Caliper vs. bushings for sizing

Signed-In Members Don't See This Ad

azamiryou

Member
Joined
Aug 14, 2010
Messages
1,015
Location
Silver Spring, MD USA
caliper.jpg


:curse::at-wits-end::thunder::at-wits-end::curse:

This apparently happened in between measuring the components and turning the barrels. I now have three sets of barrels .023" undersize.:mad::mad::mad:
 
Signed-In Members Don't See This Ad
caliper.jpg


:curse::at-wits-end::thunder::at-wits-end::curse:

This apparently happened in between measuring the components and turning the barrels. I now have three sets of barrels .023" undersize.:mad::mad::mad:

Yikes !..... I switched to cheap digital dial calipers from harbor freight so I can check my zero frequently.I feel for you. I had a .002 variance the other night when i checked my zeroed dimension and was upset.
 
I've gotten in the habit of checking zero and wiping clean the measuring faces before each use. Takes a little more time to measure, but it takes a lot more time to remake parts that turned out different than what I though I measured.

If you cast your undersize barrels in clear resin and turn to correct size, no one will ever know. ( Except for the 14,000 members who read this. :))


Ed
 
Last edited:
I too have switched to the Pittsburg digital calipers from HF. You can buy the $29.95 ones on sale for $9.95 plus the 20% off coupon. You have to turn it on if you don't use it for a set amount of time. If it dosn't read zero you just hit the zero button. Plus it reads MM or inches with the press of another button. At that price I keep one on my assembly bench, and one at each lathe so I don't have to search under everything when I need it. NEVER trust bushing for size, always measure your fittings, they are sometimes different on the cap and nib, or from kit to kit. Jim S
 
Last edited:
I also have digital calipers (from Little Machine Shop), but don't like them as much as this dual-dial set. Personal preference, I guess, I just find the dial quicker and easier to use.

Unfortunately, this set isn't made to be adjustable, as I can't seem to reliably disengage the pinion. I can rotate the face to change the zero point, but I still need to get the pinion engaged at a point where the needles are lined up when it's closed.

Edit: just saw your edit -- yes, I always measure the parts and turn to that, not the bushing size. I chose the title because in this one case, I would have been better off turning to the bushing size.
 
Last edited:
I have 3 calipers and 2 have been dropped so often they can't be relied upon for "measurements". I don't read them, I use them to "gauge the diameter of the pen parts then turn to that diameter and it always fits perfectly. The numbers don't mean anything, the fit does.
WB
 
I also have digital calipers (from Little Machine Shop), but don't like them as much as this dual-dial set. Personal preference, I guess, I just find the dial quicker and easier to use.

Unfortunately, this set isn't made to be adjustable, as I can't seem to reliably disengage the pinion. I can rotate the face to change the zero point, but I still need to get the pinion engaged at a point where the needles are lined up when it's closed.

Edit: just saw your edit -- yes, I always measure the parts and turn to that, not the bushing size. I chose the title because in this one case, I would have been better off turning to the bushing size.

actually, if the bezel will not rotate. they are pretty easy to set once you get the hang of it. you need a very thin strip of about .001 brass or steel shim stock to slide between the rack and gear. you do that with the dial at 0 then close the jaws and slide out the shim stock. i would have thought however that the bezel would rotate. give it a shot. that is the way we had to do it in the old days every time. the calipers came with a shim tool in the box.
 
Unfortunately, this set isn't made to be adjustable, as I can't seem to reliably disengage the pinion. I can rotate the face to change the zero point, but I still need to get the pinion engaged at a point where the needles are lined up when it's closed.

actually, if the bezel will not rotate. they are pretty easy to set once you get the hang of it. you need a very thin strip of about .001 brass or steel shim stock to slide between the rack and gear. you do that with the dial at 0 then close the jaws and slide out the shim stock. i would have thought however that the bezel would rotate. give it a shot. that is the way we had to do it in the old days every time. the calipers came with a shim tool in the box.

Yes, the bezel rotates. But there are two needles that are geared differently. They need to line up with each other when the caliper is closed; then I can turn the bezel to make that the zero for both inches and mm.

Using shim stock is a way to "disengage the pinion". On this model, when it's closed there's no access to get a shim out, at least not that I can find. And of course no shim came with it. (It's possible I misunderstand the shim technique, but I've been unable to find any photos or diagrams of the procedure.)
 
Unfortunately, this set isn't made to be adjustable, as I can't seem to reliably disengage the pinion. I can rotate the face to change the zero point, but I still need to get the pinion engaged at a point where the needles are lined up when it's closed.

actually, if the bezel will not rotate. they are pretty easy to set once you get the hang of it. you need a very thin strip of about .001 brass or steel shim stock to slide between the rack and gear. you do that with the dial at 0 then close the jaws and slide out the shim stock. i would have thought however that the bezel would rotate. give it a shot. that is the way we had to do it in the old days every time. the calipers came with a shim tool in the box.

Yes, the bezel rotates. But there are two needles that are geared differently. They need to line up with each other when the caliper is closed; then I can turn the bezel to make that the zero for both inches and mm.

Using shim stock is a way to "disengage the pinion". On this model, when it's closed there's no access to get a shim out, at least not that I can find. And of course no shim came with it. (It's possible I misunderstand the shim technique, but I've been unable to find any photos or diagrams of the procedure.)

yep, i didn't see the second dial hand. they're right. HF, 10 bucks on sale, i keep at least 2 on hand in case i need something to stir my coffee with.
 
Don't know how to fix your problem. I always clean mine off and set it to zero and put in in it's case every time I am done with it. Anal? yes but it works.
 
I'm with Wood Butcher. I don't read the dial either. Just set to fitting size and turn to that. I would get a second set so I could do both ends but I know I would mix them up.
 
6" Digital Caliper with Metric and SAE Fractional Readings

Is a good unit to purchase?

I saw this the other day when I was at their store.

I like the dial better than digital, but that's personal preference. Many people prefer digital. Nothing wrong with that unit. There are many available in that price range and even cheaper: Amazon.com: digital caliper

Most do both metric and inches, but they don't all do fractions, so be mindful of that if you want fractions.
 
Back
Top Bottom