Re: [CAD_CAM_EDM_DRO] CNC controller backlash question

Having different amounts of backlash in opposite directions just does not
make any sense to me. It can differ at varying points along your movement,
but I think it has to be the same in both directions at any given point.
Here is a brief write up I have on my site:

If you down load the Flashcut manual it has a pretty good section on how to
calculate backlash. Basically what you do is as follows:
1 - move an axis using the computer far enough to get all of the backlash
taken up (.100 is fine). (I.E. = If you are starting at X0 Y0 Z0 and want to
work on the X axis in DeskNC you press the "E" key and then enter: G01 x.1
and press the enter key)
2 - Put a dial indicator on the table to measure movement in the axis you
are working on and set to zero.
3 - again using the computer move the axis in the opposite direction of step
1 an amount larger than what the backlash is, but within the range of your
indicator (.100 should again work well). (I.E. in DeskNC you press the "E"
key and then enter: G01 x0 and press the enter key)
4 - again using the computer move the axis in the direction of step 1 back
to your starting point . (I.E. in DeskNC you press the "E" key and then
enter: G01 x.1 and press the enter key)
5 - The difference between you zero point on the indicator and your current
reading is you amount of backlash. When perfectly adjusted your indicator
should always come back to zero after the above procedure.

Tim
[Denver, CO]
www.KTMarketing.com/CNC.html

----- Original Message -----
> I'm using TurboCNC which allows for backlash, but am worried that an
> axis might have more backlash going one direction than the other
> direction. Has anyone noticed this?
>
> I have extra ballnuts to install on my leadscrews, but it'll be a
> while till I can install them.
>
> What is the best way to measure backlash?
>
> Thanks
>
>
> Addresses:
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