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Jack, I operate a JEOL 8200 Superprobe but have not had the problem you describe. I don't know how different the 8200 is from the 8600. I have the joystick incorporated into a knob-set and it does not use a USB connection to the computer.

I may have had similar problems with other stage drive systems. It may sound like gears slipping teeth, but the problem was usually that the stepping motors were driven too fast. The pulses were coming too fast for them to respond. Sometimes only half or less of the pulses were effective. The solution was to limit the maximum pulse rate to what the motors could reliably handle. I don't know if that is the same problem you are having.

I would think the joystick would have little to do with the root problem. Perhaps it has failed in a way to call for a faster stream of pulses whereas the computer-controlled motion is limited to a slower rate. Maybe you can simply try another joystick and see if it solves the problem. I would be interested in seeing the pulse stream being sent to the motors. I don't know how easy that is to check.

You say that the stage gears like to slip by several mm. I don't understand that. If it is under joystick control, how do you know how much it is slipping? Wouldn't you just hear the slipping and guess that the motion would normally have been good for several mm? Don't the actual stage coordinates get read from an encoder?

Could it be that the driver hardware is failing? We blew a big filtering capacitor in an old stage driver a couple of times. When it failed, we could coax the stage along at very slow speeds but high speed motion was gone. Again, maybe the joystick and computer call for different speeds. Maybe the computer rates are slow enough - for now.

Warren Straszheim
Ames Lab probe lab and
Materials Analysis and Research Lab
Iowa State University

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From: JEOL-Focused Probe Users List [mailto:[log in to unmask]] On Behalf Of jack hietpas
Sent: Thursday, June 09, 2011 10:31 AM
To: [log in to unmask]
Subject: [PROBE-USERS] JEOL 8600 joystick

JEOL Probe Users Listserver

Moderator: Ellery Frahm, [log in to unmask], Electron Microprobe Lab, University of Minnesota

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Hello Everyone- at Syracuse University, we a JEOL 8600 Superprobe.  We are having difficulties with the joystick, the stage gears like to slip (at times several mm) when moving the stage with the joystick.  Whenever we let the computer move/control the stage (i.e. overnight runs) we don't have a problem, so it seems likely that the joystick is the problem.  I was wondering if anyone knows were we could purchase either a new one, or a new used one?  The joystick has a male USB connection, which connects directly to the Dell computer (running Geller software).  We do have a joystick from a JEOL 733, but it has a male 15-pin D-sub connection, has anyone had experience with D-sub to USB converters? These cost only ~$20 on amazon.  Thanks very much for any help you can provide.

-jack