Tag Archives: troubleshooting

DrawBot – Another Successful(ish) Drawing!, and an Update

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A summer rose from our garden, drawn by a freakin’ narcoleptic robot

A summer rose from our garden, drawn by a freakin’ narcoleptic robot

The drawings are getting better with a little tinkering.  I’ve designed, printed, and installed new motor spools.  These have a thicker central core, so they should be able to collect more monofilament line with slightly less distortion.  I’ve made a few changes to the setup.  Dialing in the starting area and calibrating the starting home point were pretty important.

I’m still having a little trouble with the robot occasionally stalling out.  Although, now I think it is a symptom of the controller software rather than a problem with the Arduino.  There’s no set time after printing, no set time after running the program, or other noticeable precipitating event which seems to cause this problem.  At some point during a drawing, the controller software just reports the Arduino as being busy. 1  Here’s what I do to correct the problem:

  1. Disconnect the USB cable from the laptop
  2. Click “Queue->Export Queue” and save as a text document
  3. Open the text document and perform the following operation
    1. Select, copy, paste the first line above the first line – so now you see a duplicate.  So, for instance in the image above I had to copy “C05,2700,2370,10,247,END” and paste this above the same line – so that it would look like the robot would be receiving the same command twice.
    2. Edit the line “C05,2700,2370,10,247,END” so that I change the command to start with “C09” and delete the last two numbers and the “END” statement, so that it now looks like, “C09,2700,2370,END”
    3. Save the text document with these changes
  4. Shut down/close the controller software
  5. Restart the controller software
  6. Reconnect the USB cable to the laptop
  7. Click “Setup->Serial Port…” and click on the serial port of choice
  8. Click “Queue->Import Queue” and choose the text document I just edited
  9. Start the queue again!

The reason I suspect this is a controller software and not an Arduino firmware issue is that I don’t have to reset the Arduino at any point – just disconnect the USB, restart the controller software, reconnect the USB, and start the queue again.  I would think that if there were a problem with the Arduino firmware, I would need to reset the board itself.

The lowest you can specify as the “grid size”2 in the Polargraph controller software is “20,” but you can use a smaller value by editing the “polargraph.properties.txt” file.  In the image above I used a grid size of “10” which appears to cover 1/4 the area of the size 20 pixel.  That image probably took about five hours to draw.  I think it looks really nice.  The image above seems to have been distorted by my scanner.  It came out almost perfectly square with a slight warp to the top right corner. 3  You can see some bare spots in the image above – that’s where the pen, for whatever reason, just wasn’t making a mark on the paper.  I suspect it has something to do with that region of the paper being either slightly smoother and/or slightly more depressed than the surrounding regions.  Otherwise, there would be no reason why the next row would have a similar defect nearby.

I’ve noticed the controller software also tends to forget the machine width, page size, and page position.  I’ve updated this, saved it, and uploaded it to the Arduino several times, but it doesn’t seem to stick past a reboot of the software.  Ultimately, these are very minor concerns and really just something to be aware of when I’m printing.  I just about couldn’t be happier with the controlling software.  That piece of software plus the Arduino sketch together have basically made this a nearly effortless project.  Besides a hiccup soldering a circuit board wrong, this entire project went together very quickly and yielded almost immediately gratifying results.

I’ve done several drawings in the last few days.  I’m still having trouble getting a perfectly rectangular and centered result.  I may have to adjust the Y offsets and double-check my machine measurements.  I still also notice a slight upwards warp to a drawing in the top right corner.  But, I’m looking forward to additional experimentation – it’s all part of the adventure!

Last, but certainly not least, I want to make it clear that Sandy Noble’s software for the Polargraph/drawbot is really really great.  That I am having some minor calibration troubles speaks more to my incompetence than Sandy’s excellent program.  So, a great big thank-you to Sandy for his continued hard work on this software!

Default Series Title
  1. Aren’t we all, Arduino?  Aren’t we all? [↩]
  2. What is essentially the pixel size [↩]
  3. This one was commissioned at the request of my daughter and now hangs in her room. [↩]

Working on my automated build platform

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I had some technical trouble with my automated build platform today.  (Yesterday?  Last night?  It all blurs.  :) )

I’ve fixed some problems and found others.

Right now I think there may be a slight kink in my filament spindle box.  The extruder motor kept running but no plastic came out in one build job.  I can successfully print using the ABP as a heated build platform – but it is only really successful with single print tasks.  More than that and it screws up the raft.

I’m tempted to lightly sand the automated build platform belt to see if that helps.  If not, a friend suggested using blue painter’s tape on the platform.  I’ll try the tape first tomorrow.

MakerBot woes

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Building my MakerBot and getting it printing reliably was challenging, but totally doable by a technical novice such as myself.  I have lots of people on the MakerBot Operators group to thank for their patience and help in getting my MakerBot online. 1  Looking back, I spent about a month building and then calibrating my ‘bot. 2

It’s easy for me to forget that first month of occasional frustrations and triumphant victories, now that I’ve been printing successfully for more than eight months.  It actually makes me a little sad when I read people writing about their own frustrations and how they’re ready to throw in the towel.  The most recent example was noobcake getting frustrated with her ‘bot and getting ready to sell it off in parts.  Thankfully, Spacexula swooped in to help her out.

This brings me to We Alone On Earth‘s recent post.  WAOE are a group of introspective, philosophically and technologically minded twenty-somethings.  To give you you an idea of their frustration with their ‘bot, the post was entitled, “MakerBot: not very much fun at the moment (caveat emptor)”  Yikes. 3  I realize that WAOE has revised their original post several times since the original publishing date – but they have a lot of legitimate concerns.

WAOE list off seven problems with the MakerBot.  I’m not going to refute these points – but rather offer another perspective on them.  After several updates, WAOE offer additional comments, I’ll include them here in “[]”.

  1. The PTFE is prone to melting.  [WAOE expects the new MK5 Plastruder will resolve this issue]. I have never heard of a PTFE barrier melting.  I’ve heard of them deforming from a blockage and had one develop a clog which I had to remove.  Several people have purchased MakerGear PEEK replacements – but these are far from necessary.  I clogged my first barrier once, cleared it, clogged it again, and am now using a slice of it as an insulating washer.
  2. Inexplicable printing behavior due to noise.  [WAOE fixed this issue by twisting wires and installing a resistor]. I’ve never had this problem, but I know others have.  Like WAOE, I’ve heard of people fixing these issues by twisting wires, using resistors, or ferrite beads.  Perhaps my workstation has less electronic noise, but I haven’t had to do any of these things.  Then again, perhaps my prints suffer from a certain degree of noise?
  3. Printing large objects is hard without a heated build plate.  [WAOE notes this isn’t an issue if you’re good at soldering]. Totally true for ABS, but not PLA.4  However, this is really a problem with the print media – not with the printer, right?  ABS will warp as it cools, unfortunate but true.  I’ve had less warping problems in warm weather or during with a second print – basically when the build platform is already warmed up.  Zaggo’s printruder is one of the largest things I’ve printed.  Interestingly, his design takes into account that certain parts are expected to warp. 5  Or check out Clothbot’s train track – it was designed with a lattice/correlated bottom to prevent warp problems.  Plastic warps – but with careful and thoughtful designing, this shouldn’t be a limitation.
  4. The heated build platform is difficult to build and requires a relay kit. [WAOE notes this isn’t an issue if you’re good at soldering]. I can’t dispute either point.  I just got both and haven’t had a chance to assemble them yet.  I’m assuming the heated build platform, which requires SMT soldering, will be challenging.  Frankly, fear of SMT soldering was the big reason why I didn’t jump into buying a MakerBot sooner. 6  The MakerBot HBP is just one option for a heated platform – there’s several others out there.  Don’t like SMT soldering?  Try out Rick’s platform over at MakerGear.  More into DIY?  Well, use the plans posted for any of several other variations.  As for the relay kit – it’s not a requirement – but it will prevent MOFSETs from burning out on your extruder motherboard. 7
  5. Calibrating Skeinforge is hard.  [WAOE notes this is still an issue]. I like to use the word, “challenging.”  A better way to look at MakerBot calibration is that you get out of it what you put into it.  I have my MakerBot tuned to the point that I get reasonably good looking durable parts.  Sure, I could spend more time and get even better looking parts.  However, once I got it printing reliably I was much more interested in printing new things than refining the printing process.  I’ll get around to improving the print quality even more – but I’m having too much fun right now.
  6. The Plastruder MK4 feed system is unreliable. [WAOE expects the new MK5 Plastruder will resolve this issue]. Getting the tension on the MK4 idler wheel is just one of those aspects of my MakerBot I had to experiment with and get just right.  I’ve been printing reliably for eight months using the same idler wheel and gear.  With proper maintenance, flossing the extruder, and clearing chips out of the extruder the current setup is serving me well.
  7. The threaded rods are of poor quality. [WAOE are getting new threaded rods, which should fix their problem.]. Of my four threaded rods, one is definitely warped and two have very minor warps.  By experimenting, rotating them just so, and printing a few wobble arrestors I’ve eliminated most of these issues.  You can definitely get more expensive and straighter threaded rods and improve your build quality.

A MakerBot Cupcake CNC kit is not for everyone – but the kit can be build and operated by anyone who is willing to invest the time to do so.  It is a cheap, hackable machine that is literally going to be just as useful as you make it.  Want less warpage, higher resolution, more reliable extrusion?  You can buy an upgrade, build one from their plans, or design your own solution. 8  Want a CNC mill, CNC pencil, or CNC music box?  Design the very first one!  Then again, you don’t have to do any of these things.

A MakerBot kit is just a platform for your creativity.  It’s just that big. 9

As for you, WAOE, if you want some help – drop me a line!

  1. If I had an acceptance speech, I’d go on and on while the music played. [↩]
  2. My first successful print was on 12/31/2009. [↩]
  3. Don’t get me wrong – I love my MakerBot, but I readily acknowledge its limitations. [↩]
  4. From what I heard.  :)  [↩]
  5. It was designed before availability or widespread use of heated build platforms. [↩]
  6. Well, that and a little thing called “money.” [↩]
  7. Did I get that part right? [↩]
  8. I haven’t installed a single non-printed upgrade. [↩]
  9. Or that small.  :)  [↩]

Design-print fail

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I’ve been slowly working on the design of a printable (and fully MakerBottable) sonic screwdriver.  This model of the sonic screwdriver is built up of a number of concentric cylinders, has several significant overhangs well in excess of 45 degrees, and is larger than the MakerBot’s built capacity.  In order to deal with these design problems, I modeled it in sections.

In order to make the overall result something I could just pop/snap/slide together I designed it making some sections which were split vertically and other sections which slide around those sections to keep them together.  In order to make the parts quickly printable I designed all the parts at around 0.5mm thickness.

About 40% of the way through the print one of the vertical sections wasn’t coming out properly – probably because it was too thin.  The parts were too thin and flexible and ended up tearing between layers and just being too flimsy.

I also noticed something odd – the extrusion was too thin on that side of the model.   I can’t be sure why this is happening – but I suspect it’s due to the extruder not getting a good enough grip.  Perhaps I need to floss the extruder pulley or install a new extruder idler wheel.  However, it doesn’t explain why the extrusion was too thin on just that one side and no other spots.

Suggestions?