Hi Sandy,

First off, thanks for all your work on this really cool project. I'm new to Arduino and coding, but know basic electronics and hardware. I've been having trouble getting mine working.The machine will move up and down fine, but left and right is backwards (see wiring photo). I tried a number of configurations, but still couldn't get it working. I thought to try if it will still do to at least do some width tests, which it did only one successfully. Usually it stops, stutters or just goes off completely (see photo). I've tried both x64 and x32 versions on respective computers (PCs, Windows 7), however I was only able to get the x32 version to work on both machines. I've also tried uploading the non-compiled version with the Arduino IDE as well as the compiled with XLoader, but no difference. Any thoughts?

Thanks,

Joe

Hi Sandy,

Thanks for the quick response! Ok, so fixed the wiring, but still having some issues.

Yes, I'm running it on an Uno r3 with adafruit motorshield, using polargraph_server_a1 and the latest uploaded bundle. It's powered by 12v 1200mh power supply with 12V, 0.4A, torque 53n.cm stepper motors. I had some gears and belts made locally (I'm in China) and just using some bearings on wood for the gondola. Once it'll work the next step is to get a solenoid on the gondola and clean it up. Here are the photos of the machine at the moment.
http://imgur.com/a/DRmG7

Still a little stumped on the issue though. I can control it for a bit using move pen to point, but then it gets snagged. It happens if doing the pen test or move to point after a couple minutes.

Thanks,
Joe

I tried with the power supply directly into the motorshield without the jumper, but it does get quite hot. I then tried with the jumper, but same issue. I have ready another bigger motor driver (3A with heatsink), but I'm not sure how to connect it to the arduino (see updated photos). I also tried another power supply (800mh) plugged into the Arduino with the jumper, but same problem.

Joe

hey kongorilla,
Thanks for the help. Yes, I did mean the L293D drivers are getting hot. I bought an adjustable power supply (1000mA) and tried it at 9v, where it completes the pen test and doesn't get as hot, however now only one motor will work during the test. Not doing the test both motors work fine. I went back to 12v and same issue. I have another motor shield, would it work better?
http://tinyurl.com/d5lvpcc
A bit confused on how to connect it to the Uno though..

Thanks,
Joe

Thanks for the response.

Wiring as is, with the power connected directly into the motorshield and the power jumper off, it runs the adafruit examples on both motors. I changed the example code to test both motor ports.

For the pen test yes exactly, it just draws a straight line. The problem motor (left) is locked. I mean complete as in the sequence finishes and it's ready to receive another command.

When I "set home" they are locked and can't be moved without some force. When moving they can be stopped by holding onto the gears. Then both motors work with move pen to point, but after about the 8th movement the left motor stutters, stops and the arduino isn't able to accept commands.

I think the L293D is getting hot and switching off. Only the outer L293Ds get hot, the middle does not, does that matter? The 1200mA power supply at 12v doesn't get hot at all, but the other power supplies, 1000mA and 800mA at 9v get very hot after a few minutes of use. Here is the link to the motors I'm using in case I'm missing something.
http://item.taobao.com/item.htm?spm=a230r.1.10.203.WWxfhp&id=16048743391

Joe

If I swap the motors, it's still the same issue, they both work for a while then it cuts out. I arrived at the wiring sequence from a sheet the supplier provided showing which colors were for which coils. I also tested the shield on a Mega2560 with the coordinating code just in case the problem was with the Uno, but same issue as before.

So I've bought more L293Ds to piggyback like kongorilla suggested, also bought some SN754410s to replace the L293Ds in the motorshield since I've read they do allow higher voltages, but it may or may not work. I've also bought another motorshield in case this one has been damaged at all by the testing. I should get these in the next few days, so we'll see if one of these solutions work.
Thanks!

Joe

Hi Sandy,

So I got some new motorshields along with L293Ds for piggybacking and SN754410s to replace the L293Ds. I tried piggybacking, but it didn't change anything. Once I changed motorshields, substituted the SN754410s and changed the power supply to 12v @800mA the machine would be happy to move about using move pen to point for as long as I wanted. However, once I started a pen width test or a test image, one motor would lock up resulting in another straight line. Any thoughts?

Joe

The keyboard shortcuts are now ctrl+key, so ctrl-c. Looking at the output of the machine in the console is a very good idea. Paste it in here or email it to me if it doesn't make sense.

So you might find that there is a symptom of the crash in the software, some error that is reported. Does the software otherwise work fine after a crash - I mean, is it still responsive when it has finished it's current command?

Hum. I did have a good idea earlier, but I've forgotten what it was now.

sn

Hey Joe, you probably are correct - I don't think there are any settings in the software that would prompt the behaviour you are seeing. Bad geometry or shading yes, but not going kaput halfway through a drawing. Unfortunately there is no trick I can think of.

Is there any chance your motors are not the 12v 0.4A motors you think they are? Even both of them on continuously (which they almost never are) should be drawing 0.8A, and not melting your 800mA PSU.

sn

That kind of distortion is unexpected, and I don't think I understand how it could be coming about either. The machine itself has no concept of "height" as an axis separate to width, so it's not like it could be making the drawing shorter without making everything smaller (so narrower as well).

Is it only "render pixel" types of drawing that it happens on, or vector stuff too?

sn