toecutter
11-20-2006, 07:55 AM
So one problem I've been encountering recently is the need to trim huge amounts of brass in a fairly short amount of time. The principle caliber I am doing this in is .223. I have been looking around at the different case trimming accessories and I'm somewhat afraid of the cost that must be put into them. The other concern is that they seem like they would be difficult to adjust.
I took a look at the gracey trimmer, which they graciously provide full documentation for online. I like the idea, but don't like thier implementation.
So, I'm thinking about making my own. The system I worked out so far uses two carbide inserts (of relatively small size). Mounted on a cutting head, which has a half inch feed (I plan on using this system with my drill press). One of the inserts will cut the inside, the other will cut the outside. When complete, this arrangement will act like a pair of scissor blades, except the cutting surfaces will be on the same side. (take a pair of inserts, lay them on top of each other, then shift the holes apart) The idea here is that it acts as both ends of a chamfering tool, putting a chamfered edge on both the inside and out of the shell.
The bottom part that holds the casing, will be mounted to my drill press, and will use compressed air to drive a piston up to hold the shell in place. It will use standard shell holders.
The length will be controlled by the stop on the drill press.
I think I have most of it figured out except for how to hold the inserts. I could make some kind of arrangement that would simple clamp them in place using set screws, but IMHO then it would suffer from the same thing I don't like about other commercial trimmers I've seen. (lack of adjustability)
The other system I considered was a set screw that was held in the middle, that had a right hand on one side, and a lefthand thread on the other. So this would force both sides to move during adjustment.
The other possibility is to mount two set screws each controlling the other cutter.
Or I could make something that makes it so you get one cutter per caliber...
I took a look at the gracey trimmer, which they graciously provide full documentation for online. I like the idea, but don't like thier implementation.
So, I'm thinking about making my own. The system I worked out so far uses two carbide inserts (of relatively small size). Mounted on a cutting head, which has a half inch feed (I plan on using this system with my drill press). One of the inserts will cut the inside, the other will cut the outside. When complete, this arrangement will act like a pair of scissor blades, except the cutting surfaces will be on the same side. (take a pair of inserts, lay them on top of each other, then shift the holes apart) The idea here is that it acts as both ends of a chamfering tool, putting a chamfered edge on both the inside and out of the shell.
The bottom part that holds the casing, will be mounted to my drill press, and will use compressed air to drive a piston up to hold the shell in place. It will use standard shell holders.
The length will be controlled by the stop on the drill press.
I think I have most of it figured out except for how to hold the inserts. I could make some kind of arrangement that would simple clamp them in place using set screws, but IMHO then it would suffer from the same thing I don't like about other commercial trimmers I've seen. (lack of adjustability)
The other system I considered was a set screw that was held in the middle, that had a right hand on one side, and a lefthand thread on the other. So this would force both sides to move during adjustment.
The other possibility is to mount two set screws each controlling the other cutter.
Or I could make something that makes it so you get one cutter per caliber...