caliper

[southerntime1]

what do you recomend for a goob set of caliper i need id and od mesurments i have a cheep pair and they are in 10 of a mm and they are not working cannot get the close measurement i need.

 

[Ken Knox]

I use a Mitutoya 6 inch Absolute Digimatic caliper with very good results.
You can go from inch to metric with just a push of a button and they are very accurate

Kenny

 

[Don Dahlberg]

Mitutoya metal digital calipers are excellent. They are expensive, but I worth the price. Starrett also makes excellent calipers. You are talking about well over $100. They have an economy version, that is not worth the price.

Still, the Chinese are producing good (not great), cheap, digital calipers these days that are good to 0.001 inch or 0.01 mm. They go for about $20-30. I do not like to mail order these, because I want to check them out. I hold them up to the light and examine the closed jaws with my loupe. I want to make sure that the jaws are completely parallel over the measuring area. I also measure a specific penny with a screw micrometer and then with the calipers. A few years ago these Chinese calipers were terrible, but lately I have found that most of them live up to their advertised standards over the full range.

Don

 

[Ansomnia]

I think what constitutes a "good" pair of vernier calipers depends on what you need to use it for.

For a general horological application I think you should have at least 3 pairs. A quality pair with hardened steel jaws and an electronic digital readout would be very nice. I have a pair that converts between metric, decimal imperial and fractional imperial measures with a press of a button. I find the fractional imperial feature very useful. Here's a link to Lee Valley Tools webpage showing the (Chinese) unit. I bought mine when they had an introductory promotional price (should have bought two... sigh).

Blindman's Fractional Electronic Caliper

Next, you need a good non-electronic unit with good jaws. If you only work in metric or imperial units you can use a dial-based unit but if you use both units of measure, you need one with dual scales. You need this pair because your batteries can die on you at the worst moment and I never seem to be able to find my batteries in a jiffy when I need them.

Finally, you need a good plastic pair. I have a Swiss-made pair from HR I got dirt cheap at auction. The plastic jaws prevent damage to sensitive material. You do not always need 0.03mm (0.001") accuracy.

Actually, I also have a very cheap plain scale-based plastic pair I use for woodworking. I think all of these units are "good" in their own ways.


Michael

 

[guychampeau]

i made a nice bench micrometer using a mitutoyo micrometer and a stand...check out:
mscdirect.com
go to catalog page 1314

 

[southerntime1]

Thanks for all the info guys, what i was having trouble with was when i measure for crystals size and balance staff . As you can see by my question i am very new to the hobby. and not having the proper tool is almost as bad as not having the knowledge to do the work.

 

[Ansomnia]

If you measure delicate objects you may also want to consider spring-loaded gauges. There are special gauges for measuring balance staffs and cylinders.

You may be coming across learning issues one by one. I think what would help you more is an old watchmaker's tool catalogue plus some watchmaking / repair books. They will answer your questions en masse and you will avoid many more mistakes that way. From what I see, watchmaking and repair are well-thought-out disciplines and unless you have some very rare or complicated piece, you do not have to fumble around for answers.

Someone recently posted a URL to a PDF copy of the now-defunct Chicago School of Watchmaking. If you do not already have such books you can do a search through the forums. It was just a few weeks ago.

In the real world, people go to school for a few years, apprentice and then they mess around with complicated tasks and expensive watches. We are short-circuiting this process and that's why there are these problems. If we try to get back on course by obtaining some training, we avoid the distractions.


Michael

 

[Don Dahlberg]

Calipers are for making relatively large measurements. A 6" caliper measures from 0-6". They are good for measuring those watch crystals. I do not find them real useful for measuring balance staffs, especially pivot diameters.

For that I use a metric micrometer. I use metric because the literature measurements are usually metric and my lathe cross slide is metric. New and used micrometers in inches are easily found for $25 or less. An English unit micrometer reads from 0-1". With a vernier scale, they are good to 0.0001". I often clamp my micrometer in a small vice the free my hands to handle the staff and the micrometer screw. I do not like the electronic micrometers. I find that they drift.

I could not work without both a good digital caliper and a screw micrometer.

Don