How Sloooowwwww Can you Go? 🐢 (Probing Speed)

[[Je...]]

 

Let's suppose for a moment that your measuring task requires scanning very small, intricate surfaces in high density.  Assume that cycle time is not a priority.  You're emphasizing slow, accurate scans.  You may even scan the singular workpiece overnight.

How slow can a Vast XXT fixed mount probe, such as those on an O-Inspect, scan?  Granted that stylus length and weight as well as probe size are considerations.  Assume that the probe shaft including extensions is less than 40mm, oriented z-, and the probes are small: 0.3mm to 2.0mm.

Is there an optimal range for balancing surface scan stability and point capture?  Are any undesirable mechanical forces introduced at very low speeds?

Industry usually focuses on cycle time optimization and fast scanning, but where are the limits of capability on the other end of the speed spectrum?

I'd love to hear your thoughts on this.
 

✌️ Jeff Frodermann

[[No...]]

One thought that immediately comes to my mind is static friction. By default Calypso filters out the first few points of each scan, and one reason is static friction. If you scan REALLY slowly, you might come to a point where static friction comes into play again and the probe might move more or less in tiny jumps instead of a continuous smooth movement, thus impairing the results.

Edited May 21

[[Jo...]]

Interesting consideration indeed.

I would assume that zeiss has some guidelines for their sensors where you might find clues.

Otherwise why not take an adjustment ring or something else you know the form and size of and let a program run over night with increasing speeds.

If there are relevant factors at super slow speeds you should be able to detect that and you might find the "balance point" if existing. 

[[Ch...]]

I'm with Norbert.  If you keep slowing it down, at some point I would think static friction comes into play.  I'd love to see you run this test and see if it really happens.  

[[Ja...]]

For scanning speed/data density for our machines here, I won’t go with a step size that’s less than 0.001mm / 0.00003937”. The drive motors sometimes have trouble if I go much below that.

[[Ch...]]

a bit off track here, but if speed limit says 55mph and I am only going 2mph, am I breaking a law ? j/k I think there is a minimum requirement  😁

 

Great question Jeff, I have measured a few things I can recall where probe was so slow I could not see it moving (mainly small radii I believe)- with no issues Im aware of ...

 

[[Ja...]]

Believe it or not, I met somebody once that got a ticket for going too slow. It was considered a safety issue, and obstructing traffic.

[[Ch...]]

I set all my programs to Sunday drive mode 😀

 

\\Sunday Drive Mode, hey they're paying me double ;)
if DayOfWeek=="Sunday" then
 set InspectionSpeed("turtle")
endif

 

[[Ri...]]