[CAD_CAM_EDM_DRO] Re: Help with Renishaw TP1 Touch Probe?

>
>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.

Yes it is supposed to be there. In fact that is why it is sealed to
keep the lubricant in. The idea is to encourage the balls and rollers
to slide over each other. It also helps to stop surface films
developing on the far from perfect contact materials. I don't know
what oil was used when your example was made but you could try one of
the light switch lubricants. Now you know how to take it apart you
can always clean it of and start again if it doesn't work.

> 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.

Probably I suspect your unit is quite old. The drawings are all hand
drawn for this version and are not to clear. If it has a serial
number on it I may be able to find out more.

> 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.

On a CMM this would not matter much as the first thing you would do
is to calibrate the stylus ball position against the machine scales.
Regards
Bill

> 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
>