I am working on getting everything calibrated and going today! I have built the frame and have gotten all of the electronics run. I will probably be asking questions and checking this thread throughout the calibration process. I have the pantograph kit installed on my sled and it looks like its working great. I am on version 99 of Ground Control as well as the Audrino source code. The first question I have on the pantograph kit is how do I know if I need the radius in Ground Control set to 5.25" or 5.375"? I’m guessing that has to do with the extra link of chain?
My second issue is when trying to measure the motor distance with the chains. The instructions say to wrap the chain on top of the right motor and to go underneath and over the left motor. If I set it up this way, when I click “Pull Chain Tight”, the left motor turns counter clockwise and the chain just falls off. I tried swapping how the chain wraps around each motor and I can then get it to pull tight, but the value it produces isn’t logical (-3900ish mm). I hand measured my motor distance to be 2954.33mm. Any help would be great!
You need to start with the chain on the left sprocket as it shows in the pictures. You then feed out the chain using GC until you can put it over the right sprocket as shown in the pictures.
Chain on left sprocket in starting position:
Chain on right sprocket after you feed it out and attach it :
You then press “pull chain tight”. The chain should be on top of both sprockets.
Ahh, Thanks! I’ll give that a try and see where I end up!
I have gotten pretty good results from 5.375" rotation radius. The auto-calibration process should help you dial that in further if need be. You could also try both values and cut out a 6" square. If the X and Y distances don’t match, you can tweak the radius/motor spacing until it’s better.
Thanks, I am now using the 5.375" measurement. I just completed steps 1-9 of the calibration, On step 10, I have run into an issue though. I selected Triangluar on step 9 so I am cutting my two test lines and got a measurement of 1191.60mm for my distance between the lines. When I type in that value and then click the “Enter Value” button, I get the cannot find chain lengths error and I am told to recalibrate chain lengths. Is there something I need to be doing differently? The lines it cut look correct and it moves along the cutting surface smoothly.
Firmware and GC version 1.0 comes out tomorrow and they include a number of important fixes to improve the calibration process.
One of the issues which is fixed has to do with the inches to mm button not working in step 10 which I think might be responsible for the issue you are seeing. The problem is that the button works (switches the reading from mm to inches) but the text does not change so it’s possible for the machine to think you are entering a distance in inches while it still says mm. When the distance of 1191.6 inches is used it becomes confused.
Since you are in the middle of calibrating right now I’m happy to make a pre-release version of 1.00 and send it to you right now
Firmware and GC version 1.0 comes out tomorrow and they include a number of important fixes to improve the calibration process.
One of the issues which is fixed has to do with the inches to mm button not working in step 10 which I think might be responsible for the issue you are seeing. The problem is that the button works (switches the reading from mm to inches) but the text does not change so it’s possible for the machine to think you are entering a distance in inches while it still says mm. When the distance of 1191.6 inches is used it becomes confused.
Since you are in the middle of calibrating right now I’m happy to make a pre-release version of 1.00 and send it to you right now
If it’s not terribly much trouble, that would be awesome! But in all honesty if you’re busy or its going to take you a lot of work, I’m more than happy to just wait until tomorrow. Thanks for the help!
No trouble at all! I’m sorry for the inconvenience of having the mistake in 0.99!
I will build it right now…you are using windows, right? (from the picture 
)
I am using windows, thanks again!
Great! Here’s 1.0 as it stands now. There might be a couple small tweaks before the release tomorrow, but most of it should be in here.
Firmware-master.zip (446.4 KB)
I’m having issues getting Ground Control to upload because the file is too big, I will send you a private message to ask for your email and I’ll email it to you 
One of the issues which is fixed has to do with the inches to mm button not working in step 10 which I think might be responsible for the issue you are seeing.
Lol… I stared at the code for about 30 minutes today scratching my head as to why it didn’t work (figured I’d try to resolve something while I had time) and apparently I was staring at fixed code… sigh… 
I have installed 1.0 and everything is now working well! I completed the calibration and am now on to cutting a test that I had created gcode for and it’s looking very accurate!
That’s great news! 
After building my Maslow over the last two days, I though I’d share some ideas I had used in the process. The first is finding a way to hang the sled, this makes it much easier to detach the chains if needed. I just put a screw in the top of my frame and cut the head off it so I had a hanging point and then used a standard L bracket with a hole in it to hang the sled from.
The second is mounting the Audrino inside of a container that can then have a fan run and eliminate any heat problems that could arise. I used a Kreg screw container because it was in the shop, but I think really any Tupperware container would work. 
Nice cooling option. Is your fan exhausting or blowing on the card? Where did you get your fan power from? Any concern about addition saw dust build up with the fan sucking it in?
Its a USB powered fan, so its plugged into the PC running Ground Control. It is blowing onto the Audrino and out through the holes where the wiring is running. The router will always have a dust collector running so dust shouldn’t be much of an issue.
Is cooling really needed? Do these notoriously run hot? Just curious - I don’t know.
I have no clue either, but I had a fan so decided to use it, I touched the heat sinks and they were warm for sure though.
I did fry one of the early motor shields, when a bug tried to send the router into orbit.
Active cooling is definitely a good thing to have.
One factor to determine if it is needed, is your location and ambient climate. In Alaska it is not needed I guess 
Here in the desert, I am afraid to put the electronics in an enclosure, as I have the window AC blowing over the naked Arduino and shield.