New 4g board issue

[phil_o]

I just instaled my new 4g board in my benchtop PRT. When I enter a jog or move command the machine does not move the specified amount. eg. Typing JX 21 only moves the X car 17" I entered the units specified in the installation directions.
X and Y =1833.465
Z = 2291.831
The directions don't specify the multiplier values.

[Brady Watson]

Phil,
Your benchtop has different unit values for the 4G setup than a regular PRT. Take your original unit values and multiply them by 2.5, and that will be the correct number. Since the PRT stepper drivers are 1/4 stepping, and the Geckos are 1/10 stepping, the Geckos put out 2.5X the number of steps to go the same distance as the PRT drivers. (in case you wanted to fully understand WHY)

-B

[phil_o]

Brady,
before I got your response I checked the original values in the manual. Since the 1833.465 came up short I decided to try a factor of 10 not 2.5. For X and Y I entered 2291.831. This appears to work fine. I'm surprised the install directions didn't include the values needed for the benchtop bot.
I haven't cut anything yet but I'm impressed with how much faster and smoother my machine runs now.

[Brady Watson]

Phil,
If you were running DOS & took the unit values from DOS & multiplied them by 10, then that would make sense. The UV in SB3 is 4X more than that of DOS....take that value & multiply by 2.5 to get your 4G values.

Were you running DOS?

-B

[phil_o]

I appreciate your help Brady but when I posted this question on the forum I also e-mailed Shopbot support with the same question.

Their response came later in the day:
Hi Phil,
Your X, Y and Z should all be 2291.831
Technical Support
ShopBot Tools, Inc

2291.831 is 10x the values listed in the Shopbot manual.