Stepper Motor Shaft Binding

[edellison]

hello and thanks for looking, my newest project involves a stepper motor (15in/lbs torque) driving a shaft with 2 u joints to a power transmission feed through then to another shaft with 2 u joints and finially to a fixed shaft with a bevel gear driving another shaft and sprocket with a bevel gear at 90* to the other gear. it works when the motor is connected by only 1 shaft and a pair of u joints. in service it binds and doesn't always work. is there any way or tricks to tell where or what is binding without guessing and randomly removing anf replacing parts.

 

[pablo02]

I suspect it may be a combination of all of the parts: the u-jounts will tend to bind slightly at given angles and the beveled gear requires so many in-lbs itself to function -- you may be using up all of your torque... but this is a guess since you haven't provided any dimensions, etc...

 

[unclesyd]

I think "pablo02" has got you answer.
Just one little question are the U-Joints in phase and operating within their design limits?

 

[Barry1961]

You might be able to try measuring the mechanical slop at different points in your linkage with a finger type dial indicator.
Reduce the torque(voltage)until the the system binds then try to gently back drive it. Compare the mechanical slop at different points, the joints under strain(up stream) should have less slop than a joint(downstream) not under strain.

Barry