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Author Topic: Spindle speed control  (Read 2477 times)

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Spindle speed control
« on: May 29, 2013, 08:16:53 AM »
I got quick help last time so here's another one.  My board outputs a 0-10vdc signal for spindle speed control, what do I need to get to convert it to replace the existing speed pot on the drive? Here is the drive specs.
Thanks,
Don
« Last Edit: May 29, 2013, 08:26:55 AM by DonMarkey »

Offline zarzul

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Re: Spindle speed control
« Reply #1 on: May 29, 2013, 09:51:32 AM »
Don,
Not easy to determine with the limited information,  do you have mfg & model of controller? 
I suspect it would be the common on the black wire, and 0-10v+ on the white wire, but can't be positive without more info.
If you have a multimeter measure the black to white as you cycle speed up and down, that will give you further confirmation.
Re: Spindle speed control
« Reply #2 on: May 29, 2013, 10:01:16 AM »
It is a 0-5vdc the drive is looking for not a 0-10vdc so I assume I need something to convert the signal.  I could pull the drive and see if there is any more info, but that's all the doc I got with the unit. 
Don

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Re: Spindle speed control
« Reply #3 on: May 29, 2013, 10:07:12 AM »
a lot of the breakout boards can be scaled for something less that 10v.  But I don't think it would matter,  you could make a simple voltage divider of 2 resistors of equal resistance across the output of your breakout board and tap into the center for your output to your motor controller.
Re: Spindle speed control
« Reply #4 on: June 17, 2013, 08:40:22 AM »
Ok bear with me, I am an industrial electrical but it been a long time out of school and don't use ohms law much in the field as 99% of the time I deal in high voltage AC.  So I put two resistors in series across the breakout board, this drops the 10v to 5v across each resistor. I remove and eliminate the constant power lead off my existing speed pot. Then the old return from the pot ties into the center point of the two resistors and the common to the common on the breakout? Anything I need to do about grounding the commons? I assume just simple 1/2watt resistors, any value matter as long as they are the same?  Someone else told me to just set the max speed to 50% in motor tuning.  If I go this route how do I set it up in mach3.  I am new to mach3 and been getting along so far by trial and error and what I read here.
Thanks,
Don
Re: Spindle speed control
« Reply #5 on: June 29, 2013, 08:12:18 AM »
Ok now I am not sure what the heck is going on with this drive.  I install the new board and the spindle ran faster than the max it would with the pot.  When I was checking what wire was what with the pot in place I had 5VDC btw P1 and P3, P1 being the neg side.  On P2 I had the varing voltage so I assume that's the wiper.  I removed the pot put P1 and P2 on the boards output (after tuning it to 5V). Mach didn't vary the speed but mach did control the board properly.  So I go to check my wiring again, I disconnect the wires from the board but didn't reconnect them to the pot and turns on the drive.  The motor came on, I wasn't expecting that without anything connected to the give a signal to the drive.  While running I put my meter (digital) on the wires to verify what is what and as soon as I did the motor sped up.  So was that the meter signalling back to the drive?  Anybody have a clue to this before I put the thing back together with the pot so I can get a couple jobs out this weekend?  I assume I just have the wires mixed up and need to pull the pot out and see which is the wiper for starters (not the easiest to get to and just went by the factory wire tags were at a splice point) but started thinking maybe this drive is different that I thought.
Thanks,
Don