Thread: Digital Calipers

Not knowing what you are intending to measure, it difficult to give an answer.

Measuring close fits while working on a lathe is entirely different from measuring say across flat measurement on a hex nut.

Grahame

My honest opinion is to buy one of the $20 150mm calipers.. That is what I use 90% of the time... Most of them are OK, some are a bit dodgy...

For sure the $200 are better, but $180 better I am not sure, at least not after you drop them on the concrete...

Have a look here:

http://www.aliexpress.com/premium/di...+calipers+ip67

You can also peruse their internal/external mikes from bargain basement prices upwards.

Originally Posted by GSRocket

Hi, I would like inside and outside micrometers that measure beyond 50mm but the price is beyond me for the occasional use.
And I don't really need that sort of precision.
What do think of these?
http://www.machineryhouse.com.au/Q1861 Or
http://www.machineryhouse.com.au/M113

220 dollar for a what? Mesumax?

For that sort of money you should get a decent brand name 200mm coolant proof digital caliper. Something like a Mitutoyo absolute. The less known brand name calipers can be found for much less. The trade name Measumax MX is owned by Hare and Forbes Pty Ltd, see here: http://www.ipaustralia.com.au/applic...marks/1108240/

I have several pair of $19.99 ones that are great to use, provided that you are not working from plans for someone.
As someone replied they're great, till they get dropped on the concrete, regardless of $20.00 or $200.00. I think I'd rather drop the $20.00 unit, than more expensive ones.
Kryn

Originally Posted by Grahame Collins

Not knowing what you are intending to measure, it difficult to give an answer.

Things I've turned on the lathe to make sure they are the same diameter end to end. Bits of steel and alloy to be certain
they are same width from end to end.
I have a cheapie but ....

A couple of things that people sometimes forget about digital calipers -

• The expensive ones seem to make the batteries last a lot longer, but the cheap ones chew them and
• they are really only good to around 0.05mm. While they display typically to 0.01mm, between 0.02mm and 0.05mm is the normal value associated with the uncertainty of measuring with them.

Lately I've had a new appreciation for dial calipers. If you are only working in one system they are almost as easy to read as the digitals and don't need the batteries. Still vulnerable if dropped but could be a good starting point. From memory the dials on those are typically graduated in 0.02mm, so accuracy wise probably just as good (Mitutoyo quote 0.03mm) and maybe better than digitals.

Michael

Originally Posted by cba_melbourne

220 dollar for a what? Mesumax?

For that sort of money you should get a decent brand name 200mm coolant proof digital caliper. Something like a Mitutoyo absolute.....

I fixed one of the above links, there are also these, http://www.machineryhouse.com.au/M115.


These look pretty flash, but by the time they get here in $aussie they're not that much cheaper. ...http://www.aliexpress.com/item/1118-...031699478.html

I have had no luck with cheapo no name calipers.
Anyi have been mentioned in other threads. I have these, really like them:

http://www.anyimeasuring.com/product...r-caliper.html

Neil

I've had good luck with cheapies. One dud out of 5.
Of the working callipers I keep one in a cupboard for cross checking, one at the mens shed, and the other two are just anywhere in the shed.
I check them periodically against a 1" Mitzy calibration length from my micrometer and they have always been spot on.
Even the one that fell down behind the lathe and broke the glass display cover and got covered in swarf and coolant. It took a bit of cleaning but it's still spot on.
I have checked a couple against a set of micrometer length standards (25, 50 75, 100 nn) at work and they were all within their reading error (0.01mm).

Problems are much more likely to arise with the way they are used rather than the callipers themselves, dirt/swarf/grit, holding the material or callipers at an odd angle, using only single instead of multiples measurements, etc. These are not the fault of the caliper but the user.

I have a set similar to Neil's, but I've found when coolant gets under the slide they cease to work, I think they were about $50. My second set of digitals also cease to work when wetted with coolant, difference is they were $19 and not IP rated. They also get kicked around from one end of the shed to the other, have a cracked screen, bent slide, live mostly where I last dropped them and are about six years old, what more could you ask? I also have a third set of basic verniers that suffer no problems, other than needing a loupe to read them, they never see light of day. That aside, what I mostly use for finish sizing are a set of telescopic gauges and micrometers. These can be bought on line for a pittance if you aren't too worried about branding. I would baulk at paying $200 for an unbranded caliper...

Two of mine have had baths in coolant/lube.
The way I clean them was as follows.
Spray a fine mist of meths all over them and wipe off using a wiping action that moves away from the main mechanism, repeat a few times.
Then more meths spray and gently work the slide back and forth a few times, wipe and repeat 3 - 4 times.
The LDC numbers will go nuts for a few days until the unit dries out. This can be accelerated by placing the units upside down in direct sunlight.
I had to repeat this a few times with the 8" unit that fell over the back of the lathe but it came good and 3 years later is still working.

I tried to clean one at work by spraying a jet of meths direct into the mechanism but after two days of drying it had still not dried out so I opened it up and eventually it dried out.

I just take mine apart, dry the non electronic parts with a rag, dry the rest with air and reassemble. Must have done that. dozens of times now, isn't it amazing, no matter how careful you are there is always one screw missing!

I've owned a few cheapies, you get what you pay for though, the latest one I've bought was an iGaging one, feels very well made, and from reviews on the web they are some of the best value for money.
I know the Mitutoyo's are good(never used one myself) they seem to be the go to for engineers.
And never heard of MeasurmaX.