MakerBot Industries

I’ve been using a 1/16″ aluminum build surface on my Thing-O-Matic for weeks, with really good results. Now you can buy an aluminum platform from Makerbot, and cover it with wide Kapton tape for the ultimate build surface. I’ve been using this combination on my Cupcake CNC for a while, and it is great: parts adhere really well and there is no warping. (Top tip: wipe the platform with acetone before printing for even better adhesion.)

However, this poses a challenge: sometimes parts stick to the platform so well that it can take a real effort, and a lot of force, to get them off. On the Cupcake, I would just detach the build platform and lever the piece loose. However, on the Thing-O-Matic, the platform is fixed, and you end up applying a lot of force to the X&Y platform as you try to release the piece.

One solution is to just double up the aluminum plate, and hold it on with bulldog clips, as described here. However, I went for a quicker solution in the short term.

Wing nut holding heated build platform for easy removal

I just put M3 wing nuts on the bolts holding the platform (you only really need 4, one on each corner, not 6). When I’m done printing, I can just detach the HBP connector (power off first!) and quickly unscrew the wing nuts. This allows for easy access to the printed piece from all sides, plus I can apply quite a bit of force without affecting the structure of the Thing-O-Matic.

At some point, I’d love to see a quick release mechanism for the Thing-O-Matic platform, like this one, but for now this is really saving me a lot of time and effort.

Simple Hinge by PieterNr1

Apparently, when you properly arrange objects in an STL for printing at once, you can do so in such a way as to eliminate the need for support structures!  Not only is this a clever use of limited build space, but it also conserves plastic while allowing printing of ever more intricate designs.

PieterNr1′s Simple Hinge above is the first object I’ve seen to use this technique.  It appears from the photograph that there is some slight drooping underneath the top two ledges – but I’m guessing this isn’t enough to interfere with proper operation.  Looking at his implementation of this technique, I have to wonder whether it could be used to print some of the various tracks and treads under development on Thingiverse.

Simple Hinge by PieterBos

My attempt of making a hinge. I do not know how strong it is but it works for now at least. It a openscad thingi so you can mod it. It only hinges at 90 deg but that is what i needed ;-)

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Foam core build platforms

Last night I was moving around some of the circuit boards in my Thing-O-Matic when I realized that I couldn’t mount any of the stepper motors in the spots were the extruder boards could go.  The extruder boards are slightly larger than the stepper motors, so the mounting holes are farther apart.

Since I tend to think with 3D goggles these days, my first inclination is to fire up OpenSCAD and whip up a printable solution.  It was only after designing an “extruder to stepper mounting plate” did I realize that I had a much quicker option.  My Cupcake CNC came with a pile of foamcore build platforms.  These are great for ABS printing, but aren’t much good after the first print.  Admittedly, you can still print on the reverse side.  As a result of printing on acrylic, a heated build platform, and later an automated build platform, I’ve barely made a dent in my reserve of foamcore build platforms.

In any case, I thought up three ways to recycle those old foamcore build platforms.  Hopefully one of these will be useful to you:

1. Cover in blue painter’s tape for PLA printing.
2. Cover in Kapton tape for ABS printing if your acrylic build platform is otherwise out of commission.
3. Use in place of a printable “extruder to stepper mounting plate” by mounting the stepper board to the foamcore and then mounting the foamcore to the inside of the Thing-O-Matic in the extruder board mounting area.

Now, the electrical engineers out there will have to educate me.  Would you want to cut channels to allow air to flow under the board?

NYCDesigner's PET automated build platform conveyor belt

Sometimes there is just no replacement for experimentation.  I’ve been using my Automated Build Platform for about two weeks now¹ , but have found its utility varies with the material I’m using.  Here’s what I’ve tried along with a few notes:

• The mylar belt works much better with ABS than with PLA. ²
• Sanding the mylar belt slightly did not help the PLA stick any better.
• Heating the build platform did not seem to help the PLA stick any better.
• Using just the mylar belt with a single strip of Kapton tape running around one edge of the belt works much better than wrapping the entire belt in Kapton tape.  I noticed that when the Kapton is doubled over itself it will develop wrinkles once it has been around the conveyor.  These wrinkles then remain causing an uneven build surface.
• NYCDesigner tried out a PET belt, which he found easier to assemble than the included mylar belts, but didn’t notice the PET working any better.
• Anfroholic suggested sanding the build surface in only one direction, to preserve the peaks and valleys on the build surface.
• Feilen suggested a Kapton belt has worked excellently.
• I’ve found that blue painter’s tape works great with PLA.  I haven’t tried wrapping it around my entire conveyor belt, just the print area, but I’m hopeful it would work that way too.

And a bonus list of THINGS TO NOT DO WITH YOUR AUTOMATED BUILD PLATFORM:

• Don’t turn on the motorized conveyor belt while your object is still quite hot – especially if your object is very thin.  My test USB enclosure just became even thinner when the motor pulled it down underneath the actual build platform.
• Don’t wrinkle your PET belt.  That’s going to cause problems with an uneven printing surface and they’re difficult (impossible?) to get out.
• Don’t run your automated build platform backwards – it will make the Kapton tape pull up.

What have you learned with your automated build platform?  What are you using for your conveyor belt?  Are you sanding in any particular way?

1. And loving it! [↩]
2. And, frankly, PLA is my new favorite thermoplastic. [↩]