Author Topic: Boat Howitzer (Read 3911 times)

Powder keg · « **on:** September 07, 2005, 05:45:10 PM »

Hi, I'm planing on building a little boat style Howitzer. When machining anything you need to plan out your project. This way you don't paint yourself into a corner. .The barrel will be simular to one I found on the net sometime back.

I don't have any dimensions for this barrel but, one of the pictures was a straight on shot from the top. I recieved the material and sample ammo in the mail the other day. After measuring the material I can scale the picture and print it out the same size I'm going to build. If the barrel is to big for this print it out half or quarter scale. After you get the dimensions you can start the fun part. I've found that I like to true up the outside of the material so it is easy to hold onto. Next I like to drill the bore. I do this because drilling requires lots of torque and sometimes your piece will move or spin in the chuck. This will mahr your finish. This gun will be bored .875. I don't have a drill bit that size long enough to do this. I also don't have lots of money to spend on a long drill bit. So I'm going to modify an existing one. To do this I machined a point on a piece of 5/8 CR shaft. I then machined a point on the shank of a S & D drill bit. Next I'll tack weld the two togather and tap them around so their straight.

To be continued.....

Cat Whisperer · « **Reply #1 on:** September 08, 2005, 12:04:01 AM »

That is an art to weld together a tool end-to-end like that!

I built an extension from 5/8 rod, drilled the end, added a set screw to hold the reduced end of a 3/4 or 7/8" bit.

Good looking design on the howitzer too!

kappullen · « **Reply #2 on:** September 08, 2005, 12:42:22 PM »

PK

When I went to have a job like that welded, the welder told me to make two chisel like points instead of conical.

That involves less welding and less chance of a molton puddle when you burn thru.

Since I learned to weld, that's the way I do it too.

Good luck on your project!

KP

Powder keg · « **Reply #3 on:** September 08, 2005, 01:07:43 PM »

Hey, Thanks for the Tip. I'll try that instead.

dominick · « **Reply #4 on:** September 09, 2005, 11:54:11 AM »

Hey Wes, I used a piece of 5/8" .065 moly with a 45 degree slice on both ends and I slid one end over the drill bit shank (tight tap fit) and inserted a 1/2" cold rolled rod in the other end and tig welded both ends of the tube. It keeps everything straight. Dom

Terry C. · « **Reply #5 on:** September 09, 2005, 12:41:50 PM »

I'm a welder by trade (I'm called 'fabricator', that's just a fancy title that means I'm the only one here that knows how to weld and run the lathe) and the double v-bevel (chisel point) is the way to go IF you must weld.

But don't grind to a knife edge, leave a flat on each piece that you can butt together. Ideally, you want to penetrate completely through when you've welded both sides, but not burn through while you are fitting. If you are using TIG, a good rule of thumb with butt joints is to leave roughly the thickness of the tungsten electrode. This type of joint is also much easier to hold in line while you tack than trying to center two knife edges against each other.

But dominick has the preferable method. You will get better alignment and a stronger joint with the sleeve.

I would only use the bevel/weld technique if I didn't have enough clearance for the sleeve, this does not seem to be the case with your drill.

Powder keg · « **Reply #6 on:** September 09, 2005, 01:40:32 PM »

Hey Guys,
The guy I was going to have weld it was really busy so I decided to weld it myself. I needed the practice anyway. I welded the drill and I straightened it (By tapping it with a hammer) on the lathe while it was still a bit warm. I then center drilled the end and cleaned up the shaft and weld. There are a couple of small holes in the weld but overall I think it will work OK. Here are a couple pictures. By the way, I added 12" to the legnth

Next I'll start on the barrel. The piece's of bronze for this piece were rescued from a salvage yard somewhere in Washington state. I measured the shaft where the breech will be the thickest. And printed the picture out the same size. Took 3 tries to get it right. Next I'll just scale the picture to get my dimensions.

Thanks for the tips Guys. It's nice to have a place to share ideas on how to build stuff. I think it's weird that you can give 10 Machinists the same job and all 10 will do it a bit different.

To be continued......

kappullen · « **Reply #7 on:** September 09, 2005, 04:34:09 PM »

Quote from: Powder keg

Thanks for the tips Guys. It's nice to have a place to share ideas on how to build stuff. I think it's weird that you can give 10 Machinists the same job and all 10 will do it a bit different.

To be continued......

Pk,

You're right about that! I've seen Machinists come to near fist fights over the "PROPER WAY" to do a job.

It depends on your prior experiences, and what you have to work with, how you do it.

These new CNC guys can do some great stuff, but a dinosour like me has a good bag of tricks as well.

The Practical Machinist site has helped me a couple times, and I've had some inputs there too.

When you quit learning, you're good as dead.

Kap

Cat Whisperer · « **Reply #8 on:** September 09, 2005, 04:45:39 PM »

Quote from: kappullen

....
You're right about that! I've seen Machinists come to near fist fights over the "PROPER WAY" to do a job.

It depends on your prior experiences, and what you have to work with, how you do it.
....

Excellent techniques! THANKS for posting them.

When I was learning AutoCAD (version 1.2) we had 3 professionals come in from time to time to give demonstrations.

Same situation, I would ask, "what about doing it (this way or that way)?" The response was, "Well Mr. K if you did AC 8 hours a day like I do you'd do it THIS way."

Three completely different ways of doing the same thing.

So, I learned to teach MY students EVERY way possible, choose the best (fastest, most accurate or whatever) way that fits the situation.

It is indeed a pleasure to see several different methods for getting things done. They WILL be used later in life!

Powder keg · « **Reply #9 on:** September 12, 2005, 04:08:07 PM »

Hi, I got a bit of a start tonight. I chucked on the little nub to clean up the end on the right. I then cleaned up the ridges in the center of the shaft. This shaft was scraped because it was bent slightly, I'm guessing. The piece is a bit longer than is necessary and my next step will be to cut some off of the left end with my bandsaw. After that I'll re-chuck it in my lathe and then true up the sawn end and start drilling a hole.

Later......

Powder keg · « **Reply #10 on:** September 15, 2005, 03:12:32 PM »

My band saw blade broke

I should have a new one tomarrow. I'm excieted to see how this barrel turns out. the one in the picture sure is nice. I've never machined bronze like this before. The chips turn a neat red color. I'll try to post a picture. I'm thinking there is a lot of copper in it?

GGaskill · « **Reply #11 on:** September 15, 2005, 04:45:41 PM »

Most bronzes are at least 85% copper.

CU_Cannon · « **Reply #12 on:** September 16, 2005, 06:56:42 AM »

I really like that cannon. I drew up a version of my own last night that will be 4" dia and golf ball caliber. I think mine will be steel I don't think I could afford the bronze. That is all I need is some more projects to add to my list.

I look forward to seeing yours complete. What are you planning for a carriage?

jeeper1 · « **Reply #13 on:** September 16, 2005, 02:14:59 PM »

Ship's cannon style.

Powder keg · « **Reply #14 on:** September 18, 2005, 03:06:26 PM »

Hello, There was a slight delay this weekend on this gun. Saturday, Rick Neff one of the site sponsors called and had some questions on building a foundry furnace. I volunteered and went out to help him. It took 3 of us most of the day to form up and pore the castable refractory furnace lining. We ended up mixing 20, 55 pound bags of the stuff :coffee: Today I was inspired to finish my furnace. I had a helper and we mixed and formed the 7 bags for my furnace. I feel like I've been drug through a knot hole backwards :shock: Everything turned out good and both furnaces should work great. I'll post pictures if any are interested. I'll continue on this gun tomorrow.

Cat Whisperer · « **Reply #15 on:** September 19, 2005, 12:53:18 AM »

Post the pics?

Before you ask, the answer is YES!

Powder keg · « **Reply #16 on:** September 21, 2005, 03:50:03 PM »

I forgot to mention earlier. This barrel is being built for jeeper1. He probably thought that I had abandoned the project. Actually Murphy lives in my shop. My bandsaw blade broke. I ordered another and while waiting for it I found a used blade. It cut to the right, Bad. I threw it away. The new blade arrived. It was about 1/8" to short. There was no way to make it fit :x So, I decided to part the shaft in two. On my old 1935 vintage lathe, this is no easy task, but I got it :grin: Sorry about the mess! My shop gets worked in more than it gets cleaned.

Here is the shaft, shortened, cleaned up and a center drilled in the end.

Here is an action shot.

The drill worked perfect! Here is it buried in the shaft.

This last shot shows a neat little addition I made to my lathe. The tailstock handwheel was so small after drilling a couple of inches deep, my hands and arms would hurt. Here is how I fixed it.

CU- Go ahead and post your drawing if you like.

To be continued.....

kappullen · « **Reply #17 on:** September 21, 2005, 04:59:47 PM »

PK,

How are you going to fix the trunnions on there?

I never saw one built like that before except those that guy is always selling on ebay.

Kap

Powder keg · « **Reply #18 on:** September 21, 2005, 07:05:57 PM »

Hi, I'm planing on using hidden studs and locktite. I'll mill pockets and drill and tap a hole under each trunnion. Are you talking about the guy that uses JB weld? On a cannon with a bore this big I probably wouldn't trust it alone. I also could solder the studs on, but I've never been much good at it. maybe I just need practice :?

CU_Cannon · « **Reply #19 on:** September 24, 2005, 09:40:23 AM »

Here is my version. Once I get through my other projects IÂ’ll get working on it.

Powder keg · « **Reply #20 on:** September 27, 2005, 01:38:14 PM »

Back to the breach end. I turned the end where the cascadable is down to size and narrowed the neck of the cascadable to size. I also rounded the breach end to what looked good. Later,

Powder keg · « **Reply #21 on:** September 28, 2005, 03:13:46 PM »

Here is what I did to the Cascadable. I decided to add one of those decorative rings to it. All the work has been pretty much "freehand". I've just measured legnths with a 6" scale and the diameters I measured with my dial calipers. All the curves were done buy eye and a large radius tool. I'm saving the end until last. I'll use the nub left to chuck on in the lathe and the mill when I cut the pockets for the trunnions.

I turned the barrel around and started on the muzzle. This was all freehand also. I have to shape the big radius with a file a bit more then the muzzle end will be done. With bronze I like to emery all the scratches and tool marks out before I take it to the mill. This does two things I've noticed. One it makes the bronze less likely to get little scratches and two it speeds up the polishing process. I'll emery everything after I get the tapers cut and the rings rounded. That way I don't risk scratching the barrel with my file.

Cat Whisperer · « **Reply #22 on:** September 28, 2005, 04:07:04 PM »

Ahhhh what a cool collection of pictures this is becoming.

Question - using the round insert (assume carbide) cutter for cutting the radius between the breech and the cascabel - does it cut smoothly or do you need to watch out for chatter?

Powder keg · « **Reply #23 on:** September 28, 2005, 04:16:56 PM »

That toolholder was made by me :grin: It uses 1/2" in diameter carbide inserts and can cut to the left and to the right. If you keep your speeds down and try not to rush things to much chatter isn't usually a problem. The finish in the bottom of the neck is what I got with that tool, I haven't sanded anything yet.

Cat Whisperer · « **Reply #24 on:** September 28, 2005, 11:44:22 PM »

Thanks! That's the answer I was hoping for! (I have a few round carbide cutters in the tool box looking for a tool on which to be mounted.)

Powder keg · « **Reply #25 on:** September 29, 2005, 05:28:27 AM »

I've got the parts cut out for another tool that uses 3/8 diameter inserts. The 1/2 works good for lots of stuff. I'll snap a couple of pictures for ya. Later,

Powder keg · « **Reply #26 on:** September 30, 2005, 12:51:44 PM »

Did a bit more today. I started on the taper. It looked like it was about 2 degrees, so thats what I set the tapper attachment to. There is one more angle and the lathe work will be about done accept sanding and finishing the cascadable.

To be continued....

Powder keg · « **Reply #27 on:** September 30, 2005, 01:46:57 PM »

I finished the last taper. Off to the mill......

Powder keg · « **Reply #28 on:** October 08, 2005, 05:57:50 AM »

Hey All, It's been a bad week. I'm a Forman in a machine shop and out of 4 guys one quit, one went on vacation, And another had wife problems. To top it all off I've had a bad cold, but since I'm incharge I had to to be there

I've made a bit of progress though. I'll get some pictures later. I emeryed the toolmarks off the barrel while it was still in the lathe. And in preperation for the mill work, I turned a slug that fit in the bore so my tailstock could support the muzzle end while it was in the mill. Later,

Powder keg · « **Reply #29 on:** October 12, 2005, 04:26:50 PM »

Feelin better!!! :grin: I set the barrel up in my mill and milled the trunnion pockets. Then I drilled and tapped them 1/4 - 20 by 3/8" deep. I used my dividing head to rotate the barrel for trunnion pocket placement. I'll finish the trunnions tomorrow and this little barrel will be ready to polish. I think I'm going to make one like this for myself. It has nice lines, me thinks :grin: