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Help Build a Giant Inflatable Instructables Robot Answered

Can you keep a secret?

For the Austin Maker Faire in October, I'm hoping to build an 8-foot tall inflatable Instructables Robot. I want it to be easy to find the Instructables booth.

For his wedding, Saul, built an inflatable elephant using many of the techniques from inflatable kite design and papercraft. There's a lot of CAD work required, and since I know there are some people here much better at Rhino and Blender than me, I'm asking for help. If we can pull it off, you'll get the joy of having something you designed be made very large.

Here's the process and where you can help:

1) creating a model of the robot that is appropriate for cutting in fabric, sewing together, and inflating. chooseausername did a brilliant job here, but the model has too many polygons, and just reducing the number of polygons in his model results in something that doesn't quite work.

So first, I need a model of the robot that is less than 1000 polygons while still retaining the robot's personality. Also, since it will be inflated, the robot's wheels should be retracted (its legs should just be cylinders of the same height as its legs plus wheels). We can print on the fabric, so the line on its belly doesn't need to be physical, but its buttons, eyes, ears, and antennae should stick out as they normally do; no need for individual fingers. Make sure all the normals point outward in the model.

Saul isn't quite ready to share his CAD files, so I've included screenshots of his elephant as an example. The full grey elephant has 1000 polygons.

2) modifying the model to account for real-world limitations and to make it easy to import into Pepakura Designer. As the elephant is symmetrical, Saul cut it in half, split out various body parts -- ensuring that they exactly fit back together on the vertices of the polygons (seam lines for sewing), -- and made some part of the ears a single piece of fabric which would not inflate. In the robot's case, we would probably split the legs, body, head, and ear-and-antennae assemblies. The antennae will probably need to be a slight larger diameter than they normally are. Since the robot isn't symmetric, we'll keep it whole.

3) using Pepekura to create panels

4) arranging the panels, adding seam allowances, and sewing instructions.

5) repeating steps 1 - 4 to create the bladders for inflation with a model that's slightly bigger than the skin.

6) getting a factory to cut and sew everything together.

As you can see, step 1 is the most important part. If you'd like to help, create a model of the robot, and add it to a step of the collaboration I've started here (PM me for an invite):
https://www.instructables.com/id/ETZ3QJSFKD1LWHU/
We definitely have more than one person working, as I'm sure everyone will have something valuable to contribute.

If you're interested in other giant inflatable creatures, leave a comment here. If we can streamline this process, we might make a complete zoo!

50 Replies

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ewilhelm (author)2011-11-21
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ewilhelm (author)2011-08-12

This project is alive again!

Thanks to some unreleased Autodesk software, I was able to make versions of the robot that should import nicely into Pepakura designer. Check out step 4 of the Instructable to see those files.

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Kiteman (author)ewilhelm2011-08-13

What software do we need to read those files?

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Lithium Rain (author)Kiteman2011-08-13

http://www.tamasoft.co.jp/pepakura-en/

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caitlinsdad (author)2008-09-10

We can figure out how to put a man on the moon but it is way tougher to create an inflatables Instructables Robot...

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TOCO (author)caitlinsdad2011-02-14

This is an ambitious project but I would love to see it finished. Would you bring it each year or would you give it to someone on the instructables team? (or are you on it?) I am only 14 now and have no way of getting to maker faire but when I am older (and can make it there) I would love to still see this at the maker faire each year.

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caitlinsdad (author)TOCO2011-02-14

I am only a lowly peasant that sows the seeds of discontent around here, I am not part of the staff. I just happen to live in a place(NYC, the greatest city in the world...not really) where they decided to have a Maker Faire and Instructables set up a booth there.

Anyway, build it and put it up as an instructable. Maybe the powers that be will recognize your awesomeness and use it at a Maker Faire. I brought along my Stargate Gong and they did display it at the booth though.

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TOCO (author)caitlinsdad2011-02-15

So you did finish it and you were able to display it?

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caitlinsdad (author)TOCO2011-02-15
This topic is actually more than two years ago. I don't know if they ever created an inflatable robot.

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Goodhart (author)caitlinsdad2011-02-14

Oh that was YOUR gong.....I must not have been paying attention, but I could have sworn no one told me that.....and yet....I somehow thought it was anyways.....peripheral hearing I guess :-)

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caitlinsdad (author)Goodhart2011-02-14

You must learn to trust...the Force...or at least listen to what the dogs tell you.

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I don't believe that they finished it in time for the Maker Faire. I hope that they do eventually have it at a Maker Faire though.

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Anoniempje (author)2008-09-06

I never been a big fan of reducing polygons.
So i made a new robot this evening in sketchup.

You could export this as KMZ4 and use pepakura 2 to open kmz files and unfold it. Try it out for size.

http://sketchup.google.com/3dwarehouse/details?mid=2989802328ccb0436886015e9ff33cde

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gowithflo (author)Anoniempje2008-09-06

hoboy.
I wish i had seen this earlier, I could have saved you some time. I spent a few years of my life learning and teaching this 3-D model-to-Huge Inflatable process ( http://www.gowithflo.net for a sample) . I can tell you the latest model above looks about perfect. Those polygons on your "reduced" 3Dstudio Max model from would have been a total B to sew, if not impossible. I'm still sifting through the threads and links but have you figured out how you are going to transfer the pattern to the fabric? what fabric? what blowers? let me know if you need my advices and I wont be mad you did not use my instructable in the first place (a rejection of expensive proprietary software) https://www.instructables.com/id/Making-patterns-from-3D-objects-sans-computers-or-/
best of luck! looks exciting/

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ewilhelm (author)gowithflo2008-09-06

I actually did consult your Instructable when reviewing my options. I decided I wanted to use fancy computers as an experiment, and for the experience. Like the elephant, I plan to rigidly inflate the robot with bladders, like an LEI kite. The fabric will be cut in a sail-cloth factory on a very large CNC cutting table. If this whole process just plain sucks, I'll be posting a forum topic asking for clay models of the Instructables Robot... I'd love to hear more about how you did some of the stuff shown on your portfolio.

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gowithflo (author)ewilhelm2008-09-07

Oh thanks for the ego massage! No it shouldn't suck at all. I'm so J you are having it cut CNC style. Very impressed by the tech you have at your disposal. Oh wow I'm looking at that elephant! From the thumbnails I thought the photos at the end were CG renderings! (wait they aren't are they?) Obviously if that Saul guy is helping you'll be just fine.

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ewilhelm (author)gowithflo2008-09-09

Do you know of a shrinkwrapping tool that will create a single "watertight" mesh from the surfaces of a bunch of disjoint meshes? That's my latest thought on how to do this cleanly, documented here:
https://www.instructables.com/id/SIL5SO4FKXBQ27M/

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gowithflo (author)ewilhelm2008-09-09

From my experience it is infinitely better to start with as simple of a model as possible, much like the one Anoniempje made. Normally a hi res 3D model is good when you are making things for the screen, but in patterning for real world inflatables you can get away with a really lo-res form (fewest facets) you wont have as many pattern pieces to cut out and the very fact of it being inflated will make it blob out smoothly. Also the part with all the extra polygons from cutting into something not exactly planar would could be avoided by cutting into something um .... more planar. I know I am not answering your question, don't be mad -- but I think you are making this too hard for yourself by starting with a very complex model and trying to make it simpler. But lets say you have a good reason for doing it this way, I know you expressed an interest it being a bit "wonky". I used to use Formz's unfold tool. Also Touch Cad is excellent, will even include seam allowance. Are you using Rhino? I have heard that is great way to go, but have not used it myself since switching to clay. Might I suggest you start with a form like the one Anoniempje made and tweak the symmetry a bit here and there for desired off-kilteredness?

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ewilhelm (author)gowithflo2008-09-07

No, the images are cell-phone camera, which is why they don't look so good. But, the elephant is in fact real, and stiff enough that you can climb on its back.

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Keith-Kid (author)ewilhelm2008-09-07

You can climb on its back?! Awesome!

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caitlinsdad (author)2008-09-08

I think I am with gowithflo on that you are over-engineering this thing, but then again, we may be looking from the more creative-create-and-do point of view.

This may be the start of comment-ibles; an instructable in a comment...

Gather some plastic shopping bags to recycle and some tape.
Cut bags to rough shape and start taping seams.
The corners of the bag taped down made perfect rounded shoulders of the Robot.
Build shapes on top of each other.
Poke internal venting holes for air to inflate.
Use marker to draw on details.
Inflate with reverse end of shop-vac.
Adjust inflation with vent holes poked in back.
Let go to create projectile...

Maybe 3 or 4 polygons?
Now that was easy...

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ewilhelm (author)caitlinsdad2008-09-09

Sweet robot. I should probably make an edit to the original problem statement stating that I like learning new CAD programs, and I like over-engineering stuff. The experience of getting this to work in the manner I've outlined will be enjoyable to me. Basically, I'm an engineer, and for Instructables I write emails all day long. Reducing polygons is my idea of fun (when the wind isn't blowing...).

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bumpus (author)ewilhelm2008-09-09
I really wish I had CAD on my computer.. I would so help out with this.. But I do have a question, if you are working with a solid, (even though the robot will be inflatable, you make a solid mock-up) you shouldn't really be using AutoCAD. Autodesk Inventor is more in-depth when it comes to working with solids, however you can import drawings AutoCAD drawings to Inventor..

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ewilhelm (author)bumpus2008-09-09

AutoCAD hasn't entered into this project yet.

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caitlinsdad (author)ewilhelm2008-09-09

There's always more than one way to skin a robot. Just don't make it with a weak bladder. It will be hard to find the Little Robot's Room at the Faire. Punching keys and number crunches is good exercise.

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caitlinsdad (author)caitlinsdad2008-09-09

Another thought... Is there a Knex modeling package? You should be able to create a Knex wireframe and for those who do physical modeling where the limit of pieces approaches zero you should have the optimal solution for minimal amount of polygons. I haven't seen the Bucky Fullminster bot yet...

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caitlinsdad (author)caitlinsdad2008-09-08

OOooh, when stretched out makes one of those cool Burning Man air dancing thingys.

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comodore (author)2008-08-31
My suggestion, make it in segments:
  • head
  • body
  • left arm
  • right arm
  • left leg
  • right leg
Inflate one body part by one, if there is a tair it will be easy to repair and the robot won't collapse. Inflate it whit helium and hook up some wires to hold it. If you try to keep it inflated whit air by a fan it will fall.
I don't want to change your grate plan but maybe you could make a dancing Instructables robot. Two powerful fans blowing air upwards into the robots legs and the air escaping trough his arm...
As for the eyes,anntenas and knobs, I think it is best to make them out of foam or some plastic and attach them.
I would be very happy to help you whit suggestions, to bad I can't come and help you build it!

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=SMART= (author)comodore2008-08-31

Good idea ! p.s. why do you say whit instead of with ?

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Brennn10 (author)=SMART=2008-09-01

He is from Serbia. So he might not know the conventional spelling of some English words.

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Derin (author)Brennn102008-09-03
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comodore (author)Derin2008-09-06

Cool, where have you been?

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Derin (author)comodore2008-09-06

we just saw belgrade,then we went on to Hungary

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comodore (author)Derin2008-09-07

ooo, yea, you have to go trough Belgrade to get to the other side...

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=SMART= (author)Brennn102008-09-01

oh cool serbia ! i diddnt know that lol i thought he was American !

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bumpus (author)=SMART=2008-09-01

I got to have a conversation with Comodore in the chatroom. Its awesome to learn about different people's cultures! :D

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bumpus (author)JellyWoo2008-09-01

The instructables chatroom.

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lawizeg (author)bumpus2008-09-01

OH MY GOD. I did not know this. Where?

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lawizeg (author)bumpus2008-09-06
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comodore (author)Brennn102008-09-06

Thanks for backing me up! THANKS! :)

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whatsisface (author)2008-09-04

I found a plugin a while ago for 3DS Max that will reduce the number of polygons in a model, I'm not sure if it's useful, it may be a bit more intelligent than just reducing number of polygons in the program.

http://www.mootools.com/plugins/us/polygoncruncher/index.asp

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ewilhelm (author)whatsisface2008-09-05

I made major progress with this tool, and documented it in the above linked Instructable. Thanks!

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