[tas99]

I'd like to add a probe to my recently deliverd NM-135 and take advantage of the G31 code in Mach 3. I've tried numerous e-mails and phone calls to Novakon for help, all to no avail. Hopefully I can get better results here.

I will add that I'm satisfied so far with the mill and all the help and quick responses I've received from Khai but support is not his area of expertise. After all that I am surprised that their support is so lackluster.

Anyway, to my question. Is there a simple way to get access to the breakout board and add a wire to one of the inputs? I have a CD-100 with an integrated PC and the documentation doesn't give me that much information on this area.

I was also wondering about the interlock switch on the door in front of the spindle. It never did much - the unit seemed to work with it open or closed - and after hitting the arm twice I removed it and isolated the wires. I can't determine if one of these wires is an input to the breakout board. If it is it would be a perfect answer to my problem.

Can anyone provide any assistance?

Tom

[Frogblender]

Probing: rather than dig around in the electronics in the back of the mill, I just bought another PCI parallel port card ($7 or so), stuffed it in the computer, and connected my touch probe there. Mach3 handles two parallel ports, no problem. This ranks as perhaps the easiest thing I've ever done with the mill; it just works. I have future plans to use output bits of this port to control a pneumatic valve or two, shopvac for a vacuum fixture, etc.

As for the spindle guard: this was removed, along with the coolant tray, within about 10 minutes of mill delivery. In Mach3, Alt-7 - you can see what the parallel port bits are doing in realtime, as shown by the green boxes. Twiddle the interlock switch (or any other switch) to see what bit flips.

[David Da Costa]

Tom, the CD-100 has the C11G breakout board from CNC4PC.com, it should be a simple matter to add the probe to this card, in fact that is what I am going to be doing.

Here is the details of the board plus the manual http://www.cnc4pc.com/Store/osc/prod...products_id=46.

Section 7.4 talks about connecting a tool setter (or probe).


The spindle guard is not connected and I removed it anyway as it gets in the way.

David

[slatronic]

I looked at my C11g board today and there is an open input. Pin15 is open. There are also the two white connectors at the back of the mill. I think they are inputs but I'm not sure. Gotta look into that. Another thing is if you have the CD-100 w/ computer upgrade there should be an unused parallel port on the motherboard. Just add a C10 board from CNC4PC. They are fairly inexpensive. Plenty of outputs and inputs then.

My setup is NM-135 w/ CD-100 and computer upgrade by the way.

[tas99]

For now I took the easy way out and just used pin 15 on the breakout board. After assigning the pin#, enabling the probe input and making it active low it seemed to work. I could stop the movement by touching the wire to the bed of the mill.

But, the longer I played with it I found that it would stop randomly. I could see the input and digitize lights activate when I touched the wire but so no indication of and activity during the random stops. I thought I might have an intermittent short to ground somewhere along the way but found none and as I said, I see no indication with the lights. I'm wondering if I have a noise problem? I used just a single wire for the input because that's what everyone recommended.

Has anyone experienced this or have any suggestions?

Tom

[Frogblender]

For now I took the easy way out and just used pin 15 on the breakout board. After assigning the pin#, enabling the probe input and making it active low it seemed to work. I could stop the movement by touching the wire to the bed of the mill.

But, the longer I played with it I found that it would stop randomly. I could see the input and digitize lights activate when I touched the wire but so no indication of and activity during the random stops. I thought I might have an intermittent short to ground somewhere along the way but found none and as I said, I see no indication with the lights. I'm wondering if I have a noise problem? I used just a single wire for the input because that's what everyone recommended.

Has anyone experienced this or have any suggestions?

Tom

I'm not sure how your cnc4pc board is wired; in my case my "probe" is just a piece of wire connected directly to a spare parallel port input. The wire needs a pullup resistor to keep the input HI unless the wire touches to GND. I had the same kind of intermittent problem as you, but making the pullup stronger fixed everything.

[slatronic]

tas99,

Take a look at Hoss's site. Lots of good info on there. Here's a thread he has on his own forum about his touch probe. He used a 2.2k resistor for his pull-up and .1uf cap between +/- near machine. From my basic electronics knowledge usually 10k resistor is normal for pull-up resistor. This way when you see a 10k resistor you can normally assume pull up or pull down. I think the C11g board has internal pullups and pulldowns. Just need to set jumpers. My guess your weird stops are coming from noise. Use a cap in there. You can pick them up at most radio shacks (The Shack).

http://www.hossmachine.info/
http://www.hossmachine.info/forum/ya...ool-Probe.aspx

[slatronic]

Here's a little more info on pull up and pull down resistors. About half way down page they go over using pullup resistors. Also the Arduino boards are a great way to get into electronics and learn some programming. I haven't thought of anything yet, but I'm guessing you could use an Arduino with CNC. Lots of digital inputs and outputs all through USB. I know the small 3d printers that are getting popular use the Arduino board as their controller.

http://www.ladyada.net/learn/arduino/lesson5.html

heres a link to reprap. this is an open source 3d printer. pretty cool. a bit of topic but i think fits in with cnc.

http://reprap.org/bin/view/Main/WebHome

[tas99]

It seems like it was a noise problem. I took a look at the line with a scope and the noise and spikes were unbelievable. One mistake was to route the probe wire along with the motor control lines. It made for a neat installation but what a noise disaster.

I ended up rerouting the wire as well as replacing it with shielded wire grounded at the breakout board. I'm not sure what helped the most but the noise was dramatically reduced. If I'd read the capacitor idea I'd probably have thrown that in for good measure but it seems to be steady and reliable now.

Thanks to all of you for the help.