Tag: MakerBot

MakerBot, Mendel, Mendel-Mini Build Areas

Owning a MakerBot, I’m not even sure why someone would need something to print pieces much larger than the MakerBot build area.  Printing something as large as just the maximum build volume of a MakerBot would take ages.

While the official longest print logged on the Makerbot website is Zach’s Disney head, clocking in at 2 hours and 45 minutes, I’ve read about people printing for up to 8 continuous hours.  If the build volume for a Mendel is 4.3 times that of a Makerbot, it would take more than 34 hours to fill that build area.

When you’re printing a door hook in 15 minutes, it doesn’t pay to drive to the hardware store.  When it takes 34 hours to print a big plastic brick, you’re better off driving to the gas station, filling up your tank, driving to McDonald’s, filling out an application, working an hour, quitting and demanding your paycheck, driving to the hardware store, buying a single brick, and then driving back home.  I figure that kind of silliness would only take half a day or so.  Heck, with 34 hours, you could do this at least six times over.

How to caliberate and tune Skeinforge for your MakerBot

Update 4/21/2011: This post is more than a year old.  Since then I’ve created ProfileMaker which should eliminate the need for almost all of these steps.  Share and enjoy!

A MakerBot Operators group member, Cliff Biffle, has posted a very comprehensive list his Skeinforge tuning and calibration procedure.  Cliff owns MakerBot #69 from Batch#4, named Kallisti.  Although Cliff has a MakerBot Skeinforge tuning page, it looks like he hasn’t had a chance to transcribe his lab notebook yet.  However, Cliff has been patient enough to type up his Skeinforge calibration information twice for the benefit of the MakerBot Operators group.  Here are links to his original postings on 1/6/2010 and another on 1/15/2010.

The other day I wanted to go back and find his calibration procedure, but had forgotten who had posted it, when it was posted, and which thread it was posted.  Having now found it, I don’t want to lose it again.  It turns out that Cliff had posted it once in response to my own question about dialing in Skeinforge settings in order to print up lego pieces!  Thanks Cliff!

I’ve mashed his two posts together to put together this checklist:

  1. Adjust Temperature:  Skeinforge -> Raft
    1. Find a temperature that allows you to extrude quickly and easily without too much popping or smoking
    2. MakerBlock: I have one of the 1mm thermistors, use the Zach 1 temperature table, and print reliably at 220
  2. Adjust Layer Height: Skeinforge -> Carve -> Layer Thickness (mm)
    1. Cliff uses the default of 0.36
  3. Adjust Extrusion Speed: Skeinforge -> Speed -> Flowrate PWM Setting (if PWM Setting is Chosen)
    1. Make the extruder go slower and lower the PWM value
    2. Cliff uses 230
  4. Adjust Feedrate: Skeinforge -> Speed -> Feedrate (mm/s)
    1. Too fast and you lose the fine detail and introduce errors.  Too slow and it will be too… slow.
  5. Adjust Skeinforge to understand how much plastic is being extruded
    1. Raise the Z axis and perform a test extrusion into the air
    2. Do not pull or stretch the extrusion
    3. Using calipers, measure its diameter, D
    4. Go into Skeinforge and look up the configured layer thickness, T, from Skeinforge -> Carve -> Layer Thickness (mm)
    5. Divide the diameter by the thickness, D/T
    6. Set Skeinforge -> Speed -> Extrusion Diameter Over Thickness (ratio) to D/T
    7. Print a test piece with thin walls
    8. Measure the width, W, of a single extrusion somewhere above the first few layers
    9. Divide the width by the thickness, W/T
    10. Set Skeinforge -> Carve -> Extrusion Width Over Thickness (ratio) to W/T
      • Cliff said this setting may be in Fill, but I think he may have meant Carve

    11. Nick Ames has suggested setting Skeinforge -> Carve –> Extrusion Width over Thickness (ratio), Skeinforge -> Inset -> Extrusion Perimeter Width over Thickness (ratio), and Skeinforge -> Speed -> Extrusion Diameter over Thickness (ratio) all to the same value.  His post also has a lot of information and links about other potential Skeinforge tuning resources.
  6. Adjust other Skeinforge settings
    1. Overlap of grid corners
    2. Infill density
    3. Unpause
    4. Stretch

Replicators

Did I ever mention I have already printed up a MakerBot version of a Stargate SG-1 “Replicator” cell?  Well, I did.  I basically “borrowed” someone’s Sketchup file from the google 3D warehouse, saved to STL, and printed it up!

In any case, it made me think of a cool T-shirt idea.  The back side of the shirt would have a Stargate Replicator with a red circle slash over it, labeled “Bad Replicator.”  The front could have a picture of a ‘bot saying “Good Replicator.”

I’d wear it.

PLA on the way!

I just saw MakerBot’s blog post saying they finally got in a batch of MakerBot approved PLA.  This is supposed to be nigh magical stuff.  It prints at a cooler temperature than ABS, it has a low shrinkage factor meaning it won’t warp much if at all, it will stick to blue masking/drafter’s tape not requiring the use of an acrylic build platform, and it’s very clear.

While I was at it, I also ordered an extra brass nozzle, brass barrel, PTFE insulator, ceramic tape, nichrome wire, thermistor, and I asked for some MakerBot stickers to adorn my laptop.  :)

Heater barrel – backasswards?

Dangit.  According to the very latest changes to the MakerBot assembly wiki, I put the heater assembly together with the heater barrel upside down.  I’m not entirely sure what this means for my heater.  Clearly it was working well enough that I could extrude reasonably well.

The questions is – do I leave it as is or disassemble/reassemble?

If I leave it as is, I suppose there’s a chance I could bulge the insulator, ruining it.

I’ve already disassembled/reassembled once because of a bad thermistor connection.  If I disassemble again, I’m thinking the ceramic tape and nichrome may have had it.  Not to mention that I’m probably going to have a royal mess of plastic inside the barrel and nozzle to clean up.

My first hack

Seeing as how I already had the heater in pieces, I figured it couldn’t really cause that much harm to move the plastruder board.  I totally get why the MakerBot guys put the board on the extruder – that way all you had to do was swap out an extruder and you can roll with a totally new print head.

I don’t really intend to do printing beyond single color plastic.  This may very well change if we see a support material extruder being offered.  But for the foreseeable future, I am really looking forward to printing away with my giant coil of black ABS.

That said, I’m not attached to the idea of having totally modular heads. 1  On the right side of the MakerBot there’s a really large area above the motherboard and to the left of the three stepper motor boards.  The only things preventing the plastruder board from being mounted right there are (1) the motor wires are too short and (2) four holes in the body.

I had dissected a piece of ethernet cable for the wires running to the nichrome wire and thermistor, so I still had four wires left.  I used another two and a bit of solder to extend the wires to the extruder motor.

Sometimes when I need to drill a small hole through soft or thin material I don’t even bother with the drill.  I used a small drill bit with a rubber band wrapped around the non-drill-bitty-end to give it a grip and rotated it into the right panel of my MakerBot.  Bolt it on and…

Presto!  Now I can see all the way through the plastruder.  :)

  1. Sorry about the pun. [↩]

Things I learned while soldering opto-endstops

The opto-endstops marked the very first parts I had to solder for this MakerBot.  Not having soldering anything more complicated than two wires together, this was an adventure and learning experience.  Here’s what I learned today:

  • The 3-pin connectors used for two of the opto-endstops (on the Y-axis stage) are in the Generation 3 MakerBot Electronics Kit (Mostly Assembled) with some of the other connector bits.  I was a little confused about this for a while.
  • It helps to lay out all the little bits in an organized fashion beforehand.
  • Keep a long thin rigid stick handy for bending delicate leads into the circuit board holes.
  • Although I read the RepRap electronics fabrication guide and found it helpful, I still felt a little lost.  I found the most effective way to solder the parts in was to:
    • Get the soldering iron good and hot
    • Put the leads through the holes
    • Bend the leads a little so that they stayed in place
    • Flipped the board over so the leads were sticking up
    • Touched the solder to where I wanted the joint
    • Gently stroked the solder with the soldering iron tip towards the joint
    • This process seemed to create a pretty good joint
  • You’re going to burn a finger at some point, accept it.1
  • This almost goes without saying, but go slowly.
  • Check and double check the orientation and placements.
  • I found it helpful to take a large sheet of aluminum foil and shape it into a tray.  This helped contain the parts I was working on and was a good way to catch the flying leads that I clipped off.
  1. I burned two. [↩]

Opto-Endstops arrived today!

Huzzah!  I have been both excited and a little bit apprehensive about these parts.  I have to admit I was almost relieved that they were accidentally swapped out – forcing me to skip their assembly for a little while.  Now that they’ve arrived I need to actually solder these itty bitty parts.

I have a soldering kit I use about once or twice a year – and never for anything more interesting than connecting two wires.  For some reason I find soldering little bits more intimidating.  With my trusty soldering iron and a steady hand, on to adventure! 1

  1. “Oh, sister Magdelene won’t you fetch the
    Doctor’s flask.
    He is going to need a steady…
    A steady hand”
    Cracker – Take me down to the infirmary [↩]
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