Mill to duplicate a stock?

[cdhknives]

I am trying to 'justify' the purchase of a benchtop mill like the Precision Matthews PM30. One use I thought of was inletting stocks. Then my mind went to duplicating them. If I wanted to do a 1-off, how hard would it be to set up a locating pin on the spindle and use it as a guide to rough out a stock manually with a medium size benchtop mill using the existing stock bolted to the table as a guide? I have seen stock duplicators and they are nice, but I'd like to do it myself. Stock side by side with blank. Would it work in a reasonable manner? Yes I know shaping and final finishing would be tedious...willing to do that. Inletting the action is what I'm scared of doing by hand.

 

[T Bredehoft]

It could be done, you'd have to mount a pin in a mount clamped to the bottom of the quill which would duplicate the tool, 1/2 dia and as long as you 1/2" end mill. I could/can be done, but I've never done it, but then I don't inlet stocks.

 

[Eddyde]

The mill would be great for inletting but wouldn't be the ideal set up for duplicating, although it could work if you took your time. Better to use a router duplicator like this:https://www.popularmechanics.com/home/tools/how-to/a19751/clone-a-gun-stock-with-this-3d-router/
Sorry, I know that's 2 machines you now have to get, but on a positive note, you can use the mill to make the router duplicator as your first project

 

[kd4gij]

A bench top mill won't make a good 3d tracer. The router that Eddy posted or better yet a cnc router table.

 

[cdhknives]

If only I had space...but I'm going to have to get rid of a drill press to make room for a mill already. For my 1-2 stocks I would send them out before building the router, though it is dang cool. Maybe in 15 years when I retire...until then I need more reasons to buy a mill.

 

[derf]

Inletting on a mill is not hard as it sounds. That's the part you do first while the blank is still flat and square and you have means to hold and locate things. Once that is done, the rest is just whittlin' away what doesn't look like a stock. I done many this way until I built a duplicator and got a cnc mill.
Profiling the outside is the easiest part, air tools are your friend.

 

[cdhknives]

I have a good 2x72 belt grinder and can do pretty good slack belt work with it, so I think shaping the stock is doable. I did shape one stock in my youth with a draw knife and coarse rasps...just takes time. Inletting, however, is much more intimidating to me. The stock from my youth? Firewood because we ruined it trying to fit it to the shotgun receiver. Inletting for a bolt action rifle looks much more involved too. Just getting that done and maybe cutting the top third of the stock oversize to give a reference for shaping the rest would put me days ahead of starting with a bare block of wood!

 

[Bobby Bailey]

The mill is not a dupicator but, it can be used to hog out the inletting. Then follow up with standard inletting tools, chisels. Doing a blank only looks daunting, it is just a series of cuts with a chisel. Inletting black shows where to cut. For the outside, shaves, gouges, rasps, etc. bring the lines down pretty fast, removing all that doesn't look like the stock you envision. Taking measurements with calipers at points along the pattern stock enables you to transfer the dimensions to the blank. Hog off wood to just short of those dimensions.

 

[killswitch505]

I’ve done some inletting on my mill it’s honestly easier to do it with chisels, files and a dremmel tool for me at least. Now that popular mechanics copier would be the ****!!!

 

[derf]

I've ran my share of the panto-graph type duplicators, while they are universal, they lack rigidity. It takes some elbow grease to constantly trace every square inch of surface while fighting the torque created by the router bit. That's why when I built mine, I made it as heavy as it could be, and I added another twist. Besides being a panto-graph style, it is also a tracer lathe style. The spindles turning the pattern and the blank are motorized. Instead of a router, I used a 4-1/2" angle grinder with a 5" dia. radiused mill cutter. The stylus is a roller of the same configuration. The carriage is driven with a lead screw powered by a power feed for a mill.




This machine works like a big apple peeler. I set the spindle speed for about 18 rpm, and the feed for about 1/2" ipm, and walk away. When it gets to the end, it trips a limit switch and everything shuts down.