making an armature for a human-sized bot

What is the purpose of  your robot ?
Is it to be a "showbot" for use at trade shows or something like that ? Or
just a cool project to work on?
Does it need to be able to lift and hold 10 lbs ? Need to be able to lift
anything at all?
All of that could determine the skeleton's structure & material. Personally,
I am a fan of t-slot aluminum extrusions because you can reconfigure it
easily once you get used to how things work. You might even want to mix
materials - like having a central beam of t-slot aluminum, and hang various
other parts made of other materials off of that.

Another thing you might want to consider is using cheap 1x1 or 2x2 lumber
wood to prototype everything together. It's available from your local
building supply. I suggest wood to start because you can easily drill & cut
it with regular DIY power tools that most guys have in their tool box. You
might make 100s of changes to it and have 100s of holes drilled in it - but
you won't care because once you get your design fleshed out more then you
can change to more expensive metal or PVC.

Also, let us know what part of the country (USA ?) or world you live in.
Many of the guys on here can give you specific stores and scrap yards to
scavenge from in areas they are familiar with.

One more thing, just start Googling like crazy using phrases like "build
your own android" and see what others have done. You're sure to get some
ideas and discover parts & materials you didn't even know existed. The very
first link I found doing just that is this one:
http://howtoandroid.com/HowToBuildRobotHead.html  - which is a pretty good
writeup on building a nice head.

This page is a great jumping off point:
http://www.androidworld.com/prod02.htm

My 2 favorite How-To books on hobby robots is Robot Builder's Bonanza (2nd
edition) and Robot Builder's Sourcebook. Both have a wealth of info on
scavenged parts & things you haven't even thought of yet.

Hope that helps!
JCD

Yes, that's the basic idea.  I'd like it to be a mascot for our local
club, and also a crowd-drawer for local robotics events.


No, mostly it needs to be able to wave its arms around, pan/tilt its
head, and generally "do the robot" (i.e. dance and gesticulate).  I
might have it hand out cards or flyers, if I can think of a reliable way
to pick them up, but that's definitely a down-the-road feature.


That sounds good.  Where do you get that stuff?  And what tools do you
use to work it?


That's a point.  It also won't matter much if I'm able to make body
plates to hide the ugliness.  I can certainly make straight cuts (forgot
to mention my circular saw -- got that just a month or two ago!), but I
don't have anything that could cut shaped pieces.  Perhaps I need to
invest in a band saw, jig saw, or a milling attachment for my Dremel?  
What would you recommend?  (Now I wish I'd paid more attention in Shop
class years ago!)


I'm in northern Colorado, and I do have a good group of guys to help
with that sort of thing.  But I was looking to cast a wider experience
net when it comes to choosing the basic material.


Believe me, I've spent a lot of time surfing those sites.  It's
surprising how difficult it is to find a good reference for this part of
the process, though.  


Yeah, that's a neat one, though it starts with a very cool
robotic-looking mannequin, which the author found by luck, and he
doesn't have any suggestions on where you might find one or what to use
instead.  (I've looked, and so far haven't had that much luck, but
that's a different issue -- I think I have a plan for the head.)


Ah yes, I call this the "rainbow links page" due to the brightly colored
link list on the left.  There's a lot of fun stuff there, though mostly
about things you can buy for $20K, or being built for even more at
university or corporate labs.  Not much for the home builder, unless I
missed it.


Good point, maybe I do need to take another trip to the bookstore.  I've
got half a dozen robotics books of varying quality, but they all focus
on tabletop bots, and don't go into this sort of mechanics at all.  I
should perhaps be looking up "animatronics" instead for this project.  
Also, I don't have either of those books you mention, so I'll be sure to
look them over.

Thanks,
- Joe

--
"Polywell" fusion -- an approach to nuclear fusion that might actually work.
Learn more and discuss via:  <http://www.strout.net/info/science/polywell/>

I've been using the 80-20 brand of stuff and am selling that in my line of
robot kits. I'll be glad to post a link if you like.

I get some of the stuff from eBay and some of it locally.

But you can get thinner and less expensive aluminum channel from your local
DIY super-store. Do they have Home Depot or Lowes in Colorado? If it's going
to be hidden eventually, I would recommend that kind of aluminum. The 80-20
stuff is kinda expensive and looks really cool, I think, but why pay for it
if it's going to be hidden ?

You can also get aluminum square tube that might be perfect for your needs.
The right kind drills almost as easy as wood. You may only need a hack saw
if you're not going to cut much of it. If you're going to cut a lot of it,
get a $99 mitre saw  and a non-ferrous metal cutting blade or a metal
cut-off blade (abrasive), depending on the precision you need.

The tools I use are a drill press, mitre saw with metal cutting blade, and a
desktop milling machine. Hacksaw, set of files, and standard power drill are
also used frequently. I doubt you would need all of these, although the
Sherline mill *is* a blast!

Good luck and let us see what you come up with !
JCD

Alumunum channel is pretty good. It's readily available, cheap, and you
can cut and drill it with ordinary tools. However, I'd invest in a basic
miter saw with aluminum cutoff blade to make the work go faster.

I've built many robot frames out of channel stock over the last 20
years. When done right the frame can support in exceess of 100-150
pounds.

-- Gordon

Sounds good.  Do you have a good online source for this stuff?  Or is it
one of those find-a-local-supplier type things?

Thanks,
- Joe

--
"Polywell" fusion -- an approach to nuclear fusion that might actually work.
Learn more and discuss via:  <http://www.strout.net/info/science/polywell/>