- Joined
- Dec 15, 2014
- Messages
- 285
Sorry, but no I don’t think so, at least not my test indicators. Yes, gravity can effect an indicator if you drop it on the floor! But to have the reading change because gravity pulls on the stylus/probe??? If there was any change in the reading, then IMHO it’s probably due to lack in rigidity somewhere in the total indicator set-up and not gravity pulling on the stylus. However, when using a test indicator you can get readings that are not quantitative. 1) Using the stylus at an angle other than from its true origin (straight out) will cause cosine error in the readings. 2) Using a stylus with a different length other than the calibrated length. If you are using the test indicator just for comparison readings, as in this authors example, then the above 2 concerns do not apply. And the top and bottom readings do not apply as well…Good Luck, Dave.
I stand by my original statement however poorly described. Gravity indeed is pulling pressure away from the stylus or probe. I should have said gravity can affect the reading on the indicator because gravity has a effect on the indicator holder and indicator, which however small, can cause a sag which effects the indicated reading. This is a separate issue from cosine error. http://www.practicalmachinist.com/vb/general/headstock-bed-tailstock-alignment-257375/index2.html Thanks for pointing out my poorly worded description.
Darrell