3D Printed M1 Garand Timing Block

[usabaker]

So, I have been messing around with my 3D printer again. I needed a timing block to use on a couple of Ethopean M1 Garands I purchased. Rather than borrow one from one of the other RSOs at the range where I work, I decided to download a 3D Print file. The one I found online did not work when I tried it; it would not fit. I suppose I could have modified it, but then I would have no confidence in it.

I borrowed the timing block from the RSO I work with. It was made of steel and seemed original. After using it, I couldn't resist the urge to take measurements and produce my own 3D-print file for the garand timing block.

I tested and refined the print at every opportunity. I'm lucky in that there has been a run on folks buying M1 Garands from the CMP in my gun club, so I've been able to test it on all types and conditions. I even discovered two with timing issues.

If members here need a timing block, let me know. You pay the shipping, and you got it.

[Bob Seijas]

WAY cool, nice work!

[jamie5070]

What do you do with a timing block?

[usabaker]

What do you do with a timing block?

This is from TM9-2030-1

[ssgross]

The one I found online did not work when I tried it; it would not fit

Were the dimensions in the stl different than what you found on the original? I wonder if it might have been a calibration issue that foiled your first attempt. Not your fault. For example, I can get a 20mm test cube absolutely perfect, then immediately print a 100mm cube and be way off. I have also found falling out of calibration with changes in temp and humidity throughout the year. Changing bed and print temps, even for the same filament, will screw the calibration. I think that, even after very careful calibration, getting a measurement within ten thousands of an inch of intended is doable with practice, experience and setup, but rarely repeatable, and certainly not between two different models. Most tools I print for my shop have plenty of slop built into the design. Anything that matters (which isn't much) I spend an enormous time with a calibration-at-scale procedure with different test pieces designed specifically for what I intend to print, then some trial and error iterations before I get something I'm happy with.
That said, can you share your measurements and the stl? I'd love to give it a try.

[usabaker]

Were the dimensions in the stl different than what you found on the original? I wonder if it might have been a calibration issue that foiled your first attempt. Not your fault. For example, I can get a 20mm test cube absolutely perfect, then immediately print a 100mm cube and be way off. I have also found falling out of calibration with changes in temp and humidity throughout the year. ...
That said, can you share your measurements and the stl? I'd love to give it a try.

I notice that depending on the material, the dimensions change, but they usually are smaller, not larger. If I print with PLA or PLA Plus, the part will be -.005" ~ -.008". There is not much to play with on my Ender, though. I mess with settings in UltiMaker Cura to fine-tune my prints.

The Timing Block STL that I downloaded and was not able to get to work, was from Thingiverse at this link https://www.thingiverse.com/thing:5548769 it must print because I have seen this exact one on eBAY that is being printed by some enterprising individual that making money off others work ;/

The one I made from measurements off an original timing block took only two weeks to get just right, and I've tested it on seven Garands at this point. I just mailed four out to members here, and it will be interesting to see if they work for them as well.

[tom gray]

I received my timing block today. I tried it on 2 rifles, it worked fine. I would like to find a rifle it does not work on so I can correct the rifle.
Tom

[Matt_X]

I'll send you a PM. I have one bought from CMP that operates well when the top round is on the left, but with the top round on the right releases the op rod before catching the clip. At least that's what I've been finding with the dummy rounds.

[cgroc09]

Received mine today. Well made. Nice timing block. Now I need to wear it out.

Thanks, Paul