# Machsupport Forum

## Mach Discussion => General Mach Discussion => Topic started by: Ls123 on April 08, 2014, 08:43:07 AM

Title: Z calibration all along y axis?
Post by: Ls123 on April 08, 2014, 08:43:07 AM
Hi I've recently built my own diy cnc mill which works very well but i have found that the y axis is slightly higher one end by 1mm (slight sloped) this isn't usually a problem but when i engrave a long word the start of the word is deeper than the end.

I have tried to adjust this out mechanicaly but with such a small error and tools available in a home workshop can't get it exactly spot on both ends.

Can this been adjusted in software so the z axis will take this error into consideration?

Ive also built a z axis zero touch plate,  could this be used to calibrate the z along the whole y axis span?

Or could the whole bed height be calibrated to fix this?

Im sorry if this is a silly question,  im still learning alot about machining.  Any help or advice would be great.
Thanks for looking.

Luke
Title: Re: Z calibration all along y axis?
Post by: Fastest1 on April 08, 2014, 08:51:38 AM
I have no idea of how to do it but 3D printers have some bed calibration tools. It sounds like they do what you need. Basically map the surface and somehow compensate for undulations in the surface by regulating or varying the Z height to be constant.
Title: Re: Z calibration all along y axis?
Post by: Overloaded on April 08, 2014, 09:18:25 AM

Or could the whole bed height be calibrated to fix this?

Luke

Maybe affix a spoil board, machine it at a constant Z, then the surface will be absolutely parallel to the X and Y axis'.

Russ
:)
Title: Re: Z calibration all along y axis?
Post by: Picengraver on April 08, 2014, 10:02:53 AM
Luke,
Best to fix the machine, but you can experiment with a formula (Function Cfg's > Formulas).  I have done this in the past to fix an out of square gantry.   It may work OK for you, but other issues may limit a formula's use.

Ex: f(z) = z + (y * n)  - where n is the degree of change applied to z as y changes

John Champlain
Title: Re: Z calibration all along y axis?
Post by: Ls123 on April 08, 2014, 05:56:19 PM
Thanks for all your replies,  it looks like there isn't a simple way to do this in software. Was kinda hoping there was a calibration wizard (like a touch screen crosses) that i could use my height touch tool.

Can't really machine a spoil board flat as its only a dremel cutter but i spose i could always use shimms to correct a spoil board to the correct height.

I think im going to have another go at getting more level mechanically first . But many thanks everyones advice :)