[prcdslnc13]

Im using the 400 ozin motors and Probostep drives from probotix. Im trying to turn a 1/2-10 lead screw with a 4:1(ish) gear ratio. a 42 tooth pulley at the motor 11 tooth at the screw. The screw turns prertty freely but it seems no matter what speed/ step combo I try it stalls out. if you want to see the machine its on my build thread is here

http://www.cnczone.com/forums/diy-cn...tml#post857828

ideas? Id hate to think that a 400ozin motor really couldnt turn this screw but I guess its possible.

[metalworkz]

Hello,
Does the motor work correctly with the belt removed? I guess your are speaking about the X axis but have you tried any of the other motors/axis?

[prcdslnc13]

The motor works fine with the belt removed. Ice tried different combinations of micro stepping
from 16th to full. Things seem to work better the closer to full step I get but go back to the same issue as speed picks up.

[metalworkz]

In Mach are you using the settings for the motor tuning that are recommended by Probotics? On my small CNC build for my X axis I went from an old stepper to a newer 425oz.in. stepper which helped but I needed to play with the motor tuning settings to get it to work well with the heavy worktable I am using.
What are you using for the Step Pulse and Dir Pulse in motor tuning?
With the belt disconnected can you push the axis easily in each direction by hand, or do you feel a bind or restriction when you try to move it?

[prcdslnc13]

I'm actually using EMC2. That's what Probotix recommended
But they don't have recommended specs I was using 1/16th step with 3200 steps per in and micro stepping set to one.

[metalworkz]

I'm sorry, I have not used EMC2 and don't know anything about how it works or how to configure it for motors. My fault for assuming Mach was the controller.
You might take a look in EMC2 and see if you can find Motor tuning or another application to help get the motors setup correctly. Mach3 has an axis calibration application that makes it easy to get the motors set up and calibrated. Hopefully someone with EMC2 experience will reply and give you some good help.

[WoodSpinner]

I'm actually using EMC2. That's what Probotix recommended
But they don't have recommended specs I was using 1/16th step with 3200 steps per in and micro stepping set to one.

is it me? or do you have the gearing backwards?

[prcdslnc13]

Yes in the pictures it is. Its right now. I was using spare parts before. Every thing is right now.

[Kencor1]

What size power supply are you using? I would have at least a 32 Volt.

[mactec54]

prcdslnc13

I just looked a your photos & read a little more, you don't have a low enough gearing for the motor to drive it, on your
1 turn & it moves 2", you will need to get it some were near 10 or more turns of the motor to the 2" of travel, You may need even more than 20 turns of the motor for the 2" of travel, it will depend how much load it is trying to move

WoodSpinner
is it me? or do you have the gearing backwards?

I saw that to in Post # 1, but I then looked at the photos, & they look to be the right way, but if he does have them the way that's in Post #1 then they would be the wrong way

[WoodSpinner]

Another thought, 1/16 stepping is the weakest possible setting.

John

[prcdslnc13]

I did eventually get it all moving tonight. I think you guys are right, I have my gearing wayy too low. I did it that way hoping to get a little more speed out of it, but I think Im going to have to bite the bullet and give up some more space in the garage to direct drive the screw.

Right now I just am not getting into the torque band enough to really move anything. When I got it moving I was set to 8th step at about 1ips and acceleration at 27ips.

I was able to cut my first part at that speed, but I have quite a bit of backlash in it, Im guessing from the belt also, So one more part to cut and the belts probably going.

[mactec54]

prcdslnc13

I thought you were having trouble with the Y axes,(your chain drive) yes on your screws you could try doing them 1.1, if your belt has the right tension then you won't have a back lash problem, unless the belt drive components are not strong enough for the job