Our schoolproject, the hexapod "Spider P.I.G"

Lynxmotion Legged Robots
1

Hi,

first, I just need to say how impressed I am of Lynxmotion. It’s the highest quality robot store I’ve seen so far, and I spent a huge (really huge) amount of time looking up robot stores!

Anyway, I’m working on a hexapod as a school project. We call it Spider P.I.G! We’ve just started constructing it (We spent this whole semester on planning, funding and ordering parts). However, before We get any further, I thought it would be great to hear some of Your suggestions if there is something we planned that really won’t make it.

Here’s a couple of CAD images (sorry it’s so sketchy, I’m no good with CAD :frowning: ):i

xs323.xs.to/xs323/08014/spider_pig_leg.png.xs.jpg
xs123.xs.to/xs123/08014/spider_pig.png.xs.jpg

We will use S03T GWS servos though i ordered 6 of each of the different speeds. Thought it was a great idea when ordering, especially for the innermost joint where We’ll put the fastest servos. I’m not sure anymore though.

We already made the torso (may i call it that on a hexapod?) and here is the result (I’m pretty happy of the result considering the tools we were restricted to):
xs323.xs.to/xs323/08014/done.jpg.xs.jpg
So if something is in need of change it can’t be the torso, cause We’re not remaking it! :stuck_out_tongue: It took a whole lot of time.

[edit]The torso may look thin and fragile, but theres more to it. There will be a body of several layers of styrofoam on top of this piece (and there will be layers of plastic in between the styrofoam so that we can screw everything together).

Also, I plan on making some kind of “spider silk” for the robot. By that i mean tape ^^ Now wouldn’t that be cool? It will have to roll out a strip of tape before it arrives to an edge. Then it can easily hurl over the edge and safely roll down through the tape to the floor. Not sure how it will be done exactly, but I have lot’s of partly ideas for how it will be done.

What do you think?

[edit] We’ve come further than stated in this post. Wrote this post a couple weeks ago, but there was an issue with the spambot block so i couldn’t post it.

2

I love the silk idea.

As a matter of fact i still have some hardware lying around I was planning to use on a sort of spiderweb-slinger :unamused:
High power motor with planetary gearbox, small dc actuated clutch etc…

Aah, if only i had the time to tinker with all those ideas in my head…

Keep us updated though, I’m interested in how the body will be built up of the several layers!

3

I have made lots of progress lately. Here’s some pictures (I hate my camera :frowning: ):

This was before i turned the coxa upside down. I had to do that because there will be another layer to stabilize it:
xs323.xs.to/xs323/08016/AAAA0065.JPG.xs.jpg

This is a blurry image of the coxa when it’s turned upside down:
xs323.xs.to/xs323/08016/AAAA0069.JPG.xs.jpg

I added some improvised hinges for the layer that will stabilize the coxa (the white stuff):
xs323.xs.to/xs323/08016/AAAA0075.JPG.xs.jpg

The tibias added. If anyone need to make some fast and cheap tibias, just use a wooden stick, flatten one side 3 cm in on the stick to make it fit more to the servos flat surface and hot glue it onto the servo. Results in very much rigidity. They are somewhat temporary though. Only to complete the torso left now:
xs123.xs.to/xs123/08016/AAAA0077.JPG.xs.jpg

She is pretty huge. From one toe tip to the opposite one, it is 74 cm (29.5 in):
xs123.xs.to/xs123/08016/AAAA0079.JPG.xs.jpg

Next, I’ll continue on the torso. But I’ll probably wait with that until i can work with my teammates.

4

it’s first segment of the leg is realy long compared to the tibia. is the matal in the first segment strong enough to hold up the robot? I have an impression that there a gust of wind the torsion on the legs are going to twist those pieces of metal. maybe not… who knows :laughing:

It’s a nice haxopod! is that the finish or are you going to paint it?

5

Yeah, I know, although it is still exactly as long as the tibia. When looking at others hexapods the femur is pretty short. My motivation for having them to the same length was to make it easy to calculate the positioning of the leg.

However, if I run into a problem here, I can always beef it up a little.

6

The material you are using looks like it’s 0.04" thick sheet metal. Very bendy. At the minimum you should add some breaks along the long dimension to add strength. But knowing too well the properties of your material, I strongly suspect you are going to have fatal failures on the femur and coxa. Good luck with it though.