gecko resistor need verification

[dertsap]

ive been running gecko 201 drivers and just needed to make sure i m using the proper resistors to run my 4 amp 3v motors ,
at half winding on a 6 wire motor i should be using a resistor rated for 4 amp Right ???? 63k is what ive calculated ?
the reason i ask is i here crackling in the motors after they move to position , they have been run on a number of occasions and i don t see any problems , though the motors do get warm , but the heat is more due to the voltage i m pumping to these motors (i assume) , they are 3v motors that are being run at 56v
any input would be greatly appreciated
thanks
curt

[dertsap]

earlier post i referred to a crackle from the motors , but after farting around with the motors last nite it is more of a sizzle .
is this the excess engery that is built up in the motor dissipating

[leberen]

dertsap, are you still having this problem or is there a post I missed where it was resolved?

[dertsap]

everythings ok , the resistors are right , apperantly the sizzle is from the chopper disipating the current ,
thanks for the reply

curt

[Madclicker]

Sizzle? I don't hear anything out of mine. If I remember right the chopper rate is 20 khz.....well out of my hearing range I guess.

[dertsap]

the noise is in the motor when the motor stops not the driver itself , it s the best explanation that i ve got within the posts , anyone who may be able to explain differently would be greatly appreciated , everything is connected 100% right ,ive ran at different voltages ,and the same sizzle is in the motor when it stops , works fine so i take no real concern , or should i ?

[Madclicker]

About concern, I have no idea. This is the first time I've ever spun steppers. All I know is I have 3 completely different steppers, all run by geckos, and there's not a peep out of them when they aren't moving.

[leberen]

I have a checklist of things going on in my mind, maybe they can help: How are the steppers mounted? Have you cleaned the signals in software? Is the sound apparent at all speeds or at the greatest feedrate? Steppers are bipolar right?

[Madclicker]

Originally Posted by leberen I have a checklist of things going on in my mind, maybe they can help: How are the steppers mounted? Have you cleaned the signals in software? Is the sound apparent at all speeds or at the greatest feedrate? Steppers are bipolar right?

Boy, this has me spinning. What would mounting matter? How do you clean signals in software? He said the "sizzle" was after the move. Better be bipolar...paid good money for gecko's

[leberen]

motors could be creating harmonics when given the right set of opportunity, a consideration if its a retrofit. In Mach software, a user can use motor tuning for optimal feedrates and output. Both can be caused after moves. Just considerations for troubleshooting. should it be okay for the steppers to receive 56V though rated for 3V, regardless of current regulation?