what cnc mill do i need to make 1911 pistols

Feb xv, 2012

How to CNC an AR-15 Lower from Delrin

UPDATE (From Sebastian): If y'all choose to brand a lower from Delrin, you're safest using Nutrient Grade Delrin, which is highly x-ray detectable. While I believe ordinary Delrin should be dense plenty to be detectable past the mod equipment used for airdrome screening, it is unlawful to make a firearm, the major component (which includes the receiver) does not show its true shape on the types of x-ray equipment usually used for airport screening. Be careful nigh the types of plastic you choose. Jason did non mention this in the original post, simply I am updating now as a alert. You lot are responsible for compliance with federal police.

Afterward finishing the aluminum bolt together lower, I went back to trying to make a single piece lower out of Delrin.

The procedure described beneath is my tertiary attempt. In the first ii I had alignment problems which fabricated the correct and left sides non quite friction match upwards and gave an egg shape to some of the holes.

I likewise switched from PyCAM to Deskproto. While the people working on PyCAM accept done a nice job so far, it needs more work. For the kind of things I do its simply barely useable. Deskproto has all the things that drive me nuts in PyCAM fixed, and while its commercial, the price, specially for a hobby license, is quite reasonable (less than an AR-fifteen parts kit) and it doesn't use any nasty DRM, so subsequently you'veÂ purchasedÂ it you lot don't take to become permission from the mother ship to reinstall information technology or install it on a different computer.

In Deskproto, I added support bridges to the model that run through the buffer tube pigsty and magazine well.

This way I could utilize the outside edges of the Delrin block for holding down the office while machining the left and right sides, simply don't need to do actress machining steps afterwards to remove the supports.

Update: The 3d model of the lower is originally from world wide web.cncguns.com.

I used an inexpensive Chinese import band saw to cut the block of Delrin down to an appropriate size….

Then bolted the block downward on the mill and started machining the right side.

I did a roughing laissez passer with a 1/4 inch flat cease mill, and contouring pass with the same 1/4 inch flat end mill, a contouring pass with a 18 inch flat stop factory, and and so a finishing/polishing pass with a one/viii inch ball olfactory organ end factory.

Next I milled a slot along the back and peak of of the block that went almost all the way through the cake, and so used the band saw to cut away the excess material beyond the slots. Since I know the exact location where information technology milled the slots, this gave me skilful surfaces for aligning things when I flipped the cake over.

Here is the cake flipped over and mounted back on the mill.

Side by side I did the same procedure on the right side for the left side. What you don't run across from the other pictures is that the process is rather messy. Hither is what things looked like earlier IÂ vacuumed up theÂ debris.

and cleaned up…

Now dorsum to the ring saw to cut the outside frame away from the part. Side by side was the buffer tube mount pigsty. The Taig manufactory in its default configuration doesn't accept enough clearance in the Z direction for the lower to fit with its back surface perpendicular to the spindle, but it turns out that is piece of cake to set up. If you lot loosen one bolt the whole spindle associates slides off.

You can and so unbolt the mounting plate and commodities it dorsum on college up.

Then slide the spindle back on the mounting plate, and keeping information technology as high as possible tighten the dovetail bolt. Now there is enough clearance for the lower and and a vise to fit.

The lower was held in identify by clamping the vise downward on the remnants of the support bridges. They provide a overnice flat surface and there is no hazard of scratching or damaging the lower.

Later on machining the buffer tube mount hole..

Next was the bottom one-half of the magazine well and the slots for the trigger guard. Again the lower is held is place past the remnants of the support bridges.

While the lower was mounted upside down I took the opportunity to drill the pigsty for the selector spring. And then I used the band saw to cut off virtually of the remaining support bridges, andÂ positioned the lower correct side upwards forÂ machining the acme half of the magazine well and the fire control area. There isn't enough support textile left to provide a clamping place, but the trigger guard area has a flat surface that can be used.

At this point the lower is finished, except for a few holes that demand to exist drilled.

Beginning I did the pigsty for the front take downward pin spring.

Then I tried the bolt catch hole.

But it turns out you can't drill that hole from the front. The bulge in the magazine well gets in the mode.

Yous accept to become in from the dorsum. I should have drilled this hole while I was machining the buffer tube mount hole. Now without the support bridges there isn't a good way to mountain the lower with the front facing downwards. But by moving the spindle mounting place I was able to practise this…