1022 CNC Receiver Project

[jbolt]

First major mistake. There is an undercut inside the ejection port for bolt clearance. Part of the undercut needs to be flush with the inside face of the pocket where the bolt slides. To be cautious I reset the z zero and in the process didnt pay attention to the tool being set on tool #1 instead of tool #0. When I ran the program the machine thought the tool zero was the face of the spindle and crashed the tool holder into the part before I could hit the e-stop. I believe I caught it before doing any damage to the machine. I have run some test parts and and so far everything seems okay. The 300lb head is direct driven with a 4200 in/oz servo so I'm pretty sure something would break before it stalled.

The mark on the inside of the ejection port is where the tool shaft, which is wider than the t-slot cutter, struck the part. Fortunately this only cosmetic.

 

[jbolt]

Finished the main body test part. During the roughing operation for the picatinney rail the roughing end mill holder partially pulled out of the R8 collet by 0.148". I have heard of others having this issue with the TTS tool holders. I suspect I just didn't get it tight enough with the power draw-bar. The roughing end mill was cutting 0.100" DOC at 35 IPM. The cut is flat all around so I think the lead in to the part was too abrupt. Fortunately I caught it before crashing the cutter into the vise jaw. Unfortunately the cut was too deep to test the final bevel contour operation.

Next step is to do the lower lug.




J~

 

[jbolt]

A few more images of the interior of the receiver.

 

[zmotorsports]

Beautiful work. Thanks for sharing pics with us. I love looking at CNC'd parts.

Mike.

 

[jbolt]

Thanks Mike,

It has been quite the learning curve having always done manual machining . In the time I have spent doing the CAD/CAM and setups for this part I could have machined two manually but I'm getting the hang of it. Its a real kick to watch the machine do most of the work and not have to spend the hours cranking handles.

I hope your equipment arrives soon.

Jay

 

[cjtoombs]

Nice project. Take a look at the white paper on collet pullout on Tormachs website. I had problems with pullout until I implemented some of the recommendations in that paper. The only pullout I have had since then was because I didn't tighten the drawbar properly. How do you plan to finish it?

 

[jbolt]

Nice project. Take a look at the white paper on collet pullout on Tormachs website. I had problems with pullout until I implemented some of the recommendations in that paper. The only pullout I have had since then was because I didn't tighten the drawbar properly. How do you plan to finish it?

Thanks for the tip on the white paper. Parts will be anodized. I have a small 3 gal anodizing setup that works well. Still working out how to clean up the parts for finishing.

 

[jbolt]

Wow, just read the TTS white paper. I have always used anti-seize on the drawbar threads but never thought to use anti-seize on the drawbar thrust washer and outside of the collet. They should include the white paper with the TTS system packages.

 

[hvontres]

Thanks for sharing a cool project with us

I have a strange quesition: How do you go about using one of these receivers legally here in California? Since the reciever is the "evil" part that needs to be seaialized it seems that this could be a bit of a headache.

Thanks,

 

[jbolt]

Thanks for sharing a cool project with us

I have a strange quesition: How do you go about using one of these receivers legally here in California? Since the reciever is the "evil" part that needs to be seaialized it seems that this could be a bit of a headache.

Thanks,

At the moment it is still legal to make for personal use. If SB808 is signed into law it would have to be registered with a DOJ supplied number.