urbanrifleman
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I have some ideas for a cone depth measuring fixture. But I figured I would ask. I'm sure someone has come up with something clever.
Thank you for your help!
Thank you for your help!
Cone Depth Fixture
- Thread starter urbanrifleman
- Start date
LVLAaron
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Some guys use something that resembles an engine valve, with a 25 or 30 degree angle. I like that better than the ball bearing approach.
DaveTooley
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engine valve here
Borden recently posted he was working on something for this
urbanrifleman
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Some guys use something that resembles an engine valve, with a 25 or 30 degree angle. I like that better than the ball bearing approach.
I was thinking a 3d printed cone would be sufficient. Or you could 3d print the plunger and glue a brass cone to the front.
I made up a gauge which uses an established datum diameter as the reference. I think I went with 11/16". I'm not in the shop right now, so I can't measure it. I believe I show it on my YT channel. Pretty simple set up, really. WH
urbanrifleman
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I will not be here in 30 years. I have several headspace fixtures with printed parts. They work fine. Contact parts are steel.
My EZ Chek'r tool can do it. I have one dedicated to use for this with a 5/8 flat tip on the indicator.
I simply zero the indicator out on the old bbl, then cut to zero on the new bbl cone. Same principle if you wanted to use an micrometer bbl assembly.
You don't need a coned tip. Like a ball, it just establishes a repeatable datum.
It just slips over the tenon. Since the tops of the bbl threads can vary a few thou from bbl to bbl, I normally just use a hose clamp to allow it to adjust that few thou to be a good fit over both threads. That's critical. If the tool moves side to side on the tenon just a tiny bit, it would give error in measure or at least make it tough to repeatably center it. The hose clamp is just a simple but effective solution to that.
You could use threads but I prefer this style. Done it both ways.
I simply zero the indicator out on the old bbl, then cut to zero on the new bbl cone. Same principle if you wanted to use an micrometer bbl assembly.
You don't need a coned tip. Like a ball, it just establishes a repeatable datum.
It just slips over the tenon. Since the tops of the bbl threads can vary a few thou from bbl to bbl, I normally just use a hose clamp to allow it to adjust that few thou to be a good fit over both threads. That's critical. If the tool moves side to side on the tenon just a tiny bit, it would give error in measure or at least make it tough to repeatably center it. The hose clamp is just a simple but effective solution to that.
You could use threads but I prefer this style. Done it both ways.
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In making any gauge, the important requirement is that any measurement determined by the gauge is repeatable, every time. If you can achieve this, the gauge and method is viable. That shown above is similar to what I use. WH
I already copied your idea from the bullet touch tool and made tenon length, headspace and tenon breech adapters.
That's what I've done. I have 3 "inserts" that goes into a sleeve with a micrometer on the end. One is full diameter and flat, but flip it over and it has a raised center that hits a headspace gauge. Flat side for tenon, raised for headspace. Then a 25 and 30 degree for cones. For indexing, a sleeve that screws on and bottoms on the shoulder and in numbered all around. They have to be TPI specific.
LVLAaron
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Thread gauge and timing rings?
urbanrifleman
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My typical headspace fixture. I have one for each thread. I already had the barrel nuts. I zero on the appropriate length gauge block depending on the length of the tenon.
This one is not engraved for clocking. The others are.
Jud96
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Yes, but with a micrometer or indicator attached to it and interchangeable inserts for the common thread pitches.
This is a prototype that doesn’t have the interchangeable thread inserts. I’ve been working on it for awhile, but seemingly have endless work and projects to get through lol.
Jud96
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Thank you!
I’m working on a couple things that have held me up.
I want to be able to use the micrometer to measure the back of an unchambered tenon to have a reference point for the headspace when chambering a new barrel without a barrel to copy. The issue with that is every available micrometer head has a 5mm-1/4” spindle, which would go into the bore on anything larger obviously. So I’m working on a legit solution for that issue. I’ve come up with a couple ideas, but again I don’t love any of them.
My other idea is to just make it with its own built in micrometer, but that obviously has its own unique problems.
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