the 20's at Waterveliet Arsenal on the Hudson River across from Troy, New York will surprise you.  It has about a million grooves, none of which are any deeper than the 100 Pdr. Parrott Rifle grooves which were produced in the 1860's, also on the Hudson River, at the West Point Foundry in Cold Spring, New York.   

     Don wants to know, "Does rifling change the windage needed for a specific projectile?"  Windage is pretty much a function of the amount of tolerance placed on bore size, form, and straightness, called the "envelope of form" and a similar set of tolerances placed on the projectile's diameter, form and straightness.  Because almost all Civil War and modern tube artillery projectiles are "bore-riders" the tiny amount of clearance is only present to prevent the projectile from getting stuck in the bore.  The expanding flange, skirt or sabot prevents any windage at the rear of the projectile just like more modern driving bands or rotating bands do.  "How does cut rifling compare to button rifling on the larger bore guns?"  We are not aware of any button rifling process being used on large-bore guns.  We have not read any literature which indicates a cut-off point between cut and button produced rifling based on bore size.  We do know that the really large bores like the 12, 14, and 16 Inch Naval Rifles had their rifling cut by large disk-shaped broaches which were stacked up like huge poker chips next to the end of the bore where they were bolted on, one at a time, to the end of a long hydraulic ram which pushed or pulled them through the entire length of the bore.  Each one in turn cut just 2 or 3 thousandths of an inch per pass. 

     More tomorrow.     Mike and Tracy


It is tomorrow and, after a real busy day, we just got back on this at 9:30 P.M., Friday night, so look for a MAJOR POSTING on Saturday by 5 P.M.  We believe that everything in and bolted to the chassis can be explained by then.  All of the photos have been selected and 1/3 of the text written.  We think you will be pleased with both. 

We are on the home stretch now, just about two hours to finish the last construction detail, proof-read and post pics and text.  Approx. 7P.M. Mountain Time.      Thx, Mike



       
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Will Bison

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Re: How to Build a Rifling Machine.......A to Z
« Reply #38 on: January 19, 2007, 05:48:51 PM »
I'm paying close attention to this topic. I have already formulated some ideas for my existing rifled bore.

This is more fun than reloading the 105 mm howitzer ammo some years ago.

Keep the info coming.

Bill

Offline moose53

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Re: How to Build a Rifling Machine.......A to Z
« Reply #39 on: January 19, 2007, 06:38:57 PM »
Are you one of those people that actually had a shooting 105mm howitzer ? :o

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #40 on: January 20, 2007, 04:34:14 PM »
Sine-bar Rifling Machine Chassis and Upper Structure






Step  5      The chassis construction is pretty straight-forward.   Check out the marker board sketch.  All the important dimensions are there and all of the sizes shown are flexible.  If you need more height, then make it higher than 6”, etc., etc.  This structure is way over-built.  We did that on purpose, but you could use three transoms if you wanted instead of six.  The machine would still work just fine.  We wanted the extra weight; you might not.  That’s O.K.  We used six ½”-13, grade five, bolts per transom.  Four per would work just fine. 
     
     I think everyone understands by now that these photos and dimensioned sketches are mostly aimed at giving you new ideas or perhaps really old ideas with a new clarity.  You must make your own mechanical drawing or series of sketches just as we did.  On our dimensional sketch you can see that most of the upper structure is on the chassis centerline except for the artillery tube indexer, (lower left), the chain-drive hand-wheel and the sine-bar.  The cross-over plates are full-width and various lengths specified on our sketch.  They are ¼” thick.  Remember you must change the length and position on these if you make a shorter or longer machine.  They are dual-purpose plates, providing increased rigidity AND support for major machine components.  These plates form what we call the “Deck” to differentiate it from the ½” thick, aluminum, Sine-bar Plate. 

Step   6.     After you get the Deck installed, its time to install the parallel  Carriage Ways and their support pillars.  We used Thompson ball bushing ways which are case-hardened steel rods, 1.500” dia.  X  66” long.  These are used a lot to make custom machines and are found at machine re-build shops.  You can get them new from MSC Supply,  a large supplier of machine shop tools and materials.  We inspected them on our calibrated surface plate.  They were straight within .0025” which is really good for 66”.  The size was right on at 1.5002”.  We placed them in the clamping pillar-block supports and placed them on the Deck before tightening the two clamp bolts at each end.  The placement dimensions are not critical, just align with the edges of your chassis sides and lengthwise dims. are not critical either.  Do you see all that space in front of and behind the sine-bar?  From now on non-critical dims. will be designated with a   NCD  and the critical  ones with a      CRITICAL.   The ways should be co-planer within .0015” and parallel within .0015”.  This is CRITICAL.  If you have a surface plate the first is easy, if you don’t, just build the carriage accurately out of good quality flat stock and be sure that  the four “ way” bearings are all in the same plane within .0015”, CRITICAL, and use this structure as a gage to position the way supports up or down with precision steel shims or feeler gages until the carriage slides freely back and forth on the ways without binding or chattering.  Buy slippery plastic bearings for the carriage supports and save a ton of money.  Caged ball bearings of this size are VERY expensive.  The parallelism of the set of ways can be measured with a good vernier or digital caliper, as our photo shows.  We left about .125 of each end of each way outside the front and back surfaces of each pillar block to help align our four foot vernier caliper.  Because the “cross-over plates which form the Deck are not perfectly flat and the U-channel flanges, upon which the Deck is mounted, are not perfectly straight, you must install the way pillars in the following precedence:  First mount one way as parallel as you can to either the right or left side of the machine, which ever side seems to be most straight.  Tighten your two ¼-20 bolts moderately tight with a small 6 or 8 inch wrench which will firmly secure each of the two way pillars to the ¼” thick deck.   Second, mount the way and its pillars opposite the first, being sure to drill the ¼-20 clearance holes in the deck large enough to allow a bit of side to side adjustment.  .030” over the .250” dia. bolt size should be enough.  Tighten those last four bolts finger-tight only.  Measure the distance between the outside of the ways at both ends.  Make these numbers match within .001 if you can.  The spec. for parallelism is .0015.  This means .0015 or Less.  Once you get to this point, tighten this set of bolts moderately tight.  The methods for getting this assy. Into a “co-planar condition where all top dead center points on each of the two ways are all in the same imaginary “plane” have been previously discussed.  The proof that all this has been done accurately is the fact that the close fitting plastic bearings in the carriage pillars must slide freely upon the ways allowing the carriage “chatter-free” movement as to goes from one end to the other.  Several trials and some shimming may be necessary to achieve smooth carriage sliding.  Crank down on the way pillar bolts as much as aluminum will allow when you are sure that free carriage movement has been achieved.
 
Step 7.     The photo with Mike standing next to the completed chassis is used to show that we placed all the various loose components on the Deck to see if our sketches allowed for enough clearance here and there.  This “reality check” can save you some heartburn later on!!  We built the chain drive next which was pretty simple.  We bought enough industrial “power transmission” roller chain to form a continuous loop around two 4” dia. sprockets with the proper tooth spacing to fit the chain’s link spacing.  You will have to dismount the two cross-over plates which hold the sprockets so you can cut the slots or notches in them to allow clearance for the bottom of the sprockets.  The 1” dia. sprocket axles are secured to the deck in four inexpensive Browning pillow blocks with grease fittings.  The spacing is 115-48=67”.  Buy ENOUGH CHAIN and three  “connector links”, one spare, for attachment to the carriage attachment hardware.  Make sure that you buy a long-enough 1” shaft upon which to mount your 12” dia. hand-wheel outboard of the machine’s side and bench edge if you support the machine as we did.


Step  8.      Look in the MSC catalog for these items.  If you are comparison shopping, be sure to check out the large McMaster-Carr catalog too.  They have all this hardware in their “Power Transmission” section including roller chains and roller chain sprockets.  Adjust the alignment of these components until the chain goes around and round smoothly.  NCD here.  You get about 3:1 mechanical advantage with this set-up, ignoring friction, of course.  This is plenty of power to cut grooves of up to .350” width, even in pre-hardened, chrome-molly steel, 28-32 Rc as long as you limit your depth of cut to two tenths, .0002” or less.  The next two photos are displayed to give a general sense of how the components are interrelated.  If you look closely you can see that we used four heavy duty O-rings where the way ends intersect the way support pillars.  These act as bumpers for the carriage which normally does not get near them.  You can also see a small mistake.  We did not account for chain droop by making the second, third, and fourth transoms an inch less in height.  We cut chain clearance notches with a hacksaw and filed the waste out from each notch rather than take the whole chassis apart.  That task was fun……..NOT!!  You can see the T-shaped , chain-end to carriage connector hardware (2x) we milled and drilled.  We use cycle chain lube on it before each job.
 
                You can tell by now that we joined the first two
                Sections of this explanation together and the Chassis
                and Drive Mechanism Sections have been merged.







Step 9.     Use the photos above as a general guide to build this Artillery Tube Indexer next.  Again all these dimensions are NCD.  You can see that the dimensions which you use must be suited to your tube O.D.  We used a ¾” O.D. plunger with a taper on the end which fits nine 60 deg. countersinks which are machined in the indexing collar which is bored to a slip-fit with the still-cylindrical cascabel and attached to it by 5, ¼-20 set screws down in the bottom of five of the nine collar countersinks.  If this indexing collar slips half way through the rifling job, you will be VERY UPSET and will be forced to toss the tube into the scrap bin or to ream to a larger size if you have a rifling head for that size.  Tighten those set screws accordingly, but don’t strip the threads in the aluminum collar.  We think five is a minimum number to have, because of the CRITICAL nature of this application.  The taper-end plunger is about 6 inched long and has a reduced size journal inside the supporting block shown, for a coil-spring plunger extender.  You must pull the exposed knob outward against the spring action to retract the tapered end of the plunger from the c’sink in the collar.   Please note that we use a very sophisticated plunger knob retractor.  It looks just like a small pry-bar, doesn’t it?  CRITICAL…..Place the centerline of your plunger at the same height above the Deck as the axis of the pinion gear shaft.

Step  10.     Build the breech-end, 90 deg., V-Block tube support next.  Look at that scale for dimensions here.  The are all NCD except the height at which your particular V-block holds your particular size of breech on your cannon.  Simplest way to do this is to draw it out full size and build accordingly.  We suggest you buy some 1/8th inch thk. solid carbide pads (4) to JB-Weld to the V-block surfaces.  Your tube will rotate much easier if you do.  A small dab of gun-grease is good for this application too.  Size the thickness of your V-blocks to match the standard width of the carbide pads available.  Usually the 1.50” wide pads that we used are available.   








Step  11  Lets build the muzzle-end, 90 deg., V-block support and muzzle-stop now.  Again, the height is whatever you need to get your tube axis up to and co-axial with the pinion gear shaft axis and should be coordinated with the breech end support to have the entire artillery tube axis co-axial with the shaft axis.  Drill the Deck clearance holes a little large, about .280 dia., for a ¼-20 bolt to allow for some multi-directional adjustment.  Make a muzzle clamping bar also.  We used 3/4 x  ¾” stock  and  two pieces of all-thread about 4” long and two ¼-20 flange nuts.  Leave these blocks unaligned until you complete the carriage and pinion gear assy.  At that time you can clamp a 4”x 4”x1/4” thick piece of flat stock to the end of the shaft nearest the V-Blocks and mount a Magnetic base with a test indicator on it.  With the pinion gear shaft in its bearings FREE TO ROTATE without any follower contact with the sine-bar,  sweep the contact surfaces of each V-Block at the front edge and the back.  When the four readings are the same or within .002 or .003”of each other, then tighten the V-Block hold down bolts.  Repeat this procedure on the other V-Block and fasten it to the Deck as well.  The muzzle stop is a simple, steel block as tall as your situation needs it to be by 2.0" x 1.5”.  Its length should provide clearance for the rifling head which passes over it.  This stop is there to prevent the artillery tube from pulling out of the V-Blocks as you cut the grooves.  We clamp a medium size angle plate to the deck at the breech end to prevent the tube from sliding out of the V's in the other direction.  Build your V-blocks to handle the largest diameter tube you anticipate building.  As one of our photos shows, you can bush a smaller tube to bring its axis up to be co-axial with the axis of the pinion gear shaft. 





 Step 12.     The carriage consists of a 4142, pre-hardened, ground steel plate .50 inch thick and two 4142, ground steel bars to contain the rack.  They are nice and flat with a smooth ground surface so all you need do is cut them to length and drill and tap them for the assembly screws. You will also have to mill a long groove under the rack, through the .50 in. carriage plate so the follower pin can reach the rack and move left and right as it tracks along the sine-bar.  Remenber the length and position of this groove is based on your specific range of rifling twists and a careful sketch should be made before you cut the groove, which includes where your sine plate is placed and how much it diverges from the tube's axis. 

The Four pillars which  contain the linear bearings are attached to the bottom of the carriage plate at the corners.  They should all be bored out to accept the bearings".  The  size will depend on what bearings you use;  we used spit plastic bearings,  because they were cheap and they work great.  NOTE: this bored hole’s location is CRITICAL, the distance to the mounting surface with the .50 in. steel plate should be held as close as possible (.001in.) .

     The rack is held in place by the two steel bars and the bars should be tall enough to also capture the teeth of the pinion gear.  The rack should be stoned on the sides and bottom to remove burs.  It should be a sliding fit in the assembly with very little to no play side to side. All this should be heavily greased.

     The pinion gear is attached (should be a push fit with two set screws)to the tube/rod, called the pinion gear shaft, that supports the cutting head. This shaft is held parallel to the carriage plate by two ball bearing pillow blocks.  These blocks are positioned so the pinion gear will engage the rack with minimum play yet allow smooth movement; use shim stock to achieve this condition.

     A follower that tracks on the sine bar must be attached to the rack, it is usually attached at the end of the rack with the sine bar located on the backside of the machine.  We positioned ours on the middle of the machine between the linear ways to save space.  This can limit adjustment and ease of use to some degree.  We bored a blind hole (.50 in.) in the bottom of the rack then fitted the follower pin in the hole with a tight sliding fit, very little play, because the follower needs to be able to be rotated in the rack.  The other end of the follower is a square block with a wide central groove cut to match the sine bar width.

     The sine bar should be wide enough to prevent flexing as the follower moves along it. If you are going to use straight, non-progressive rifling, then a wide bar ( one inch) is better.  If you are thinking of using gain twist, progressive rifling, then the bar must be curved.  Bending a one inch wide bar will take quite a bit of force;  we used a .50 in. wide bar and held it to the sine-bar plate with three screws to prevent flexing.

     To ensure that the hook cutter follows the same track every time, backlash in the gear and follower assemblies should be eliminated.  We used a moderately wound clock-work spring, attached to the pinion gear shaft at the back of the carriage and to the chain/carriage connector hardware as well. 







Step  13.     Let’s build a sine-bar and install it.  We used 4142 steel, pre-hardened to 28-32 Rc, precision ground flat stock, .500” wide x .750 high x (your twist no. goes here, one turn in ‘X’ inches) plus 6”.  It’s nice to have an extra 3 inches on each end for sine-bar follower over travel.  We will show how to calculate the gain twist for one turn in 36” first, then we will explain how to do it for a straight twist.  The harder one first is explained thusly: 



     Take a look at this Sine-bar shape explanation marker board sketch and math.  Basically there are 3 Critical dimensions that we used to produce, then set up, the two sine-bars.
           




     They are these:  36”  Our 1/6th scale Parrott Rifle has gain twist which means that it goes from zero twist at the start to one turn in 36”.  The sketch shows what the two bars look like on the sine-bar support plate.  Also we have distance the rack travels which equals the circumference of the pinion gear’s pitch diameter, 5.026” not the gear’s O.D.  Finally, the very important radius of the circle, R 131.442”, which is tangent to the start point (T) of the rack’s follower travel along the curved sine-bar. 
 To make the curved or gain-twist sine-bar,  we cut our .500 inch X .750 inch, 4142 pre-hardened flat stock to about two feet over the chord distance which is 36.349” or  5 feet.
Then we swung an arc with a tape measure having a pivot hole at 132.442 inches and a pencil hole right at 1.000 inch.  We used a piece of butcher paper on a smooth board placed on the floor to take the arc.  We bent the bar every .500” in our Kurt ang-lock vise by placing one inch steel pins cut from drill rod stock between the jaws, two at either end of the movable jaw and one centered on the fixed jaw supported by a thin parallel bar. Hold the bar between the pins, starting at about 9” from the end, with the .750 dim. up and down, crank down on the vice handle.  Easy does it; use moderate pressure until you see how much bending is going on. It was bend and try, bend and try, over and over until all parts of one side of the bar were coincident with that 131.442 radius line.  The bar shows no perceptible wear even though the follower has been over it almost 12,000 times! 

The straight twist is simple.  Pin your straight bar at the breech end and kick the other end over to the right by 5.026” at a distance of 36”.  Clamp it down.  Slip the follower over the end.  Your done.

That’s about it.  Hope the math agrees with your’s. 

Tracy and Mike      Seacoast Artillery Company

     




Step 14.     From these photos, you can get a pretty good idea how to build the pinion gear shaft support.  We used the structure show which is aluminum plate .75” thick and two bolted gussets of the same thickness.  The oil-impregnated sintered bronze bearing we used was 1.00” O.D. and .7505” I.D. to fit a 4130 pre-hardened shaft, (tube actually), with a .7500 O.D. and and a .4375” dia. through hole.  This 7/16th inch hole can really save your bacon if the rifling head ever gets stuck somewhere in a BLIND HOLE.  You just throw the BACON SAVER ROD of 3/8th inch diameter steel down the tube until it disengages the bottom wedge and lets the hook cutter retract into the body of the rifling head.  Viola!   The head, she moves out of the cannon’s bore, and you can breathe once again! 
Step 18     The CRITICAL dimension here is the distance from the Deck to the center of the pinion gear shaft/tube taken just ahead of the front edge of the carriage.  Let’s say that you measure to the top of the shaft, take half the shaft dia. away and get 3.039 (ours).  Well, just make sure you accurately indicate the center of that hole on your .75 aluminum plate where your shaft/tube bushing will go.  If you are not dead-nuts with this one, you will probably have to shim it until the shaft will pass through without any chatter.  We did this and also put a thin film of epoxy aluminum under the whole structure, then put 200 pounds of barbell weights on it to squeeze the goo out.  After it sets up and hardens, tighten your ¼-20 bolts from under the Deck, three on the main plate and two each on the gussets.  Be sure to oil those shims if you want to get them out of there after the goo sets up.  Before you assemble this structure and glue and bolt it down, don’t forget to shape the top of the main plate so it doesn’t look like a left-over floor tile.

Now Mike and I can start working on the rifling head photos and explanation.  It will be AT LEAST 5 days before you will see this last, and most anticipated section.  We hope to provide some answers to those excellent questions as well on Tuesday or Wednesday.

Tracy and Mike      Seacoast Artillery Company

P.S.     Yes we know that the big radius in the marker board sketch of the sine-bar lay-out is 131.442 in one place and 131.443 in another.  That's my fault, not Mike's.  I forgot to round off the number, but .001" in almost 11 feet is not much to worry about.  My fifth grade teacher would wrap my knuckes with that thick, solid maple ruler she always carried, if she saw me do that, but you can't.  Yes, I forgot the upper arrowhead on the 7.9xxxxxxx angle too.  If we had a nice autocad program and a top-notch instructor like Cat Whisperer to teach us, we would not have these little irritations to deal with. 
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #41 on: January 22, 2007, 04:30:00 PM »
                                                                   Q&A on Rifling or Rifling Machines

     Cat Whisperer wrote, "Aside from the question of Rate of Twist, questions that accompany the question of the number of grooves/lands are those of WIDTH of lands and grooves, DEPTH of Grooves and Shape of same.  Having talked with rifle barrel manufacturers, I'm aware of the WEAR on the rifling is primarily on ONE side.  Shape affects this to some extent, and also influences cleaning." 
     We have to limit our comments to what we have seen and what the results of our experiments reveal, because we ARE NOT mechanical engineers specializing in ordinance design.  We would agree with those barrel mfgs. who say the WEAR is primarily on one side.  It make sense that more wear would occur on the side of the groove that forces the bullet to rotate.  If you take a look at Civil War seacoast gun rifling in the photos posted in this thread, you will see several that have a more robust, higher groove side, on the "rotational forcing" side of the groove, namely the 7" Brooke with its flower petal or scallop shell design.  The only straight line in the Brooke's unusual groove configuration is the "rotational forcing" side of the groove.  Take a look at the British Armstrong 150 Pdr. Gun as well.  Not only are the "shunts" unusual, but the loading groove/driving groove configuration has a taller groove side on the forcing side of the "driving groove".  The slant/hook rifling style also has similar features.  Parrott rifling has equal groove and land width as does the James System rifling and others. 
     The only comment we can make on the number and width of grooves and lands is this:  Our first successful tube which we rifled has a 1.000" bore with four grooves that are equally spaced and only .187" wide each and .010" deep.  4x.187"=.748"    1.000xPi=3.1416"-.748"=2.3936/4=.5984"  The width of the lands is huge at almost .600", but this barrel grouped 5 solid steel bullets of Brooke, milled base, design into 3.25" group at 100 yards.  Talk about a design that should have failed badly, this is it!  The accuracy astounded Mike and I.  The fact that the traditional nine equal width lands and grooves put 4 rounds into an inch and a half before a flyer ruined that group proves only that historical Parrott rifling is slightly more accurate.  We will venture just a single opinion here.  We believe that consistency and uniformity is far more important than one specific form over another.  Perhaps there is an enginneer among the members who can shed more light on these questions.  We do not have any solid facts on groove depth, therefore, we will only produce scale versions of historical depth, which works very well with the Parrott.

     I think we have provided all the information on alignment as it relates to building the various inter-functional structures of the rifling machine that we could think of in response to Don Krag's comment, "A detailed section on alignment proceedures would be nice." If he or anybody else needs more info on this, we sure would entertain any further questions.  Ask away!

     
Running that hand wheel round and round turns your arm to rubber!

So why is the wheel hand turned instead of electric motor turned?  You need the feel?
  GGaskill,  I confered with Mike quite a bit on this one, because he was in charge of cutting the first three tubes.  He said that the "feel" was very important when his use of the rifling machine was in the early stages.  It helped him quickly detect "grabbing"  or the initial portion of a "gouge" being initiated or barrel steel being torn out.  You could also, he says, tell if the tool edge failed due to increased resistance to the handwheel rotation.  He says he still likes it, even after the 7th rifling head, because the "feel" will signal when resharpening of the hook is necessary.  Without a sharp tool, you won't be cutting anything.  As for negative rake hooks, he says,"Aaaarrrhhggg!!".  Maybe Tropico can translate that for us.

     Well, I think that's it for Q&A.  Any questions on any of the material presented so far would be welcome now.  We will work on the Rifling Head photos and explanation every evening this week.   Hate to predict, but MAYBE by Saturday we will have something.  Hope so!

Until we see a question, we remain.

Mike and Tracy

Seacoast Artillery Company
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Will Bison

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Re: How to Build a Rifling Machine.......A to Z
« Reply #42 on: January 22, 2007, 08:06:47 PM »
Mike and Tracy;

You have well exceeded the limits of my technical expertise but I continue to follow the discussion (at the least I can read).

So, BTT

Bill

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Re: How to Build a Rifling Machine.......A to Z
« Reply #43 on: January 24, 2007, 01:28:44 PM »
Will Bison,                       

Thanks for hanging in there with us; we sure appreciate that.


-Regards
Mike and Tracy
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Cat Whisperer

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Re: How to Build a Rifling Machine.......A to Z
« Reply #44 on: January 24, 2007, 02:12:38 PM »
Mike, Tracey -

You have a wealth of material here - worth putting into a book.

Tim K                 www.GBOCANNONS.COM
Cat Whisperer
Chief of Smoke, Pulaski Coehorn Works & Winery
U.S.Army Retired
N 37.05224  W 80.78133 (front door +/- 15 feet)

Offline Will Bison

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Re: How to Build a Rifling Machine.......A to Z
« Reply #45 on: January 25, 2007, 09:52:51 AM »
Tim, Mike and Tracy;

Just wondering about the possibility of reducing this thread to a PDF and posting in the reference section. I always hate to see this type of good info disappear as the thread gets old.

Bill

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Re: How to Build a Rifling Machine.......A to Z
« Reply #46 on: January 25, 2007, 05:02:09 PM »
     Will Bison and Cat Whisperer, Mike and I sure are thankful for your vote of confidence.  I don't think we will ever put this info in a book; we are simply willing to share our knowledge in the hope that it will spur someone or maybe a few of you out there to create one of these machines and promote the hobby of shooting muzzle loading artillery, the rifled kind.  We think that Bill has a good idea about the PDF in the reference section, but that is strictly up to the moderators and Greybeard.

     On the " Rifling Head, the Final Segment" I may have spoken too soon.  Our time is being consumed by the building of, yet another, machine fixture this week.  It is a deep hole drilling fixture which will turn our large lathe into a deep-hole drilling machine so we can drill long distances in solid, white oak which is  being used on our latest seacoast gun, the Confederate, 7 Inch Treble-banded Brooke Rifle.  Working in the evening hours to stay on schedule with this project, is eating up time we wanted to use to complete our commitment to you Blackpowder Mortar and Cannon members, so, next week we will kill two birds with one stone.  As we create our eighth rifling head, the one which will be used to rifle the exotic, flower-petal  looking Brooke rifle grooves and lands, we will let you guys in on EVERY SINGLE DETAIL, the turning, the milling and the grinding, too.  Mike agrees that simple, less complicated,  sketches, and photos of every single machining operation will really clarify this complex, but crucial, assembly.  The Rifling Head is the HEART of a rifling machine.  Any question on the previous rifling machine material on this thread will be cheerfuly answered as we see them.

Mike and Tracy
Seacoast Artillery Company

P.S.     Our explanation will be every bit as thorough as our manufacturing plan is on the 1/6th scale 100 Pdr Parrott Rifle.  If it take 37 steps, so be it, 47, O.K., 57 steps, well, I guess, more than that, you bet!!  We will do whatever it takes to get everyone up to speed on this important topic.  Just another week, guys, but it will, by golly, be done correctly and completely, once and for all.
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Don Krag

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Re: How to Build a Rifling Machine.......A to Z
« Reply #47 on: January 26, 2007, 08:42:01 AM »
So we're having a BYOB (bring your own barrel)rifling party at your place next weekend, right? ;D ;D Hah!

Great job on the write up. Looking forward to more.
Don "Krag" Halter
www.kragaxe.com

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Re: How to Build a Rifling Machine.......A to Z
« Reply #48 on: January 26, 2007, 07:39:34 PM »
Mike & Tracy, Your work really shines, mabey some day I'll be able to approch your level. One can always hope. I await the cutter head portion with baited breath. Thanks gentlemen.   Butch

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Re: How to Build a Rifling Machine.......A to Z
« Reply #49 on: January 27, 2007, 07:15:05 AM »
So we're having a BYOB (bring your own barrel)rifling party at your place next weekend, right? ;D ;D Hah!

Great job on the write up. Looking forward to more.

     Very clever, Don!  Maybe someday.  After you make your rifling head and get a tube gundrilled and reamed, let us know.  Just one more prerequisite, BYOB (bring your own barbeque).  Mike and I are dedicated barbeque chompers and we've heard good things about Texas style.  I just took a good look at your website, WOW, very impressive indeed.  Axes, armor, knives; you are a very talented craftsman.  I just love ancient weapons which display what happens when artistry and execution come together. 

     Butch,  Thanks for your kind comments.  Remember though, we are NOT the rifling experts.  The barrel makers across the country who do this on a real production basis are the true experts.  When you are running two or three machines at once for more than five years, adjusting and precisely sharpening cutters, while keeping your ears and eyes open for possible trouble, then maybe you can be thought of as an expert at what you do.  The Rifling Head Segment is coming soon.  Thanks for your support.

Mike and Tracy
Seacoast Artillery Company
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Rickk

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Re: How to Build a Rifling Machine.......A to Z
« Reply #50 on: January 27, 2007, 12:38:46 PM »
Mike and Tracy, there is a bring your own cannon bbq scheduled tentatively for april/may at my house (depending on when winter ends and the mud clears) ... Not too far from the "seacoast", but prolly the wrong one... western Massachusetts.

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Re: How to Build a Rifling Machine.......A to Z
« Reply #51 on: January 27, 2007, 04:52:52 PM »
Mike and Tracy, there is a bring your own cannon bbq scheduled tentatively for april/may at my house (depending on when winter ends and the mud clears) ... Not too far from the "seacoast", but prolly the wrong one... western Massachusetts.

Rickk,

     We might just take you up on that offer; I lived in eastern, upstate NY for 25 years just west of the Berkshire Mtns.  Western Mass. sure is beautiful country, white-tail deer country too.  If you love history the way we do, western Massachusetts is a great place to live, what with Ames Manufacturing Co. making all those bronze Civil War cannon in Chicopee, Mass. and Westfield based Stevens Arms and then Savage Arms Co., Springfield Armory, Smith&Wesson and Dan Wesson in Springfield, Mass. When you have a firm date, let us know.
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #52 on: February 04, 2007, 09:39:05 AM »
Quote
Wes, out of the kindness of my heart,  to help a young guy out, so you have a test bed, feel free to use my  Parrot Rifle Barrel  to learn how to rifle, gratis no charge, glad help out, think nothing of my generosity.... ;D ;D ;D ;D ;D ;D ;D ;D

     Mike and I feel that a reply to Double D's comment to Powder Keg on this thread at the bottom of Page One has long been missing.  All of the following is said with
"tongue firmly in cheek".  Mike and I wondered what could Double D's motivation possibly be for this most generous of offers?  Who would do all of this, absolutely "Free
of Charge"?  We thought, what a magnanimous gesture of educational assistance!  But why?  Ahah, just maybe, all the generous use of his free time to deliver all those donated books to the children of South Africa created a changed man.  What a guy!  Wes, you better take him up on this wonderful and kindhearted offer before he changes his mind!

     The next installment of "How to make a Rifling Machine A to Z, specifically, the first half of "Rifling Head, the HEART of a Rifling Machine" will appear right here, sometime after the Superbowl is over, NOT BEFORE!

Regards,

Mike and Tracy
Seacoast Artillery Company

     
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline seacoastartillery

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Re: How to Build a Rifling Machine.......A to Z
« Reply #53 on: February 04, 2007, 04:43:49 PM »
This is the first half of “Rifling Head, the Heart of the Rifling Machine”
brought to you by Seacoast Artillery Company


 




Step #

1.   Obtain a 4.25” long piece of alloy steel rod pre-hardened to 28-32 Rc and of appropriate dia. for your use.   We used 1 3/16”, (1.1875”) dia., 4142 for it’s dimensional stability and abrasion resistance.  This size is over our bore dia. which allows enough clean-up to provide a smooth turned surface on the entire length of the rifling head.  Face off one end.
       
2.   Center drill.

3.   Use live center; rough turn to .015” over your bore size or until full clean-up occurs. 1.182” for us.

4.   Cut off to 4.25” length.

5.   Swap ends

6.   Face off.  Resist the temptation to put a chamfer on either end of the head.  DO NOT chamfer or radius either end.  LEAVE EDGES SHARP.  This keeps chips from getting between the head and the bore which can JAM THE HEAD IN THE BORE, a condition you really don't want.  Your bore should have a 60 deg. countersink so it can be polished between centers; this will guide the head into the bore after you remove the chips from the head and re-oil the hook for the next stroke. 

7.   Center drill.

8.   Pilot drill .250” dia. hole, ½ head length.




9.   Drill .500” dia. hole, ½ head length. 

10.   Swap ends; repeat steps 7, 8 and 9.

11.   Place head vertically into a v-block in the milling machine vise and clamp gently.  Find the center of the .500” hole and off-set toward you by .422”.

12.   Drill .262” dia. clearance hole for a ¼-28 set screw, .800” deep.

13.   Tap drill .213” dia. Hole, 2.210” deep.

14.   Tap ¼-28, .250” deep for set-screw. 





15.   Remove from mill; place in three-jaw chuck on lathe with just the .500” dia. Hole facing out.  Bore .500” dia. hole to .615” dia. X 2.25” deep.

16.   Ream to .625” dia. X  2.25” deep.  Cut 60 deg. X .700" countersink.  Swap ends; bore .500” hole to .750” dia. by .750” deep.  Cut 60 deg. X .900" countersink.  Remove head from lathe.

17.   Place a 1.00” dia., 3.00” long piece of alloy steel rod in the three-jaw and turn an accurate 60 deg. taper on the end of it.  This makes a very accurate “dead center”.

18.   Place rifling head body between the dead and live centers. 

19.   Accurately measure your reamed bore size to the closest .0001”.  Ours was 1.1671”. 

20.   Turn your “rough-turned” head down to the bore size, (1.1671”), NOT LESS.  Take very light cuts, so as not to overcome the “friction-drive” being used to rotate the head.



 

21.     Try fitting the turned head in the end of your reamed bore.  It probably won’t  fit if the head and the bore are the same size.  This is called a “line to line fit” and items in this condition almost always refuse to mate.  If this is the case, put the head back between the centers and rotate at 400 rpm, polishing lightly and evenly with 400 grit wet and dry paper backed by a flat stick for about a minute, after wetting the paper with kerosene or knife sharpening oil.  Try to fit and repeat the polishing until the rifling head just fits the bore without ANY looseness. 

22.   Place the head in the milling machine vise oriented as the photo shows.   

23.   Remove the Pinion Gear shaft/tube from the rifling machine.  Shove the close fitting shaft end into the .750” dia. hole in the head until it bottoms out.

24.   Center drill for a .187”, top dead center, thru hole, .433” from ¼-28 clearance hole end of head. With a solid carbide,(stiff), .187" dia. drill bit, drill through both the head and the Pinion Gear shaft/tube.  Remove all burrs.

25.   Make two .300”  long pins to match these two sets of holes to attach the head rigidly to the Pinion Gear shaft/tube.  The class of fit you need is a force fit, (light drive fit).  You don't want these pins falling out when the head is in the bore for obvious reasons.

26.   Place the Pinion Gear shaft/ tube back into position on the rifling machine.  Make darn sure that the clearance hole for the set screw is at top-dead-center when the head is in  the “withdrawn from bore” position, against the Pinion Gear shaft support.  Now, with the carriage at the far end of the sine-bar, tighten the two Pinion Gear set screws to bind the shaft to the gear.  All this makes sure that the “chip retainer recess” in front of the hook will be in the “UP” position for clean-out purposes when the head is withdrawn from the  bore.

27.   This step is not pictured, because, when I went to the door to see what goodies the UPS guy brought us, Mike went ahead and clamped our drilled and reamed practice barrel into the v-blocks and ran a well-oiled head up and down the tight-fitting bore to determine if any more polishing was necessary.  Slow Ahead on this test.  You DON’T want to get the head stuck in the  bore.  If it rubs a little and wants to stick a little, take it off, remount between the live and dead lathe centers and polish a little, just a LITTLE!  You do not want a loosey-goosey fit. No way do you want any more clearance than is absolutely necessary. 


     That’s about it so far.  We will get the second half done as fast as possible, maybe by Saturday or Sunday.  There is a lot more to do on this one than the last including special off-set grinding fixtures, etc., etc.  Any questions or comments we will respond to as soon as possible.  I want to take this opportunity to thank my son, whose handle is ZackaryX,  for all of his computer expertise on loading and manipulation of photos and blocks of text.  Without his knowledge and super fast touch typing, Mike and I would posting this in June of this year!

Regards,

Mike and Tracy
Seacoast Artillery Company



Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Double D

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Re: How to Build a Rifling Machine.......A to Z
« Reply #54 on: February 05, 2007, 07:09:12 AM »
We thought, what a magnanimous gesture of educational assistance!


Actually magnanimous is correct. Well kinda sorta.

The cannon tube is question is my test bed tube. It is the very first all made by me as I was learning how to operate a lathe and milling machine and weld tube that I started about 20 years ago.  I learned a great deal building this tube.  I learned that trunnions are at 180 degrees not 170. I learned how to weld in plugs and remachine the contour.

If Wes were to take up rifling, he would not have to be concerned about ruining a barrel.  It would give me great pleasure to support Wes in his quest for higher education. Wes has already sent me an email expressing his gratitude for my kindness, something about being out of my mind to make such a genoreous offer.....

Offline CrufflerSteve

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Re: How to Build a Rifling Machine.......A to Z
« Reply #55 on: February 06, 2007, 09:02:06 AM »
This has been a fascinating thread. I don't think your prices are out of line considering the detail. As soon as I win Powerball I'll be ordering one. :)

It is a challenge to work with the pre-Greenhill rifled cannon. Right now I'm agonizing over projectiles for my Confederate 2.25" Brone Mountain Rifle. It has a liner made by Ken Kurdt with the original rifling. 3 groove saw tooth with a 1 in 120" twist, I think. A lead projectile that matches that would be suicidal.

Where do you shoot? I see from your address you're in Broomfield. I'm in Castle Rock and am waiting for the plains to dry from our long wet winter.

Steve

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Re: How to Build a Rifling Machine.......A to Z
« Reply #56 on: February 06, 2007, 10:28:40 AM »
Steve,

     Glad you like the thread; it has been quite an education for us as we never really documented all these steps with photos before.  Hope you win Powerball as well.  It will be a win for both of us!  I remember seeing photos of your Confederate Mountain Rifle just after Mike and I discovered this site.  What a nice piece it is, just beautiful.  I wish we could suggest a sure-fire projectile to try, but neither of us has any experience with this size or rifling configuration.  Probably an oversize minie-ball would work, but with that much lead in contact with the bore you would want some lubricant for sure which would most likely point to a custom mold.

     If you could get ahold of some leadloy a little larger than 2.25" let us know; we would love to take you up to our remote, high plains range north of Denver for a day of shooting.  We could turn a half dozen experimental bolts with the same style of expanding skirt which we copied from Confederate Commander Brooke's experiments.
The rifling cutter we are presently making is his design variant from the typical slant-hook or saw-tooth rifling.  Send us a PM or give us a call. 

Regards,

Tracy and Mike

Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Will Bison

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Re: How to Build a Rifling Machine.......A to Z
« Reply #57 on: February 06, 2007, 06:33:52 PM »
I'm following along on all this but it's all over my head and well beyond my hammer and screwdriver shop. I am going to try some Read projos in my 47 mm gun.

Anyway, just wanted to BTT the topic.

Bill

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Re: How to Build a Rifling Machine.......A to Z
« Reply #58 on: February 07, 2007, 07:23:59 AM »
Bill,

     Glad you are still with us on this topic.  Mike and I think that you made a good choice with the Read type projectile.  That excellent suggestion made by guardsgunner earlier in this thread should work, we believe, and should be a lot of fun to experiment with.  Good luck.

Tracy and Mike
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Don Krag

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Re: How to Build a Rifling Machine.......A to Z
« Reply #59 on: February 08, 2007, 05:26:20 AM »
I'm hoping to have a 50" x 1.7" bore barrel to rifle late Summer. I was originally going to do some sort of button rifling process, but cut rifling has really peaked my curiosity now. Your device has certainly given me some ideas to play with. I'll have to cut/paste and print everythign out so I can read everything all together...I'm one of those old-fasioned, "hard-copy" type learners! ;D

Thanks for all the work y'all are putting into this!


P.S. I need to update my site. I think the newest pics are from two years ago. :-[ I've built some much nicer equipment and after a couple more years' experience under my belt, I have some really nice knives and Viking sword/armour combos I need to get some pics of!

Oh yeah....When it comes to chili and grill'n BBQ...I'm a Culinary Ar-teeeest. ;D
Don "Krag" Halter
www.kragaxe.com