All for my new robot project - a Hexapod. I did a quick 3d renedering on how it is going to walk. If I have anything of interest to show I'll make a new 'robot' entry :)
Hey - btw; Your robot looks awsome!
And to what I wrote above; Notice that you can chose how so see the comments!
"I would like to see roboteers have editorial rights over their own robots, so they can tidy up the pages" Well they already have! JUst click edit!?!
Are you talking about the comments? Well - we cannot edit them, excactly; Someone may link to them. Click on the headline of a comment. You get the URL with that comment. I sometimes link to that, and should do it more often. Say when someone is making a good remark on a component, I / we ought to enter the component (that anyone can edit btw) - and write "Here is a comment related.."
Robot or blog?
If you feel youmostly are going on about your life, what you think of stuff etc, it is a blog. If you are focusing on a robot-project, it is a robot that you should enter.It is absolutely to prefer to enter a robot as a robot!
Have a look at my 360bot- project. I am not showing all images on the page, but link to an online album. Considering what you do make keep the page cleaner.
And people commenting can also help, by refraining from too many non relevant postings etc :)
I'd love to have the system to use multiple pages etc, but it is a thin walk between feutures and usability. Heck, we have people who find it difficult to enter a robot as it is! (And I am going to make some instructions on that some time)
So I made a few quick sketches today of how I want to make to robot look. And how the mechanical part is going to work. After putting my ideas on paper I downloaded google sketchup and made a 3d model of it. Then rendered the google sketchup with pov-ray. And I must say, I'm impressed on google sketchup / pov-ray. I looks really nice IMHO. Well... see for yourself
Hopefully my robot will look like the image above when finished. Back to the drawing board for a nice 2D cad file with metrics, so I can begin cutting the wood (by hand :( It would be really nice to have a CNC for this project, ah well, you can't have everything).
Hmm, I should make this a blog or robot entry. It's getting out of hand.
If you can find some plastic or aluminium box section extrusion about 30mm by 20mm (about the width of the servo body, but slightly taller) and fit the servos into it, that gives you and nice "bottom" (!) that you can bore into and stick a bolt through.
I did this once with PVC and it was very very good. The biggest pain is cutting the square hole for the servo.
I couldn't find the extrustion again, so I used 30mm U-section aluminium extrusion. It was less good and much more difficult to cut the holes.
First, yes. That is brilliant looking and I hope you see it through.
Second, "POV-ray"? Does Sketch up render in POVray? I've been using POVray for years and did not know this.
Last, Robot or blog. Hmmmm.... You got do both. You're getting loads of good feedback here. You could make a "robot" and put a request on it that anyone who wants to comment comments to the blog.
I have found this problem with my robots as well. the Rboto pages becoem cluttered. I think we may need to make an executive decistion. I would like to see roboteers have editorial rights over their own robots, so they can tidy up the pages. The danger is that some useful information might get lost.
I'll put it on the agenda for the next admins meeting.
That is looking nice. I see you're only using two screws to attach each of the first two servos for each leg to that block that connects them. Will that be strong enough? It seems like this robot could end up weighing a decent amount, and I'd be worried that it would rip those screws out of the block.
Power-wise, BOA may be right that you'll need something more hefty (I think the 7.2v R/C car pack sounds perfect), but it doesn't hurt to try it with the 4 AAs and see what happens.
This definitely is coming together enough that it would make more sense to post it as a robot. You've got CAD pictures and everything :) I'll have to give Google Sketchup a try.
"4 DD cells, 20 servos, I like it :)"
- Indeed it are 4 rechargable AA cells, not DD :)
"What is your servo controller?"
My servo controller will be this the serial-servo-controller-32 (SSC-32). It can handle up to 32 servo's at a time, simultaneously. It is a very powerfull board with open source software. The microcontroller which is going to give the serial commands to the SSC-32 will be the Atom Basic Pro 28 (used earlier in my Rebel robots).
"Will your hexa be blind?"
No it won't be blind, but for the time being I will first try it to make it walk. Baby steps :) Once I succeeded in making it walk and turn I will ad a pan and tilt system with a ultrasonic sound sensor mounted on it.
"How are you going to hook them up?"
I make everything with some light wood "triplex" (don't know what it is called in english?) First I will design everything in some cad program (already started with that) and then cut everything, and then the fun can begin.
"BUT, drawing 600-900mA from your pack is going to cause a voltage drop on your PIC and it will brown out."
First, the uC won't be a PIC but a Atom Basic Pro, and indeed I will power the uC with a 9V battery and the servo's with 4 AA cells (maybe a 7.2 pack in the future). I hooked up all 20 servo's and moved them at the same time, everything worked fine, so no problemo. If it turns out that it will reset, I wil buy more batteries :)
"Could this not be done with 9 servos?"
I want 3 DOF (degrees of freedom) for each leg. So the bot can lift it's leg, turn the leg ford and back and also adjust the body height. It has 6 legs, so 6x3 = 18 servo's. Then I need 2 more servo's for the pan and tilt system I will make for it's "head". So it's head can move left, right and up, down.
First, the uC won't be a PIC but a Atom Basic Pro, and indeed I will power the uC with a 9V battery and the servo's with 4 AA cells (maybe a 7.2 pack in the future).
Noted. Force of habit. When you're used to the best, it's hard to accept that some folk still use inferior technology :-)
I hooked up all 20 servo's and moved them at the same time, everything worked fine, so no problemo. If it turns out that it will reset, I wil buy more batteries :)
Of course you can make them move, but can you make them all lift 100g at the same time? Let me put it another way: I can make the windscreen wiper motor of a car move from 4 AA cells, but I doubt it would carry around a 190lb adult.
I don;t think you need worry about teh servos "reset". The analog control board will definitely brown out under load, but because it's analog, it'll pick up again right where it left off and you'll probably not even notice.
You know what? You might be better off with four DDs! Here's the paradox: you'll probably need more power to lift the batteries!