Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: nissan20det on January 30, 2016, 07:03:42 PM

Title: Here it is the first piezo touch probe...well that I made..
Post by: nissan20det on January 30, 2016, 07:03:42 PM
Okay guys here's the first piezo probe I made yesterday. I think its freaking awesome!!!! You say .1mm for that switch,  this is like purely just contact!!! I think it'll work great, what do you guys think?


https://www.youtube.com/watch?v=ell4Q1IH_XA (https://www.youtube.com/watch?v=ell4Q1IH_XA)

Damn I forgot to put that in vid, It works touching down as well!
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: BR549 on January 30, 2016, 07:28:40 PM
What is teh overtravel limit before it breaks something. The faster you probe teh more overtravel occurs.  Also Mach3 is not 100% perfectly dependable in teh G31 and sensing teh signal what happens if it blows through teh stop ?

Might want to plan on a torque limiting feature of the  arm to prevent it getting torn up and an overtravel event.  Also a secondary STOP signal is good IF by chance it did blow through teh G31 trip. 

Just a thought, (;-) TP
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: RICH on January 30, 2016, 07:37:52 PM
Hmm...
My probing is setup such that you manual get close to the work and then start the probing at a rate which will not over travel on touch.
The probing  rate is an input / can be changed to suite your nerves. Beats bending once and coming back to confirm at a slow rate.
But it's for the lathe.

Job gets done and nerves are calm! ;D

Just a thought........
RICH
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: nissan20det on January 30, 2016, 08:05:35 PM
No thats a good thought. The final product will probly need a break away... Maybe the rod can be breakable? Like on a ball so it rotates all directions but kinda snaps to center? Total deflection is probly .010in before it permanently bends the Piezo disk, or cracks the ceramic element on top.

But what do you guys think? Cool, Stupid , waste of time.....
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: RICH on January 30, 2016, 08:18:03 PM
KIASAP......................

Keep It AS Simple As Possible

Too much stuff for me in that one, BUT, that's just my opinion FWIW,

RICH
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: nissan20det on January 30, 2016, 08:39:46 PM
I'm confused way to much stuff ? It's literally a housing a piezo disk a rod and a ball. The circuit it a bit much but I'll scale it back and size it down quite a bit. Whole circuit will fit in housing and be the size of a pinky nail.
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: bfgstew on January 30, 2016, 08:40:46 PM
How about this, maybe a bit overkill but darn accurate!

http://www.homemetalshopclub.org/news/12/presentation_1202.pdf
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: BR549 on January 30, 2016, 09:20:37 PM
I think it will be a great idea (;-) TP
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: Davek0974 on January 31, 2016, 03:49:24 AM
Man, do i want a cnc mill :)

I'd convert the Bridgeport but I doubt the backlash compensation runs to 1/2" ;)
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: BR549 on January 31, 2016, 02:40:40 PM
DAVE , don't do it  >:D  Once you slig chips with a cnc mill you WILL throw rocks at your plasma cutter.

(;-) TP
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: BR549 on January 31, 2016, 02:43:04 PM
One other thing to think about in your design. You NEED a way to center the tip on the centerline of the mounting shaft(spindle).

(;-) TP
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: Davek0974 on January 31, 2016, 04:02:21 PM
;)
Title: Re: Here it is the first piezo touch probe...well that I made..
Post by: nissan20det on February 01, 2016, 12:47:48 AM
LoL I was thinking about that right when I chucked it... I need help with some ideas on how to center the probe. One thought was to use a Piezo ring that has a holw in the center, using the hole to bolt the probe to, but I cant seem to think of an easy way to have that adjustable wile assembled. Maybe like four set screws on bottom and on top, tightening two washers together pitching the Piezo... :( Sloppy but it'd work...

I'm leaning towards the same design as shown, the probe being bolted, or soldered like it is now, to the center of Piezo, then making the ledge where the disk rests slightly large(instead of exact fit like now). The adjustment would be snugging the Piezo retainer(threaded instead of pressed) and  just enough to get a little movement to tap it to center then tighten it down once centered? or have the adjustment just tilting the Piezo slightly maybe....

What do you guys think?