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  #1  
Old Wed 31 August 2011, 20:33
Rusty Nuts
Just call me: Gary #86
 
Valley Grande, AL
United States of America
Need help, two nights and no sleep

I'm working on the kitchen table project. Everything is wired up with the motors on the table. My problem is I cannot get any speed from the motors.

My setup:

PMDX-126 BOB
PMDX-134 Mother Board
Gecko G203V drivers
82k Resistors (checked with ohm meter 83k)
Antek 50v 20amp Power Supply
PK-299 4.5 Stepper Motors
Mach 3 (Demo Mode)

I set up the PMDX in test mode. All LED's lit per manual, no faults. Gecko drives LED's green. Test mode set push to start and push to stop. Start the test, motor turns about 25 rpm and never ramps up. Adjusted the drive. Motor runs smooth and sounds good. No heat build up in motor or drive. Push to stop, motor stops. Push test button again, motor reverses direction at about 25 rpms no ramp up. Tried different resistors and tried no resistor, still the same. I checked voltage at idle all motors holding torque at 50.1v. Pressed test again with meter still connected and was 49.7 with motor turning. Next I by passed the PMDX-126 and hooked the PMDX-134 up to the computer cable and still got the same rpm. I up the motor tuning in Mach and was able to ge maybe 60 rpm. Hooked the PMDX-126 back up with same results, about 60 rpms through Mach. Also adjusted jog speed to 100%.

I'm stumped and can't sleep. Need help

Gary
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  #2  
Old Wed 31 August 2011, 20:38
Rusty Nuts
Just call me: Gary #86
 
Valley Grande, AL
United States of America
Forgot to mention the steppers are wired half coil and also tried bipolar parallel.

Thanks
Gary
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  #3  
Old Thu 01 September 2011, 12:29
Richards
Just call me: Mike
 
South Jordan, UT
United States of America
You've got a lot of variables that we need to address. What parameters did you set in motor tuning in Mach 3? Exactly how are the PMDX boards jumpered? (My PMDX-122 can be set to either work with the "common" set at +5VDC or at 0VDC.) How is everything wired together?

When things don't work as expected, I've found that starting over, at the beginning is the best approach. I check the jumper settings on the boards that I use. I check the settings in Mach 3 to verify that they are correct. I check the voltage settings for the power supply.

My test bench has MANY variables. More than once, I "messed up" by changing something unintentionally. Because I use G202, G203v and G540 modules, I sometimes forget to set things up exactly as required. More than once, I've blamed software or hardware when the blame should have been directed towards me.

If you post your jumper settings and your Mach 3 settings, we might be able to "look over your shoulder" and help you find the problem.
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  #4  
Old Thu 01 September 2011, 13:29
Rusty Nuts
Just call me: Gary #86
 
Valley Grande, AL
United States of America
Quote:
Originally Posted by Richards View Post
You've got a lot of variables that we need to address. What parameters did you set in motor tuning in Mach 3? Exactly how are the PMDX boards jumpered? (My PMDX-122 can be set to either work with the "common" set at +5VDC or at 0VDC.) How is everything wired together?

When things don't work as expected, I've found that starting over, at the beginning is the best approach. I check the jumper settings on the boards that I use. I check the settings in Mach 3 to verify that they are correct. I check the voltage settings for the power supply.

My test bench has MANY variables. More than once, I "messed up" by changing something unintentionally. Because I use G202, G203v and G540 modules, I sometimes forget to set things up exactly as required. More than once, I've blamed software or hardware when the blame should have been directed towards me.

If you post your jumper settings and your Mach 3 settings, we might be able to "look over your shoulder" and help you find the problem.
Hi Mike,

I don't think there is anything wrong. I had emailed PMDX support and I received an e-mail from them this morning. When reading the manual I misread 1000 rpm as the ramp speed but the manual states 1000 steps per second. I really need to get a good nights sleep When controlling the steppers through Mach3 I was able to double the speed (about 60 rpm, also need to adjust motor tunning). I believe I have read where Mach3 limits the speed in Demo Mode but I don't know how much. I have Mach2 running on my other router on a different computer. Tonight when I get off of work I'm going to see if I can move my license from Mach2 computer to my other computer with Mach3.

Is there any numbers I should start with in my motor tunning in Mach3 to determine if they are coming up to speed and do you think I should stay with half coil on the steppers?

I'll post more after I'm finished tonight.

Thanks for the help and any other suggestions you can offer,

Gary

Here is the reply from PMDX:

Hello Gary,

The test mode on the PMDX-126 board will only ramp up to 1000 steps
per second. Your G203V microsteps at 10 microsteps per full step, and
the motors have 200 full steps per revolution, so you need 2000 steps
per full revolution. This should result in the motor turning at 1/2 revolution
per second or about 30 RPM in test mode.

I suspect that everything is fine, just different from what you expected.

Regards,
Steve Stallings
PMDX
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  #5  
Old Thu 01 September 2011, 16:20
Richards
Just call me: Mike
 
South Jordan, UT
United States of America
Hi Gary,

That's good news.

Half-coil should work just fine. That's what I use on all six-lead motors. Either half-coil or bipolar-parallel can be used with eight-lead motors.

Given a few parameters, i.e. 1.25" pitch diameter on the spur gear, 1:1 ratio (no gear box or belt drive), you could use 509.29 steps per inch as the starting point. Use a very moderate acceleration value and see what happens.
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  #6  
Old Thu 01 September 2011, 20:44
Rusty Nuts
Just call me: Gary #86
 
Valley Grande, AL
United States of America
Quote:
Originally Posted by Richards View Post
Hi Gary,

That's good news.

Half-coil should work just fine. That's what I use on all six-lead motors. Either half-coil or bipolar-parallel can be used with eight-lead motors.

Given a few parameters, i.e. 1.25" pitch diameter on the spur gear, 1:1 ratio (no gear box or belt drive), you could use 509.29 steps per inch as the starting point. Use a very moderate acceleration value and see what happens.
Thanks Mike,

I will leave the steppers wired half coil as you suggested. If I remember the pinions are 1" dia. pitch but will have to double check. I"ll be using 3:1 belt reduction. I transfered the license from Mach2 to Mach3 without any problem. Was able to run a full cut file to check the steppers and all went great. I'm off work now till Tuesday and hopefully will have the MM moving on it's own by Sunday or Monday. Won't have any limit or homes switches to install as they will be added soon after getting the MM dialed in.

I'm here to tell you that one reading mistake (thinking I had read RPM instead of steps per second) really had me stumped. That just goes to show I have a double case of CRS (can't remember sh** and can't read sh**)

Gary
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  #7  
Old Fri 02 September 2011, 07:48
MetalHead
Just call me: Mike
 
Columbiana AL
United States of America
I asked Steve from PMDX about the 126 and he said the

SI12-C2 NPN NO H
and
SI12-DCE8 NPN NO H S

Can both be wired and powered by the PMDX-126 without the need of aditional Relays. Should help offset the added cost of the PMDX-126 over the PMDX-122
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  #8  
Old Tue 06 September 2011, 16:35
ger21
Just call me: Ger
 
Detroit, MI
United States of America
Quote:
Originally Posted by Rusty Nuts View Post
I believe I have read where Mach3 limits the speed in Demo Mode but I don't know how much.
Kernel speed is limited to 25Khz, but there is no other speed limit in demo mode.
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  #9  
Old Tue 06 September 2011, 19:37
Rusty Nuts
Just call me: Gary #86
 
Valley Grande, AL
United States of America
Quote:
Originally Posted by ger21 View Post
Kernel speed is limited to 25Khz, but there is no other speed limit in demo mode.
Thanks Ger

I transfered my license from Mach 2 to Mach 3. I upped the kernal speed to 35000 and made a big improvement. I have limited the top speed to 900 ipm.
although I was able to get over 1000. I'll have to experiment with actual cutting speeds to see what works best with each bit. My current home made router was only capable of 60 ipm. This is a giant inprovement.

What is everyone using for there acceleration setting when using gear reducers? I had mine too high to begin with and the granty jumped track on the first touch of the arrow key. I have it set now and everything is running smooth, wiil have to check to see what I ened up with.

Did an air cut this afternoon running a file which lasted about 30 minutes. Motors only warm.

Gary
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