X axis - 2 steppers 1 gecko ?

[andy_ck87028]

Hi All

Can I use one gecko and slave another stepper off it?

Either I have one 400oz stepper with belts either side of the x slaved together through a rod on the gantry or I buy 2 identical ( =>200oz ?) steppers and use two identical ball screws.

I would prefer not to then have to buy another gecko so therefore is it possible to share the gecko across two identical motors?

I'm sure there will be voltage (and hence power losses) in which case what is the practical approach to this problem?

Cheers

Andy

[jeffserv]

I believe you could have 7 steppers hooked to one drive. If they are not loaded to beyond the amount of current the drive will handle. The G201 will handle 7Amps. If each motor on each ball screw only has a max of 3.5 amps then you could safely use two motors. If you verified that the load on each motor in your system would not draw any more than 1 amp you could put 7 of them on one drive. There are a lot of factors that put a load on the motor. The size of the ball screw, its resitance to turning... which is small in most cases. The type of bearing of your screw and carriage. The weight of the carriage.

The negative to using two motors would be there power. A 4.5 amp single motor that has 400 oz inch torque would be my choice over two motors that only have 3.5 amp ratings at say 150 oz inch.

Contact Marice at Gecko drive for the best tech. support on this issue... He is always glad to help.

And real world experience is also the best way to learn. Build your carriage and try out both senarios. Not hooking up the motors permanently. Most manufacturers will except returns with only a small discount when returned.

One motor is simple, the simple solution is usually the best. The other issue with two motors is How will you recover or resychronize them if one side gets out of wake... You would need permanent marks that you could see... so you could put them by hand without power back in sync... With one motor this is not an issue.

Go one motor... it will be better... although you could do the other. The other will be more hassle, most likely less power, and cost more in the end to mount and wire.

Good Luck,

Let me know how it works.

[ger21]

Mariss recently posted on his Yahoo group that it will work at slower speeds, but you may start seeing problems above the 180-300RPM range.

[andy_ck87028]

Thanks guys

Exactly the response I needed

Andy