Help !! :(

[wayne_webb]

My shopbot wouldn't move, was in E-stop mode, I finally got that fixed and was told to set the software back to "default", Only problem is, the unit values in default don't go with my machine. Mine is an old PRT standard with the white "tower" controller. Board is PRT 42501-00611

The default unit values "733.386" had the machine moving about 15" for every 10". I finally figured out that setting the x and y to 509.2596 had them almost dead on. But the z will only move a maximum of about 9/16" to 5/8" when instructed to move to 1" safe height. I have tried every number tech support has given me to no avail. The pinion appears to be either 20 or 25 tooth but I can't count them without removing the motor. I'm pretty sure I tried both unit values for those however. Maybe I'm looking at the wrong chart? All the motors are identical 1/8 step and the pinions are fully engaged to the racks. I sure could use some help because I have a job to finish before Thursday.
Thanks!
Wayne

[srwtlc]

Here's a list of unit values/pinions. http://shopbotwiki.com/index.php?title=PRTInchUnits

[wayne_webb]

Here's a list of unit values/pinions. http://shopbotwiki.com/index.php?title=PRTInchUnits

Thanks!
I have that list but have had no luck getting the z to move the right distance.

[srwtlc]

Check the # of teeth on that pinion to be sure. What version are you running? Look at the VU settings and see if there is an option for resolution multiplier and make sure yours are '1'. I've had it be the other way around on an Alpha, so maybe it could get the wrong setting for a PRT as well.

[Brady Watson]

Pics would help...Take a pic of the following:

1) Any X or Y motor label.

2) Z motor label.

3) Control board showing motor drivers.

Also, how many teeth on X or Y ? (Yes, spend 5 min to pull the motor to count the teeth.)

Pinions could be 18, 20 or 25 tooth.

-B

[wayne_webb]

Check the # of teeth on that pinion to be sure. What version are you running? Look at the VU settings and see if there is an option for resolution multiplier and make sure yours are '1'. I've had it be the other way around on an Alpha, so maybe it could get the wrong setting for a PRT as well.

Running version 4.2.7. I pulled the z motor. The pinion has 20 teeth, just like the x and y. all the resolution multipliers are set to "1"

[wayne_webb]

Pics would help...Take a pic of the following:

1) Any X or Y motor label.

2) Z motor label.

3) Control board showing motor drivers.

Also, how many teeth on X or Y ? (Yes, spend 5 min to pull the motor to count the teeth.)

Pinions could be 18, 20 or 25 tooth.

-B

The x,y and z motor labels are the same.
I pulled the z motor. All three have pinions with 20 teeth.
Here is a photo if the board.http://www.talkshopbot.com/forum/attachment.php?attachmentid=26524&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=26523&stc=1

[Brady Watson]

OK...

1:1 motors

1/8 stepping IMS drivers

20T pinions all the way around

Your unit values should be: 509.2958 for XYZ

I got these numbers by taking the values for a 1:1 motor running a 4G, and divided it by 10 (microsteps), then multiplied it by 8 microsteps. I verified it again by taking the value for 1:1 1/4 stepping drivers and doubled the number to get 1/8 microstepping. All of the values (including 1/8 stepping setups) are in the chart Scott linked.

Try that number for X, Y and Z and then see how it pans out.

You said the Z motor doesn't move as predictably as you think it should. Does it have a different motor decal on it by any chance? If so, tell me the step degrees at the bottom right of the label. It should say: 1.8, 0.5 or 0.25. The one you show says 1.8 deg/step on the red part.

If Z is 0.5, then look up the value for a 3.6:1 motor @ 1/8 stepping. If Z = 0.25, then look up the value for 7.2:1 motor at 1/8 stepping.

-B