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Author Topic: phantom limit switch  (Read 10559 times)

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Offline Chip

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Re: phantom limit switch
« Reply #10 on: March 11, 2008, 01:01:30 PM »
Hi, Spiwrx

I'd check the laptop volt's any way, low volts to the opto diodes in the BoB  can cause problems also.

in Config, Motor Tuning, Set the Step/Dir Pulse's to 5, See if that helps,(It gives the OPTO's a little more time to see the Pulses)

On the Gecko's, It depends on the size of your steppers, There are some jumpers inside the box.

What's your power supply Voltage and amp's rating, It should be close to 75 volts minimum for top speed.

Your steppers should be hot to the touch after being on for awhile if your current resistor is set properly for your stepper's.

Thanks, Chip
Re: phantom limit switch
« Reply #11 on: March 11, 2008, 01:32:10 PM »
I have a solid 5v on the DIR and about 1.5v on the STEP.

From another post on this thread I suspicious now of the GND on the printer port. Would this just be common between the BOB and laptop/printerport or should/must there be an earth ground?

Offline docltf

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Re: phantom limit switch
« Reply #12 on: March 11, 2008, 01:42:12 PM »
HEY CHIP
         
           after reading your post in this thread and all the good setup info for the new users.and other post in the mach forum over the last 20 months.how come you and the
           other moderaters have not compiled this info under  the F&Q department for quick referance.

bill

Offline Chip

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Re: phantom limit switch
« Reply #13 on: March 11, 2008, 02:12:27 PM »
Hi, Spiwrx

Your BoB isolates the machine from the computer to protect the computer port's from machine generated spikes.

Both are/should be grounded to a Earth Gnd. at your power panel through,  Neutral and Gnd, Pin's, On Both.

Thanks, Chip
Re: phantom limit switch
« Reply #14 on: March 11, 2008, 02:22:22 PM »
There is no 120vac ground connection on my BoB. I doubt my Dell laptop power supply has a GND connection either.

I'll refer to the BoB manufacturer for direction.

Offline Chip

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Re: phantom limit switch
« Reply #15 on: March 11, 2008, 02:29:05 PM »
Hi, Bill

It's an all volunteer group around hear, I've started to several time's, Have a list I work from (Note Pad File).

Just haven't got around to it, No Good Reason.

Thanks, Chip, 
Re: phantom limit switch
« Reply #16 on: March 11, 2008, 02:43:21 PM »
BTW, my motors are NEMA 23 269in/oz and have ratings of phase current = 4.2 amps & phase resistance = 0.46 ohms
My power supply is measuring out at 44vdc..

Offline Chip

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Re: phantom limit switch
« Reply #17 on: March 11, 2008, 04:29:58 PM »
Hi, Spiwrx

With 45 volts your not gong to get top speed, The faster a stepper goes, More volt's are needed to keep the current/speed up.

When the volt's top out the stepper will start to lose there Torque/slip, So basically your losing about 30-40 % of your top speed.

What are your current Velocity and Acceleration, Sounds like you need to reduce the Velocity some more.

Yes some laptops don't have Ground's, But there even more isolated, Don't think this is the problem though.

If you have a variac and your gecko power supply is Transformer type.

You could see the difference by boosting the power supply primary volts up some "temporarily" and see the difference.

Thanks,Chip
Re: phantom limit switch
« Reply #18 on: March 11, 2008, 05:29:56 PM »
O.K. I can try that, I have another transformer but we calc'd the output to near 78VDC and the drives are limited to 80 so I opted for this other I had laying around , however just for good measure I did the Driver test again and now I have crazy spikes.....

Almost a solid wide black line...

Perhaps I didn't have the driver loaded properly on the previous test???

What can be done now??

I was shooting for crazy high speed, I just really want the motors to smooth.

Offline Chip

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Re: phantom limit switch
« Reply #19 on: March 11, 2008, 06:04:51 PM »
Hi, Spiwrx

78 volts is at the top, But Mories at gecko drives, Sed there drives have 100 volt mosfet's in them.

Thy de-rate them so people won't use over 80 volts, Safety margin, And need a Good Heat Sinks.

That's 80 volts 7 Amp's, 560 Watt's, You would be at 80 volts 4.5 Amp's, Watt's 360

Rutex another MFG. Rates there drives at 100 volts, Thy Both use the same type Mosfet's.

If you don't have another computer to test then go through this Link.

http://www.machsupport.com/optimisation%20XP.txt

It describes things to turn off in windows, do some of the first items then re-boot and try the driver test again.

See if Quick-Time is installed, It causes problems also.

Thanks, Chip