Building the MakerBot CupCake

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Wednesday 2009-09-02 I started building the CupCake, together with a few friends.

Actually, the package had arrived on 2009-08-20, but I've been away from home for about ten days, and I couldn't build it as soon as it arrived. I had photographed the package's contents, though:

The package's contents

Having all the pieces, and the instructions, we start building.

The USBtinyISP programmer

(link to the instructions)

It would not have been strictly necessary, since the batch #5 CupCakes come with pre-programmed microcontrollers, but it was in the package, and maybe one day I'll need it, so I built it.

PCB, resistors, ICs, connectors…
The USBtinyISP kit.
Dakkar working the soldering iron
The soldering.
Soldering iron touching the PCB
Soldering detail: an IC's pins.

Motherboard and controllers

(link to the instructions)

Now we start building and testing the rest of the electronics. After having connected the motherboard to the steppers' and extruder's controllers, we turn it on: the technical name of this operation is "smoke test".

Smoke test

Although I had read the warning about the power supply, I managed to blow up the nice power supply included in the kit. Luckily I have a few of my own!

Powre supply, motherboard, controllers
Electronics, plugged in and turned on.
Motherboard with lights
Detail of the motherboard, you can see the green lights; in the background, the extruder controller, also turned on.

Assembling the body

(link to the instructions)

Nothing hard: the assemblage with tabs and captive nuts is a stroke of genius.

CupCake's body, with Z belt
The body, essentially completed, including the threaded rods for Z translation, and steppers for Z and X.
Z belt and pulleys
Detail of the top part of the body; note how the pulleys on the rods have been aligned by simply having them touch the bearing brackets.

(Yes, I've skipped a few steps, I haven't shot everything)

Body, completed
X and Y stages built and installed, electronics installed, including the end-stops.
Electronics in its place
Electronics installed in place; cables for the end-stops and the extruder controller are still missing.
X and Y stages
X and Y stages built and installed; you can see the Y end-stops and the (paper) tabs to trigger them.
Y end-stop, glued
While I was tightening the bolts for this end-stop, the wood broke. I then fixed the end-stop with hot glue.

I stopped here for the first day, also because it was already dinner time. I started again the following morning.

The extruder

(link to the instructions)

It seems that for many people this part is the hardest, and the one giving the most problems: I did not have any particular difficulty.

Extrusion head
The completed extrusion head; the red wire is connected to the nichrome resistor, the black wire to the thermistor.
Extrusion mechanic, completed
The mechanic part of the extruder, completed.
Pinch wheel and idler wheel
The idler wheel aligned perfectly on the first try.

A note on the alignment of the idler pulley: I followed exactly the alignment instructions, then I put the wheel inside the extruder body: on one side it was too near the motor, on the other it was precisely centered.


Someone built a double-width idler wheel, by gluing together the two wheels included in the kit. In my case, and apparently also for someone else, the resulting wheel is too thick to fit between the flanges of the pinch wheel, so it's impossible to use.

Extrusion canal
View along the extrusion canal; the hole at the end is the exit of the melted filament.
Extruder at work
Extrusion test: it works! Note that the short black ABS wire I used for the test has been extruded completely.
ABS filament
Results of the extrusion test: a black ABS filament, randomly curved.

First print

Finally, I can print! The test object is a clip-on Z end-stop trigger, since my kit's Z platform doesn't have the slots for the triggers.

CupCake printing the first layer of the raft
First layer of the raft.

This is actually the third try. The first try caused a head crash, resulting in a small hole in the print platform; the second try started too high, and the raft did not adhere to the platform.

CupCake finishing printing the clip
Final layers of the clip.
Finished clip
The finished clip: I must study SkeinForge's parameters before obtaining something actually usable.


About 19 hours of work, very few problems, and a working printer: probably the best-spent two full days of work so far :)

DatesCreated: 2009-09-07 09:15:47 Last modification: 2009-09-07 15:55:04