Hi, good post, fun to read and very interesting, will look at this MPG, look great.
What was the price of yours including board, and everything else
First of all, this is what I'm referencing:
Homann Designs MP-03 Pendant Kit
I mentioned some time back that I was going to be getting one of these, and I did, but I haven't been well lately had hadn't had the time to do much of anything. This last week I've been dealing with a stupid ear infection too, and getting antsy, so I figured a little soldering might do me good. With that in mind if I sometimes seem out of it over the rest of this post you'll know it's me, not you.
So first off let me just say that I've got this completed and it took about 3 hours with me being sick so it's not too big of a project. To top it off I LOVE this pendant, at least so far - I've only used it for a couple hours playing around. But it tickles my gadget fancy and really does have me excited.
If you've ever worked on electronic projects you know none are ever totally complete - largely due to the fact that most projects allow one degree or another of flexibility in the build, depending on what the user wants the "kit" to do. This one is no exception, however I'd say it's 95% complete. That makes it great for a "beginner" level project. That said, if you hate soldering don't get this kit.
So before we delve into the build, what are the functions available for this pendant? Peter Homann covered this in this zone thread (Mach3 ModIO Handheld Pendant), which is actually where I first heard of it and became interested. You'd be well advised to check it out. I'll highlight that besides the usual functions it has the ability to use custom functions.
So, on with it. Looking around online I found there really isn't much on the actual build & install. There's this page which isn't complete yet, and a few posts here and there. If I could say there's 1 problem with this kit it would be that it could be confusing to someone without electronics experience trying to assemble it. It's supplied with a wiring diagram & some pics of the case and the parts mounted in it, but really that's not where most would have a problem. It's with the wiring. I could see someone who could finish this in a few hours spending days messing with it because of not being familiar with electronics. So hopefully this post will help any of those who may be around...
The first thing, if you're like me, you'll do when you get the kit is open it up and look at the goodies for a while. And here's what you'll see (once again, excuse my terrible pics):
Now, if you wanted to get the kit routed you could have that done at purchase time for an extra $8. But I wanted to play with the mill, so I didn't bother with that. Also note that you don't necessarily need to order the LCD, and that you COULD have ordered an optional "latching" E-stop switch, which you would then normally hard-wire as outlined in the Mach documentation to cut power to the axes & spindle. I had no need for the switch since I'll be standing next to the hard-wired one on the mill. You still get a momentary software E-stop.
So if you didn't get the case routed that's the first thing to do. Peter supplies some g-code files for the cutting, one for the latching E-stop and one for the momentary e-stop (don't use the wrong one!). If you want to use his code you'll need an 1/8" endmill. He also provides a DXF if you want to generate your own. I just used his...
This might be a good time to note that if you just received your NM-200s2 ensure the axes are properly configured. I think I may have mentioned that in another post, but when I received mine everything was wrong, but not obviously so. It was cutting inches in metric mode, so inch mode was WAY off. As well the speeds & acceleration needed to be adjusted. Just follow the instructions in the Mach3 setup to set it up, and note that the screw pitches are all 5mm, as noted on Novakon's website.
In this next pic you'll see the origin location:
Note that it's centered over the corner of the edge where the heights drop off for the recessed section. I zero'd the Z to the recess. The Kurt works fine for holding it as long as you're confident in how much you should tighten it down. It's actually sitting on the vise ways.
A couple of things to note: I think, judging from some comments I've read by Peter elsewhere, that the g-code was generated to be milled on a Taig or Sherline. At any rate, the feed rates are VERY conservative, to the point I was afraid the plastic would start melting rather than cut.. I overrode it to 200% and it was better, though it probably could have been higher. The spindle speed was fairly low too, so that affects it. If I were to redo it I'd probably look up the plastic type & the suggested feedrates. It's also a very conservative DOC, doing most holes in 4 passes IIRC, including the final cleanup pass.
As for the second note, take a look at the part fresh off the mill first:
Notice the 2 small holes below 2 "medium" sized holes, just above the cutout for the rotary encoder. Look oblong? That's because they are, but I have no idea why. I'm guessing because of the switches normally being installed slanted (see below). The code starts with a hole drilling, then moves at full depth on an angle for a short distance, probably about 1/8". The finish location is the actual correct hole location. It's for a locating pin for the 12 position switches. At any rate, if you want you can edit the G-code to remove this, though it doesn't really cause much problem & it is covered.
Now we need to do some modification to the inside of the top of the case (the part you machined). As mentioned above, if you installed the 12 position switches as-is they would be tilted because of 2 extrusions of the plastic:
So cut them off:
Next we modify the bottom of the case. You have the option with this kit to locate the ModIO board in the case or at the mill. I figured, as most seem to, that it's easiest/best to locate it in the case & bring power up to it. If that's what you're doing you first need to locate & drill 4 holes for the board (see below for pictures of the mounting orientation - you can mount it differently, but this is the way a fellow zone member did his and I liked it).
Before doing that, though, you need to remove 2 more extrusions. I didn't realize this at first. I had intended to mount the board spaced off the back of the case with the little plastic mounting clips (similar to what comes with a motherboard) that came with the board. However there isn't enough room to allow the case to close. So first remove these 2 extrusions:
Then mark & drill for whatever screws you'll use to mount the board. Technically the board can't really go anywhere, so you probably don't need this, but I did it anyway. Note that you will need to supply the mounting screws/nuts!
Then drill the bottom for the cable:
Next we can populate the top with the hardware. You only need to be aware of the location of the red pushbutton switch, and the red vs. green LEDs. I kept the anodes & cathodes of the LEDs oriented the same way for simplicity:
Here's a pic with cut-down resistors soldered to cut-down cathodes. One thing I would have done differently is to have bent the leads of the LED 90 degrees and soldered to it horizontally. I didn't realize at the time now close the fit would be. As it was it all fit, but it could have been better.
For simplicity sake I tried to keep things color-coded. Red=+ve voltage, black=gnd, white=LED "signal" side, green = switch/pot signal. Note you will have to supply your own wire, as well as shrinkwrap if you're using it!
So here's the white lines connected to the (cut down) resistor leads:
Here's the red wires supplying +5V, which I took from pin 1 of J1. Note that I left the rotary encoder off as I wired it to +5V on J10.
Now is just as good a time as any to mention this oddity:
That's the potentiometer. Typically you'd only see 3 pins. What's with the 4 pins??? One is a dummy pin. I believe it's the leftmost pin, but ohm it out to see for sure. If you're not familiar with potentiometers, between the center pin (signal) and the other 2 "outer" pins you should get a rising resistance on one pair while you get a corresponding falling resistance on the other. The center pin goes to pin 5 of the ModIO. One of the other 2 gets +5V, the other ground. Which gets which? It depends on the logic, if it's going high (+5v) or low (gnd). If you wire it wrong the pot will work backwards. I actually had this problem. Just switch the wires around.
Moving on, here's the black (ground) wiring as well as the green (signal) from the potentiometer & the 2 12 position switches.
Notice that the ModIO board is now mounted. I'd suggest for when you're doing this that you remove the screw terminals from the board (the blue strips on top & bottom). They pull up as a long strip - work it a little at a time from either end. Then when you get it wired you can plug it back in.
Here the rotary encoder has been wired:
Now you install the serial cable into the bottom hole you drilled for it (through it's holder/tail, obviously). Now we get to wiring the signal lines for the rs-232 & the power lines. Again I chose red & black for power, and arbitrarily chose blue, yellow, green for signal. For simplicity's sake (and because I didn't have a second one available to use for connecting to the PC) I chose to cut off the 9 pin serial connector and wire it directly to the cable. Here you see the equivalent of pins 2, 3& 5 (from L-R) exposed on the 10 pin wire from the header on the ModIO board:
FYI, in case you're not aware, the pins in the cable bounce back & forth from the top row to the bottom, so 1, 6, 2, 7, 3, etc.
Here's the communcation & the power supply wired. I used some more single-strand wire to go from the serial cable to the screw terminals because I was concerned the wire from the serial cable wouldn't hold in the screw terminal. Note that if you end up using crimp connectors you'll need to supply them!
Now with the LCD installed here's everything together:
The completed front:
Now we get to the NM-200. I drilled a hole in the bottom of the electronics cabinet, installed a grommet, and ran the wiring in. I ran the wiring up to around the area of the serial port & connected the wiring via crimp connectors to match the signal lines in the pendant. But what about power? The manual specs 8-24V DC or 6-12V AC supply, with higher voltages risking higher heat produced in the case. The easiest source for this is the computer's power supply. Cut a yellow & black line (one at the end of a run so it doesn't have 2 wires going in to it - otherwise everything past that connector will be dead), attach a couple of connectors, and you've got power. Alternatively, and even better, would be to use one of those molex power adapters typically seen on auxillary case fans, which usually run at 12V, such as seen on this fan from Newegg. I literally used to have hundreds of them when I was doing some different work. Unfortunately I don't have any lying around anymore, and there's no local source. So the plugs it is!
From there it's just configuring the software. The "driver" is on the included CD. That said, I couldn't get into the configuration manual without first running through the Getting Started section of the ModIO manual (up to the point of hooking up some LEDs, and note that I didn't bother making a copy of the configuration). Then you can go into the plugin configuration, click help, and it walks you through all the rest of the steps. Sweet!
Anyway, I hope that helps someone. I know this post doesn't really show much as to what the pendant can do, I'll leave that for someone else, or perhaps I'll post some vids later on. But it should give you some idea what's involved with setting this up.
Next on my to-do project list is to get that 24k RPM spindle I mentioned before and install that. I'll post when I do.
Last edited by JoeBean; 10-21-2010 at 07:55 AM.
Hi, good post, fun to read and very interesting, will look at this MPG, look great.
What was the price of yours including board, and everything else
There seems to be something wrong on the HomannDesigns website with the shipping estimator. It's giving an error in shipping calculations and saying $26 flat rate, at least on my iPad. It actually cost me $52 to Canada, for a total just under $320.
One of the things I didn't mention is the function of the LCD. Besides displaying positional info it labels the 3 buttons below it, which vary in function as you rotate the left knob, and can display custom labels for your custom button actions. Without it I would probably want to do some sort of reference label to mount in it's place.
I'll see what I can do. I added a few custom commands, one for GoTo Zero which I use a fair bit, and one for auto Z zeroing with a temporary setup I've been testing based on systems posted here. I'll hopefully finish it up soon and take some pics/vids of it and the pendant in action. Been busy lately though...
I agree with speedscustom, more pics and vids
Keep up the good work!
Ok, so here are a few pics and vids showing a few functions. The first pic here is of the simple modification made to the basic Mach screenset allowing you to see what functions are available with the right switch in it's current position. The LCD display for the button functions only changes with the change in position of the left button, so that's why this is necessary. I actually don't find I look at it much now that I'm familiar with the functions.
Here's a pic of the overall pendant. I should mention that the overlay is something I whipped up in my preferred 2D cad and layout software (PowerCADD) and printed on a full sheet transparent label, then cut the holes out and affixed it to the pendant. It was just supposed to be a test to see how well it would stand up (thus the terrible wrinkling) but it's actually held up so well I haven't bothered replacing it.
As well, I should mention that in order to get the multiposition switches to work right I had to modify the resistance values in the pendant's software screen as there was some overlap (basically the SW is looking for a resistance in a range, say 200-1200 ohms, for position 1, and the switch's PCB simply adds resistors as you turn the knob. So if position 1 is 1150 ohms actually read in the pendant's screen set it'll be so close to the next switch that it can cause the software to think you're on position 1 instead of 2). This was a very simple thing to do, but I was getting Y and Z randomly swapping back and forth when I first was trying to jog the axes.
And here's a closeup of the LCD and the list of "standard" functions (ie. what each switch under the screen will do when pressed) depending on the left button's position.
Here's a vid from youtube showing me going through some functions of the pendant (spindle operation, jogging axes, running a very boring cycle I realized after, etc.). The original software that came with the pendant would not allow completely smooth jogging, but that's since been fixed, and the vid is with the new software.
[nomedia="http://www.youtube.com/watch?v=H5BoDWSb9cY"]YouTube - 004[/nomedia]
And here's a movie that simply shows the feedrate overide. I have a fairly wide "dead zone" in the middle of the potentiometer's travel, that's why you see it slowing down or speeding up then jumping to normal, then slowing again or whatnot. I did this simply because I'm a klutz and after the 5th time scurrying around trying to figure out why the program wasn't running at proper speed (all slow, and all on plastic nonetheless - quite a mess) I modified this. Again, that setting is in the pendant's software.
[nomedia="http://www.youtube.com/watch?v=s9wb54iZo90"]YouTube - 005[/nomedia]
As I get a chance I'll add some more.