Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: RICH on August 30, 2009, 07:22:37 PM

Title: USING DIFFERENT STEPS PER UNIT
Post by: RICH on August 30, 2009, 07:22:37 PM

Will using different lead screws ( you would have different steps per unit values ) create any problems in Mach?

RICH

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: BluePinnacle on August 30, 2009, 07:50:02 PM

No, just use the motor tuning menus to allow for the different screw pitches. Set up the steps per unit for each axis.

mixing metric and imperial screws may give you problems as you can only have one set of native units ;)

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: Greolt on August 30, 2009, 08:17:21 PM

Quote from: BluePinnacle on August 30, 2009, 07:50:02 PM

mixing metric and imperial screws may give you problems as you can only have one set of native units ;)

Makes no difference. I believe Mach calculates all numbers to ten decimal places.   MMs or Inches,  they are measurement units.  To Mach they are just numbers.

Whether Screws happen to metric pitch or imperial just set native units to what ever you would normally work with.

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: RICH on August 30, 2009, 08:17:33 PM

Have never seen anything posted on this. I know some other controlling programs had a problem if the axis screw pitch was different such that it  screwed up circular interpolation. May be a mute point as i am kind of stuck with using different screw pitches for the X & Z on my cnc lathe conversion.
RICH

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: derekbpcnc on August 31, 2009, 09:02:59 AM

Hi Rich,

I have a metrix X and an imperial Y ball screw  AND the standard ACME on the Z set up on my BP - it's been working fine for over 18months now ;-)

ATB
Derek

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: Graham Waterworth on August 31, 2009, 09:06:37 AM

You can have anything you want on any axis, think about a 4th axis its not the same as X,Y or Z

Graham

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: alenz on August 31, 2009, 06:30:56 PM

Quote from: Graham Waterworth on August 31, 2009, 09:06:37 AM

You can have anything you want on any axis, think about a 4th axis its not the same as X,Y or Z

Graham

True, but this only reinforces Rich’s concern, since there are feed rate issues associated with certain linier/rotary interpolation moves.
Al

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: Hood on August 31, 2009, 06:58:25 PM

On my very first retrofit (manual Bridgeport) I just used what I picked up on eBay, Z axis was 16mm pitch, X was 10mm pitch and Y was 5mm pitch. Never had any problems at all.
Hood

Title: Re: USING DIFFERENT STEPS PER UNIT
Post by: RICH on August 31, 2009, 07:56:12 PM

Thanks All,
Just reinforces what i figured that there will be no problem.
The conversion progresses!  ;)
RICH