Re: [CAD_CAM_EDM_DRO] EMC Acceleration

Jon Elson wrote:

> I've always felt the default values were very high. In
> inches, turn it
> down to about 3 to start with, and listen for the acceleration ramp.
> You should
> definitely hear the ramping up and down with that setting. (For mm, try
> 50.)

I agree that Sherline's EMC default acceleration is high. The values
that you suggest are much better than the defaults but may also be a
struggle for the Sherline mill.

I usually allow a full second to ramp up to the max speed of 20 inches
per minute. That is 20ipm/sec or about 0.333 inches per second squared
or about 8.4 mm per second squared. This allows a definite sound as it
accelerates over a 1 second interval.

When 0 to 20ipm in 1 second is a problem I start looking for mechanical
binding or driver problems. But those are pretty much ruled out since
TurboCnc works ok here.

FYI, if 1 second to accelerate is not a problem and I am impatient I
might set it to a higher value but I have found little gain by doing so.
1 second to full speed is my rule of thumb for my Sherline mill.

Tom Hubin
thubin@...