AXIS CONFIGURATION Question

It would help if you stated the pitch of the screw ie is 8mm the diameter or the pitch

since this acme rod is in mm i had to find someone to help convert to inches since that is how the system is set up.. this is what i found
threads per inch 12.7
number of turns 4

For future reference you can divide mm by 25.4
That screw appears to be 4 start 2 mm pitch

So I think the nut will move 8mm per turn.

So 8/200/4 microstep would be .01mm (.0004 inch) per step
(I think with the multistart thread)

Leon82, thank you for all the help,

Make some testmove
if your ace is correct
use a Dieal for correct Backlash Numbers

Thank you again to all that helped me with this ... I got it working and all the measurements are exact... such a great group for resource

how precise did you got it
Backlash ?
and please check in 1weeks time again

AND good advice is to keep the dial on side to measure bevor real precise work start
it gives you a advantage for your part precision

a little history for you, my machine was belt driven on the y and x axis and lead screw on z axis, i struggled to get the machine to travel the same measurement as the computer was telling it, it got worse the longer the travel,,, i new that the settings could be the issue and i new the belts were skipping...

i converted the x and y to acme lead screw, with the help of this group i was able to get the machine to move and measure the same regardless if it went 2 inches or 30 inches, this was big...

for the exact, with the limited tools i have, using a tape measure, i can tell the machine is exact, i know that in reality that is probably not a true statement but i do not have the ability to measure in mm, and at this point i am going to run with it and start cutting and make adjustments as i go... This was because of the help i received on this page...

I am working on the backlash work in progress, and yes i will be checking this as time goes on, on my machine the backlash will come with time because of the acme blocks i use and they will wear out in time....

any way, thanks again to everyone great help,,

if you realy can afort it go to a leadscrew even a Trapezional 2meter Spindle at low cost
around 50USD can go preciser then a Belt

We got so many mashine in use for education and they realy do a good chop at minimal costs
The Backlash is there but it is the same wherever you are on the table