1 Topic by ne14pez

  • ne14pez
  • Member
  • Offline
  • Registered: 2013-08-13
  • Posts: 94

Topic: Correct Way to Measure with Calipers

When using calipers to measure filament diameter, test prints etc., I can get a different reading depending on how hard I press with my thumb.  This is very important when measuring something like calibration wall diameter which could range from .48mm to .43mm with just a slight variation in pressure.  What's the "correct" way to do it?  Thank you.

2 Reply by ronsii

  • ronsii
  • Member
  • Offline
  • From: PNW
  • Registered: 2012-10-28
  • Posts: 1,723

Re: Correct Way to Measure with Calipers

Not sure how you are getting that much change :0) I can barely get a .01mm change pushing with a good 5 pounds of force... but mine are Mitutoyo's.

Make sure you are measuring as close to the root of the calipers as possible as the cheapies have more flex.

I you want to measure the OD you have to come into contact with it but don't deform it .

3 Reply by dubbsd

  • dubbsd
  • dubbsd
  • Member
  • Offline
  • From: Northwest florida
  • Registered: 2012-09-30
  • Posts: 748

Re: Correct Way to Measure with Calipers

Digital calipers spring real easy. You have to have a real light touch.

Ultimaker S3.

4 Reply by IanJohnson

  • IanJohnson
  • Moderator
  • Offline
  • Registered: 2012-08-07
  • Posts: 2,815

Re: Correct Way to Measure with Calipers

Also make sure you are holding them flat to the filament, don't let them tilt.

5 Reply by ne14pez

  • ne14pez
  • Member
  • Offline
  • Registered: 2013-08-13
  • Posts: 94

Re: Correct Way to Measure with Calipers

All great pointers… thanks!

6 Reply by techbuilder2175

  • techbuilder2175
  • techbuilder2175
  • Member
  • Offline
  • Registered: 2013-07-22
  • Posts: 338

Re: Correct Way to Measure with Calipers

Apply a slight pressure once you make contact as if you were trying to grip a ping pong ball with some pliers. 

Measuring plastic consistently can be a pain since the calipers can
scratch the plastic and even squish the plastic depending on the size and alter the measurement.
Metal has the benefit of holding dimension more accurately with calipers but too much pressure and it will bend the
tips of the calipers and again give you false measurements.

You can practice on a 123 block if you want to learn how to hold a consistent measurement or purchase a spring tensioner for
your calipers to do it for you  ttp://blog.cnccookbook.com/2010/12/14/a-caliper-pressure-device/

It's a skill to get calipers consistent I can tell you that with knowledge since I do it for a living

IanJohnson is correct make sure you don't till the calipers or you will have an inaccurate measurement.

Powder coated steel enclosure, 1/4" Surface grounded hardened aluminum plate, MK2A Heat bed, .200 Polished fused quartz plate, Machined quick change hot bed mount, E3D hot end, Ramps 1.4, DRV8825 stepper motor drivers

7 Reply by dubbsd

  • dubbsd
  • dubbsd
  • Member
  • Offline
  • From: Northwest florida
  • Registered: 2012-09-30
  • Posts: 748

Re: Correct Way to Measure with Calipers

I went to Harbor Freight and got a digital thickness gauge to use on the filament.
http://www.harborfreight.com/digital-th … 66319.html

Ultimaker S3.

8 Reply by techbuilder2175

  • techbuilder2175
  • techbuilder2175
  • Member
  • Offline
  • Registered: 2013-07-22
  • Posts: 338

Re: Correct Way to Measure with Calipers

That's not very accurate
try to steer clear of harbor freight and purchase
a good set of calipers or mic.

Your looking for +/- .001 not .004 that's .1mm off and I can tell you they can be off by a lot more.

If you want to save money buy a fowler
it's the cheapest you want to go on a brand name measuring device

Powder coated steel enclosure, 1/4" Surface grounded hardened aluminum plate, MK2A Heat bed, .200 Polished fused quartz plate, Machined quick change hot bed mount, E3D hot end, Ramps 1.4, DRV8825 stepper motor drivers