[Jkountz]

Peak or RMS? Shouldnt I supply more than the 3.0 amps? I dont know and thats why Im asking here but I know what happens when you try to run too many things without enough amps, something trips usually. Like trying to run a circ saw, a shop vac and some lights all on a 15 amp circuit would trip a breaker for sure because the total amps supplied is less than what those items need to run. Wouldnt this hold true for DC steppers too? If I have a motor rated at 3 amps, isnt it going to need a little more than that to run good?
Anyone?

[cambosoup99]

well is the motor at rated 3 amps peak or rms?

if its rms here's how to get the peak value. look at the bottom of the pdf. http://www.linengineering.com/line/c...otorBasics.pdf

[Jkountz]

Duh, ok I get it now, thanks!! That makes perfect sense and I feel stupid that I didnt think of that. My motors are rated 3amp RMS or per phase, so the peak is 4.23. Just so happens that I have a setting on my drivers that is exactly that, 4.20 max and 3.0 RMS. Answers my question!!

Thanks Cambo!!

[Jkountz]

Not much shop time this weekend but I did manage to get some things done. My screw came for the Z axis so Ive been playing with that a little. I put my drill on the acme screw just to move it up and down, may sound silly but it was exciting to me!!
Heres a short clip showing all the "action"

[Jkountz]

Ok so Im doing some bench testing of my steppers and I connected two axis just to get a handle on things. For now both are set exactly the same in Mach and on the drivers. One is performing just fine while the other is running SUPER slow. Im talking really slow. Like one revolution every 2-3 seconds. If I set the SPM in Mach to something ridiculous to say 25000 I can get it to run about one revolution per second but thats about it. I thought maybe it could have been a power supply issue so I swapped the wiring from one motor to the next, it made no difference. Could this be a bad motor or driver or ?? Im at a lost as to what to do. I tried this test under load and free spinning to make sure it wasnt binding up or something.
Any ideas?

[Devastator]

Ok so Im doing some bench testing of my steppers and I connected two axis just to get a handle on things. For now both are set exactly the same in Mach and on the drivers. One is performing just fine while the other is running SUPER slow. Im talking really slow. Like one revolution every 2-3 seconds. If I set the SPM in Mach to something ridiculous to say 25000 I can get it to run about one revolution per second but thats about it. I thought maybe it could have been a power supply issue so I swapped the wiring from one motor to the next, it made no difference. Could this be a bad motor or driver or ?? Im at a lost as to what to do. I tried this test under load and free spinning to make sure it wasnt binding up or something.
Any ideas?

I'd check the wiring very carefully. Even if you have to unhook everything on the suspect axis and start over. Could be as simple as a loose connection or swapped wires. Take your time. Then let us know. EDIT...Be sure to check all wiring that goes from any breakout boards to your drivers too, not just the motor wiring. Also, your "virtual wiring" which is your pin out settings for your motors. You might find something swapped there. Compare the settings on the working axis to the settings on the non working axis to see if there is a difference between the two.

[Jkountz]

Ok update. I started to troubleshoot my problem by process of elimination. So to start I disconnected all but the Z axis, the one Im having trouble with. I then started with the wiring and all the connections. One by one I took them apart then put them back together again to make sure it wasnt a bad connection. No joy. Then I took the wire from the working axis and connected it to my Z. It worked! Now then I thought, the motor is fine, its just a connection OR a bad driver. So I swapped out the driver and reconnected everything on the Z the was it was. No joy. Still not working. So I power cycled the whole thing and restarted Mach. It worked!! The Z axis is flying up and down faster than I would ever dare run it. So I set about tuning it in, set my IPM to about 150 and my accel up a bit. Smooth and fast still. Everything was good. I then reconnected my Y axis, played a little more jogging it around, then went in to get some lunch. Came back out...........No joy......The damn Z is crawling again. Barely moving at all, if it werent for the screws on the coupler I couldnt even see it move. Thats how slow Im talking here. I didnt change a thing yet the problem is back. I have exhausted every angle I know of and still nothing.
I tried different micro steps, I checked double checked and triple checked all the wiring.
Im using a 1/2"-10 single start lead screw. I have my pulses per set to 1/8 or 800 on my driver. I then multiplied that by 10 so I set the SPI in mach to 8000. I tried every other step setting on the driver and still nothing. Yes I tried EVERY step setting on the driver.
This makes no sense, how is the other axis working fine but this one acts stupid?
Anyone?

[Devastator]

If restarting mach fixed it I'd suspect something running in the background. Are you sure your steps per inch are correct? Should be leadscrew TPI X Motor Steps per rev. (200) X number of microsteps. So if your leadscrew is 10 TPI and you are using 8 microsteps with 200 step per rev motors, you should use 16000 SPI. Also, when you make changes in the motor tuning setting, you have to remember to hit save, otherwise it will revert back to the non working settings.

[Jkountz]

Hhmm Maybe but wouldnt that affect all the axis?
One thing I forgot to mention but I dont think is the trouble. For the time being and just for testing purposes I am using 22awg 4 conductor solid wire. The kind used for security systems. Its NOT shielded. I mention this just in case although again, Im using it on all the axis and only the one is giving me trouble.

[Jkountz]

Ok Im really confused on the driver settings now. Mine doesnt say 1/2 1/4 1/8 and so on. It says 400 800 1000 1600 2000 and so on. So whats what here? Would 1/8 microsteps in fact be the 1600 setting on my driver thus 1600 x 10 TPI = 16000?
Another example to make sure Im getting this. Say I want 1/4. So it would be 4 X 200 = 800 x 10 = 8000. Is this right?

[ger21]

Ok Im really confused on the driver settings now. Mine doesnt say 1/2 1/4 1/8 and so on. It says 400 800 1000 1600 2000 and so on. So whats what here? Would 1/8 microsteps in fact be the 1600 setting on my driver thus 1600 x 10 TPI = 16000?
Another example to make sure Im getting this. Say I want 1/4. So it would be 4 X 200 = 800 x 10 = 8000. Is this right?

Yes, 16,000 and 8,000.

[Jkountz]

Thanks Gerry, I think I got it now. After setting the driver to 400 and my SPI in Mach to 8000 the Z axis came to life! Its moving at a normal speed now. Problem is now its not moving as far as Mach thinks it is. In mach the readout is saying the Z is moving12-14 inches when its only really moving about 4.
This stuff sure is fun but it can be quite aggravating at times too!!

[Devastator]

Thanks Gerry, I think I got it now. After setting the driver to 400 and my SPI in Mach to 8000 the Z axis came to life! Its moving at a normal speed now. Problem is now its not moving as far as Mach thinks it is. In mach the readout is saying the Z is moving12-14 inches when its only really moving about 4.
This stuff sure is fun but it can be quite aggravating at times too!!

I believe you have it set wrong. These are all divisions of 200 motor steps per revolution so:

400 would be 1/2 step. Using a 10TPI leadscrew SPI setting would be 4000
800 would be 1/4 step. Using a 10TPI leadscrew SPI setting would be 8000
1000 would be 1/5 step. Using a 10TPI leadscrew SPI setting would be 10000
1600 would be 1/8 step. Using a 10TPI leadscrew SPI setting would be 16000
2000 would be 1/10 step. Using a 10TPI leadscrew SPI setting would be 20000

Make a chart and put in in your machine folder if it works for you.

Have fun!

[Jkountz]

Well after much trial and alot of error heres where Im at. I tried the settings you specified above Devastator but it was still way off. Mach was saying my Z was moving like 10 inches when it was only moving 2-3. So I set the driver to 400 and the SPI in Mach to 8000. This got me really close. Like within 1/4" but its still off. I clamped a digital caliper to the Z and raised it, then zeroed the caliper. Dropped the Z a couple inches and read the caliper. It said 1.547. Mach however said 1.793 so roughly 1/4". The Y axis which is rack and pinion driven using CNC Router parts R & P drive is right on the money. The Z, not so much!!

[Devastator]

I tried the settings you specified above Devastator but it was still way off. Mach was saying my Z was moving like 10 inches when it was only moving 2-3. So I set the driver to 400 and the SPI in Mach to 8000. This got me really close. Like within 1/4" but its still off.

hmm....the math is not working out so well on that......Are you sure you don't have mach set up for metric? There is a way to compensate the mach settings to account for offsets in actual distance traveled, but that should be a last resort after everything else is dialed in.

[hp84117]

Use the axis calibration function in Mach 3.

To get there, click on the Settings tab from the main screen. In the lower left hand corner of that screen, just above the red reset icon, click on the "Axis Calibration, set steps per unit" button. Tell it which axis, then how far you want it to move. After it moves, measure and enter the distance it actually moved, then Mach 3 will calculate the steps per unit.

[Jkountz]

Ok I obviously have some deeper problem. Now it randomly works, the Z axis that is. Without changing a thing besides just powering down the drivers and the PSU, I went out to try hp's suggestion. I powered everything up, started Mach and the Z would hardly move, missing steps, not turning at all then taking off all the sudden. I played around with some more settings and got it going again then tried to run the SPI routine. Yeah boy that went over like a fart in church. I told it to move 2in. It moved .975 so I told Mach that. Mach spit out its calculated settings and asked me if I wanted to keep them. I said yes and tried the Z again. It wouldnt move. The motor hummed and it sounded like it wanted to but nothing. So I disconnected the coupler thinking again maybe something is binding. Nope same thing.
Now then Mach set the SPI at around 4k and the IPM at like 75 and the Accel at 20. Well the problem lies in the SPI setting because If I reduce that to 2k or something low like that the Z WILL move. Its not moving accurately but its moving at a good clip. So with the SPI set low enough for the Z to move I did the test again. Same thing, Mach wants to set my SPI in the 4k range. Now this prevents my Z from moving at all. However!! And this is the fun part folks........It was working just fine at 4k before I came in the house to check email.......Damn.......so its a random problem and I have no idea where to start. Cables? Printer port? If the port is the problem, why only the Z axis? Anyone live near 26704?? :-)

[Devastator]

...Damn.......so its a random problem and I have no idea where to start. Cables? Printer port? If the port is the problem, why only the Z axis? Anyone live near 26704?? :-)

If you can't isolate it to software and driver settings, I'd trial and error as much hardware as you can working backwards. First check all wiring, then swap motors and test, then drivers and retest. If those check out, then dig into breakout boards and parallel port.

During testing, I'd set the driver to 400 and the SPI to 4000 and leave it there. If you do change the SPI in mach, you also have to change the driver microstep setting to the matching value. The driver microstep settings and mach SPI settings are directly related. If they don't match up, the distance traveled and the speed settings in motor tuning will be bogus and a waste of time. That's why you are getting more speed by setting the driver to 400 steps per revolution, but telling the software to send 8000 pulses per inch. By doing this you are turning the leadscrew 20 times instead of 10. Then in the motor tuning screen it will be impossible to set your motors up correctly because your speed numbers would be lower than actual, so if you set it for 75, it would really be trying to move @150 and may stall because that may be too fast for your motor using a single start screw.

I went through all of this when my driver wasn't changing to the proper microstep mode, so I feel your pain.

[Grunblau]

I can't believe I missed the start of this thread! I have been so incredibly busy prepping steel and tapping holes... I hope you have gotten things figured out and can move on to the fun stuff again!

The 1/2"-10 TPI screw is a bit of a fine pitch for such a large format. The ones I used on the original machine were 5/8"-4 TPI. I think we discussed this via email, though. The only time I experienced unexplainable weirdness was when my printer cable ended up laying across the power strip. This resulted in missed steps in the Z axis. I probably fought with it for a week before thinking to change the wiring on the floor.

The electronics look different from the ones I spec'd too, but if the BOB has an additional axis, you might try wiring the driver up to that one and change it in the software. It is strange that it is on and off again. This would lead me to think that it might be either computer issues, or BOB issues. If you switch all of the drivers and ports (manually and software), the problem still eventually shows up in the Z axis?

[Jkountz]

Hey Brian, glad you stopped by! Ive been a bit stalled lately due to life getting in the way but Im still working on it here and there when I get a few minutes.
The problem with the Z axis really has me puzzled. Ive switched everything I can think of and yet I cannot make the Z move the right distance no matter the setting. I think I may replace the screw I have with a 5 start and just tweak the whole thing while Im at it. Again, I havent even messed with it too much lately but I hope to in the next few days or so. I will post my results then.