Author Topic: Nano-mortar (Read 41130 times)

Rickk · « **Reply #30 on:** December 23, 2006, 11:20:48 AM »

Since there arn't any federal guidelines yet defining what this is about, I guess so El Cazador . What caliber is it?

I upped the charge in mine to "max" ( like, I couldn't get any more powder and toliet paper in there) and it actually got loud. It is about the same as a 1 1/2 inch salute.

I picked up some oak and some nylon wheels at the hardware store a few minutes ago, so I may have a carriage together tomorrow.

Cal.45 · « **Reply #31 on:** December 23, 2006, 01:26:52 PM »

The bug has bitten me definitely!

Today I started with the cannon version in 3mm (.118 inch = #5 shot-size).
[OK, we're about to work out a standart here: BB-diameter is “nano-size” then #5-shot is “pico-size” – right?]
It should resemble an English 32-pdr, but I missed the dimensions a little: at the muzzle it went out to be a bit too small.

I need to buy me a lathe next – that's for sure!
Files and emery paper just don't do it, if you wanna get it into scale and detail.

Anyways:
I could not wait this time to proof fire it, until it was finished (Hi Rickk, I know what you mean!

).
So I just held it between my fingers and gave it a try with 1gr of black. A nice cracking sound did rupture the room. What a joy!
Kids don't do this at home while Mom is around...

This time I didn't use my kitchens door as target though: I fired into a board of Styrofoam and the pellet went into it quite a bit!

I'll update you when the carrige is finished.

Rickk · « **Reply #32 on:** December 23, 2006, 02:35:25 PM »

Using an angle grinder really took the metal off fast for me. I ran the drill press on a somewhat slower speed and just started grinding.

I wasn't even sure what shape I was going for when I started. I cut the threaded end and the head off the bolt and started drilling the bore. I found that I was able to drill it way easier than I thought, and all of a sudden I was looking at something too long to be a mortar. So I said "I'm making a naval cannon and started grinding. I used a file and sand paper to clean it up. After I did the brazing I put a wire wheel in the drill press and started polishing.

What I am saying is this was sort of a "wing it and see what happens" adventure. Next time I might actually have a plan. I am thinking that an air powered cut-off wheel will shape some nice reinforcing bands pretty quickly.

What did you use for material to start with, and what diameter is it?

How you gunna attach the trunions?

Cal.45 · « **Reply #33 on:** December 24, 2006, 02:54:06 AM »

Quote from: Rickk

What did you use for material to start with, and what diameter is it?

Rickk!

I just took some metal bar that was lying around, so I don't know its composition (at least it is no stainless, so brittleness shouldn't be a problem). Its diameter was originally 10 millimeters (a little more than 3/8th). When you look at the pictures, you may see, that I actually missed one reinforcing band. But it was somewhat difficult anyways, to get the dimensions close to the original design. Remember: This was done (as well as the mortar) without the luxury of using a lathe.

Quote from: Rickk

How you gunna attach the trunions?

With the trunnions, due to the size of the piece I need to do some compromises:

What I am concerned is, when I drill into the barrel to fit the trunnions into it, that will decrease the wall thickness at this points substantially (especially true due to the 60 degrees tip of each common drill):
Where the trunnions should be positioned, the wall thickness is just about 2 to 2.5mm (5/64 inches to a little more then 6/64th) the trunnions are about the same diameter, so if I would drill into the barrel at this point, the remaining wall thickness would be close to none.

Therefore I will leave the barrel like it is and file the corresponding surface of the trunnions to fit the outline of the barrel. After that I will glue them on with epoxy.
From the standpoint of stability I would always choose welding before soldering, before gluing: but in this case it is just too small to do so.
To catch up with recoil, the barrel will be welded from the bottom onto a steel plate that is located at the end of the carrige. The sides of the carrige are to be made from wood (beech) that has just 3/4th of its final thickness. Then I fix those "boards" with metal screws to the bottom plate and glue the remaining 1/4th ontop of that, so the screws will be invisible. The rest of the carrige will be done out of wood as well, so basically that metal plate is invisible.

I know that this is just a mean trick, but I would rather go safe than to be closer to the original design (this "gun" shall be fired, not just looked upon). With the small dimensions of the piece it is not possible otherwise I guess.

By the way: it is nice to see, that we came up with nearly the same procedure to get rid of excess material:
But I used a grinding wheel and did fit the barrel-to-be into a drilling machine (moved by hand) that rotated in the opposite direction.

Merry Christmas to Everyone!

Rickk · « **Reply #34 on:** December 24, 2006, 03:30:25 AM »

I was worried about trunnion hole breakthru as well, which is why my barrel taper starts after the trunnion hole. I also brazed the trunnions in place. I ground the trunion end a bit pointy to match the end of the hole for a deeper fit.

If you don't have an oxy-acet or oxy-propane torch you can braze it with MAPP gas that comes in the regular 1# propane tanks if you have a propane torch head that will adjust for MAPP. Most local hardware store should have 1/16 inch brazing rods and MAPP gas. You can also silver solder it with propane if you can find the correct solder and flux.

Epoxy with no holes probably won't work well. Epoxy generally has poor shear strength. It will hold a pin in a hole, but won't hold it well just stuck on the side of something. If you ever have one of those jokers at work that epoxy a quarter down to the floor just to see how many people will try to pick it up, just glance your foot sideways off the quarter and it will usually pop loose... then reach down and pick it up and keep walking with your new-found loot.

My plan for the next one is that once I have a drill hole started I will switch to a second drill that the end has been ground down flat. I should be able to come up with a more shallow, flat hole bottom. If I can find a 3/16 inch end mill someplace I should be able to finish it up with that and get a nice shallow hole.

Evil Dog · « **Reply #35 on:** December 24, 2006, 07:36:51 AM »

Here's an alternative which may or may not work. For the cannon version, if the trunnions are a larger diameter than the bore will be, could you not drill the trunnion hole completely through, place a one piece trunnion and then drill the bore through trunnion and all?

I'm starting to get the bug too.... thinking along the lines of a bb firing Dictator. That might call for a 7/8 or 1 inch bolt though.

Rickk · « **Reply #36 on:** December 24, 2006, 08:29:08 AM »

Yup, if it was silver soldered before drilling. Brazing would work too, although it would take some serious practice to get it to flow thru nicely.

I've been out in the workshop building the carriage and wondering if there was an easy way to get the trunion holes to be centered, in-line and exactly 180 apart from each other. I think I have an idea for a jig for my next attempt. I'm going to find a piece of pipe/tube/whatever that is 3/8 ID, drill it thru both sides where the trunnions would line up, and drill and tap one side for a pointy set screw. The I can use the non-tapped side for a guide to drill a trunnion hole in a 3/8 inch rod. After I drill one hole, I can reverse it, tighten the set screw in the first drilled hole, and then flip it over and drill the second side.

Hardware store is closed now... a project for later this week.

Rickk · « **Reply #37 on:** December 24, 2006, 10:37:52 AM »

copdoc · « **Reply #38 on:** December 24, 2006, 04:43:20 PM »

I have really enjoyed seeing the other nano guns. I have not had time to soldier the trunions on mine yet. Darn flu season. I thInk i will make one just a little bigger(bb bore) when time permits.

MERRY CHRISTMAS EVERYBODY

Rickk · « **Reply #39 on:** December 25, 2006, 06:42:32 AM »

Copdoc, as I recall, you started this, so you have little choice but to finish it

BTW, the nano-cannon I built I gave to my 4 year old for CHRISTmas... he has been driving it all over the place like it is a sports-car.

Once the rest of the toys are under control we are gunna go out and shoot it

Rickk · « **Reply #40 on:** December 25, 2006, 08:02:25 AM »

We went out side and blasted a few paper towel ball projectiles.

My son has been shooting mini-guns for almost a year now, so I gave him the glowing quick-match and he knew exactly what to do.

I found the smoldering paper towel pieces about 15 feet away, and the gun recoils back about 6 inches!

BTW, for BB caliber, Q-tips make excellent cleaning rods.

Rickk · « **Reply #41 on:** December 25, 2006, 08:07:55 AM »

One other thing, in case others are teaching their youngsters how to do this...

You dont want to light a fuse and then come up with a plan to get away... you want to plan a retreat to a "safety zone" before advancing to light the fuse. If you call it a "safety zone". it goes over better by the way.

We always pick out some object to act as the safety zone marker before hand. Today I used his sand pail, placing it about 10 feet away at a 45 degree angle to the rear.

Come to think of it, this safety technique doesn't have to apply only to 4 year olds

Powder keg · « **Reply #42 on:** December 26, 2006, 02:22:38 PM »

These are great little Guns, guys! I like the action shots of the grinding of the barrel. So Q-tips work good fer bore swabs, What are you planing on using for a worm?

Keep your powder dry, Wes

Cal.45 · « **Reply #43 on:** December 27, 2006, 10:49:47 PM »

I need to think a little longer about the facts that you came up with, concerning fixing the trunnions on that little cannon I am working on (see above). $:-\$ :

Quote from: Rickk

Epoxy with no holes probably won't work well. Epoxy generally has poor shear strength. It will hold a pin in a hole, but won't hold it well just stuck on the side of something.

So I just made me a BB size coehorn yesterday evening (needs to be blued and fit to its bed still – will be done today).
Here a brief step-by-step overview:

1.
Start with a rusted bar of metal that happened to cross your way; bore it and bring it into shape from the muzzles end:

2.
Roughly bring it into shape at the back and cut it to length:

3.
Grind the bottom with a drilling machine and a wheel grinder (careful: easily overdone):

4.
After some final filing and smoothening with emery paper, you end up with a nice little mortar:

Total time for this: about 3 hours.
(Well, it just takes time not to flinch, while you are working with the files on that tiny thing)

Quote from: Powder keg

So Q-tips work good fer bore swabs, What are you planing on using for a worm?

Worm? What about a little unwinding a small spring, fixed on a toothpick?

Thanks to you guys: for a nice new hobby!

Evil Dog · « **Reply #44 on:** December 28, 2006, 02:22:25 AM »

Worm spring? Look inside a retractable ball point pen.

Div Arty · « **Reply #45 on:** January 08, 2007, 04:02:11 PM »

What happened to the nano arms race? Guess Seacoast Arty turned the tide on that one. (Boy, would I be a pest if they were my neighbor. Even just to clean their shop. Not that their outfit needs it. Shades of Norm Abrems).
But what a form, thanks to GBO and it's moderators D-D & C-W. Have been reading & reading, still haven't scratched the surface.
Just to get things started again, I'm encloseing a picture of the only surviving example of my preteen battery. (circa 1948). Though my attempts at home made BP phizzeled. Yeh, now I know, Charcoal. I found that the copper overflow tube from a non-ferrous toilet ballcock, peaned at one end over a small nail, would with the aid of a paperclip, accommodate a ladyfinger firecracker and a BB. Great for punching holes into waxed milk cartons. Remember those. The rest of the lost collection were Revell plastic cannon models with the above tube set into the barrel with plaster of paris. I guess this is realy a testimon to Duco household cement,in that it has been acting as truninos for the past 50 plus years.
Well, thanks for the new home and I have a few more projects to be posted on other topics.
Div Arty

seacoastartillery · « **Reply #46 on:** January 08, 2007, 05:37:36 PM »

Well I certainly hope not! We stand by our early comments on this thread. As soon as this rifling machine matterial is presented Mike and I are eagerly looking forward to entering the micro-cannon arms race with some sort of smooth-bore .177 cal gun. We have only two requirements for it. It must be capable of firing a pellet with a miniscule chg. and must loosely resemble some historic gun. It will probably look as rough as a cob, but it will really be nice to make something just for fun!

Thanks for posting a picture of your cannon. All the guns of my "early teen" battery blew up before I could get any pics.......

Tracy

Cannonmaker · « **Reply #47 on:** January 08, 2007, 06:44:18 PM »

Have we any Watchmaker in this group? Let's see just how small we can get these mortars. Oh, just kidd'n, they look good, a nice converson piece that works.

Rick

Cat Whisperer · « **Reply #48 on:** January 09, 2007, 12:44:40 AM »

Div Arty -

WELCOME to the board! Your name implies lots of firepower! You started off right from the beginning right - with the GOEX can in the pix too!

Looking forward to seeing your current collection/activiteis/plans ....

CU_Cannon · « **Reply #49 on:** January 09, 2007, 03:58:31 PM »

I think we have discovered cannons that anyone can build. For one thing they won’t break your wallet or back.

What about a nano rifling machine?

If I have time this weekend I’ll see if I can do some more experimentation.

EL Caz 66 · « **Reply #50 on:** January 15, 2007, 12:25:20 PM »

Here's photo's of my little one's making smoke ... Videos soon to come...

EL Caz 66 · « **Reply #51 on:** January 15, 2007, 12:32:11 PM »

Videos to view...
http://www.youtube.com/watch?v=-88iy7xVzYw
http://www.youtube.com/watch?v=Bv1T4lyIVH0
http://www.youtube.com/watch?v=AFfbT6O96LA

http://www.youtube.com/watch?v=HzyR_7OHA8g

DANLK66 · « **Reply #52 on:** January 23, 2007, 06:56:57 AM »

Here is my first try and my first cannon. I had hoped for a bowling ball cannon but this will have to do (per my wife).
Boar is .177 and 10mm deep. I will let you know once I finish it.

Dan

DANLK66 · « **Reply #53 on:** January 23, 2007, 07:47:47 AM »

This might work better

MOD Note: To post picture just highlight link and click on the picture icon or copy the link that looks like this

Code: [Select]

[img]https://www.gboreloaded.com/mhp/images/DANLK666/minimortar2.jpg [/img]

Santa Dave · « **Reply #54 on:** January 23, 2007, 08:44:11 AM »

All you do is set that little beauty into a bowling ball and Voila! A bowling ball cannon!
Dave

It May pretty close to an "O" guage bowling ball cannon.

seacoastartillery · « **Reply #55 on:** February 14, 2008, 06:05:24 PM »

This was a very popular thread about a year ago and we think it's worthwhile to revive it. There hasn't been a whole lot of actual building of cannons or mortars within this group lately, with a few exceptions, of course. Mike and I would like to promote more participation among the membership, some of whom have never built a single gun for a whole host of very good reasons. So today, we declare, that if you own a few common household items and an electric hand drill, you too, can enter the Nano-Mortar/Cannon Arms Race and have a lot of fun doing it!! Over the next week we will select one to build ourselves, one which will not require any lathes, milling machines, band-saws, ect., etc. We are leaning toward a cannon which looks like the fairly common, 10" Rodman Seacoast Gun. If anyone has a better suggestion just post it.

Well, what do you guys think? Is this possible?

Regards,

Mike and Tracy

MikeR C · « **Reply #56 on:** February 14, 2008, 07:36:25 PM »

I just bought some fuse for a golf ball mortar I'm finishing up, I ordered it from WWW.skylighter.com. I bought some Chinese green Visco that mics out at about .094, some 3/32 yellow Fast visco (it is fast!) which mics out at .125.
But to stay on topic, they also have 1mm fuse which mics out at .042 and fits loosely into a 1/16th hole. I bet it would fit into a #55 drilled hole if you cut the fuse with a razor. It comes in 50 foot packages for $15.74, stock# GN1010, Visco, Cross-Match.
Their shipping was reasonable and they shipped the next day, USPS.
I have a .177 and a .25 bore cannon and this fuse works perfect with a 1/16" touch hole. I was pulling the paper fuse out of firecrackers but it wasn't all that reliable.

Thx
MikeR C

seacoastartillery · « **Reply #57 on:** February 14, 2008, 08:18:33 PM »

Thank you very much for that fuse info., MikeR C. That is just the type of information we need to make these little guns shoot. We found a 1/16 fuse, real HOT chinese visco stuff which mics at .062- .065". We use it all the time with a .075" Dia. vent. But yours, at .042", is better, because a smaller vent just looks closer to scale on these nano guns. We also should mention that the .177 or .22 cal bores which are pretty common in these nano guns indicate a 1/2 to 5/8 ths inch breech diameter. The expense of the material is very small and bolts can be used which pretty much eliminates the "Mystery metal" objection that some raise when building larger, more powerful, cannons.

The .042" fuse link is below: Look for: Visco, Cross-Match GN1010

www.skylighter.com

Any other suggestions to help our first-time builder members would really be appreciated.

Regards,

Mike and Tracy

KABAR2 · « **Reply #58 on:** February 15, 2008, 12:54:12 AM »

Comment deleted

Allen <><

KABAR2 · « **Reply #59 on:** February 15, 2008, 01:01:26 AM »

Quote from: EL Cazador 66 on January 15, 2007, 12:25:20 PM

Here's photo's of my little one's making smoke ... Videos soon to come...

Your little mortar is a commercialy made cha-ka cast in pot metal, I know I have one.
I don't think I'll try putting any powder in mine
even with the added repaint I don't trust what it's made of to hold up to even a small charge.