2nd Nano-Cannon Arms Race.........We Build a No-Lathe, No-Mill Nano Cannon

[seacoastartillery]

Dear MikeR C,

     The Official High Plains Council of Nano Cannon Production Rules and Regulations just met and has handed down it's final determination.  There are many important guidelines and absolute regulating factors presented in it's edict, but you may glean your answer from this most pertinent segment of the voluminous whole:

    " ...................and persuant to the Acceptable Tools and Methods Edict the definition of acceptable tools, machine and hand type, includes all of the following items:  any and all tools, having among their principle properties, complexities ranging from the common drift punch through the common drill press, either floor or bench mounted, inclusive."


     And there you have it, Mike.  Speaking frankly, since there are no prizes, this is not really a contest, so, the more, the merrier!!  Welcome to the Nano Arms Race, Mike.  With your skills, you will have little difficulty overcoming the inconvenience of not using modern, conventional lathes or milling machines.  Can't wait to see what you are planning to build!  Once again a challenge is issued to any and all members who have a little free time in their schedule over the next month or two.  Just do it!   

Best regards,

Tracy and Mike

Just one pic from the Nano 24 Pdr. Flank Howitzer build.  Terry C., a dimension you were looking for is there.  Nano dimensions are in parentheses.  These paper sight gages merely point to places on the tube to center punch and then drill holes for the vent and two trunnions.  They are aligned and glued to the tube before prick punching and center punching occurs.

[Terry C.]

Thanks for that reference. I checked my trunnion placement and I was off exactly 1/2" at full scale, .083" at 1/6 build scale. That's about the width of some of the lines I was trying to pull dimensions off of. The drawing was blurry to begin with, then enlarged about 300%.

Also, I don't know if it's a fact (but it seems to make sense) but I read that the trunnions on howitzers of the period were often the same diameter as the the powder chamber. I do know that the chamber on this howitzer was the same diameter as a 12-pounder bore.

My trunnions were close, but just a little large (more of those blurry lines) and they seemed to look more accurate after this adjustment.

Was this standard practice?

Hopefully the drawings from Maryland Silver Company will give me the rest that I need. Assuming of course that they make it here and are the right ones. Not overly confident at this point.

[dan610324]

the oldest proportional drawings I have seen are the drawings on the www.arkeliet.net
they are from 1698 I believe it was
on all drawings there the trunnions are equal to the bore both in diameter and length on cannons
so I would guess that the powder chamber of a howie would be correct

[seacoastartillery]

     You fellows are both correct on the trunnion diameter.  It is equal to the chamber dia. of this howitzer, at 4.62" dia.  With the bore at 5.82"dia., I don't know where the rimbase dia. came from.  The rimbases are 6.62" dia.  I don't know if this was standard practice or not, but I bet this relationship shows up in more than one cannon of American manufacture.

     Had to do more car stuff today, but I found the trunnions and rimbases are difficult to make with these tools and methods at this 1/32 scale.  1/10 or 1/8 scale would be much easier.  At least I DID NOT drill through into the bore in the trunnion locations.  The vent drilling went perfectly too.  Got the 5 deg. slant with a 1/16th drill bit after very carefully prick punching, center punching and center drilling.  Those paper gages worked perfectly as I knew they would.  Pics Monday night, too late now.

Tracy

[seacoastartillery]

     What the heck!  More car work today so other work and pics will have to wait 'till Tuesday, so I'll post what I took this afternoon now.

Tracy

Placement of the paper Sight-Gages on the tube.




Alignment of the Prick-Punch point with the intersection of the verticle Sight-Gage line and the circular scribe line on the tube becomes the vent location.




Taking the photo and holding the Center-Punch straight up and down can be difficult at times, so a little adjustment to the right was made before the punch was hammer-struck.




Drilling the angular 1/16" vent using the center drilled hole as a starting point.  Hold steady and No flinching with this tiny, fragile drill bit. Very light thumb pressure and the weight of the hand drill push the slender bit downward.

[1Southpaw]

Amazing stuff here . As a farmer with big hammers , and a cutting torch I don't see my self as a builder of nano "stuff"   

But I am working on a warm place to work , perhaps organizing 40 years gatherings , (I hate the mess organization brings )  I used to know which pile or corner to look in , now it's getting organized I can't remember where I put it !   

I love following this type thread but it  gives me too many ideas running over the top of ideas .....

[KABAR2]

M&T,

How about a piece of round stock with a hole the size of the trunnion area

centered in which a hole for centering the trunnions is then drilled, opposite

this a threaded hole for a set screw keeps it lined up, an end mill with a stop

is then used to cut the pockets for the trunnions.

[seacoastartillery]

    1Southpaw,   I know just what you mean, that's why our workbench is so cluttered in all the photos we take.  Why put the tools you use everyday away?  You will Always find magic markers, carbide scribes, files, crecsent wrenches, centerpunches, bits of drill rod, at least three quarter sheets of wet and dry paper in 3 different grits, a small pc. of oak board for a sanding block, a hacksaw, some masking tape and some duct tape, a tailstock chuck key and a three jaw chuck key for the mini-lathe, etc.  If all these things were put away, instead of being, 'At Hand', two things would happen, One, we could not find them when we needed them, and, Two, we would waste at least one half hour each day trying to find them and then putting them all away!!  The only things we put away religiously are drill bits, because they get lost quickly if you don't.  We Do Not fault craftsmen who are neat as a pin and put everything away, but that would drive us bonkers very quickly.  Each to his own.

     A warm place to work is good.  It hasn't always been that way at Seacoast, in a former shop, a detached, one car garage with cinder-block walls, it got so cold one winter, we started adding a little coal to our pot-bellied stove in the corner.  The bottom half glowed a nice cherry red and we had heat in at least half the shop!  Good luck with the reorganized, heated shop, Ernie!

     Allen, your idea for a work holding and tool alignment fixture would work very well and small diameter end mills can be had for very little money in 3 days from MSCdirect and other online sources.  We made one of these two years ago when the Nano Rodman was being built.  It was made from a scrap of cocobola and steel tube inserts.  The devil is in the details, Allen.  We would add a short pc. of brass rod in front of the set screw to protect the tube opposite the hand-milling.  It's a good idea that we proved would work last time.  This time I wanted to try everything free-hand to see if I still had the eye or not.  I think I do, but we'll find out.

     Thanks, Allen, this is a solid idea that anyone can use for more precise results as long as they can inspect the fixture they make for accuracy.

Two inches of fresh, blowing snow and car work to do.  WHY did we convert the garage into a shop?  Why??

Mike and Tracy

[seacoastartillery]

    I did a little more work on the Nano this morning, but I'm way too backed up today to do more.  A few new pics are below.  Captions tell the story.  MikeR C we are hoping you are planning something kool; I bet you are.

Tracy and Mike


     The first things I made today was 2 of the two dia. trunnion pieces, .144" x .106" x .167" long.  I forgot to take a photo.

The second thing I did today was to draw a tube, trunnion and rimbase full size, but I put the Nano, 1/32 scale, dimensions on it so I would not confuse myself.  As you can see, the trunnion is a two diameter piece, being .144" dia. for the exposed part and .106" dia. for the part that goes thru the .110" dia. hole in the rimbase and into the .110" dia. hole in the tube.  All three parts will then be clamped and brazed together.




I found a pc. of low carbon rod .375" dia. and filed it down to the rimbase O.D. which is .207".  I had plenty of .250" dia. drill rod, but heating these pieces up to cherry red for brazing and then letting them cool relatively quickly, the o-1 or drill rod steel can become very hard and brittle.  LC, low carbon, 1018, 1020, or 1026 steel is a Much better choice.  It's long enough for two or three rimbases.  After center punching the squared off end, I drilled a .110" dia. hole about .625" deep.




Holding the rimbase w/drilled hole up in the vise, I used a small triangular file to cut two notches in the tube mating surface of the future rimbase.




Next, using a large triangular file, I filed a larger notch where the two small ones were.  This notch is used to center the large Rat Tail File that I used to produce a fully formed tube mating surface.




The end of the First Reinforce is .375" dia.  In the trunnion areas the Tube dia. is .381".  Fortunately our large Rat Tail File is very close in dia. at .383", so we can shape the rimbase mating surface with the large end of that file.  It is centered in the triangle shaped notch.




This is what the rimbase mating surface looks like after Rat Tail filing.  It is pretty rough, so we will glue a pc. of 220 grit wet and dry paper on a .370" dia. mandrel I filed down from .412" yesterday and grind the rough file marks off so it fits the tube better.  Almost forgot, can you see that the Rat Tail filing was done at a 1.5 to 2.0 degree angle?  That will match the first reinforce taper on the Tube.




More on Wednesday.