making moulds on a lathe

[craveman85]

i would like to start making my own moulds for my rifles. i was wondering if it could be done on a lathe. im thinking with a 4 jaw chuck you could center the blocks, drill the hole with a drill chuck, then use piece of tool steel cut to the profile you want you could simply move the tool off the the side in very tiny increments until you get to the desired size. i know some guys use milling machines with a boring head on it but wouldnt i need a lathe to turn my cutters on as well? i cant afford a mill and a lathe while paying for my shiloh and i dont have the space for both machines either. anyone see any problems in this? any other ideas? i would also have other uses for the lathe such as making other little tools and some lathe turned bullets as well.

[craveman85]

i also thought about making some old push through moulds like the lyman ideal from round stock with this process using the 3 jaw chuck. of course they would only be for paper patching. but with my scrap aluminum and other things i could make enough moulds to pay for the lathe rather quickly with its savings.

[rbertalotto]

I can't see why you couldn't do it quite easily.

Two halves of the block in a 4 jaw as you suggested.

Using a boring bar, bore out the boolit shape you want or grind a "spade" reamer to bore it out.

Using another boring bar ground to the shape of the groove you want to cut, cut the internal grooves like you would internal threads............

Sounds simple!

[3006guns]

There was a thread on here showing that exact technique using a shop ground D bit and it worked well. In fact, I modified a Lyman 8mm mold to a plain base with a four jaw chuck and small boring bar. I lined it up by placing the blocks in the four jaw and a lathe center in the tail stock. I ran the center up to the blocks and carefully inserted it in the existing hole, then tightened the jaws. Ran true.

[dragonrider]

I do believe that Buckshot posted a thread of the very same technique with photos.

[craveman85]

sounds good ill be ordering a lathe today then.

[Doc Highwall]

Pay attention to the through hole size in case you want to thread and chamber barrels.

[theperfessor]

Don't know if this will provide any useful information, but here is a link to a Word doc I wrote on the topic:

http://www.usi.edu/science/engineering/moldfixture/MakingBulletMolds.doc

It's about 70 pages w/lots of photos.

[trk]

THANKS! THat paper is pure gold! I've oft thought of building such a fixture.

[theperfessor]

I've improved some things since I wrote that. My mold halves are 0.700" thick, I cut them down from 0.750 stock. The cavities are 0.600" from the end. So I turned a stainless steel cylinder about 2" long and 1.400" diameter. Then I cut a flat halfway up one side 0.100" deep (it measures 1.300" across). Now I just clamp the plug in the fixture and use a dial indicator to align the fixture by making sure the plug is concentric. It locates position perfectly. I also made some studs that thread into my faceplate's 1/2-13 holes and are cross drilled with 1/4-20 holes for some socket head cap screws. I use these to adjust fixture on faceplate.

I tried using lathe center on predrilled hole in mold mounted in fixture to line things up and wasn't satisfied with results.

Also had a good DRO put on lathe, worth every penny.

[JIMinPHX]

This topic has come up a few times before. If you use the search option at the top of the page, you should be able to find a bunch of information. This is one of the more recent threads - http://castboolits.gunloads.com/showthread.php?t=110402

[cajun shooter]

Accurate Moulds, Hoch and others are all done on Lathe. The secret is block placement and what fixture is used to line up the blocks the same.

[craveman85]

i saw a post where another member showed how he made them. he use a piece of 2 inch stock with a .25inch nub in the middle. he had a .25inch hole in the bottom of the mould blocks so they were always perfectly lined up on center. he had an aluminum clamp securing the block in place with a hole in it to bore the cavities through. i ordered a grizzly mini lathe. i figure with my tooling ill have more than enough room to work with on a lathe that i can easily carry if needed. that means i can make moulds in the garage, my bedroom, the bathroom... ive done most of my indoor casting in my bathroom... not while dumping though. it has a very easy to clean tile floor and walls and has a super duty exhaust fan to rid the air of my fumes. it works well on the lead fumes too

[markinalpine]

the bathroom... ive done most of my indoor casting in my bathroom... not while dumping though. it has a very easy to clean tile floor and walls and has a super duty exhaust fan to rid the air of my fumes. it works well on the lead fumes too
Thanks for sharing that! :veryconfu

Best laught of the day! :bigsmyl2:

Mark [smilie=s:

[craveman85]

wow i wasnt even thinking i could use the faceplate to secure the mould blocks to and would have no need for a 4 jaw chuck at all.

[JIMinPHX]

I have a small face plate that has a 3" hub on the back of it. I grab it in my 3 jaw chuck for quick set ups. It's real handy for stuff like that. The time killer with a face plate is getting everything centered up real well. Face plates do open up a lot of options for you though.

[theperfessor]

The 10" 6 jaw chuck on my lathe won't hold anything smaller than 1/2" diameter, so I bought an inexpensive 5" three jaw chuck with a plain back and reversible jaws. I made an adapter plate to mount it to my faceplate. With four adjustment screws in the faceplate I can zero it in dead nuts every time and can hold very small diameter stock now.

Much easier than making a custom backplate to fit my spindle nose.

Faceplates can be VERY handy to have.

[rmcc]

Like DOC said, you can't get spindle bore too large!!! Most bar stock for barrels is 1.250"

Good luck!!

Rich

[Buckshot]

http://www.fototime.com/EC6E32186093ED1/standard.jpg

...............Even on my 11" Logan you can spin this fairly fast, without worrying about counterweighting. Not as fast as the smallish bits normally used for HPing want to be turned (if the bit were being spun :-)). Setup isn't too onerous leaving the clamps just snugged and then taping the vice around on the faceplate with the TI reading in the cavity. However I find the 4 jaw chuck faster so that's all I've used and the above photo was from a special deal.

I know a couple folks who've simply used a couple small angle irons bolted to a faceplate to locate the mould blocks, and have lathe bored VERY passable one and 2 cavity pistol boolit moulds.

.................Buckshot