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Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 6:04 pm
by Justsomedude
I'm pretty much just showing how I do my cuts since I don't have a nifty CNC machine. I made the fixture plate which has sped up the process quite a bit. You also CAN NOT find any specs for the front and rear radii online. Theres a bunch of guesses but nobody was right. I did it with some direct measurements, DRO and edge finder and they're perfect to the thousandth. I've also had discussions with people telling me that it's no good if they don't have the alignment posts, and that may be true for a sloppy cut but this thing is a snug fit that can't move front to back and can't twist because of the 2 differing radii. It's how I do all of them.
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Re: Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 6:28 pm
by CPJ 2.0
https://www.optics-trade.eu/blog/footpr ... ot-sights/




List of all the specs for most sights.


But, no radius. I ended up using the drawings from that WWW, measuring the OAL length, drawing it all in CAD. It was easy to determine the radius once I had it drawn.

Re: Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 6:41 pm
by Justsomedude
Yep, I had scoured the internet forever trying to find the radius measurements to no avail besides a few forums where the guys were way off (now that I know what they are.)

Re: Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 7:07 pm
by CPJ 2.0
And actually, I don’t even know what radius it was. Drew a three point arc, a point on each edge and the “imaginary” line that represented the overall length. Fusion did the rest for me and then I 3-D printed a chunk to make sure it fit.

Re: Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 7:52 pm
by Justsomedude
Dammit, I still need to learn how to operate Fusion. I keep telling myself that and then forget when I have the time. That's a good idea on doing a test print though and I cant say I would have thought of it.

Re: Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 7:58 pm
by CPJ 2.0
Plastic is cheap. Slides are not. 🤣



I can’t remember the last part that I DIDNT print first. It’s accurate to well within my tolerances, and gives a good confirmation that it’s correct. And parts that require a “feel”, it’s silly to not print them. You can hold it in your hand and make adjustments from there. Also, and probably most importantly, I can print a part and then figure out how I’m going to hold it for all operations. Looking at it on screen is one thing. Holding a plastic mock up in the vise is another. Total game changer.

Re: Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 8:28 pm
by Wambli Ska
I like it when you metal shaving manufacturers talk. Some goes over my head but I always learn something 👍

Re: Time consuming but gratifying (rmr cut)

Posted: Thu Jul 17, 2025 10:32 pm
by CPJ 2.0
So not an option on a Me-NC machine…unless you’re a sadist.
But, I’ve seen some leave a “tower” where the threads go. That way there’s a butt load more thread engagement other than what can be had with just tapping the top of the slide. Technically stronger, but if you’ve machined a pocket….it can’t move to or fro.

Re: Time consuming but gratifying (rmr cut)

Posted: Fri Jul 18, 2025 4:03 am
by Justsomedude
I've actually done those before by reaming holes for the posts and making ones that are threaded and slip fit then held in with green loctite but it's really overkill. You can actually get quite a bit of thread engagement, even on the screw that's above the extractor rod.

Re: Time consuming but gratifying (rmr cut)

Posted: Sat Jul 19, 2025 1:35 pm
by Bigslug
Me-NC machine. . .I love it! :lol:

I like that you're making the socket tight enough so that posts aren't necessary. Though I imagine you could take a tip from the Springfield Echelon and make pin sockets if you had to. . .assuming the slide had the meat for it.

I'm guessing that this turns each job into a one-off setup because of minute differences between optics supposedly sharing the same footprint?

Re: Time consuming but gratifying (rmr cut)

Posted: Sat Jul 19, 2025 10:50 pm
by Justsomedude
Bigslug wrote: Sat Jul 19, 2025 1:35 pm Me-NC machine. . .I love it! :lol:

I like that you're making the socket tight enough so that posts aren't necessary. Though I imagine you could take a tip from the Springfield Echelon and make pin sockets if you had to. . .assuming the slide had the meat for it.

I'm guessing that this turns each job into a one-off setup because of minute differences between optics supposedly sharing the same footprint?
Ironically all of the manufacturers are really good about keeping to the exact same footprint and dimensions. The length of them always mic the same.