Hi there,

My conversion of my Proxxon MF70 is nearly complete.
Now I'm looking at setting up an edge finder so I can zero my machine to the material I want to process.
I've been searching this site and others on how to do this with Pokeys, but can't find anything on this subject.
I did find a pin setting, "probe" , this is probably used in digitizing an object, but can I use this pinsetting for edge finding as well?
I also read that you need a VB script for Edge finding, but this is probably a question I need to ask in a different forum. New to VB scripts...
Any help and advise/examples on how to do this is very welcome.
Hope that someone can give me push in the right direction!

Thanks in advance!!

Greetz,

Tom


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Hello Tom:

A recent addition to Mach3 functionality is the "Probe-It Mach3 Wizard", produced by CraftyCNC.
see:  www.craftycnc.com

The cost for license is very reasonable, and the functionality is the best I have seen. The author has devised a method for creating an automatic  offset table, that will correct for the probe offset differences when probing at different angles to a plane, using a ring. He has videos on the site demo the machine probing around an object, and producing a true dxf file automatically.

The Wizard has all the typical probe setting functions, i.e., finding a corner, center of slot, etc.

The probe function is supported in the Pokeys drop-down menu when setting the pin I/O. The Pokeys will do every Mach3 function DRO there is.

John

Hi John,

Thanks for the info, looks interesting!
Certainly going to take a closer look at this. I'm probably not going to do anything with 3D digitizing, but maybe in the future when I have fully come to grips with mach3 and its possibilities.

Many thanks!

Greetz Tom



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Hello Tom:
The probe function is used perhaps more often for 2D edge finding, and part/tooling placement. A probe is an "edge-finder" and not specifically for 3D work, although it can do that.

One of the problems with probing a part for dimensions, is the diameter of the probe tip not being in a 90 degree alignment to the surface relative to the motion of the probing motion. In the case of the Crafty-CNC wizard, the probing action determines the slope of the surface by comparing two points and then correcting the angle of the machine axis travel to be 90 degrees to the surface, and then using the look-up table to calculate the actual point of contact. Every probed point is compared with the previous point to constantly re-calculate the slope of the object surface. This is a quantum step forward in the method of probing when digitizing a shape.

Another method of "edge-finding" is to use a Laser probe, and watch for the beam of light when it illuminates the material edge.
This kind of edge finding is totally manual, and has no way of becoming automated.
Such an edge-finder is sold by http://www.littlemachineshop.com, but it is as costly as a probe, and only does one thing. It also, is not as accurate as using a probe.

My final point is to mention the Mach3 screen set, "2010 by Ger." This screen set has built-in tool setting routines, using the G31 Mach3 probe function and custom scripts written specifically for the task. This is a handy feature when you don't have fixed toolholders, and must change tools in the spindle collett. Although the screen set was developed for routers, it is very usable for milling, and is elegantly clean and simple. Look in the Mach Screens section of the forum. I use it on my mill, and appreciate it's simplicity, and visually clean look.

Regards,
John

You could also look at this thread: http://www.machsupport.com/forum/index.php/topic,22888.10.html

I posted a VB script there for tool height setting.  I also have a script for edge finding using an isolated-tip probe that interfaces to the offset screen (replacing the macros it normally uses); and one for hole centre finding; which I'd be happy to share.  Why use Pokeys?  Just need to use the probe input on your BoB.

John

Why use Pokeys?  Just need to use the probe input on your Board.

It was my understanding that the OP is using a Pokeys board for control and I/O.

John

Hi Guys,

Been kind a busy last couple of days, Thanks for all the input you are giving me! Really appreciate it!.
It is as John (mr Precise44) stated in his last reply, I'm Using a Pokeys card as my BOB/pulsegenerator coupled to 3 Postep 25-32 driverboards.
The reason I chose this hardware is to keep cost down, since I'm new to CNC machining as well as the USB functionality with MACH3. Don't have a computer/laptop with a LPT port. Further more it seems like a good little bit of equipement, in everything I read about it. Secondly, I could use it as an input device for MS FSX (flight simulator.)
Pulse engine is doing fine for my learning purposes. Allready have my axis setup and running. Even made a couple of brackets to to mount my CB 4 pin connectors to. Digital inputs however is begining to be a bit of a pain in the behind.
Some how I can't get the limit switches on the X-axis setup correctly(no input output signal in the pokeys plugin screen. During every fase of connecting and setting everthing up hardware wise, I got good read outs o the diagnostics page of MACH3
All the limit switches are wired and as recommended bij Polabs set up pull up resistors in the circuit. Soldered a 15 pin D-SUB connector (female) to all the wires in the circuit. Every switch has 2 separate wires allocated. Measured everthing though and got a good connection. Even had 3 pins left so reserved 2 wires for the probe option.

I downloaded MACHBLUE screen with the MACHBLUE edge finder addon, Got on to this after a google search leading to an Aussie guys post.
Wired the hole thing up, to be able to implement the probe function. Did not want to have to take everything apart again.
The LEDS in MACH3 diagnostics screen even worked ok, got a green led on closed circuit, even in the pokeys plugin configuration it came out alright.

With the Machblue screen addon it should be possible to use the probe function, didn't work hoewever. Looking at the script in the vB script editor. I noticed it was written for Inches not mm.
Like my machine is setup for. Just now I read another post in a different forum here, that this script is no longer compabile with the latest version of Mach3.

Problem still remains with the probe function not working propperly anymore. yesterday I got it to work, the led indication on the diagnostics screen that is..
I by the way the probe circuit is wired NO and does not have a pull up or pull down logic circuit(wouldn't know how to do the latter.

John H thanks for the input and I will take a look at the VB script you posted.

Any ideas on matters above?

Greetz,

Tom

Hi, Tom

You should configure the limit switches in the 'Pulse engine' tab - do you have the latest PoKeys software and firmware 3.1.6 installed?
For testing, click on 'Open status' on the 'PoKeys IO status' tab in plugin configuration. Do the appropriate inputs light up when limit switches are activated?

For NO contacts, it is advised to use additional pull-up resistor to either 3.3V or 5V. Again, check 'IO status' first if probe signal is detected, then check Mach3 signals for probing.

Regards,
matevž

Hi Matevz,


I updated to version 3.15 yesterday when I opened PoKeys program, thought that was the latest version, but I'll run the update again when I finish typing this.
I haven't configured the switches yet, because I still get a bad signal on my X-axis switches. but I am aware that the pulse engine tab is where to do that.
the x-axis limit switches are not giving the right signal.
The Y and Z axis are working fine.
When I measure the wires of all the axis at the Pokeys pin and ground  with my Multi meter (pokeys not powered), I get good signals for every limit switch (beep when NC, no beep when NO).
The same goes for the probe pin.
When I power my pokeys up with the USB, The Y and Z-axis and Probe give me 3.3V when NO and drops when NC. Which is how it is supposed to, Right?
On both + and - X limit wires there  is no change. In the Pokeys I/O status tab I get a green square on the + (with switch NC) and a blank square for - (with switch NC), when I push either switch, there is no change.
All the other switches are blank squares with switch NC. and green with switches NO. (which is how it is supposed to be, right?)
The problem with the x-axis switches, seems to me like there is a short somewhere, but like I said I, I measured all the wires and they where good.
I wil update to firmware 3.1.6. and than check everything again.

One last question, Is it ok to deviate from the standard limit switch pins assingnment to say for instance pin 22 to 28? That would make wiring everything up a bit more practical.

Hope you can shed some light on my problem

Greetz,

Tom

Hi, Tom

Since the updated version of the PoKeys plugin for Mach3, there is a possibility to fully customize your limit switch wiring (with manual as the guideline). Try other pins if it solves the problem. Do you have anything other mapped to the non-responding pins? How are they configured in PoKeys application (try clearing all settings there and checking the pin states again).

Regards,
Matevž