Mach 3, Gecko's and BP sigma steppers?

WYO_123

20

Mach 3, Gecko's and BP sigma steppers?

« on: April 02, 2007, 03:08:18 PM »

Hello,
Is there anyone else with this combo that can help me out on IPM and Accel for these motors.
I am retrofiting a series II BP mill, My gecko's keep faulting and I have no idea what these motors should sound like.
Thanks

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Hood

Re: Mach 3, Gecko's and BP sigma steppers?

« Reply #1 on: April 02, 2007, 04:25:41 PM »

I would imagine they should sound like any other stepper, a very musical whine varying in pitch with speed. Screams are out as that is them losing steps. Try setting the Velocity at around 50 IPM and the accel low then increase the Accell until you start losing steps then back off a bit. This should get you going and after a while you will find out what steppers sound like and you can start increasing the Vel and messing with the Accel to find the sweet spot for your setup.

In what way are your Geckos faulting? something doesnt sound right there, mine have never faulted but as I dont use the original Bridgeport steppers I dont suppose its really a relevant comparrison.

Hood

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WYO_123

20

Re: Mach 3, Gecko's and BP sigma steppers?

« Reply #2 on: April 02, 2007, 04:39:19 PM »

They just stop working, I have to cycle power to get them to work again.
I thought I read somewhere that they some kind of diagnostics. They also have a reset term that I think would probably reset them without having to cycle power.
Any ideas as what might cause this?
Thanks

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Hood

Re: Mach 3, Gecko's and BP sigma steppers?

« Reply #3 on: April 02, 2007, 04:42:30 PM »

mmmmmmmmmmm could be the geckos are just too small for the high current requirements of these motors. You could try putting in a current limiting resistor to see if that changes the faulting. Obviously you would be limiting your motors torque but it might be an idea just for testing.
Hood

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WYO_123

20

Re: Mach 3, Gecko's and BP sigma steppers?

« Reply #4 on: April 02, 2007, 04:53:27 PM »

Yeah that could be, they are wired in parrell I could probably rewire them to series and this would give more resistance.
I think the drive thinks it is shorted. Are there any other drives out there that can handle more power?
Thanks

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Hood

Re: Mach 3, Gecko's and BP sigma steppers?

« Reply #5 on: April 02, 2007, 05:17:56 PM »

Here in the UK there are Chinese drives that supposedly handle 7.8Amps but its not much of an increase. Not really sure what others are out there, maybe someone else will chime in with info and reccomendations.
I think there are a few guys using the geckos and the sigmas/superiors, in fact I am sure JohnS is using the Geckos with the same motors on his Beaver mill, might be worth giving him a PM.
Hood

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