What is the metal, engineering equivalent of an erector set?

April 6, 2006 9:53 PM

I need to make a relatively small (incorporating 1/4" rods) metal assembly. What is the metal, engineering equivalent of an erector set?

I'm designing a widget, and could use some sort of product that would allow me a lot of design flexibility. The metal assembly I'm trying to build needs to rigidly connect to some aluminum plates, have some moving joints, have other parts that are rigidly connected to a 1/4" aluminum rod (a wheel axel), give me a place to attach a spring, etc.

Is there an engineering product out there that's kind of like an erector set, and would let me tinker until I get it just right? I'm looking for something a little more versatile than drilling the hell out of thin aluminum plates and Ls and stuff, but something that is not so specialized that it won't accept thin aluminum rods and plates that I've drilled the hell out of.

Bonus points if the main support devices (lets pretend they're strut channel*, which may well be my solution) are relatively small, say between 3/8 and 3/4" in diameter.

* -

posted by sirion to Technology (13 answers total)

Response by poster: Followup question: If I'm looking for widget-building stuff, and it's not at mcmaster or smallparts.com, where else do I go?
posted by sirion at 9:54 PM on April 6, 2006

Local machine shops?

Local laser/water cutting shops?
posted by PurplePorpoise at 10:29 PM on April 6, 2006

So based on your picture, are we to assume you've already looked at something like Unistrut, and ruled it out?

They do have a line of 13/16" channels shaped like you show above, in ASTM B221 (Type 6063-T6) extruded aluminum.
posted by pitchblende at 10:29 PM on April 6, 2006

Response by poster: All I've looked through is McMaster-Carr and SmallParts. I'll check out unistrut; certainly looks promising.
posted by sirion at 10:50 PM on April 6, 2006

"80/20" bills itself as "The Industrial Erector Set"
http://www.8020.net/
It may not be what you need, but just putting it out there.
posted by blenderfish at 10:52 PM on April 6, 2006

Meccano?
posted by normy at 11:35 PM on April 6, 2006

Here are some other useful vendors with large industrial type inventories.

http://www.grainger.com/Grainger/wwg/start.shtml

http://www1.mscdirect.com/cgi/nnsrhm

http://www.fastenal.com/web/home.ex

Happy Hunting!
posted by tbird at 12:16 AM on April 7, 2006

Street sign posts often are similar to your diagram: channeled or square stock (galvanized steel?) with regularly spaced holes. The only example I could find in a quick search is this. I don't know if the dimensions would work for you or how you'd acquire any other than scrounging. I once used some (that I got from the town dump) to make a heavy-duty bench for a piece of machinery.
posted by TimeFactor at 12:33 AM on April 7, 2006

Small Parts, Inc.

This page is a huge list of suppliers of all kinds of components (the people who built the page like robots).

Stock Drive Products (SDP) has lots of small bearings, gears, etc. Their stuff is high-quality.
posted by Kirth Gerson at 3:58 AM on April 7, 2006

To echo Kirth, Small Parts isn't exactly cheap, but to get materials cheap, you need to buy in huge quantities, and that's where Small Parts helps. They're really good about getting orders out, and I've never had a problem with them.

Personally, I think your channel is right up there in the good idea category, and with a bunch of square tube and a drill press, you could make a version of it quickly. Add a mill, and you can even get the U channel version pretty quickly, at the cost of some strength.
posted by eriko at 6:03 AM on April 7, 2006

Have you looked at emachineshop? They're perfect for small custom jobs like this. Not always the cheapest option though. A local jobber might be your best bet.
posted by bonehead at 6:55 AM on April 7, 2006

8020 and Unistrut look absolutely awesome! In retrospect, I've seen bits and pieces of it around, but I've never thought about it seriously..

It would have made my thesis cheaper.
posted by Chuckles at 7:37 AM on April 7, 2006

Response by poster: 2nd impressions are that the unistrut 7000 series might be just right, and local suppliers only carry the bigger ones. Hmph!
posted by sirion at 8:49 AM on April 7, 2006