Is the 5HP Colombo too heavy for the gantry?

[stargategfx]

I took deivery of a new Shopbot a few months ago and love it...
With one exception; when cutting either tight radius corners, circles or right angles I seem to be getting a lot of "bounce" at the transition between Y and X movements.
I've been able to work around the problem by slowing the feed rates down to a glacial pace, but there must be a better solution short of spending yet more money on the PRT Alpha.
I can actually see the spindle assembly shaking when it makes these moves and all I can attribute it to is excessive flex in the gantry design.
Any suggestions?

[elcruisr]

Sounds like you need to tune your ramping values and possibly the circle tolerances. I also run a 5 hp spindle and have the same problem if the values aren't right. I'm not at the shop right now and recently upgraded to alpha step drives so I haven't got any numbers handy but a quick call to Shopbot ought to smooth those moves out.

Eric

[stargategfx]

Eric, thanks.
After re-reading my manual it sounds like you may be right about my problem.
Would it be asking too much to email me your preferred settings (Pre Alpha)?
bgodfrey@telus.net (mailto:bgodfrey@telus.net)
Also, do you feel the Alpha upgrade was worthwhile?

[elcruisr]

Very worthwhile for us. It's pretty much doubled our production and right now that's very important as we are cutting some very large orders. I used to think one order, that occurs about every three months, of 500 parts was big. Right now we are cutting an order of 80,000 parts. Pretty good for a 'bot! We've shut the mouths of more than one critic who says these aren't machines capable of serious work. When I get to the shop today I'll see if I've got those numbers around to e-mail you.

Eric