Basically it’s a hexapod turned sideways with half of the legs moved what was upwards but now sideways.
This design gives it the possibility to roll using its legs pushing it forward. It can also crawl or maybe more like swimming in sand. It can also walk just like any normal hexapod.
It will be autonomous and I’m planning to make it able to chat with it (i’ll see how much power i can squeeze out of that main board). I’m just gonna try to do as much as possible with it. It’ll be a really great development platform for me to learn about robotics.
In the pictures above you can see one of the flat sides of the cylinder that makes the body. There will be another disc on top if this with holes for ball bearings that will be attached to the servo horns. Is there anyone with an idea on how i could do that? The ball bearings doesn’t need to be directly attached to them. They are pretty large and have a 7 mm hole so I could cram in a 7 mm rod into it, but then that rod needs to be attached to the servo horns. Any ideas?
Oh yeah, I lost my track a little. Yeah, so the body is constructed out of acrylic which is a quite neat material. I created my own acrylic glue out of small acrylic pieces and acetone. I was really surprised of how well it works. Glueing with this stuff is more like welding so the glued pieces literally becomes one piece. This makes it easy to create complex shapes without any extra material like spacers , screws and such.
I found a solution to what i asked about in my previous post.
On the servo horns, i glued a piece of acrylic with a hole shaped lite a hexagon, just like the head of some screws. Then i just stuck such an screw through the ball bearings and then fitting their heads in the hole at the acrylic piece. The result is shown below. The three screw outputs should now be attached to three legs that I will be making as my next task. Then I’ll just repeat the same process again for the other side and attach them to each other, plus the electronics of course!
Yeah, I didn’t make that really clear. It wouldn’t still be really normal, because the legs is composed a little different.
It could be solved by having the body rotated is such way that one of the legs is as near ground as possible. Then the other legs will have to rotate so that they’re angled downward. The nearest angle compared to downward will however be ±30 degrees. But if they have an angle of ±40 degrees it will be enough for walking.
Anyway, thanks for all the feedback. I’ll soon update with more pictures when i have the first leg done.
I also received my embedded board! I have tons of fun playing with it now and thats the reason the legs got delayed two days.
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So this is how the legs will look. They are made completely out of acrylic except for the screws that holds the servos, the servo horns and the ball bearings.
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Legs retracted. They get really compact which will be neat because the idea is that i should be able to carry this robot around in city and such.
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Retracted leg again. I don’t know if you are able to see how looks like because of the image quality, but the acrylic above the servos is the tibia and lays right on top of the femur.
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This is how the legs will be attached to the body. So think of three of these legs attached on each of the screws. In addition to that, imagine another side of the robot that is this side but mirrored and. That is how the complete robot will look.
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This is the main hardware that i will be using. In the top is the webcam, to the left an Arduino board, to the right, the embedded board, and in the middle an SSC-32.
Great work! The parts look great. I’m realy looking forward to see more off this exciting project!
Just a little hint about the pictures: Use a tripod or something to hold your camera stable while taking photos in low light. 0,6 sec shutter speed is too slow (I checked the EXIF data ). Using higher ISO or flash might help too.
It’s been a while now since my last update and I haven’t made too much visible progress either - I’ve had too much of a summer . However, I’ve made at least one of every kind of part, so now it should be fairly easy to remake the same process. Last time I wrote here, I had made one leg, which is what I still only have, plus a half made one. It’s completely remade, but in a different material. Now I’m using shapelock. a plastic that melts at pretty low temperature, but doesn’t melt completely and instead become reshapeable, somewhat like clay. It’s much faster to produce parts with shapelock instead of acrylic.
Thanks for all the tips about taking photos. I would’ve used them if I wasn’t stuck with my old camera (It doesn’t have any ISO settings and can’t take very sharp photos anyway). xs130.xs.to/xs130/08310/aaaa0001777.jpg
Cool! Have you made all these (white) parts with shapelock? Isn’t that the same material Crabfu used?
Hmm maybe I’ve to google shapelock first before I ask to many questions about how you did it…
Or, wait a minute… I think I saw some other parts in the background, did you put the shapelock on the outside of these plastic parts?
Great work, looking forward to see more of your poject.
Correct, the white parts is made of shapelock, and yes, it’s the same material Crabfu used.
The C-brackets are made using the mold in the following picture. It’s made of acrylics as well. The moldable shapelock is thick and will not run out of the mold but instead stick to the walls of the mold. I just put the right amount of shapelock to fill the trace. It’s really not a big deal if there is too much or too litte. I can just sand off excess material of put some extra on afterwards.
The extension on the tibia is handmade though. But it’s easy to remake the same shape because it follows the side of the femur when completely retracted.
I’m a little stuck at the part where I have to drill through M8 screws to be able to fasten them to the coxa parts. It’s really, really hard to drill in them, both because it’s a hard material and round in shape. I managed to destroy several of my dads tools in the process Any tips on drilling through a screw? I have two screws left to drill and i don’t want to break any more screwing bits or something like that.
I’ve actually considered painting it - with a white color. The shapelock seems to get a little yellowish hue after a time, but i want it to stay in pure Mac-white color. I will probably color it along with the transparent acrylic.
Next up, I will make the second end of the cylinder body and then I will connect them, make housing for electronics and such, and then I’m pretty much done - with the mechanical parts. So then it’s finally time to program it and make the thing alive!
I hope I’ll get done soon, because in 9 days i will move, to study. You know what i will study? Yes, correct! I will study engineering in robotics at Mälardalens university in Sweden. And I’ll be there for five years! Could my life get any better? I won’t have any equipment to work on the mechanical stuff at the apartment I will live in so if I want to get Pirrh done I will have to do so before I move. Of course there is a workshop at the school (and they even have a 3D printer!), but I don’t know how long it will take before we do some work there or if I’m able to work on personal projects in the schools workshop.
) is the continuation of my previous project, Spider P.I.G.
). Using higher ISO or flash might help too.
Any tips on drilling through a screw? I have two screws left to drill and i don’t want to break any more screwing bits or something like that.
