Thats the one thing im continually trying to do… think of a “useful” robot.
The only thing is, i much prefer the “cool” factor over “purpose”. 8)
Well, everything you build seems to have quite a coolness factor, at least in my book, so I don’t think you have to worry there. Eight legs would be very useful for climbing also - I mean serious climbing. The usefulness of this would depend on the body design and leg spacing though.
Remember my design for Walk-N-Roll? Longer body with wider spacing between the legs.
8-Dale
thanks dale. i think we are all inspiring from each other and the community here is second to non, and i think that plays a massive part in our builds, designs and ideas. im very interested to see what’s waiting round the corner. 
id like to build a small or “Compact” strong robot and i feel the design of the T-hex leg gives that. They have an excellent range length, and look really cool.
At the moment im experimenting with the idea of making a T-hex quad, and it should then move on to Hex, followed by Octo!
8)
Hey Jonny,
I hope you didn’t take that guy apart yet. 
I was thinking over the long weekend. We need to make a custom chassis for that beast. Can you tell me the smallest diameter circle the legs would work at without touching each other? 8)
no iv not taken it apart. plenty more play time left in that. a custom chassis would be cool. in fact iv been thinking about it to.
anyway i did mention that to zenta that with the round chassis when standing neutral the legs are 80mm apart, and 30mm when moved in a “rotating” fashion.
coxa distance is 136mm on the round chassis, so in order to shrink that distance you may get away with 106.
i will take a picture later when i get home and we can work it out properly.
Here is another video of the ID3. i thought it deserved another play.
Looks great! You are doing a lot of great work!
Kurt
thanks kurt,
cant get enough at the moment! lol.
Once i get my other project finished i have another idea in mind!! 8)
any other thoughts on this. im thinking of trying out the in-line chassis too.
I was waiting for you. Something about taking the time to do it right… Plus I was a little distracted with the whole new website thing. lol Yes I would like to send you a perfectly sized smaller body for the final video. You need to borrow a better camera.
Lol. i can draw up a design if you wish, seeing that i have the leg dimensions here and can test ideas. yes the new website looks fantastic. very clean. not that it was messy before you understand, but i do like the new look. 8)
i have a really good camera but it doesnt have a memory chip that i can plug into my PC. its a mini “TAPE” one. very good quality too.
ill sort something out.
thanks.
Jonny,
Seems like 3DOF legs would be a little wasted on an in-line 'bot.
How about different leg lengths? More spider-like?
Alan KM6VV
That’s a possibility. duplicate IK routines to handle the different DOFs. We make 6 (4) calls to the IK code, so it would be simple to use two calls. Might even be able to add a parameter for controlling the DOF in the call.
How do the insects and spiders do it? Spiders, I think have longer leg parts to differentiate their usages.
I was considering different leg lengths for little cat. Might get there yet.
Alan KM6VV
I just saw a parallelogram drive structure that I think might apply here. It’s called a Sine/Cosine drive (at least by us) and is used in a slave arm (company drawing is of course much better, but I can’t publish it).
http://www.Marconettengineering.com/SineDrive.jpg
You’ll notice that the two linkages are relationship to each other, i.e., or in quadrature, if you prefer.
Not being an ME, I can’t attest to the advantages with out doing some research, but I’m guessing that it eliminates “singularity”, the tendency for mechanisms to “lock up” at certain points in some designs.
I don’t know if this technique can be applied here, or even if it would be useful. I’d like to know the part numbers of the links and balls used in the current indirect-drive leg. Maybe I’ll order some parts and try it out!
Alan KM6VV
http://i531.photobucket.com/albums/dd355/innerbreed/jimsdesign.jpg
just to make one Mechanical drive you would need:
1x lynxmotion.com/p-339-ball-li … -pair.aspx
1x lynxmotion.com/p-338-threade … -56-6.aspx
2x lynxmotion.com/p-505-hitec-s … apped.aspx
1x lynxmotion.com/p-484-ball-be … b-kit.aspx
and obviously servos, a cross brace (femur).
how you construct it would be up to you.
this should give you the main parts needed.
Hi Jonny,
Thanks for the links!
lynxmotion.com/p-339-ball-li … -pair.aspx
I looked at this again, and I can see a group of faint yellow.
I played with the contrast and gamma of the pix, and I can now make out the plastic pieces that slip over the ball ends (rod ends). That was what was confusing me before, I couldn’t find the rod ends!
Seeing all the parts makes it obvious.
Thanks!
Alan KM6VV
I’ll take a new picture. Maybe I can come up with something that will be a little more clear. Sorry for the confusion.
Edit: This should be a *little *bit better, yeah?
much better.
Yes, much better!
Thanks for the update. Now I know what I’m looking at!
Alan KM6VV