Turning a lathe into a case trimmer

[mud99]

So i'm preparing to order the various pieces to reload .223 - the one thing i'm very unsure about is the case trimmer.

I've looked at the various trimmers, and the cheaper trimmers look like they will waste a lot of my time, and the price for something like a giraud is very high, and it means one more piece of unitasking equipment floating around my shop.

So, i've been thinking - why not just make an attachment for my lathe? Has anyone seen this done?

I'm thinking the attachment would mount to the cross slide, and it should accept a column of stacked cases from above.

A handle would feed the cases into the lathe when pushed towards the cutter, and when the handle was pulled back it would drop the rounds into a container below.

The cross slide adjustment on the lathe would be used to control the final trimming depth.

Any thoughts? I can't be the first person to think of this.

Mark

[damndave]

Either the Possum Hollow Kwick trimmer or the World Finest Trimmer will work good for u.

[mud99]

Hmm....

The possum hollow is cheap and will fit perfectly in my lathe and do everything I need...

But building an autofeed would be a lot of fun...

[chim-chim7]

No need for those items. Take the jaw chuck off your lathe. Use a collet of the right size and add a stop to the inside of the collet to locate on. Stick your mighty mag and 1" travel indicator on the ways to measure the "Z" depth in cut. trim to size then set your "0" on the indicator. You will get the exact same trim everytime. Thats how a machinist would do it.

[chim-chim7]

If you want a case feeder, make one. You have the perfect tool to do it. Should use a spring loaded tube that feeds through the spindle and out the chuck. Use a rest to locate the brass mouth on. You could fly through brass trimming. Have fun and be safe.

[CSACANNONEER]

No need for those items. Take the jaw chuck off your lathe. Use a collet of the right size and add a stop to the inside of the collet to locate on. Stick your mighty mag and 1" travel indicator on the ways to measure the "Z" depth in cut. trim to size then set your "0" on the indicator. You will get the exact same trim everytime. Thats how a machinist would do it.

That will give you an OAL that is consistant, just like any lathe type trimmer which indexes of the case head. However, other trimmers index of the inside of the case heads and others index of the shoulder. So, one needs to decide which datum point they feel is the most critical to use. Personally, I feel that the should meathod is superior but, I have all three types of trimmers.

[mud99]

My only hesitation to feeding the brass from the spindle end is that I would have to turn the lathe on and off for each case, and whatever mechanism I use would have to withstand spinning forces.

If I feed from the toolpost, I can leave it running while loading/feeding brass.

I think the feeding isn't too difficult, but i'm not sure what the best way is to hold the brass without it spinning, while making it quickly removable - maybe something like two v-blocks with a rubber pad that pinch the round between them. .

Another option would be to use my milling machine instead - I could use the coarse feed arm for trimming, and make a mechanism which indexes cases each time the arm is cycled.

Quite a few options here.

[Whiterabbit]

doesn't dillon make trimmer dies? and presses with case feeders? wouldn't that get you where you need to be at the same price?

I'm all for building, but the value of the lathe IMO is to chuck the possum hollow in there and go to town. Then chuck the debur bit and go to town. then chuck the.....

[Fyathyrio]

The milling machine would be pretty easy I think, make an adapter to bolt a shell holder to the table, set the height of the trimming blade, make a pass, swap in a new case. That method will still be based on case OAL and not the shoulder though.

[Whiterabbit]

replace the cutter with the possum hollow and remove the hard stop. Now datums on the shoulder. Assuming your mill has a drill press attachment.

Another option is to build a mount to hold a motor over an RCBS trim die and attach a cutting head. By that time, you've made yourself the dillon trim die.

-------------------------

Here's another idea. You can start with an RCBS trimmer with the 3-way cutter for .223. Then you don't have to debur or chamfer. Then rather than chucking in your drill, you chuck in the lathe and attach to a slide so the entire trimmer body slides into and out of the lathe.

No stopping the motor. You'd be using the trimmer as a glorified case holder.

[1in9twist]

I like where this is going. Come up with an idea and bring it to life. I have a video somewhere of a tool I built to remove military crimp. Twas fun!

eta, found it.
I don't run the bit down in the vid, cuz I had already run this batch.



I ran all the brass I had, then ended up devouring it for its components....

[wash]

It sounds like you want a turret lathe with the turret holding a bunch of shell holders and a cutter spinning in the headstock.

A setup like that could use some type of automatic case feeder mechanism for really fast trimming but you would have to trim a whole lot of brass to amortize a setup like that.

[30Cal]

It's worth spending money on something that is fast and easy. I use a $6 Lee cutter and a drill press.

[chim-chim7]

My only hesitation to feeding the brass from the spindle end is that I would have to turn the lathe on and off for each case, and whatever mechanism I use would have to withstand spinning forces.

If I feed from the toolpost, I can leave it running while loading/feeding brass.

I think the feeding isn't too difficult, but i'm not sure what the best way is to hold the brass without it spinning, while making it quickly removable - maybe something like two v-blocks with a rubber pad that pinch the round between them. .

Another option would be to use my milling machine instead - I could use the coarse feed arm for trimming, and make a mechanism which indexes cases each time the arm is cycled.

Quite a few options here.

What type of mill do you have? Bridgeport type? Does it have a quill feed?