Author Topic: Golf Ball Coehorn (Read 8719 times)

CU_Cannon · « **on:** January 16, 2005, 11:41:56 AM »

I've finely got a start on my golf ball size coehorn. The machine work is going good. I like making cannons, other than the bore the dimensions are not all that critical. This is my first experience machining 4140. I especially like the bright blue chips when you try to cut it too fast. It took a while to get the speed right but I managed to get a light straw colored chip that was about 5 ft long so I must have had it pretty close. It will be interesting to see how it bores out.

This is what I have so far. I hope to start boring it later this week.

Cat Whisperer · « **Reply #1 on:** January 16, 2005, 12:24:00 PM »

You are getting there!

4140 turns a little differently that CRS - not as easy to get a smooth finish as it crumbles more when you cut it, but it will take a high polish.

Design looks good too.

I'd love to see how you cut the radius and the groove for the trunion. I'm building a radius cutter currently, along with a steady rest that should go up to 7 or 8" diameter.

Double D · « **Reply #2 on:** January 16, 2005, 07:03:23 PM »

Watch those long stringy straw colored chips, they move quick and cut like razors. Not all bad though, they are hot enough to cautherize the wound sometimes.

I use my dremel tool and a cutting wheel to put a chip breaker on the tool.

warf73 · « **Reply #3 on:** January 17, 2005, 11:34:11 PM »

Quote

Watch those long stringy straw colored chips, they move quick and cut like razors. Not all bad though, they are hot enough to cautherize the wound sometimes.

:-D :-D :-D :-D :-D

Ya they do sometimes.

CU_Cannon · « **Reply #4 on:** January 18, 2005, 03:50:15 AM »

I thought about building a radius tool but I have another idea that I might try. I made a excel file that will calculate the x and y coordinates for a circle. Since the lathe has a stop that you can adjust in .001 increments I will set it for the distance found in the excel sheet make the cut, adjust it for the next and so on. The end result will be a stepped circle that can be smoothed out with a file.

The grove for the trunion will first be cut with a ball end mill. The largest I have is a 1 in. It should be enough to remove the bulk of the material. To remove the rest I will make a boring bar. It will be held between centers in the lathe and the mortar will be clamped on the cross feed. I plan on using an old ¼ in drill bit ground for the tool and two set screws, one to secure the tool another to feed it in and out. I have a little bit of room for error so if it doesnt work I might have to try something else.

Ive caught the bad end of chips before. Its not much fun. You learn quite quickly to keep your hands out of the way.

CU_Cannon · « **Reply #5 on:** January 23, 2005, 08:06:49 AM »

Yesterday I got the bore roughed out. Most of the time was spent sharpening drills so they cut half way decent. I also made a holder for a ball end mill. The end mill alone would not have been long enough to reach the bottom of the bore. So far I'm very pleased with the progress. It shouldn't be long before I can throw some golf balls.

Cat Whisperer · « **Reply #6 on:** January 23, 2005, 02:26:44 PM »

CU -

Sounds like your project is going well. Like you, when I want to make anything I start by making the tooling I need.

I'll be making a radius cutter to fit the tool post soon. (I'm working on a golf-ball caliber scaled version of the 1841 10" seacoast this time.

Cat Whisperer · « **Reply #7 on:** January 23, 2005, 02:31:36 PM »

CU -

Looks like you've got a good grip on techniques as well - the machining at the bottom of the bore looks very smooth!

CU_Cannon · « **Reply #8 on:** February 06, 2005, 05:29:17 AM »

Well its almost done. The final bore is 1.728, a golf ball fits it quite nicely. Rounding over the end went well. I did get a little impatient with it so it didn't turn out exactly round but the originals were not exactly round anyway. I milled the trunion grove with the 1 in ball end mill I used to mill the powder chamber. It took a little bit of figuring on how to get a 1 1/4 in round grove out of a 1 in end mill. I ended up milling the groove to full depth and the milling out each side to 1 1/4. It worked quite well. I need to do some clean up with a die grinder and a file to get an exact fit. The only other task is to drill the vent. I like to make this the last operation. It is at that point that it changes from a chunk of metal to a cannon.

This project took a little bit longer that I thought it was going to. I guess I didn't take the learning curve into account. I think all together the machine work has taken 25-30 hours including making the jigs and tools I needed. I guess thats still not too bad. I figure there should be around 15-20 hours more to finish it completely.

Once I get access to a digital camera again I'll post a pic.

CU_Cannon · « **Reply #9 on:** February 07, 2005, 10:42:41 AM »

Here it is:

There is still some fine tuning that needs to be done on the trunion groove. If I go slowly with a dremel tool I should be able to get a perfect fit. With a little polishing it will be done. I plan on bluing the barrel. At first I had thought of rust bluing it but I think I will just cold blue it for now. The project has taken enough time and I can always rust blue it later if I so choose.

On to the construction of the base. More pictures to come.

Evil Dog · « **Reply #10 on:** February 07, 2005, 11:37:14 AM »

Instead of bluing..... consider browning. It really looks neat.

Powder keg · « **Reply #11 on:** February 07, 2005, 01:33:53 PM »

Thats a nice looking tube! Great job! keep us posted on the carriage. Powder Keg

Cat Whisperer · « **Reply #12 on:** February 07, 2005, 03:25:00 PM »

CU -
Great job! For comparison here's a pix of golf-ball and beer-can caliber CNC made 4140 coehorns:

Three are in-the-white, one is parkerized.

4140 takes a good polish too.

CU_Cannon · « **Reply #13 on:** February 19, 2005, 04:09:57 PM »

I have had several requests for my plans so here they are. They are in pdf format so they can be scaled up or down without distortion and they print to scale. If anyone wants it in autocad format let me know. I will post some drawings of my base once I get it done.

http://www.geocities.com/jeanluc83/cannon/Golf-Ball-Coehorn.pdf

Do what ever you want with the plans. Make copies give them to your friends as long as you don't directly sell the plans it doesn't bother me any. The only thing I ask is if you build a mortar from my plans send me a picture of it or post one on the board.

CU_Cannon · « **Reply #14 on:** February 23, 2005, 04:27:20 PM »

I started working on the base. It is made out of red oak. The plank had been outside for a while but it cleaned up pretty good. There is a little checking is some spots but they shouldnt cause any problems.

Cat Whisperer · « **Reply #15 on:** February 23, 2005, 05:19:01 PM »

CU' - thanks for the pix. It's fun to see the projects come together a little at a time!

CU_Cannon · « **Reply #16 on:** March 17, 2005, 06:49:21 AM »

I finely had some more time to work on finishing things up. I just about have the base done. Carving out the recess for the barrel went well. It took a lot longer than I had thought. Ive been going slow as it is much easer to take wood off than put it back on. On my next mortar I will use two pieces for the base instead of laminating six together. It took a while to get all the holes to line up. Ill post some pictures when I get everything done.

CU_Cannon · « **Reply #17 on:** March 24, 2005, 02:35:43 PM »

I was ready to finish things up tonight and the forestner bit I needed is mia. Once I buy another I know I'll find it. Here are some pics of the barrel on the base. Its almost done. I can't wait to see how it shoots.

Powder keg · « **Reply #18 on:** March 24, 2005, 04:17:12 PM »

Very nice looking carriage! How are you going to finish it? Stain? Paint? Are you going to add handles to the side? It looks realy nice. Thanks for posting pictures, Later

CU_Cannon · « **Reply #19 on:** March 28, 2005, 07:56:34 AM »

I'm going to finish it with linseed oil. I like the looks of just the oil on the wood. The hardware I have on it now is just temporary. I plan on forging more authentic hardware sometime over the summer. I have never done any blacksmithing before so it should be a lot of fun. I'll be building another mortar shortly so I wanted to get the hardware done for that one at the same time.

Powder keg · « **Reply #20 on:** March 28, 2005, 01:10:00 PM »

I to like the looks of oiled wood.

Double D · « **Reply #21 on:** March 28, 2005, 06:23:01 PM »

Confederate bases were linseed oiled.

Cat Whisperer · « **Reply #22 on:** March 29, 2005, 12:41:55 AM »

(this should be obvious to any woodworker)

Just make sure it's BOILED linseed oil. I've seen raw linseed oil that hadn't dried - it was 30 years after it was applied.

CU_Cannon · « **Reply #23 on:** March 30, 2005, 11:25:25 AM »

I put a coat of oil on the base and blued the barrel. Everything looks great. The bluing is a little streaky. A few more applications of the solution would have cleared that up but I had oiled it before I noticed.

Over all I'm very happy how it turned out. I have around $35 tied up and materials and 40 or 50 hours of work. If I build another one it will take considerably less time.

I still need to make a set of hardware for it but that will not be for a while.

Test fire this weekend if the weather is nice.

CU_Cannon · « **Reply #24 on:** April 10, 2005, 12:12:12 PM »

I finely got out to the range to do a test fire. I only could get pyrodex from the gun shop. It worked quite well though a lot is required to get any distance. I got distances of around 100 yards from 400 grains. Anything less is pretty disappointing.

Here is what it looks like in the sunlight. You can really see how streaky the bluing is. I guess you have to make a few mistakes before you get it perfect.

Here are a few action shots using the John N technique.

Cat Whisperer · « **Reply #25 on:** April 10, 2005, 12:20:10 PM »

Good pix! It's tough to get the flame at just the right time.

Cannonsight · « **Reply #26 on:** April 10, 2005, 03:08:35 PM »

I made a golf ball morter several years ago.I still haven't made a set of handles that look good enough to put on it.I sometimes shoot it in my back yard using a hollow plastic practice golf ball and 30 grains FFFFg. My boys love to be downrange to retreive the projectile.

Cat Whisperer · « **Reply #27 on:** April 10, 2005, 03:36:15 PM »

Cannonsight -

WELCOME!! Good to hear stories! Post some pictures if you get a chance. We'd love to know what it looks like.

I took a friend out this afternoon with his two boys. Something else to see expressions change right after the big boom!

Double D · « **Reply #28 on:** September 26, 2007, 07:02:06 AM »

Quote from: CU_Cannon on February 19, 2005, 04:09:57 PM

I have had several requests for my plans so here they are. They are in pdf format so they can be scaled up or down without distortion and they print to scale. If anyone wants it in autocad format let me know. I will post some drawings of my base once I get it done.

http://www.geocities.com/jeanluc83/cannon/Golf-Ball-Coehorn.pdf

Do what ever you want with the plans. Make copies give them to your friends as long as you don't directly sell the plans it doesn't bother me any. The only thing I ask is if you build a mortar from my plans send me a picture of it or post one on the board.

Did you ever make the plans for the base?