Machsupport Forum

General CNC Chat => Building or Buying a Wood routing table.. Beginnners guide.. => Topic started by: wes709 on July 19, 2016, 03:39:46 PM

Title: trying to figure out steps per mm
Post by: wes709 on July 19, 2016, 03:39:46 PM

Trying to figure out my steps per mm Using the Rep Rap Calculator

Here is the link to the NEMA 23 Steppers that i bought as a kit with the cnc controller.

http://www.ebay.ca/itm/3-Axis-3A-Stepper-Controller-Cnc-Kit-Nema23-24V-Psu-For-Milling-Machine-/401075212293?hash=item5d61f21005:g:Hq0AAOSwzJ5XZ8Oz

Here is the link to the leadscrew i have selected

http://www.banggood.com/T8-800mm-Stainless-Steel-Lead-Screw-Set-with-Shaft-coupling-and-Mounting-Support-p-1062920.html

From the above sites i was able to determine my:

Motor Step Angle 1.8
Leadscrew Pitch 2mm

I have the dip switches on my cnc board set to be at 1/8 micro step.

The part that i think im messing up is the pitch preset where i am only guessing that is m8 1.25 mm per rotation.

With the above information i get 800 steps per mm which seems absurd
PLEASE SOMEONE HELP ME if i roatate the rod 1 full revolution it travels 8.1mm

Am i just messing up the calculation???

Title: Re: trying to figure out steps per mm
Post by: ger21 on July 19, 2016, 03:49:34 PM

Looks like the screw is labeled vaguely, and the lead is actually 8mm.
So with 1600 steps per rev, divided by 8, you should have 200 steps/mm.

Title: Re: trying to figure out steps per mm
Post by: wes709 on July 19, 2016, 03:53:56 PM

Where did you get the 1600 im curious

Title: Re: trying to figure out steps per mm
Post by: wes709 on July 19, 2016, 04:06:49 PM

I have entered the setting at 200steps per mm , if i get my calipers and move the z axis down 10 mm on mach3 display should that be 10mm of travel on the leadscrew ?

Title: Re: trying to figure out steps per mm
Post by: ger21 on July 19, 2016, 04:46:19 PM

If the display (DRO) shows 10mm, then the Z axis should move 10mm.

Title: Re: trying to figure out steps per mm
Post by: wes709 on July 19, 2016, 05:12:00 PM

Thanks for your quick replies i think im on to something . I have a video here to show you what i actually get when i move the z axis down 10 mm on the DRO



https://www.youtube.com/watch?v=r5UPgpz9q7o

Thanks again for your help it looks though as if im only seeing close to 5 mm when i move it 10 on DRO any ideas?

Title: Re: trying to figure out steps per mm
Post by: ger21 on July 19, 2016, 05:20:02 PM

Then change it to 100 steps/mm

Title: Re: trying to figure out steps per mm
Post by: wes709 on July 19, 2016, 05:49:08 PM

it was actually the other way . it was 400 steps per mm. Thanks so much for your help!

Title: Re: trying to figure out steps per mm
Post by: ger21 on July 19, 2016, 07:56:31 PM

Quote from: wes709 on July 19, 2016, 03:53:56 PM

Where did you get the 1600 im curious

Steppers are 200 steps/rev.
With 1/8 microstepping, it's 8x 200.

Title: Re: trying to figure out steps per mm
Post by: wes709 on April 15, 2017, 08:52:32 PM

Im Back !!! i am trying to add a rotary axis,,, i cannot get the axis to move as the A , only the X and is there some sort of settings to change this to be a rotary axis in mach 3?  here is a video to help explain.

https://www.youtube.com/watch?v=o54M_phYJpY

Thanks!

Title: Re: trying to figure out steps per mm
Post by: wes709 on April 15, 2017, 11:37:54 PM

Update https://www.youtube.com/watch?v=x1sjG1qWfMo