Servo not tight as I'd like it - how to improve?

[energyforce]

Hey,

My total reduction is approximately 9:1 on the y axis. The reduction consists of pulleys-belt and sprockets-chain.

Youtube movie here shows how much the y axis moves when I put about 20 lbs of force on it. Crappy-ass dial indicator indicates about .08 of movement.

Movement is, for the most part, coming from the motor not being able to hold it tight (motor shaft is moving).

Is this bad or good compared to all them other homebrew router tables out there? How can I improve?

I know a ball or leadscrew system will eliminate this as it is not "load-reactive." But what else can I do?

Thanks...

[packrat]

This looks more like a back lash/ clearance problem in your drive. Roller chains are full of clearance and so are gear reducers. Are you using a rack and pinion? More back lash if not set-up right.

Even a acme screw drive (not a ball screw) would be better.

[energyforce]

Originally Posted by packrat This looks more like a back lash/ clearance problem in your drive. Roller chains are full of clearance and so are gear reducers. Are you using a rack and pinion? More back lash if not set-up right. Even a acme screw drive (not a ball screw) would be better.

Actually the motor is doing the moving, not so much the backlash/clearance. The motor is reacting to the load we are putting on it through the belt/pulley and chain/sprocket...

[ger21]

Can you explain exactly what the reduction is and how it's connected? And what size servos, and what drives?