Hacking together a cupcake

I'm building my first 3d printer and have decided to go with hacking together an acrylic makerbot cupcake. Two reasons that I'm going this route- First I have access to a laser cutter and lots of acrylic. Second, I got a good box full of parts from makerbot as grab bags.
So some things I was wondering, as a laundry list:
Where are the best source files for printing out the case?
What's a good print head to adapt over?
Good single board electronics?

so, yeah basically "How to do everything?"
Thanks
Mike

Been there, done that. Routed mine in 6.7mm plywood. Printer rods and bronze bushings. Files are on thingiverse.

Advice is: don't

Why? 100x100mm print area, non-upgradeable.

And I'm not sure the kits with belts and pulleys are still available at Makerbot

Otherwise works trustfully with modern electronics and a good homegrown extruder.

Advice: wait for the imminent release of Nophead's Mendel90 and build that. That design is a pure fruit of experience and problem-solving.

Already have the belts, pulleys, shafts, stock plastic bushings. I'll need to pick up some m8x1.25 threaded rod, and the smaller nuts and bolts, and that's it for the case parts.
There are two local people that have huxleys with sanguinololu boards, I'm trying to figure out what route to go. I'm going to build a bigger one as a second machine.

So you're pretty much set up. Have a look at the few frame updates on thingiverse, some seemed interesting, but I do not think they were cut by more than 1 or 2 persons. Otherwise the revised, updated frames from the Makerbot repository will do.

Have a look at the improvements that were made to get the Z axis guided on smooth rods (prior to thing-o-matic), there is at least one design thought for lasercut. maybe it is beter to use it than to stay with the four wobbly corner threaded rods. Actually check if you could use the belts you have in a thing-o-matic frame, you'd gain some cms of printing area. the Z motor might have to be re-positioned for using a coupler instad of an integrated leadscrew.

If you find used printer smooth rods and brass bushings, do the mods for that, the orignal cupcake plastic ones are quite.. crappy.

Any electronic capable of running modern firmware (Marlin...) and a heated bed will do: RAMPS, Saguinololu, Gen7...
I can send you my current config file for Marlin.

Honestly, you should start with a Prusa or a MendelMax something. The Cupcake is a pretty awfully out of date machine, with poor layer consistency, a small build platform, outdated electronics. By the time you upgrade enough parts to get it printing tolerably, you'll have basically half-built a RepRap, albeit a noisy, non-standard, difficult-to-upgrade one.

The Prusa is mature, upgradeable, fast, and has a build area four times the size of the Cupcake's. And a MendelMax is more rigid and has a large build platform still.

you will want to use pirated cupcake design as a refference

[reprap.org] has the files you are looking for. according to the wiki the person also has electronics working for him as well. i think he went with makerbot gen4 electronics.

get electronics with sd card, if you use dc extruder you will not want pauses.
good luck

Edited 1 time(s). Last edit at 01/29/2012 08:41PM by jamesdanielv.

The files on ponoko are set up to the correct size for my laser bed, but I have access to 4.5mm acrylic, not 5mm. It looks like I'll have to adjust a lot of slots.

Do you have access to plywood? it may be a better choice for some parts, especially those that touch the motors.

The X motor (I used a SY42SHT47-1206A I think, use something with more power) tends to overheat (or lose steps if you reduce current) so it will need some additional cooling.

There's at least two or three layered wade's extruders on Thingiverse ready for lasercut (including mine: the gears will need adjustment though, offset the perimeter by 0.75 minus the laser width) , there's not a single reason today to go with a DC extruder and outdated, pricey electronics.

Note that I wouldn't call the prusa a mature design, I have spent much more time fiddling with the prusa than with the cupcake. Yes, in the end the Prusa can be accurate and fast, but so does the cupcake with modern electronics and a stepper driven geared extruder.

I can't get the plywood for as cheap as I can get the acrylic. I work at the local plastic store. I was thinking of putting vents in around the X motor, and printing two right (left?) sides of the outer case so it will be open all the way around, especially since I will mount a much smaller control board.

The x-y carriage on the pirated cupcake is already sized out to be made of 3mm acrylic. I also found out the ponoko files are not so clean- lots of line segments, the all cupcake components on a 2x4 on thingiverse is excellent, clean lines and up to date. The ones at makerbot are of the second generation.

Plywood is cheap anyway ;-)

The X motor (right side) is near an opening (at least in the original design), I put a 12V computer fan over it.
The Y motor (on the X carriage) is smaller and trickier to cool. Might be good to have provisions for vents, and even better, a 40 mm fan .

The "all cupcake" looks ok, I wouldn't go with the plastruder mk5 which is obsolete, but the extruder base is OK for all


Did you check the possibility of building a TOM frame instead?

[wiki.makerbot.com]
"Thing-O-Matics ship with a 228-tooth x-axis timing belt as well as a 272-, 267-, or 265-tooth y-axis timing belt."

Cupcake:
"264 tooth continuous timing belt (the second-shortest one)"
"196 tooth continuous timing belt"

Also check this, was Pandelume's second revision of the files:
[www.thingiverse.com]

at least one guy cut it. Maybe you could try to ask PirCapAdi for some feedback about how is it going.

The case printed very well, from the ponkono files. I changed a little bit- added the window to the right side, and took the bump off of the front opening. I will have to do a second print to make the x and y sleds out of wood- there is a lot of kerf on the laser I have access to, especially for 4.5mm acrylic. Also found out that 14mm long hardware works.
parts I need:
extruder, hot end, steppers, Z belt, control board. Everything except the Z-belt can go into future builds!

Did you go with the old "belt and 4 corner rods" z ?