Author Topic: Biting the bullet  (Read 268 times)

Terrywerm

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Biting the bullet
« on: March 26, 2019, 06:26:31 PM »

For years I have relied on my Starrett micrometers, some Chinese mics from 2" to 6" (they work and test out fine) and a pair of Scherr-Tumico dial calipers, one 6" and a 12". Life was good.


Until today. I detected a 'bump' in my 6" dial caliper, on every third revolution of the dial, which told me that there is something stuck in one of the teeth or there is a damaged tooth on the pinion that travels on the rack. After moving it back and forth a few times, the needle jumped several thousandths, and my caliper is now useless. I briefly attempted to disassemble the unit and remove the screws that hold the rack to the frame. Sadly, long ago (before this caliper was mine) somebody had disassembled it, or at least tried to, and messed up the screw slots in three of the five screws that secure the rack.


I decided that it was not worth pursing a repair any further, so started hunting for a new dial caliper. I've always been a fan of dial calipers as they never need batteries, and you never pick it up to find that the battery is dead. This was a common thing with the digital caliper that I have, a cheap import that I purchased over 25 years ago at "Tools and More".  Even when shut off, it's battery would go dead in a matter of a couple of weeks. Anyway, MSC had a model 120A Starrett that would cost me $186 after my discount. A hard pill to swallow, but that model is still American made, which I prefer.


One of my former employers had a Mitutoyo Digimatic 6" caliper that I used frequently, as did a few other guys. That thing never needed a new battery, at least not that I know of. I also realized that if I had one of those I wouldn't have to worry about getting any chips in the workings of the dial caliper AND I would now have a way to do metric measurements as well. A quick look in the catalog found one of them for $129 after my discount, a price I could live with.  Naturally, I had to get a few other odds and ends that brought my order up to $206.  Today's discount and free shipping kicks in on orders over $199, so I got the whole shebang, tax included, for $172, and I am not complaining!


I guess today was a good day to have my old trusty dial caliper bite the dust!
Terry

Making chips with old machines!

4GSR

Re: Biting the bullet
« Reply #1 on: March 26, 2019, 08:02:20 PM »
The 120A is a  nice one to have.  Bought my first one new back in 1977.  By 1997 I had to retire them from too much wear on the jaw tips, only 0.001" but I could tell it in my measurements.  Replaced with a Mytotyo 8" digital pair that died on me several years ago.  Found a halfway decent Starrett 799 digital in a local pawn shop.  So far so good.  Also found a 12" Starrett dial caliper in another pawn shop that turned out to be virtually brand new!  Has the original owners name ground in it.  I have all sorts of digital ones I've picked up over the years.  I'm caliper poor!  Oh, did I say I have one pair that goes up to 40"?
Ken

pep

Re: Biting the bullet
« Reply #2 on: March 26, 2019, 08:47:16 PM »
Terry I think you will like that caliper just fine. I've read many complaints regarding the batteries. Have had two digital calipers. One had a small battery, and was dead many times. Also would die just stored as mentioned.

The one now has what is known as a coin battery, same size found in the auto dark welding helmets. Easy 2 years, same battery.

 Not to hi jack, was going to post this in an old thread, but this will suffice. Speaking of calipers, I remembered several talking about the inaccuracy of them. Being one that must find out, and bored with TV did some testing.

To cut to the chase they are, how I proved it to myself. Using a Starrett feeler gauge, digital caliper, old school Starrett mic (acquired 1963), and digital Matayo mic

Reference Starrett feeler gauge  .010

1 caliper .027
2 Satrrett .010~
3 Matayo .010~

Conclusion, if reproducing a made or broken part. The error found in a  caliper is no big deal, will do fine, and produce an accurate duplicate.

On the other hand working off drawings, a mic is a must. Common sense tells me never use both.

That was much more interesting than TV  .............. LMAO

Pep


Terrywerm

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Re: Biting the bullet
« Reply #3 on: March 26, 2019, 10:05:08 PM »

I will use either one, depending on what kind of tolerances I have to work with. I never do any commercial work, so most of what I do is my own stuff, and frankly, if I measured it with a yardstick it would usually be close enough! ;D   But when I'm working on something that needs to be done to tighter tolerances, the micrometers come out and get some exercise.

The caliper that I had been using was dead on when I checked it against various standards for my micrometers or against some gauge blocks, up until about 5" anyway. Beyond that it started to pick up some error. Thankfully, most of the stuff I work on is smaller than that.


Terry

Making chips with old machines!

jpigg55

Re: Biting the bullet
« Reply #4 on: March 27, 2019, 08:38:50 AM »
Wish I knew you were looking. I bought one of the iGaging digital calipers https://www.igagingstore.com/6-Digital-Caliper-ABSOLUTE-ORIGIN-Digital-IP54-Ex-p/205450.htm and haven't had any issue with it. With the exception of the battery size, it's looks exactly like the Mitutoyo one I picked up later
I've had it over 2 years now and never had to replace the battery. I've checked it on things of known dimensions a few time and it's been nuts on every time, the latest instance checking a 1-2-3 block, it read 3.0000".
SB 9A, Clausing 8520, Sanford MG 612

woodchucker

Re: Biting the bullet
« Reply #5 on: March 27, 2019, 08:43:48 AM »
Wish I knew you were looking. I bought one of the iGaging digital calipers https://www.igagingstore.com/6-Digital-Caliper-ABSOLUTE-ORIGIN-Digital-IP54-Ex-p/205450.htm and haven't had any issue with it. With the exception of the battery size, it's looks exactly like the Mitutoyo one I picked up later
I've had it over 2 years now and never had to replace the battery. I've checked it on things of known dimensions a few time and it's been nuts on every time, the latest instance checking a 1-2-3 block, it read 3.0000".



1,2,3's are not necessarily accurate. There use is for so many non measuring things...
I have an Igaging and like it.. Accurate? I don't have a full set of gauge blocks.. so i can't tell. It does good on Mic standards.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

4GSR

Re: Biting the bullet
« Reply #6 on: March 27, 2019, 08:50:56 AM »
A thought to keep in mind.

I have a older pair of Mitytoyo digital calipers that will calibrate dead on at 1", 2", 3" and so on.  When I check them at say 1.125", 2.125" or any other increment, the readings are off as much as .009" depending on the measurements.  But go back to 1", 2", 3", they measure dead on.  Now figure that out!  Out of all of my digital calipers it's the only one that checks out like this.  So be careful in calibrating your digital tools.  Ken
Ken

pep

Re: Biting the bullet
« Reply #7 on: March 27, 2019, 11:06:32 AM »


This is the same one I own and used for my non scientific calibration testing....   The battery is the key to run time, celebrate the battery LOL ......

That battery is in 100% of the the servers, around the world .

Pep

Wish I knew you were looking. I bought one of the iGaging digital calipers https://www.igagingstore.com/6-Digital-Caliper-ABSOLUTE-ORIGIN-Digital-IP54-Ex-p/205450.htm and haven't had any issue with it. With the exception of the battery size, it's looks exactly like the Mitutoyo one I picked up later
I've had it over 2 years now and never had to replace the battery. I've checked it on things of known dimensions a few time and it's been nuts on every time, the latest instance checking a 1-2-3 block, it read 3.0000".


Terrywerm

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Re: Biting the bullet
« Reply #8 on: March 29, 2019, 08:47:54 PM »
No problem, guys. I'm looking forward to trying out the new one.

I use a caliper quite a bit, but like I said earlier, if I have to hold tighter tolerances, I go back to using a micrometer. I figure that a good caliper is cheaper than a good micrometer, and both will wear as they get used. So, I use the caliper the most and save my mics for when I need them.
Terry

Making chips with old machines!

GNAP

Re: Biting the bullet
« Reply #9 on: March 30, 2019, 07:54:49 AM »
Damn!! Now I got to buy new shit, you guys are killing me, I just spent lastís month budget on a new yardstick.............