The Home Machinist!

Hi all, This is a close look at how I drilled, reamed and cut rifled the barrel for my Sharps rifle. I think I said that the barrel was going to be 1215 steel, but as I also had a 31.0" x 1.230" dia shaft of 4140 steel and as some were saying this is best, I listen to the ones how know more than I do, and the receiver 4140 as well. My lathe is a belt driven and .900"b/c, at the back end a steel tube was made up to thread on to a bit of bearing nut thread, It had fore grub screws to true up the barrel stock and a round flange welded on with six holes on the edge for rifling register . The barrel stock is trued up at each end and a fine cut made for register on the o/d, and faced off on the end . pic`s, Homebrew.357.

And also the back end and then turn around and the same again. Homebrew.357.

The gun drill has to be started dead centre in the barrel stock, so I made up the gun drill guide in three bits. The housing holds the gun drill guide and it is a taper press fit, the housing has two screws to holed it in my angle bracket and the guide stub is to line it up true, it is a sliding fit in the gun drill guide, same size as the gun drill tip and set up in the fore jaw chuck turning true. pics, Homebrew.357.

The drill guide is set up true on my angle bracket clamped in front of the chuck, using the guide stub in the 4 jaw chuck to line up the gun drill and the two screws set, now the bracket can be removed . The barrel stock is set up in the lathe and drill guide and angle bracket is clamped back in place all lined up, o ring stops 0il leaks. pics, Homebrew.357.

With the barrel in.

Oops, Gremlins getting in, PICS,825,826, gun Drill is rough way around in bracket. And pic 833 the bracket is pushed onto the stub and clamped, then the drill guide housing is screwed tight. Now It can be removed and barrel stock set up, then angle bracket is replaced back in and all lined up. Homebrew.357.

Ok, the barrel stock is in and lined up with the drill guide. Now to make the gun drill move in, I made up some ali blocks to fit and slide on the lathe bed ways and mounted my X/Y vice on top, bolted in. A bracket was made up to fit under the saddle with a turned up bit to catch in the front. So when the saddle is in drive, it pulls it all along, and in goes the gun drill. pic`s, (arrows show the bracket) .
Homebrew.357.

Hi, Now that I had the drill in feed sorted, I had to think about the slow in feed for the drill. A lathe at it`s finest feed is to fast for the gun drill, it needs to be a lot slower for small swarf /chips so the oil cad flush it out. So a dig around in my (Don`t ever throw away box) I found two Vbelt pulleys, a small one and a large one from a old washing machine. The back of my lathe has a forty tooth drive gear to a large double gear, 127/120 tooth, to gear it down I changed the forty to a thirty tooth gear to drive the 127 one. Now that gear had fore holes in it ,so I made up a bracket and two ali plugs for mounting ,with the small Vbelt pulley in the centre . An extension arm was made to mount this gear on so it could be moved for drive and belt tension onto the large Vbelt pulley , and this was fitted to the gear box drive on the lathe and it is set at finest feed. Now there was no triganomtey, algbra ,sin, cos, and tan in this, just plain luck, I got five turns of the chuck to 0.010mm of in feed, So I had really gear in down. . The photo shoot, Homebrew.357.

Hi, Heck, after 5 posts and 25 pic`s , NO comments?, I like to hear something ,
Any way some more pic`s, Cheers, Homebrew.357.

Hmm... to post or not to post that is the question... if i don't post the suspense keeps growing...

Regardless if I post or not, I am following your progress on this endevour of yours and enjoy seeing the creativity with which you use to solve the problems that you face. Seeing how you accomplish things encourages me to think outside of the metaphorical box to sovereign my own problems. At the end of the day it doesn't matter how you accomplish your goals as long as the results are what you want and it is done safely!

you are in a area that leaves me surprised at every turn, many, many have started down the path you travel. few have gotten this far along.

we are watching and enjoying the progress in a home shop manner..

Ok, now I had the slow in feed and drive sorted, this is how the gun drill works. At the back the drill is clamped in the vice at lathe centre hight with the oil in feed attached. Two steadies put on to keep drill straight and chip box with seals are fitted , oil and chips go back to tank, chips are stoped with the fine mesh catcher. To start the drill, the pump is turned on and oil is just going to the tank with the red tap open, drill tap is shut. Lathe is started at 1200 rpms , drill tap opened and red tap shut off, all the oil is going through the gun drill at 300 psi, the lathe feed is engaged and in goes the drill, very slowly. After a bit the chips start coming out and when getting full it has to be empted . The pic`s should help to figure it out. Homebrew.357.