I would like to switch to using a touch probe instead of the touch plate - would save some time, especially once ATC comes out. I was looking at the ones on Centroid’s website, but I am not sure which one makes the most sense to buy, or if there is a third party option that is superior or has better value, or is even compatible.
Centroid’s offerings: CNC Touch Probes for Digitizing, Part and Tool setup. Renishaw and Marposs Alternative for Haas, Fagor, Fanuc, Mach3
Any recommendations?
Get the KP1
It requires two inputs. (One for the probe and one for “probe detect”) the second one is optional for extra protection.
They sell it with an Avid plug already.
The software for the probe is already in our wizard.
I use the Centroid KP-3 and love it. Also buy yourself a setting ring. Software will calibrate the probe diameter and store it in the tool library.
The Centroid stuff is more expensive, but CNC12 is designed around it and their stuff is really well built (in the USA).
Setting ring is key.
You can calibrate your probe using the BORE probe routine. Or if you dig in the NCfiles directory there’s a probe stylus calibration utility that does the same thing, but automates if for you
(this will be a first class citizen on our next update)
Thanks guys.
Is it possible to run the cable for it through the X and Y cable tracks so that its always near the spindle?
Most time consuming part about using the touch plate is unraveling/raveling the cord for it, if I had to do the same for the touch probe it wouldn’t save much time.
Are there any wireless probes that would be compatible?
It won’t be long enough. I’d suggest you get in touch with Centroid regarding splicing. Their cables seem to have shielding. IDK if there are any special considerations.
Last I checked on wireless probes, they are sort of hard to come by inexpensively. I get the sense they are tricky to implement well. Centroid had been working on one and shelved it.
You can run the cable however you’d like. You will just need one that’s long enough. You can order the right from us: M12 Proximity Sensor Cable | Avid CNC
Look in the Centroid schematic repository, it shows all of the probes they support.
https://www.centroidcnc.com/centroid_diy/schematics/pbrowse.php?term=probe
The centroid one won’t be long enough, but it’s got an M12 connector on it. You can use any of our sensors cables (linked above) to extend it.
There was another company that made one at one point, it got shelved as well. Wires work. 
Would you need A M12 panel mount connector to get it into the box?
It goes into Aux 5 so if you have that plug you are good to go, if you don’t you’ll need to get a panel mount from us.
I ordered and received a KP1 probe from centroid. Can you clarify the pinout or wiring directions for AUX 5?
I should add, I selected the avid option at checkout and was expecting a M12 connector. I actually got a bare wire USB-C wire.
So I have:
(1) red
(2) green
(3) black
(4) white
Thanks
You can hook up probe detect if you want, you’ll just have to pick another input to use. You could use input 7 as that’s meant for the plasma torch.
There’s also a feature in the probe setup that will put it into “probe detect” mode when a certain tool number is selected. Not quite as safe as wiring it in, but pretty good.
@Eric could you please advise on what length cable I should get for a 5’ x 10’? I’ve just ordered the CNC so I’m not sure how long the extension cable should be.
I’ll be ordering the KP-1 probe this week from Centroid.
I believe you want a 28 footer (our longest cable)
On a 5x10 that will get you from the control box to the Z axis. If you have a smaller machine you can always coil up the excess.
20 ft is just a little short for a 5x5 so I’m going longer! ( Plugs are on the front now)
Off topic: Why are you having to use the touch plate so often? If you store an offset you should be able to recall it and use it again and again.
But yeah, I want a probe too for the times I do need one!
Until some shop monkey changes tools and forgets to update the tool table.
Or the tool wears down.
Or breaks.
For my scripts, the tool length is a hint - if it’s set, the machine can optimize the time taken to re-measure the tool, else it takes the slow cautious path. But it always measures a tool it just changed too.
Then today this happened:
I had to restart the machine’s controller (linuxcnc) and forgot to remove the tool (or tell the machine that it still had a tool in the spindle), and when it tried to “change” tools… it just drove the installed tool through the new one. (no real harm done, due to breakaway mounts and foam floors)
DO NOT TRUST THE SHOP MONKEY.
corbin:
If you store an offset you should be able to recall it and use it again and again.
Until some shop monkey changes tools and forgets to update the tool table.
Luckily, Centroid allows one to “lock” an offset table, not allowing the user or GCode to change it!
Or the tool wears down.
Or breaks.
But yeah, you can’t stop user-error or failures. I was thinking of adding a per-tool option to “always re-measure”.
For my scripts, the tool length is a hint - if it’s set, the machine can optimize the time taken to re-measure the tool, else it takes the slow cautious path. But it always measures a tool it just changed too.
Then today this happened:
I had to restart the machine’s controller (linuxcnc) and forgot to remove the tool (or tell the machine that it still had a tool in the spindle), and when it tried to “change” tools… it just drove the installed tool through the new one. (no real harm done, due to breakaway mounts and foam floors)
Shouldn’t LinuxCNC remember the tool in the spindle across reboots? Centroid (and some scripting) can do this.
But yeah, always touching off is the safest!
Corbin
What I ended up doing for my ATC code is this: I use the tool numbers to encode how to deal with them. The tool number tells you if the tool should be measured or not, if it does in a pocket or not, etc. I.e. the laser’s tool number says “no pocket, don’t measure”, the 1/4 bit says “in pocket, measure each time” but the 3" slabber is “in pocket, don’t measure”
So you can’t fix the table if you change tools? That’s the opposite of helpful.
Something for me to research, I’m sure. I typically unload any tools before parking the machine for shutdown, so I wouldn’t normally have the chance to find out. There’s a chance that darn shop monkey told the machine the spindle was empty when it wasn’t.
@corbin I am usually doing triple ops these days- top, bottom, rotary.
G54 is set to the top of the workpeice, so needs to be remeasured every time.
G55 is set to a permanent jig cut into my spoilboard with holes for dowels, these holes are also cut into the top of the workpiece in g54 so the flip is perfectly aligned in XY
Measuring the top as a new g54 and then having g55 set to the bottom (top after flip) means my stock doesn’t have to be the exact right z-height (within a couple mm) in CAM or in reality and it will cut correctly. Takes out some z error that would happen if g54 and g55 were both set to the work surface and the stock height didnt match CAM exactly.
Then G56 is always set to the front of the rotary chuck jaws-- so nice these days with the THS because I just have to measure the tool and I am good to go for my permanent work offsets.
Sorry, I mean “WCS” offsets, not “Tool” offsets!
