Saturday, September 19, 2015

New Trigger Guard for the CP1-M Pistol

My single biggest complaint about the CP1-M pistol centered around the "too small for my finger" trigger guard.   Found some time this week to do something about it.













Started with a chunk of 6061 aluminum. 





















At 0.625" thick it was too wide to fit the inletting in the grip. 





















 I milled down to ( I think) 0.550".























It was the right size when it just fit into the wood.




















Winging it with the layout.  Nothing new there.  There's a bit of stock to hog out.































To get the stock out quickly, I drilled a 1" diameter hole.




































Followed by a 7/8" hole.  This removed about 80% of the material.




















Scratched some lines to connect the holes and swapped milling vises to one with a different base.  As the guard will have a tapered slot,  I needed the ability to swivel the vise. 




















Milled out the web between the holes.




















Had some concerns about the guard collapsing and binding the milling cutter as the last of the web was removed.  Went easy on the vise clamping pressure and took lighter cuts to compensate.  Note the metal left at the extreme right for support.  It was later removed with a hacksaw.





















Milled a slot in the top of the guard for the trigger blade.  The slot has to be both centered and have the correct clearances to fit around the trigger block.  The sides of this slot block in the trigger pivot pins to prevent them from walking out.




















And a relief slot for the sear.






















Milled some angles into the guard to lose excess metal and make it marginally less "blocky".






















Hand filed the curve at the top to fit into the front of the inletting.







 












 Test fit. 






















Used a transfer punch through this hole to locate the 5mm mounting screw location.































Drilled for the aforementioned screw.   Not shown:  Turned the guard over, lined up the hole again and drilled a counterbore for the head of a M5 SHCS.  (that's a Socket Head Cap Screw)



















 More shaping.  Less blocky.





















About done.  Here's the counterbore.  Started to deburr the edges.  Needs some sanding and spit and polish.























Obviously, it's not a full wrap guard.




















A bit chunky, but it'll work.  Besides, all the metal in the front is hollow for the mounting screw





















 Some milling marks.






















You can see the trigger housing nested in the oval slot.



















After more sanding, blending, edge relief then a light bead blast.






















Gave it a shot of black epoxy paint.  It's a pretty close cosmetic match to the anodized breech.










































































Much, much more comfortable now to shoot.  Instead of being annoyed by the guard, I can focus on the dot alignment.  I see a few areas for improvement (which were ignored while rushing to get it done) that I may revisit--if I can talk myself into stripping the finish.

Thanks for checking in.  More soon. 

6 comments:

Jaromír said...

It is super.
GunsmithJM

dhc8guru said...

Nice work! I always enjoy watching your design and machine work. You should consider sending the prototype to Mrod and to have the SPA incorporate that in the design.

Anonymous said...

Nice! The open back end of the guard gives your pistol a Flash Gordon look. I like it!

Norris said...

Nice, I love to read articles as well written as this with such good pictures. Nice workmanship, and gives non engineering people a better insight into how involved and time consuming projects like this can be.

Mark Bookbinder said...

WOW
Great job, you should send you idea to Mrodair, it looks great
If you are ever bored and feel like whipping up another one I would be more than happy to take it off your hands.
I would also be more than happy to pay you for it as well
I wish I had your talent, and a milling machine. Really nice work.
Mark_bookbinder@yahoo.com

Mark Bookbinder said...

WOW
Great job, you should send you idea to Mrodair, it looks great
If you are ever bored and feel like whipping up another one I would be more than happy to take it off your hands.
I would also be more than happy to pay you for it as well
I wish I had your talent, and a milling machine. Really nice work.
Mark_bookbinder@yahoo.com