Strange Probe Issue

[andy_con]

got a strange issue

when I first set my probe up I had the second touch as f50, then after a few weeks I got an error on the second touch where it said it couldn't find the surface. which was odd as the probe had stopped against the surface and it had been triggered.

this has since gone on and im now on f90 for the second touch.

when I put in anything lower the f90 I get an error saying cant find the surface despite the probe being triggered against the surface.

any clues?

[DaveCVI]

Hi,
Are you running imperial or metric units?
F90 seems very fast for a 2nd touch operation if that is inches/minute. I assume the 1st prove feed rate is even faster.

When having problems with Surface not found like this, the issue is usually noise on the prob line or to sl;ow a feed rate and you are getting contact bounce. These symptoms are described in section 8.11.1.1 of the user manual.
In general working thru section 8.11 of the manual will idenitfy problems and get the probe feed rates set up for a specific machine.

Dave

[andy_con]

should have said sorry, metric.

ive got a renishaw probe.

but why wont it let me use a slower one? once I get this error I can only pick a higher number not lower?

will have a look through the manual

[DaveCVI]

Hi,
I tend to think in imperial units so excuse me while I do some conversions...
F50 metric is about 2 ipm - In my experience, that's way too slow for a 2nd probe feed rate.
I usually do my first probes at 40 ipm or about 1000 mm/min.
Now I've never had the pleasure of having real a Renishaw probe, but on the cheap probes I have, if I go any slower than about 15ipm (381 mm/min) for the 1st or 2nd probe feed rate I get exactly the problem you describe due to contact bounce effects. Teh exact sequence of events that is happening in this case is laid out in section 11 of the manual.

I know it's counter intuitive, and everyone wants to run their probes really slow for fear of breaking one, but the fact is that slower is now better below some level. I suspect the low feed rate is the source of the issue - work thru section 11 of the manual step by step and you'll find what rates your probe likes to run it.

Re "not letting you set a lower rate" - MSM does not restrict the feed rate that can be entered. I'd need to see a screen shot of the message that says it won't take a rate to track that further.

Dave