Probe Interface Board Design (resistance switching)

jmelson wrote:

No, I have a Blum TC50 probe.  It uses IR to communicate, runs off a 9V battery, and takes fast pulses of IR to turn on/off, and then the probe output is very similar to what you describe.  But, it uses a short cone segment attached to the probe fitting, and that is pressed down on another code segment for centering.  Any deflection of the probe lifts the cone, and a rod breaks a laser beam.
This scheme removes the3-lobed pattern of sensitivity with the Renishaw balls and bars design.  Not that that pattern is anything I'd ever be aware of on my machine!
Jon

 

Ah, something like this? With the bar (or something poking out the top) to break the laser beam.
 
Makes a whole lot of sense if you can keep out anything that might set it askew. I don't think my machine would notice the pattern either!

fletch wrote:

jmelson wrote:

No, I have a Blum TC50 probe.  It uses IR to communicate, runs off a 9V battery, and takes fast pulses of IR to turn on/off, and then the probe output is very similar to what you describe.  But, it uses a short cone segment attached to the probe fitting, and that is pressed down on another code segment for centering.  Any deflection of the probe lifts the cone, and a rod breaks a laser beam.
This scheme removes the3-lobed pattern of sensitivity with the Renishaw balls and bars design.  Not that that pattern is anything I'd ever be aware of on my machine!
Jon

 
Ah, something like this? With the bar (or something poking out the top) to break the laser beam.
 

Makes a whole lot of sense if you can keep out anything that might set it askew. I don't think my machine would notice the pattern either!
 

Yes, that is the concept.
Jon

The Mostly Printed Probe is now officially a side project...
 

All the stl files are now on github: github.com/Stutchbury/MostlyPrintedProbe (there is a mag-safe version in the works).

I will write a print/build guide soon, but enough distraction for now, back to the interface board!
 

Well, someone had to try it out on a real CNC... Up until now I've been using a bench fixture & wedge to control the contacts & opening speed for the probe interface board.

www.youtube.com/shorts/06nPOA94Pbk

I am pleasantly surprised by its competence - I repeated the probe 4 time and was within 0.002mm each time. Yes, that's way beyond the limitations of my machine and yes, the plastic will likely move with temperature and humidity changes but hey, it's a Mostly 3D Printed Probe!

That is impressive, for sure.
I have to remind myself to build one ... or 12 !
Right after i finish my mill ... started gathering parts several years back...