Anyone know anything about the cupcake CNC machine?

[Ed Kapuscinski]

http://www.msnbc.msn.com/id/33012751/ns/technology_and_science-innovation/#sp-ss/slide-7

[C855B]

http://www.makerbot.com

Be warned that the site is über-slow. This is a DIY kit (which they happen to mention is out of stock, and will be for a while, get in line). Finished-piece resolution is unspecified. They give a bunch of very optimistic specs for XYZ positioning, with no indication of expected mechanism slop.

[bbussey]

I have a Sherline mill with the CNC interface, utilizing BobCad software on the PC.  BobCad imports a number of digital solid file formats without conversion, including Rhino and SolidWorks.  It probably will cost around $4G when you include everything you need (mill, computer, software, mounting table, etcetera) - but it works well in cutting brass and diecast as well as plastic, wax and resin.

[C855B]

Bryan, the "CupCake CNC" is sort of a misnomer because it isn't a CNC mill - it's a rapid-prototype 3D printer which uses a hot-melt extruder head, sort of like a precision glue gun. Materials are ABS and HDPE. The ABS especially caught my attention because everybody else says "resin" without revealing a lot about compatibility with the usual plastics we're used to in mass-produced models.

This is very, very helpful: http://wiki.makerbot.com/faq-frequently-asked-questions

I've done lots of research on stereolithography for over a year (but no hands-on yet), and these guys are saying all the right things. With a few 3D drawings in various stages of completion I'm finding it very hard to keep from ordering one. Biggest downside at the moment is no ability to handle support material, but it's on their "we gotta do!" list.

[bbussey]

What is the resolution?  What is the thickness of the layers it builds?  I'm not familiar with 3D printers being able to build ABS layers at thinner slices and higher resolutions than resin.  This definitely would warrant continued interest if the layers are thinner than .0006".

[C855B]

On digging deeper, no joy.  :'(

The extrusion size is 0.4mm, which will be your minimum XY voxel. It was implied that you could move all axes in 0.1mm increments, but whether that translates to the ability to deposit 0.1mm layers isn't easily answered in what I could find. Inevitable conclusion is that this isn't ready for model builders and may never be given the limitations of the extrusion process.

So I guess I'm back to saving my pennies for a Perfactory or something like it.

  ...mike

[Philip H]

I think its an interesting concept.

[DKS]

Rather than buying your own machine, how about "renting" time on another?

http://www.shapeways.com/

[lashedup]

Man, when the price comes down on these and the proficiency of 3D modelers goes up, the possibilities will be endless. Need an E5 shell with micro-crisp prototype detail? No problem. It won't be super cheap, but you can make as little as one and have a shell that has amazing detail.

- jamie

[sirenwerks]

If that happens though we should probably become proficient at creating our own mechanisms as well, because the manufacturers will be packing it up.

[C855B]

I wouldn't worry about it. 3D drafting is friggin' TEDIOUS. The only thing that keeps me going at all in it is the faint hope that I might just finish something useful and to my satisfaction. I've been working on a long hood for nearly a year now (off and on) and am about at the point to bag it and just start scribing some brass.

[Walkercolt]

I have a very good freind who is a REAL CNC machinist. He can "cut tape" and make masters. For a 1914 motocycle three of us restored, he took the pieces of the original pistons and from billet aluminum, made us two pistons on his own time. Now they had to go to the engine machine shop for final sizing and cutting the ring recesses and the pin had to be bored and the bottom-end sized, because now we're talking a MAXIMUM of +/- .003". If this had been one of his "production jobs", a 3-D draftsman (designer? programmer? engineer?) would have "spec'd-out" what should be CNC'd, turned and bored. Very, very few parts are totally CNC machined. There would be the need to change tool bits and mounting, etc., and many things can be done on cheaper equiptment, with cheaper tools. The drill press still gets lots of use in even the most precise "gizmo" making.
What is most promising for models, is using a laser to cut wax or plastic with super-fine detail, and use that for a "lost-wax" casting process. My new $2300 gold tooth crowns are being made that way, and the "Invisaline" clear plastic tooth "braces" use that process to move teeth from where they are, to where they want them. You can buy the machine for about $750,000, then you need a program and a 3-D Auto-Cad geek. Really, watch the jewlery and dental professions for "break-throughs" in 3-D "prototyping" and production methods. I've got cyano-acrylic epoxy holding my temporary crown in, and brother, did it taste BAD!

[wcfn100]

I wouldn't worry about it. 3D drafting is friggin' TEDIOUS. The only thing that keeps me going at all in it is the faint hope that I might just finish something useful and to my satisfaction. I've been working on a long hood for nearly a year now (off and on) and am about at the point to bag it and just start scribing some brass.

I haven't tackled a long hood yet, unless you count an FM 10-44, but for smaller parts like boxcar doors and ends, specialty item like cabooses and short hoods with light packages, the work is pretty rewarding for the time you put in.


As long as I don't have to ever redo any of my drawings as the machines get to higher resolutions, it's worth it.


Jason

[Walkercolt]

Jason, that's a big part of the process. Your drawings are probably in a format (language) the dental machine made now don't "understand". I was talking to the guy at the video store today about the new Blu-RayII format protocals just announced in this month's "Rangefinder" professional photgraphy magazine. It will "unify" the digital (Play Station/X-Box) and normal video formats. Expect it to hit the "consumer" market in 3-4 years when the 8000 line TV's do. All that's needed is higher def video cameras (most already are) and a "smarter" computer processor chip in the TV. (Think Pentium II to Duo-Core P-4+)
Maybe in 5-7 years the costs of the laser cutters will come down enough, and the needed software will appear for "one-off" production of plastic models (or pieces). Joe Semi-Average can buy and operate a laser cutter for wood kits and some will cut thin metals too. I don't see a Star Trek "replicator" in the near future for our toys! ;D