# Machsupport Forum

## Mach Discussion => General Mach Discussion => Topic started by: Big Pop on March 02, 2014, 11:03:06 AM

Title: Need Help with steps per unit
Post by: Big Pop on March 02, 2014, 11:03:06 AM
can someone help me steps per unit (inches)

Motor = 200 steps /rev
Driver is set for 3200 Micro steps/rev
Acme lead = 1 start 10tpi
Title: Re: Need Help with steps per unit
Post by: Fastest1 on March 02, 2014, 11:25:50 AM
I am not sure what your driver setting means. Are you meaning 1/16th micro stepping (200 x 16 =3200). If that is the case your step per unit value is 200 x 16 x 10 (tpi)=32000 steps per unit.
Title: Re: Need Help with steps per unit
Post by: Big Pop on March 02, 2014, 12:03:34 PM
I believe that my driver table does the fractional math for you. It's dip switch chart indicates Pulse/rev as 400, 800, 1600, 3200, 6400, etc.   Not 1/4, 1/8, 1/16, 1/32,   Am I reading this correctly?
Title: Re: Need Help with steps per unit
Post by: Big Pop on March 02, 2014, 12:20:00 PM
Maybe I should state this more clearly so I don't confuse everyone.  On my driver is a dip switch chart which shows what position to place the dip switches for different micro steps.  Example,  my driver does not give fractional values.  It will state, when placing   switches 5, 6, 7, 8 in the on, on, on, off position, this will equal  = 400 pulses/rev.  It does not show  on, on, on, off = 1/2 micro stepping.  I am assumingthat they mean the same thing and the above formula is correct.  any comments
Title: Re: Need Help with steps per unit
Post by: jimthefish on March 02, 2014, 01:28:33 PM
Why don't you use the calibration option on the settings page of Mach (alt 6). its just above the RESET button. Mach will do all the calculation for you, just follow the instructions. Use a digital vernier clamping the fix jaw to the table and use a bar in the collet to move the sliding jaw, just make sure you move the correct way as you don't want to wreck your vernier. I did this and got perfect dimensioning.  Do a trial away from the table as you need to check what Mach has defaulted to Metric/imperial before you touch the vernier.
Title: Re: Need Help with steps per unit
Post by: Hood on March 02, 2014, 01:55:08 PM
Yes that is the way the Chinese drives do things, they assume you are using 1.8 degree steppers which are the most common, so 32,000 steps per unit is correct if you are set up in Imperial units in Mach and assuming you do not have any gearing between motor and screw.
Hood
Title: Re: Need Help with steps per unit
Post by: Fastest1 on March 02, 2014, 03:04:33 PM
Why don't you use the calibration option on the settings page of Mach (alt 6). its just above the RESET button. Mach will do all the calculation for you, just follow the instructions. Use a digital vernier clamping the fix jaw to the table and use a bar in the collet to move the sliding jaw, just make sure you move the correct way as you don't want to wreck your vernier. I did this and got perfect dimensioning.  Do a trial away from the table as you need to check what Mach has defaulted to Metric/imperial before you touch the vernier.

Though this will work, if you dont understand how the units are calculated you will can get into trouble regardless of the units of measure. Use the calibration tool after you have got the basic set up close.