Stuart Stevenson wrote: > Gentlemen, > The cinci is a very heavy machine. I have noticed no klunks or > noises during homing. The B axis has a problem though. I have had to > open the following error tolerance. When the B axis hits the home > switch and starts to move away it oscillates a large amount (a degree > or two). The control seems to catch it and then the homing finishes > just fine. > I had to move the home from the B positive limit switch to a home > switch with the B axis vertical. With the B axis homing on the > positive limit switch the weight of the head is hanging on the servo > system. About 1 time out of 4 the head would seem to overpower the > servo system and fall to the positive hard limit. The drive gear would > be off the rack. > Maybe this is the answer to my B axis homing question. I thought it > was probably a tuning issue as I see none of this action on any other > axis. The normal noises probably mask a lot of 'things'. My recollection is you have Gettys phase-controlled amps on that machine. They have VERY limited bandwidth, maybe 60 Hz tops. This klunk issue is a one servo cycle pulse on the command out, and so a large part of that is going to just disappear as your servo amps can't respond to anything that fast. But, it could be enough to upset a servo that is marginally stable. To try it out, you need to update to the recent development head and then add a couple lines to the hal file to link the index-enable net to the pid's index-enable input for each axis.
Jon ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
