Re: Help with Renishaw TP1 Touch Probe?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Graham Stabler" <eexgs@n...>
wrote:

>
> the reply to my post was post number: 71142
>

Thanks for looking that up! The follow-ups to that post have some
very good (and important!) information. I'll look up the patents next...

Gram, Jon, and Bill,
Thanks for taking the time to reply to me. You all have been a great
help.

After getting the probe apart, there was some obvious corrosion on the
balls. Q-tips and isopropyl alcohol cleaned them up. Put it back
together, and, well, only slightly better. I took it back apart this
morning for a better cleaning. There seems to be some sort of light
oily substance in there. I hope it wasn't supposed to be there,
'cause it's gone now! I have no idea how it could have gotten in
there. This thing is sealed air tight. I soaked the gold springs in
alcohol and cleaned up every surface with more q-tips and alcohol.
The plastic tubes that held the springs had that substance in it too.
The springs seem not be symmetric. One end looks like a "normal"
spring (the coils are flattened out, so it can stand on end if set on
the table), the other looks like it was just cut off. I put the flat
ends in contact w/ the PCB, and the "cutoff" ends in contact with the
ball bearings. Hope that was right... I figured the PCB needed more
contact area in case the spring just so happens to touch the solder
part on the PCB. I used "Tech duster" to dust off and dry everything,
and touched as little as possible with my fingers. Long story short,
it seems to work now. I thought I still found a few dead spots (where
it was showing open circuit with nothing touching the probe), but it
seems to be less often with time.

I was hoping to use this probe for edge finding when setting up my
stock to be milled. The shank has a lot of adjustment; will take some
fiddling to get the tip concentric with the shank. I hope the tip
shaft is parallel to the shank, otherwise I don't think I'll have much
hope of using this as an edge finder. I bought one of those $20
electric edge finder, but was quite disappointed that the tip had no
'give'. I think I already screwed that one up a bit due to poor
electrical contact and a low battery. If you buy one, right away
replace the battery with a "real" one.

Thanks again. I'm planning on posting the schematic I come up with
for the probe circuit when I'm done.

Steven Ciciora