Hello Guest it is May 20, 2019, 01:03:33 AM

Author Topic: Touch Probe Problem  (Read 4274 times)

0 Members and 1 Guest are viewing this topic.

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: Touch Probe Problem
« Reply #10 on: January 19, 2014, 08:39:38 AM »
LOL - Hey Kolias it's your gig, your free to do this however you like.

You posted a link to your manufacturer's manual and refered to page 9 fig 8. For some reason you've decided to ignore it and come up with your own scheme - that's cool - nothing wrong with that per se, but here's a couple of questions for you.

Q: In THEIR scheme what happens if you accidentally earth your clip or if your tool is grounded (which they often are and worse intermittently)

A: The probe input is activated, Mach lights a LED and it gets better - if you're probing - Mach stops.

Q: In YOUR scheme what happens if you accidentally earth your clip or if your tool is grounded (which they often are and worse intermittently)

A: Absolutely nothing (to alert you) and it gets worse - if you're probing OR go on to probe (because remember you've had no sort of indication) - Mach just carries on and probes it's way through your table. Sh1t you say to yourself as you race for the E-Stop - maybe I should have listened to that tosser Stirling.

Personally I do it slightly differently - I reverse the scheme in your manual and ground my spindle with the clip and I put my plate onto the input. Why? because then I don't care if the spindle is grounded by itself or worse intermittently grounded because I now KNOW it's grounded. Of course this only works if your table and work are not metal and grounded but that's the case here. Anyway - even if you have a metal table, you can't have the plate AND the tool at ground if you want any "ohmic" contact scheme to work so you're going to have to insulate at least one of them and the plate is usually easier.

The point is, EITHER way you do not need a resistor - you're better off without it. In yours the only reason you need a resistor is (IMVHO) to bandaid a poor solution.

But like I say - do it any way you like - it's your gig.  ;)

Offline kolias

*
  •  1,011 1,011
    • View Profile
Re: Touch Probe Problem
« Reply #11 on: January 19, 2014, 10:30:33 AM »
I wish I understood what you are saying Stirling but unfortunately I don’t. As I mentioned before, my knowledge in electronics is very basic and therefore I can't grasp your ideas

Terms like pull up, pull down, earthing, ground etc is so confusing to me and at my retirement age I don’t fell like going back to school to educate myself LOL

For convenience, I have a DB9 connector on the side of my machine where I plug the probe when is needed. After I set my height, which only takes a second or so, the probe is unplugged. So I can't imagine any situation where my probe will probe its way through my table. But I will be more cautious now you mentioned that there is a possibility for this to happen
Nicolas

Offline RICH

*
  • *
  •  7,330 7,330
    • View Profile
Re: Touch Probe Problem
« Reply #12 on: January 19, 2014, 01:36:39 PM »
Quote
at my retirement age I don’t feel like going back to school to educate myself LOL

Fortune cookie had the following:

Wise man once said, that learning never stands still, the mind will progress or regress, it's a law of nature that one must
accept, so it is that the flower either blossoms or windles and dies.

FWIW......... :D
Stay with us now....... ;)
RICH

Offline kolias

*
  •  1,011 1,011
    • View Profile
Re: Touch Probe Problem
« Reply #13 on: January 19, 2014, 03:50:34 PM »
LOL RICH, that's a good one

But… I do progress my mind with the mechanical side of a cnc and just a tinny tinny tinny bit of electrical.

Besides that, lots of wood working projects around here to keep the flower blossoms, lol
Nicolas