Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: doomcuroe on February 18, 2012, 08:35:59 PM

Title: Cant get motors to calibrate
Post by: doomcuroe on February 18, 2012, 08:35:59 PM
Motors turning, yay.  I went through the procedure to calibrate the motors and its not working.  I'm using the sherline driver setup with motors  800 steps per revolution (microstepping), equates to 16,000 steps/inch.  I setup the machine in inches but it seems its moving in metric, how can I tell what units the dro is showing?  When I auto set the axes, the steps per are huge sometimes 30,000 and when I restart mach3 I get a warning that the kernel speed is too low for the setting. 
Title: Re: Cant get motors to calibrate
Post by: Fastest1 on February 18, 2012, 10:18:55 PM
Shouldnt the steps be 200 per rev? Most steppers are. Stock screws on the Sherline? 1/4-20? I would have thought with 10x microstepping you would be in the 2000 range. How far does it move when you ask for 1". I am pretty sure on the General Config page, the very first dialog box "Lock DRO's to Set Up units" needs to be checked.
Title: Re: Cant get motors to calibrate
Post by: Fastest1 on February 18, 2012, 10:24:09 PM
I just went and looked up my settings for my Sherline lathe as it still has the stock screws. I was showing 8000 steps per for both axis. Stepper at 200 steps per X 4 turns per inch on the screw X 10X microstepping = 8000 steps per. I am running a G540 or a HCNC pro not the Sherline electronics. Shouldnt be any different.
Title: Re: Cant get motors to calibrate
Post by: Hood on February 19, 2012, 03:36:26 AM
8000 would be correct according to the info you gave, if its still not quite right try using Sherline Mode as it seems some people with the G540 needs a wider pulse.
Hood
Title: Re: Cant get motors to calibrate
Post by: RICH on February 24, 2012, 08:25:49 PM
200 steps/ rev of motor X 10 ( microsteps) x 20 screw rev / inch = 40000 steps per

- 200 steps / rev are the norm 1.8 deg steppers but there are others like .9 and even better
- assume you are microstepping at 10x
- with no gear reduction it takes 20 revolutions of the screw to move the axis 1 unit = 1 inch

Depending on the velocity you will define or desire, you may need  to use a higher Kernel speed. The kernel speed will be llimited by you computer.


RICH