3D printed a dial indicator holder

[guy_with_boolits]

I'm sure this has been done before, but I made one from scratch. I wanted a way to precisely measure case lengths since I am new to rifle loading and am doing quite a few operations on each (random range pickups, decapping/full length sizing,primer pocket swaging which expands the case mouth, then quick trimming with a drill, followed by a final run through the full sizer to remove burrs). I want a final QC on each case to ensure the case lengths are consistent. When I get better at reloading I will probably not need this anymore but for the moment I want to see every case length.

Some other possible uses for a press mounted dial indicator would be a powder cop or ???

Anyways it was easy to print, it mounts to the quick trim die. The mouth pops up through that die and the dial indicator plunger tip has a washer on it that makes it stop on the case mouth.

It seems like to make the measurement accurate (and detect changes of a few thousandths), you need a hard stop right next to the measurement, otherwise you can too easily change the measurement by just pushing harder on the lever. So I mounted a die next to it that bottoms out on the plate.

https://i.postimg.cc/4NZzZLf7/case-measurement.jpg
https://i.postimg.cc/6pbRrBdn/dial-ind-1.jpg
https://i.postimg.cc/sDc52Yxn/dial-ind-2.jpg
https://i.postimg.cc/rwwxRDtq/dial-ind-3.jpg

[smithnframe]

I measure my cases with a vernier caliper!

[guy_with_boolits]

I measure my cases with a vernier caliper!

dont you get tired??? I have to process 1000 cases today

[Rcmaveric]

You know what.... that will be my next thing I design. A 3d printed max case gage. Like the Lyman metal one the looks like stairs.

Wish we could 3D print cartridge head space gauges. 50 to 90 bucks for one may not seem bad but tack on the fact I reload for 6 different calibers and it adds up quick.

Good job I like it.

You will learn quickly though its tedious. Actually length is less important. What is important is making sure you aren't over max. Depending how you reload you may hardly need to trim once the first one is done. Some calibers I have never trimmed.

Now start pushing magnum velocities and you may trim more often. Light to mild loads won't make your brass flow.

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[guy_with_boolits]

You know what.... that will be my next thing I design. A 3d printed max case gage. Like the Lyman metal one the looks like stairs.

Wish we could 3D print cartridge head space gauges. 50 to 90 bucks for one may not seem bad but tack on the fact I reload for 6 different calibers and it adds up quick.

Good job I like it.

You will learn quickly though its tedious. Actually length is less important. What is important is making sure you aren't over max. Depending how you reload you may hardly need to trim once the first one is done. Some calibers I have never trimmed.

Now start pushing magnum velocities and you may trim more often. Light to mild loads won't make your brass flow.

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Thanks so already having gone through 200 cases I'm noticing some problems:

the poor-mans flat contact point (washer clamped under dial indicator plunger tip) isn't working out. I think the dial indicator tip is simply touching inside the case neck (especially if there is a burr) and getting stuck a tiny bit, showing a giant deviation in case length on the dial which is false.

So instead I swapped the tip entirely over to a semi-flat tip (best would probably be flat). Now that problem seems to be resolved.

Going through a few hundred cases, I did detect and pull out of production about 5 cases that were more than around +/- .005" from nominal. (my reject threshold) I confirmed they were actually outside the bounds with a digital caliper afterwards.

For maybe 10% of the entire batch I checked them with a caliper immediately after the dial gauge measured them to see what I was getting. In general it seems its accurate within +/- 0.003", but I think the setup is very sensitive to burs in the neck and/or misalignment and pressure on the lever.

Still, I think the setup does give me reliable enough, fast measurement, to detect any cases that are 0.010" out of nominal for sure, and maybe .005" out. But below that, I dont think so, especially with random range brass that has been quick trimmed in a way that is not entirely consistent (some case mouths are not square).

Also the 3d print was not strong enough. A crack is forming. This would be easy to fix by just changing the model to be thicker and printing at a higher infill, so this prototype has served its purpose and I'll print a thicker one now.

Ya its too bad about had space gauges. I am a little surprised those arent pumped out for cheap given they wouldn't have geometry or tolerances more precise than dies, but maybe i'm wrong about that.

[Rcmaveric]

Case length doesn't need to be uniform. Just under max. Becarefull what rabbits you chase down a hole

A plunger style would work best. Anything that goes into the case neck mouth has a potential for snags and snares and not fully seat square.



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[smithnframe]

I think you're over-thinking this!

[MrWolf]

I think you're over-thinking this!

He might be but what he learns just might be the ticket on something else. Go for it guy and good luck. I still have to learn to program my 3d printer but I did make a handle for my Craftsman floor drill press that saved me $70 towards the cost of my printer @ $299.

[Three44s]

If you have enough stations I say why not?

I will stay with my caliper however for the For see able future.

On a side note, I was going through a number of 20 ct. ammo boxes of fired .257 Roberts brass and encountered some of the batches I acquired from a neighbor and was shocked!

Trim to length is 2.223”
Max is 2.33”

THESE were consistently running 2.240-2.245”

It made for a whole lot of crankin’ I tell ya!

I like to trim to the suggested length and be done with it for generally some time.

Three44s