BrundleFab - a thermal fusing powderbed printer

I'm working on BrundleFab, a repstrapped thermal fusing powderbed printer, focusing on sugar printing.

The theory of operation is very similar to the HP Multi-Jet 3D printer, which lays down binder via inkjet, then thermally activates the binder.

In my design the binder is in the powder, not the ink. The ink adds liquid to activate the binder, and changes the heat absorption rate of the binder + powder. When the thermal fuser passes over the inked powder, the liquid evaporates, and the binder and powder (should) become solid.

I am beginning material tests this week, but I've already learned a lot about motion control, Arduino, mechanical engineering, real-time control, GCode, etc.

My firmware is a from-scratch implementation of the RepRap GCodes - since my early prototypes used DC motors + Encoders instead of steppers.

My current system is steppers for the Z, E, and X axes, with the Y (printhead) on a velocity controlled DC + Encoder.

Plenty of pictures on the RepRap.org wiki page.

(I wish that [[WikiPage]] worked...)

Edited 1 time(s). Last edit at 08/09/2015 09:02PM by Ezrec.

Very interesting! Are the prints intended to be edible, or is sugar used because it is cheap and readily available?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

The initial intent was to have edible prints, but the thermal fusing of colored areas is my current area of focus.

My HP C6602 cartridges still have their original ink, and are a bear to clean out - and probably can never be made 'food safe'.

I have a 'clean' unused CISS system for a Canon i9900, and that will be what I will be using for testing food-safe inks, after I have the basic technology down. The Canon i9900 will replace the current HP C6602 system, with a PC sending a 'page' to it (layer) and the Arduino will fake out its paper presence and position sensors as the i9900 drags along the powder area.

The Canon i9900 was selected (out of my pile of junk) since it has no 'mandatory' mechanical parts below the print head.

Sugar is very cheap and available, and if I can get the binder process right, it should result in a resonably high part strength.

For 'permanent' objects, I am considering using a epoxy coating, or maybe a product like Plasti-Dip for direct conversion into a functional object, or using a 'lost sugar' casting technique - put sugar object in plaster or latex cast, let dry, dissolve out sugar, then use mold to make epoxy objects.

What is the binder?

I suppose the sugar is it's own binder, or what?

Your "thermal fuzing" sounds like drying?

What's is the printer cart squirting out?

Two part Part 1 in powder Part 2 liquid in cart?

In these material tests, the binder is the sugar itself.

The ink cartridge is only used for pigmenting the sugar. The idea is that the colored sugar will absorb more heat from the halogen fuser lamp, and carmelize before the uncolored white sugar.

I have other recipes to try for non-caramelized applications, where the fuser will only be used to assist in drying the powder + binder, but they require a refilled ink cartridge.

See my my RepRap wiki page for some of my material recipe experiments.

I am currently attempting to empty this cartridge in a productive way, instead of pouring it all down the drain - hence the 'pure sugar + fusing' material tests.

Sugar is cheap, even retail - I can afford to waste it. And a shop vacuum cleaner makes a great portable depowdering system, when you can afford to throw away unused material. (Actually, it all goes into my garden mulcher).

I've updated my [reprap.org] page with my new (v2015.8.23) sheet aluminum layerhead build.

I'm still waiting on the ceramic halogen lamp sockets and I2C thermopile, but in the meantime wanted to show off my 3-hour build.

(Well, it took about 16 hours of measuring and design work in OpenSCAD first, but the actual build only took 3 hours!)

For utlra-light load bearing parts, such as my layerhead, cheap aluminum door signs ($2 USD at an office or hardware supply store) are a great way to make quick parts, using the Stick-It-Cut-It method.

You can cut the stuff with household scissors, and with some knowledge of sheet metal folding techniques, can be made relatively stiff for its thickness (0.010"). And if you screw up - it's cheap. Make another.

Hopefully I won't get too much thermal warp once I turn on the halogen lamp, but if I do I can always rivet on an aluminum flat or two for additional stiffness.