Re: narrow timing belts- and old plotter conversion

Thanks Dave, I looked at SDP but I had got it into my head 2mmGT was
2mm wide and it is the pitch that is 2mm then I sort of missed the
1/8th wide stuff out of discust for my stupidity. I think that
could work.

Josef, thanks for the link. HP printers have very narrow belts but
I guess they also have encoders and spring tensioning so it makes
less of a difference.

As it turns out I no longer need the belts at all. Basically about
a year ago I rescued an A4 plotter/chart recorder from distruction.
This was pretty old but would still do the test page very nicely
however no drivers could be found for using it with a PC.

I came to throw it away this weekend as it is one of many rescued
items but I thought I should check it for decent parts. As soon as
I took the end off the box I couldn't throw it away. It contains a
really nice wire drive system which drives both sides of the gantry
and push-pulls the pen. All antibacklash and all really nice to
watch in action. Currently it uses a servo motor and a potentiometer
for feedback. I want to replace that with a stepper motor but the
servo couples to the drive via gears and these are not
antibacklash. I decided the best bet would be to replace gears with
a belt as antibacklash gears would be expensive. There is
insufficent room for a wide belt. As it happens if I skip that
stage and drive the pulley direct with the stepper I still get 0.1mm
(half step) resolution and with microstepping that will be just fine.

I intend to use is as a plotter but I will replace the sides of the
box with perpex to watch the mechanism and I have already stripped
out the origional electronics which will be replaced with a tiny
switched PSU I have and two microstepping drives I have spare.

A bit of fun really but it should also look pretty sweet and with
intergral electronics will be a nice stand alone plotter. It also
has capacitive paper detection as an added feature.

Cheers,

Graham