Re: [CAD_CAM_EDM_DRO] Z axis servo reduction gear

Monitoring the temperature is actually a very good way telling if you
are overloading the motor. If you can't hold on to it, you have a problem.

> Are there any design rules or criteria that I could access because I'm going
> to have to do calculate the ratios for XY drives also.

How far do you want to go? Like anything, specifying motors gets more
complicated the closer you look into it. The most difficult bit though
is deciding on how much linear force you need on each axis. Once you
have that you can work out the required torque. You then need to decide
how fast you want the machine to move. Once you have these two you can
then work out the required motor specs and power supply size.

This is usually an iterative process. You go through the numbers then
tweak a few values and try again. For instance you may not be able to
achieve the required speed with your chosen reduction ratio. You then
need to try changing the ratio and see how that affects the motor
torque. Usually you end up with a compromise.

Les

Denis Casserly wrote:

> Hi Les
> thanks for the reply, I checked the Nook catalog where it specs the nut as
> being 36% efficient. I like worst case calculations too, so I think I'll go
> with a drive ratio of 1 off the motor shaft to 1.5 on the screw shaft to
> couple the motor to the screw. I think this will provide a safety margin.
> What would be a good way of determining I'd overloaded the motor?
> The only method I know is if it's too hot to touch, then it's overloaded. Are
> there any other methods to determine if a motor is being overload.
> Are there any design rules or criteria that I could access because I'm going
> to have to do calculate the ratios for XY drives also.
> cheers,
> Denis
>