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3D models of mac plastics

bbraun

Well-known member
Kind of an oddball question, but has anyone tried or thought about attempting to use either additive (printer) or subtractive (milling) 3D printing methods for reproducing hard to find plastics or frequently broken bezels on older machines? I'm thinking of things like the front LCD panel on the powerbook 500 series is almost always broken off. Or CDROM or zip drive bezels for Q900/950 machines. Things like that.

I guess the first step would be getting printable 3D models of the plastics. So has anyone tried any of it? There are services online where you send them an STL file and they send you back the printed object, and figured it might be worth a shot.

 

Trash80toHP_Mini

NIGHT STALKER
I've mostly been looking at making vacuum forming bucks for some larger clear ProtoMac case part knock offs.

CNC and stereo-lithography output from such models will be the next big step in Retro-Computer Hacking. Most of the prototyping service bureaus also have 3D Scanners for doing rough modeling which can then be tweaked on a half way decent CAD Seat before output time. Kinda like scanning in and cleaning up Logos/Line Art in 2D back in the day.

Check out the articles in PopSCI(?) about Jay Leno's CAD/CAM/Prototyping Playpen for ideas on how to go about doing your project. :approve:

 

bbraun

Well-known member
Yeah, the 3D scanning seems to be the key. There are home made 3D scanning solutions that look to be probably poorer quality than the tolerance required to make replacement parts, plus they all look exceptionally time consuming to clean up the scanned results. 3D scanning services seem to be expensive to generate a printable model, presumably because of the time involved in cleaning up scanned data.

 

Trash80toHP_Mini

NIGHT STALKER
Don't forget the time/expertise of the human scanner, the amortization schedule of a high end 3D Scanner and the overhead to house them!

Being an ex-small businessman, I keep thinking about these things . . . ::)

Maybe that's the next business I'll start when I grow up! :eek:)

edit: Post some links about the home-brew solutions you mentioned and we'll give'em a good look over! :approve:

 

bbraun

Well-known member
The DIY 3D scanner setups I've seen:

http://www.makerbot.com/blog/2010/09/14/new-makerbot-3d-scanner-kit/

http://www.makerbot.com/blog/2011/05/26/3d-printing-with-kinect/

I've been lusting after some of the low end 3D printers, now that they're in the sub-macbookpro price range, and looking to justify the desire with additional uses, such as replacement plastic parts.

http://botmill.com/index.php/3d-printers/glider-105.html

or milling & scanner in one!:

http://www.rolanddga.com/products/scanners/mdx15/

But it always comes back to the 3D scanning portion.

 

Trash80toHP_Mini

NIGHT STALKER
This looks a lot like your case bezels, it must be a packing foam mould.

img5.jpg


Cool! The Roland MDX-20 only costs about a fifth of what I paid for my first 2-D Drum Plotting (no scanner, that was another 10k$ for the MacSignMacker System a year or so later) CAD/CAM system . . .

. . . in 1986 $$$$$$$!!!!!!!!!!!! 8-o

 

Bunsen

Admin-Witchfinder-General
There's always the old-school way of getting the dimensions - with callipers and a pen & paper. Doesn't look like that much more work than cleaning up a point cloud.

Or how about casting a negative mould from an original piece, and resin-casting the pieces from that?

 

Trash80toHP_Mini

NIGHT STALKER
Resin casting is severely size limited. Injection moulding and casting iron, BTW, require oversize machine tooling/lost wax blanks/sand moulding patterns etc. so that the finished parts will come out the proper size when cool.

Plastic and cast iron aren't so bad, but you should see the size of a toilet before the ceramic is fired! 8-o

CNC Milling and Stereo Lithography are definitely the way to go for this kind of thing.

Good point about the manual model-building method though, that's not too bad. But like in 2D graphics, it's a LOT easier to clean up a scan's pixel pancake in Illustrator than to scale it in manually. Point clouds in 3D are probably a similar deal at a CAD seat. [;)] ]'>

 

trag

Well-known member
OMGosh, that's tempting. $600 for a home 3D printer. $50/spool for supplies. About .1mm resolution. Which seems weird, since they also say the print head extrudes at .35mm, so how do they manage .1mm?

Edit: On closer reading, I think what they mean is that the precision for edge placement is about .1mm, but the finest width of an extrusion is going to be something larger than .35mm, maybe up to .5mm. So you can lay layers of plastic .5mm wide with .1mm precision, or some such.

I have this little piano lamp I've used as a reading lamp for years, and the lampshade thingy -- the tube that confines the light to one axis has disintegrated. The thing is more than 40 years old so no chance of getting a new one, but I love this lamp -- probably not $600 worth though....

But one of my Outbound Model 125 Laptops is also missing a couple of little latch thingies, and I could make replacements for those -- a bear to model those though.

And model rockets. I could do so many cool shapes for model rockets. Custom nose cones, and fin cans, and stuff.

And I have a ten-year-old....I could replace him with plastic -- uh, no, that's not what I meant. He would love it.

Any idea whether the ABS plastic is typical for 3D printing? I've read that some of the plastics used are extremely durable and strong, but I don't remember what kind that was. I think it was for a powder sintering process.

The cool thing about this little lamp is that it has a tiny little cylindrical base (small footprint) about 3"D X 2"H and then there's a telescoping boom mounted on that base, like an old radio antenna. The boom pivots forwards and backwards on the base, so it can stand straight up from the base, or lean way over forward, to reach over the music and keyboard of a piano.

The lamp part is at the end of the boom, and it pivots and rotates on the boom. The lamp portion is also a cylinder, the same diameter as the base, and about 3" long with the shade. If you collapse the boom all the way, you're left with the two cyclinders sitting on top of each other, and you have a compact little package about 3"D X 5"H

The base contains a simple transformer, and the lamp bulb is a car 12V/14.7V tail light bulb.

A few new lamps come close, but they either have a (relatively) giant base, or the boom doesn't telescope, or other similar limitations. This one is such a clean and elegant design. It has a few electrical contact problems, mainly where the boom connects with the pivoting/rotating lamp portion, but I bought an electroplating kit to remedy that. And I had to rebuild the bakelite portion of the guts out of perf board at one point.

 

olePigeon

Well-known member
Printing might work for smaller pieces, but if you want to replicate an entire case, you're probably better off with a 4-axis CNC router and block of plastic (could get away with 3-axis if you make sure to line it up perfectly for each side.)

 

Trash80toHP_Mini

NIGHT STALKER
You're forgetting that with a plastic welder, you can join any number of 6 x 6 x 6 sections together to build anything you desire . . .

. . . you can even print your own perfectly matched welding rod in 6" sections! :approve:

A block of ABS of the proper size would be markedly more expensive, rough casting a blank might be an answer . . .

. . . I wonder how many times you can re-cast ABS pellet waste, bad parts, etc?

Gotta figure out which rare lens, accessory or Leica knock-off I can live without. :'(

trag, I checked out your rockets, great stuff! Lemme know if you want the trick to getting perfectly sharp lines on your next V-2. [;)] ]'>

 

tt

Well-known member
I would rather measure parts and make models from scratch than do 3D scans. Most parts are probably simple enough. 3D scanning could be a good second source to verify some tricky measurements like curved surfaces and mating interfaces. For making parts, there has to be some competitive shops that can make stuff for you with tools that are 10x the cost of your budget with much better results. MakerBot ≠ 3D printing (a very crude representation of the possibilities of 3D printing)!!!

 

Trash80toHP_Mini

NIGHT STALKER
Digitizing 2-D shapes from manually taken measurements is ZERO fun, trust me on this one.

Now for an alternative to a $5k+ SolidWorks Standard license? :-/

 

tt

Well-known member
I have done it quite a lot and it is not too bad if you have the patience...but I do 3D modeling for work (sometimes) and have access to SolidWorks 2012 so my perspective is a little different.

I think it would be cool to have a super detailed model of a compact mac case, but printing one now would not be a good idea, maybe a front bezel would be fine, like making a MacTwiggy. Once someone makes a model once, if people are willing to share models, others don't have to do it again and can shop around for 3D printing houses.

 

Trash80toHP_Mini

NIGHT STALKER
I found that doing so for graphics was tedious, as was digitizing on a tablet as well. Fontographer's tools and scanned templates were the bomb!

I'd be happy with just designing the TwiggyMac bezel model with tabs on the inside to clamp 6 x 6 x 6 sections together in alignment. Welding the sections together with MEK and then removing thin tabs would be a breeze.

Heck, you could design the tabs to click together without the need for clamps or even hassling with alignment! }:)

Local lil' bro runs SolidWorks at work too, but that's out of the question for me. Is there any freely available open source package running under Linux that might be usable?

I could upgrade to a better version of X if I had to for the Mac as well. Would the Mini be up to the task if there's a package that's affordable?

Maybe I'll need to sell off a bit more of my toy collection and go whole hog on this new hobby, I'll need to ponder a bit, no rush, the longer I wait the better the trade off should get. This is no time to be selling collectibles and the new toys will be getting larger and less expensive while I wait for the right time and the right buyers.

 

tt

Well-known member
Several years ago I tried Alibre Design Xpress. I think it was decent at the time, it might have some limitations if it is still free. I'm not sure if 3D rendering programs would be good for making engineering models. Sketch-up just doesn't seem precise enough and exporting can be limited for free versions. Autodesk might have something free.

 

bd1308

Well-known member
Ya know, this is something I want to do someday. I went to a local conference and went to a Kinect seminar where the host (he works for Microsoft) was talking about leveraging the new API for Kinect, and that by using it, you can somewhat get a 3D model of an object in space. The example was pretty darn accurate too, he modeled his mouse, and each point corresponded (from the point of view of the kinect) pretty acuurately where it should be.

Very interesting, but for simpler parts, I'd just measure with some calipers and such. 3D printing is awesome, I have seen/used them at college (I was in ME) and it seems "cheap enough" to build -- $900-1300+ depending on size of the object you want to print is.

 
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