cup trimmers

[BUTCH HAIRFIELD]

just to through someting else into the pot on copper tubing cup making.
doyal gracey makes a case trimmer that i have converted to a cup trimmer that allow you to do an id and od debur at the same time and also trim your cup to a fixed length that you determin for consistant lengths.   it does a real good job but a little slow for me.  

also dave has come out with a comerical grade of adjustable cup trimmer for the hydro and chp 1 presses this seems to work vary well on the heavy wall cups i make up through .030 wall.   but you need to have the cup at least .100 longer than required to use it.   the smaller versions of the trimmer are ok for .018 wall cups and thinner but not for the heavy wall tubing cups.   but like all of daves equipment it comes at a price ( $400 ).   there are also tools out there that you can chuck up in your drill that will debur both the id and od at the same time and for a 1/2 inch cup they start at $40 dollers and go down.

one problem i have noticed with the pinch trimming of a cup is it puts hirline splits in the cup mouth and if the cup is to hard this will result in the fold over of the cup mouth.   by anealing the cup mouth it melts the cracks back togeather so this goes away.   just something to think about.

richard use to make a 5c collet trim press that worked pretty well also but i do not think he is making it anymore.   it worked quite well for this type of application also.

well you all enjoy and keep thinking outside the box
butch

[Donna]

Hello All,

I have an RCBS power case trimmer and have been thinking of how I could set it up to trim jackets. RCBS has that “three way cutter” that trims, chamfers, and deburrs at the same time and it is fully adjustable, one nice bit of engineering. Their old case trimmer used collets to hold the cases in but now it is held in by a type of shellholder that grips the case by the extraction groove or rim.

Butch and the rest of us swagers out here/there, a copper tubing cutter saw is fine for cutting the tubing, but something like a universal jacket cup trimmer that could be used on any reasonably thick cup would be worth its weight in….copper. Lets get a working proto type going here, so that everyone could benefit.

Could you tell us a little more about these tools that are chucked in to the drill that will deburr and chamfer at the same time and for a 1/2 inch cup they start at $40 dollars and go down? And where can these tools be found?

Hello Mr. Butch hairfield, welcome to the bullet-swaging forum. I have heard a lot about you and I am pleased you have joined us. All the guys and gals here are wonderful people, just pardon my occasional out burst of PMS. :wink:

Donna

[Leftoverdj]

I do believe that I would start off with a bench drill press. More power and durability than the motorized  trimmers. I've trimmed a good many cases with a Forster shaft chucked into my drill press and a simple stop clamped to the table to keep the Forster base from turning. Make up some pilots to work with your cups and modify a collet. if you need to, to grab the cup and you should be set.

Another way to go would be to run a 3/16 endmill or altered drill bit up into a spare chuck to give you a solid stop to index cup length against. Very simple shopbuilt gizzies clamped to the table would let you do anyting you wanted to to the cup with a pretty good degree of precision.

Could be something I'm missing. I never made a jacket cup in my life. I'm just a guy who has done a pile of radical case alteration with more ingenuity than money. Sure looks like the same problem, though.