Quote Originally Posted by m_c View Post
Without seeing the videos (my broadband is currently not working, so am limping along on mobile broadband), if you're using a parallel port, you really need to use a charge pump for safety, regardless of what software you're using. As Clive has already said, parallel port pins can act randomly during loading. If the BOB you are using has no charge pump, the easiest option is just not to power up the machine until the computer is fully loaded.

The Clear tecknic servos do seem good, however you have to remember as they need the step/dir signal directly, it adds in a lot of extra potential for interference and losing/missing steps. If I was to use them, I'd be looking at adding differential signal drivers to avoid potential noise issues.
Plus I think they're more closed loop stepper, than what's more commonly referred to as a servo. Good in the fact they're better for direct driving ballscrews, but does mean top speed is limited.

Performance wise, you're more likely to be better of with some good Nema23 motors, and adding a 2:1 drive ratio. Nema 34 really need high voltage drives to get the best performance from them.
Thanks for the reply. What's a "charge pump"?

Re Clearpath - they are true servos rather than hybrid servo/steppers. I take your point about interference. I might pose the question to Teknic and see what they say - they've been really helpful so far.

There seem to be as many opinions about drives and motors as there are drives and motors. I did canvass this forum and others quite extensively before buying drives and the consensus seemed to be that Leadshine AM882s at 70v was the way to go. Still, the Z axis is fine, and the X&Y drives can be redeployed. If I do make some change to the X and Y drives it will be to servos - not poncing about with these poxy stepper things any more