Touch Probe Install on NM-145

[cteufert]

Installing a Wildhorse Innovations Econo-Probe / Touch probe.

To make the installation quick and painless I choose to purchase a pre-wired stereo headphone cable from Radio Shack, PN 42-2492. The cable is 8 feet long and only 3-4 feet are needed so I cut the cable in half. The cable I purchased had the RED wire attached to the tip, the BLACK wire attached to the middle ring and the bare wire (shield) attached to the lower body.

A quick check on the CG11 Break Out Board (BOB) installed in the control cabinet showed only one input available, #15. I attached the RED wire to that terminal and the BLACK wire to the common terminal that already had a green wire in it. I used one of the existing holes on the connector plate to get the cable in to the cabinet. That is it for wiring.

The MACH3 configuration needs to updated to activate the probe input. Under CONFIG / Ports & Pins / Inputs you will find the PROBE entry. Enter 15 for the pin number and click the check box to enable it, leave the red X's active low and emulated columns.

To check that the probe is working the RED LED on it should be OFF when not touching anything and turn on when just barely touched. Mine came on without being touched but I wiggled the probe tip around a couple times and cleaned off whatever crud was on the contacts. On the MACH3 Diagnostics screen you should see the PROBE indicator turn on and off when you touch / release the probe. If you got the wires backwards the indicator in Mach3 will work but the LED on the probe won't.

Calibrating the probe is tedious as you have to adjust 3 set screws to align the probe to be centered under the spindle. WildHorse includes the procedure in the manual so I won't go over it here.

Once everything is installed and calibrated all you need is some probing software for Mach3. There are several versions out there. I tried a couple but decided to start with the screenset Hoss came up with last year. However there are a couple problems with it. Don't even think about using while your display has Machine Coordinates active it will move the axises in the wrong direction more often than not. It also assumes the machine is in G90 mode (absolute moves) but after probing it leave the machine in G91 mode (relative moves) so if you probe twice in a row the machine may move much further than expected. I re-wrote some of the code to solve the problems permanently but my code isn't quite ready for prime time yet. When it is I will likely post a a screen set with probing and a couple other features I am working on.

With everything together and running it sure is a pleasure to have the machine align itself over various features on what is being machined. Finding an edge, corner, center of a hole or center of a block are quick and easy. I will be working out using the probe to set tool height next.

Charlie.

[mvcalypso]

Charlie,
When reading your post, it sounded as if your desire was to make use of a probe rather than have to roll your own software. If you'd prefer a software package wich already integrates probing support, you may be interested in taking a look at MachStdMill at Calypso Ventures, Inc.

I believe MachStdMill (MSM) has the best probing support available for Mach. Of course, I'm the author so I suppose I could be accused of a slight bias...

Basic probing ops (edges, surfaces, corners etc) necessary for setup are in the release version, for the extended operations (pockets, post, valleys, ridges & A&B axis alignment), see the current beta release. The software also includes auto measurement of tools and setting of TLOs so it could save you that task also.

Dave

[t300]

Thanks for the writeup. Made it easy to get the probe working on my 145 last night. Used hossmachines screenset and we had to change the = to <> (or the other way around) as indicated on his website. Also added the "G20 G40 G49 G50 G80 G90" initialization string in mach.

[cteufert]

be careful... the macros programmed into the Hoss Screen set have an issue with what mode the machine is in when you start using the probe. The machine can be in either relative coordinate mode or machine coordinate mode. It will NOT work properly if in machine coordinate mode. About 1/2 the time the movement will be in the wrong direction and can actually result in the probe being driven downward far enough and with enough force to bend it.

Changing the = to <> solves one problem but still can result in movement in the wrong direction at times. Always make sure the machine is in relative coordinate mode before probing.

I have written new macros but have not completed the work on the screen set as of yet... too many other things to do. When done I will present it here.

Charlie.

Charlie.