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Help on attaching threaded rod to motor Answered

Hello all quick question for you: what is the best way to attach a threaded rod to a motor shaft. This would be similar to a CNC setup. I know you could use a dual shaft collar but I was wondering if there's perhaps a simpler solution?


The cnc machines I've worked with weigh as much as a car, have a full horsepower or more on the cutting head, and perhaps 1/4 horse on the x, y, z feeds. That stuff requires a solid connection.

But... If you are doing a little desktop cnc 3d printer, you could attach the motor to shaft with surgical tubing. This sort of connection allows flex, so the alignment of the axis of the allthread and motor shaft doesn't have to be perfect. you'll need some sort of bearing on the allthread, of course.

the best way? pull the motor apart, chuck the shaft in a machine lathe, and cut threads into the shaft.

if you want a merely adequate way, how many hp, or how many amps is the motor? how much load will be placed on it? will there be abrupt changes in torque, like a tree chipper or lawnmower exerts on a shaft? if the power take off is not perfectly centered on the motor shaft, will you regret it? is there a flat on the motor shaft? a keyway?

For absically and motor shaft type you can get the right coupler.
Usually stepper motors are used, which have a great variety on couplers available to check.
Most simple solution for bigger motors is a double plate with rubber blocks in it.
Allows the shat to move a few mm in all direction to avoid vibration or problem with the alignment.

You have to have a solution that can take the torque without it ripping apart. You could build up a collar with some epoxy putty but unless the shafts are rough, it will eventually slip. Good luck.