- posted
20 years ago
Some amazing video of Vstone Robovie-M
- Vote on answer
- posted
20 years ago
Here're some other good links:
Robo One:
- Vote on answer
- posted
20 years ago
I wanted to buy a kit from vstone, but they never replied to my queries (emailed them in Japanese and English). Do you or anyone else here know of a place that would have a walkthrough on building a similar robot? I've looked around for a while, and haven't found anything. Just very small pieces of information for particular joints and such. Thank you.
- Dave
- Vote on answer
- posted
20 years ago
I'm building a clone of their robot right now. It's not too hard. I'm willing to release copies of the drawing files I'm using. I've got the two-axis joints all made and the thighs right now and I'll be working on the shins and the feet in the next week or two.
I bought a cheap bandsaw, ordered 0.062" thick aluminum, printed up outlines of the parts and cut the aluminum to size. It's been fairly easy to do. The aluminum cost me about $30.00 and 12 servos (I'm just concentrating on the legs for now) should cost about $110. I'm using 1/8" x 5/16" flanged bearings for the joints which I can get for about $1.75 each (12 x 1.75 = $21.00). The bandsaw cost me $80. Total Costs so far:
Item Cost Bandsaw $80.00 0.060" Aluminum $30.00 12 bearings $21.00 12 servos $110.00 ------------- Total $241.00
I already had a drill press and vise to bend the aluminum so I'm not including them in the cost.
The one thing that's been slowing me down is the cost of the servos (I've set a monthly hobby budget so I'm not going ordering everything I need all at once). I'm designing with Hitec HS-311's which are not very strong (but available at $8.95 each). I haven't ordered all of the servos but I'll probably do it in the next day or two. I'll know in the next few weeks whether they're suitable or not. My initial tests are pretty promising, but having more powerful servos is always better.
The good thing is that the more powerful servos have the same dimensions so I should be able to substitute them later. It may not be that easy to substitute, but it's certainly doable.
Cheers, Ed L
- Vote on answer
- posted
20 years ago
I've posted a cheezy website outlining my work so far:
- Vote on answer
- posted
20 years ago
Great!!! Thank you so much for this. I will be following your website closely. Thank you very much for planning to release your drawing files too! This is exactly what I (and I'm sure many others) have been looking for. What do you guesstimate the final cost to be around? Saving $100 per servo is huge so far. I hope they work out.
- Dave
- Vote on answer
- posted
20 years ago
I'm going to guess that the whole thing will be under $500 using the HS-311's. I'm almost positive that the servos will be under powered so I'll have to upgrade later. The cost of better servos will be much more; the coreless servos which produce 3 times the torque of the HS-311's seem to cost between $80 and $100 each. In summary, my estimate of the cost using the HS-311's and the high torque servos is (not counting tools):
HS-311 HiTorq 22 x Servos $200 $1750 22 x Bearings $40 $40 Aluminum .060 $30 $30 #4 Screws $5 $5 #1 Screws $5 $5 ----------------------- Total $280 $1830
I've just finished up an 8 channel servo controller using an AVR and I've just upgraded the design to 16 channels. I'll be using these two controllers (or two 16 channel controllers) for the biped. It's pretty cool to see a bunch of servos slewing under command simultaneously. The hip joint that I have done moves the thigh pretty nicely. I'll soon be able to judge the suitableness of the HS311's.
Cheers, Ed L
- Vote on answer
- posted
20 years ago
Ah, unfortunate news about the weaker servos. But even with the more powerful servos, it looks to be just over a third of the cost of the kit. One thing I'm curious about. You're looking to control each joint directly? What about the movement animations? Are those held in the remote controller? Or in the robot itself? I'm also ignorant of any open source/publicly available software for animating robots. Does any exist? And where are you getting the information for the size of everything? Are you estimating based on the videos?
Hah, sorry, I have tons of questions here. This project just highly interests me. Thank you very much for your time. If anyone else can answer any of these questions, I (and I'm sure Ed) would appreciate that. Thank you.
- Dave
- Vote on answer
- posted
20 years ago
Yes. I've already got my servo controller so that, with one command, I can make all servos move to a specific position simultaneously. This will allow me to move sets of servos to goal positions simultaneously.
Eventually they'll be held in the robot. I'll start off by controlling through a cable from a laptop/desktop until I get some good sequences. Once I do, I'll transfer them to the bot software. They'll be like behavioral sequences initiated externally but the sequences will be on the robot. Even with an AVR controller, I should be able to hold dozens of sequences. If I need more memory, I can just use a serial eeprom.
I'm sure there is. I'll probably write my own. I've already written a little GUI for my servo controller. It's pretty simple but it won't be much more to extend it to store particular sequences. There'll just be a button to create a named sequence, a button to store the current servo position settings and a "done" button. Then one can select a stored sequence for playback.
I've got just about every picture I can find on these bots, I know the size of the servos and then I'm scaling from there. My dimensions won't be perfect but that's OK.
That's fine. I've started putting my files up on the website. They're not dimensioned because they are the correct size for printing. I usually copy several copies of the cutout patterns onto a single drawing so that when they print out I get enough of the patterns I need.
Cheers, Ed L
P.S. Here's a 16 channel servo controller using an AVR:
- Vote on answer
- posted
19 years ago
Here's a link to an Italian biped based on Robo-vie style robots:
- Vote on answer
- posted
19 years ago
Nice. Looks a little bulkier, doesn't it? Better battery?
- Dave
- Vote on answer
- posted
19 years ago
It's entirely machined from solid aluminum blocks. That would seem to me to add weight (but also solidness).
It probably does have a better battery than the Robovie because he probably has more room in the computer chassis.
Cheers, Ed L
- Vote on answer
- posted
19 years ago
I've added a picture of 10 degree of freedom (DOF) legs to my website. This is an intermediate step to having 12 DOF legs because I'm still working on making the thrust washers work properly for the ankle. I'll probably be done with the ankles in the next few days but I'll be able to work on programming the walking sequence now.
Cheers, Ed L
- Vote on answer
- posted
19 years ago
I saw your postings and your website. WOW!!
I have been bitten by the robotics bug, but I have no experience in programming. So I am learning. I was planning on building a Hexapod similar to this one
I found these servos
Thank you for posting drawings of your bot, this is a grat help for a beginner like me. Do you also plan to post the code when you are finished?
Lastly where did you find the bearings for your project at?
Tim
- Vote on answer
- posted
19 years ago
Ohhh exciting! I often wondered about the official Robovie-M software. I'm a 3D animator by profession, and would LOVE something that can convert joint movement in a 3D animation to motor controls. That would be heaven for me to animate in that way. But I'm not sure how the official software works. I'm guessing that generally, robotics software just has a list of joints, and you use a slide bar or something on each joint to move it while creating a timeline for the animation. But looking at the Robovie animations... it sure looks like someone with experience in animation created them. And I'm not sure how well animators could use that software. Do you know anything about it?
Also, I checked your current progress. It's looking very good! Close to the original! You said that the cheaper servos won't be strong enough. Are you using the cheaper ones here? Or did you go for the strong expensive servos? Is there anywhere that the cheaper servos would work? I can't think of where you can skimp, as the arms have to be able to carry the weight as well.
- Dave
- Vote on answer
- posted
19 years ago
Thank you.
You may want to think about doing a hexapod first, just to get some experience and then move onto a more complicated project like a biped.
One difficulty is that there are a lot of parts. Tolerances are also a bit of a problem in some areas. I've had to experiment a bit to get things to fit just right. If I do another one, I'll probably use a CNC mill to cut the parts out. However, I wanted to use the cheap bandsaw and drillpress to show that it could be done with simple tools. Otherwise, I have to say it has been fun and exciting for me too.
Yeah, I'm thinking about doing either an upgrade or a second version after I've done the basic experimenting with this one. The servos you pointed to look good. I think that I would like to scale things up like you suggest. Being able to use higher torque (and relatively cheap) larger servos could be good.
I use an AVR based board of my own design.
I highly recommend the BasicX24. I've used it in the past and I'm using it in another project right now. It is a very nice, very powerful processor. One benefit is that you program it in a visual-basic like language which is very powerful.
Yes. I'll post some of the basic control software as I develop it.
I used 1/8 x 5/16 flanged bearings from this site:
Ed LeBouthillier
- Vote on answer
- posted
19 years ago
I used Babel fish to translate the VStone website in the past (it doesn't seem to work lately). The software they deliver seems simple. I already did a visual basic program that does essentially the same thing as their software (although without keyframing).
That's what I got from reading their online literature. Its almost like keyframing. My program records a list of servo slider positions and allows them to be played back.
I don't know a whole lot about their software, but I would agree with you that someone has played around with motion sequences and got some really fluid motion. However, I've seen motion done by some students using Robovie-M's and theirs was pretty smooth too. Maybe the software simplifies things with keyframing but I didn't get that from their online literature (I'm just guessing).
I'm using the cheap servos. I'll find out how well they work in the next few days. I need to solder up another servo controller board tomorrow and then I'll have enough ports to control all the servos. Based on my initial experiments, though, I was surprised at the power and speed of the HS311's. As I get some video, I'll probably put some online (unless it's too many megabytes).
Cheers, Ed L
- Vote on answer
- posted
19 years ago
I also found these servos for only $14.95 here
S06STD Specs:
- Vote on answer
- posted
19 years ago
I now have pictures of the 12 DOF legs at my website.
- Vote on answer
- posted
19 years ago
Ed,
Your progress looks good. I was working on something very similar to the V-Stone when I stumbled across the robo-one websites. Some of the video clips are very impressive. Maybe we can have a mini robo-one when we are finished. I'm using the Hitec HS-645MG servos. They have about 133 oz-in torque. I only have the legs done, well actually I'm rebuilding them just now, but I have all of my rev B parts cut, drilled and bent. I just have to complete the rev A tear-down and build up rev B. Rev A was too tall at about
20" and the servos could not "stand up" from a "squat" position. The knees were just too weak at 5 volts. I will run the servos at a higher voltage to get more torque, but if it's under powered with the legs alone and no top half, then it's just under powered. My legs are 12 dof with the "twist" at the hip. I'm currently using a ServoPod from New Micros for a processor. The built in Fourth is easy to use, but UGLY to read. The free small C is !FREE! but had some serious limitations and Code Warrior is $$$! I'm thinking about just making a couple of PIC boards. What are you using for a processor?--Steve