PDA

View Full Version : Bioloid "Gorilla" Configuration



Obscene
12-01-2008, 10:39 PM
When I first decided to buy the Bioloid kit, it was mainly because of the ability to build custom configurations. After having built the humanoid and king spider, I decided to go with a custom gorilla design.

The shoulder servos won't be strong enough to do much considering the size and weight of the arm, but hopefully I can get enough out of them to get started on the movements in robot terminal. At least until I can afford to make a custom torso fitted for the Dynamixel RX-28, and buy about six of those babies.

Here's some shots of my first configuration:
http://forums.trossenrobotics.com/picture.php?albumid=38&pictureid=124
http://forums.trossenrobotics.com/picture.php?albumid=38&pictureid=125
http://forums.trossenrobotics.com/picture.php?albumid=38&pictureid=126

I'm using an aluminum kitchen heat lamp frame as an adjustable support for "training" the robot. I'm going to make a harness (bra) eventually for better "support".

http://forums.trossenrobotics.com/picture.php?albumid=38&pictureid=127
http://forums.trossenrobotics.com/picture.php?albumid=38&pictureid=128
http://forums.trossenrobotics.com/picture.php?albumid=38&pictureid=129

I'm customizing the AX-S1 by putting its guts into a new casing:
http://forums.trossenrobotics.com/gallery/files/2/4/8/9/dsc02274.jpg

Oh, and as you can see, I've shortened the arms by using the short brackets coming off of the shoulder servo and it's mobility has already improved tremendously.

I'll upload some video's once I get some better movement out of him.
http://http://forums.trossenrobotics.com/gallery/files/2/4/8/9/dsc02352sm.jpg

Sigma X
12-02-2008, 03:47 PM
maybe you can just add a counter weight to ease the servo torque
and keep balance this would probally be a more cost efective way to have those large arms
although you'll probally need some stronger weights for the leggs
it's just my two cents

Obscene
12-02-2008, 04:32 PM
Yea, I was thinking of mounting some springs to counter the weight, just not sure how yet. The rear end of the robot is pretty balanced out as I'll keep his torso posture mostly horizontal when he's moving around. I got him moving on the smooth glass surface of the desk by walking with his back legs and moving his arms just enough to slide the fists forward.

I'd like to add some rubber to the bottom of his feet and possibly some big black rubber balls to the end of his fists. (I know, that sounds wrong.) :o

Sigma X
12-03-2008, 09:34 AM
you could add springs underneath the arm from the shoulder to elbow
also you could make those big arms as leggs (sorta how a real gorillia moves)
this way it can move faster

Obscene
12-03-2008, 10:53 AM
you could add springs underneath the arm from the shoulder to elbow
also you could make those big arms as leggs (sorta how a real gorillia moves)
this way it can move faster

Yeah, hopefully that's how it will move. The hard thing, later down the road, will be implementing any kind of kinematics for the gorilla configuration. I did find some information on a university in Asia that is working on a gorilla with advanced inverse and forward kinematics, and it takes on tasks like climbing (slowly) across "monkey bars".

@ Adrenalynn: Sorry to scum up the thread with all of this talk about gorillas.

Sigma X
12-03-2008, 12:18 PM
there's mot much more I can do to help out now due to my lack of owning a robot
but when I get my kit(hopefully before christmas)i'll be able to provide more info

@ Adrenalynn:I too am sorry I got caught up in wanting to help out

Adrenalynn
12-03-2008, 12:32 PM
Voila! Easily fixed. :D

Sigma X
12-03-2008, 12:34 PM
Wow!! the magic of a woman LOL

Obscene
12-03-2008, 02:13 PM
Rofl, ty. :happy:

ScuD
12-03-2008, 03:12 PM
I only have one thing to say : that thing is probably the coolest robot configuration i've ever seen.Period.

Pure awesomeness!

can't wait for the movieclips!

4mem8
12-03-2008, 10:33 PM
Sure looks cool, But as you say the shoulder servos are going to have to have some more punch to lift that arm. nice job.

Obscene
12-03-2008, 11:36 PM
Thanks for the compliments guys. I'm currently looking for some rubber spheres, something like neoprene or nitrile(sp?) maybe something non-abrasive and pliable to mount on to the "fist" of the robot, within one of the angled brackets. I think it would need to be 1 5/8"-1 3/4" diameter to make a decent fit, but I can't seem to find that size.

Cosa used some rubberized spheres on his custom bioloid hexapod, and it looks like exactly what I'm looking for.

If anyone has any ideas or links, hit me up with a PM or a post here, please.

Thanks in advance.

sthmck
12-04-2008, 07:53 AM
So is this classified as a four legged bot or a two legged bot?

Sigma X
12-04-2008, 08:55 AM
i'd say it's a two legged still

@Obscene: i'll look for some links for you

ScuD
12-04-2008, 09:22 AM
Two legged, two armed, one headed? I say we refer to it as a monkey.

Obscene
12-04-2008, 11:19 AM
Well, if I could get the arm servos strong enough, it could balance on it's arms, and maybe that could be a part of the kinematics? :p

ScuD
12-04-2008, 12:15 PM
If you can get the arms to "lock up" in a fully stretched position, you could use a sort of pendulum like motion, swinging the body through the arms.

I don't even want to think about the kinematics and dynamics of that, though :veryhappy: but it would be a ridiculously cool way of having your bot trot around the house

Adrenalynn
12-04-2008, 12:36 PM
How about the rubber stick-on non-scratch feet for electronics?

There's also the non-scratch felt stick-ons used on the bottom of lamps and such. Both are available from your handy local home improvement big-box store, in "Hardware" over by the chain cutting area. ;)

Obscene
12-04-2008, 12:40 PM
lol! Yeah, I think I'd have to get someone to help me with the types of calculations and programming involved in that. I have been watching real silverback gorillas walking, climbing, horsing around, etc on youtube just to get a sense of their gaits and how they traverse.

The best I can do right now is to use robot terminal to program the movements.. The aluminum frame he's hanging from helps to hold his posture while I make adjustments to the limbs.

One day I'll get into the programming aspect of it and hopefully hone my skills enough to get some kind of balance out of it all. *dreaming* :D

Obscene
12-04-2008, 12:42 PM
How about the rubber stick-on non-scratch feet for electronics?

There's also the non-scratch felt stick-ons used on the bottom of lamps and such. Both are available from your handy local home improvement big-box store, in "Hardware" over by the chain cutting area. ;)

That's actually a great idea. I'll have to check that out.

Sigma X
12-05-2008, 11:58 AM
I did a quick search (I know it took a day but i'm working on projects too)
and the closest I got was auto shops but Adernalynn has given a beter answer

Obscene
12-17-2008, 11:16 AM
I appreciate your help, Sigma.

Really, it seems like these servo's don't have a problem lifting the arm (at all) now that I've shortened it. I just take care not to leave them in a torqued or held position for long. The walking gait has proven to be fairly difficult to get down, considering the majority of the weight is in the arms themselves, other than the battery pack and legs.

If you can imagine, what I've had to do is to use a hurried downward arm movement for him to catch himself as he falls into the weight of the arm, which is tricky, but it's actually working.

I'll upload some videos soon of the different stages of walking that I've progressed through with this configuration. The reason I haven't gone very far with this is that I'm waiting on some "squash balls" to arrive in the mail because that's what I'll be using as feet and fists, and I think they will tremendously improve freedom of movement and mobility.

Thanks to Cosa from Robosavvy for the squash ball idea. I'm American, so I'd have been using foosh balls instead, and they just don't have the right bounce, nor pliability.

Stay tuned!

gdubb2
12-17-2008, 01:50 PM
Obscene.. have you looked at Mcmaster-Carr for rubber balls?? They have all kinds of different ones.
www.mcmaster.com (http://www.mcmaster.com)

Obscene
12-17-2008, 04:34 PM
Obscene.. have you looked at Mcmaster-Carr for rubber balls?? They have all kinds of different ones.
www.mcmaster.com (http://www.mcmaster.com)

I did.. I just needed something slightly bigger than 1 3/8" and smaller than 2". McMaster doesn't have that listed. Squash balls usually fall into that range, plus they're usually cheap, hollow, and abrasion resistant.

Sigma X
12-18-2008, 01:53 PM
Squash balls what are they?

Adrenalynn
12-18-2008, 02:29 PM
Squash is kinda like US Racquetball, only the ball is smaller and a little "faster". It's called "squash" because the ball is "squashable", IRC (or at least I was told so). A Squash ball is about an inch and a half in diameter, and a racquetball is about 2.25"-ish in diameter, if memory serves.

Sigma X
12-18-2008, 02:31 PM
OH ok I think I get it like one of those srtess balls right?

Adrenalynn
12-18-2008, 02:44 PM
No. Either a Squash ball or a Racquet Ball are much higher pressure and much lower compressibility than a stress ball. Squashing a Squash ball flat is going to be an exercise in stress rather than a stress reliever

Obscene
12-18-2008, 03:07 PM
Squashing a Squash ball flat is going to be an exercise in stress rather than a stress reliever

Unless you relieve stress by smashing things with big machinery. :p

Adrenalynn
12-18-2008, 03:08 PM
Ok, I grant you that. I have a 10Ton press that would add new meaning to "squash ball". ;)

Sigma X
12-18-2008, 03:13 PM
well I still think I got it

@Obsene hows the gorillia?

I wish I could give better advice but just you guys wait
I got alot of innovation when I build my competion biped

Obscene
12-18-2008, 03:51 PM
well I still think I got it

@Obsene hows the gorillia?

I wish I could give better advice but just you guys wait
I got alot of innovation when I build my competion biped


It's good. It's perched on my desk right now, reminding me that amongst school, work and holidays, I still have to give it some attention. I wish I had some beefier servos! But I think anyone who's ever wanted to build a robotic gorilla just knew they wanted strong servos. Or hydraulics and a predator style shoulder-turret.

DresnerRobotics
12-18-2008, 07:43 PM
It's good. It's perched on my desk right now, reminding me that amongst school, work and holidays, I still have to give it some attention. I wish I had some beefier servos! But I think anyone who's ever wanted to build a robotic gorilla just knew they wanted strong servos. Or hydraulics and a predator style shoulder-turret.

RX-64s... you know you want them. 1000+ oz-in of torque... MMMMMM...

Obscene
12-18-2008, 08:58 PM
Yeah, I'd have to buy one a month for the next year before I'd have the amount I'd need, not to mention the CM-2+, webcam and wifi/bluetooth, brackets, etc. But you already know what I'm talking about.

I wonder what a solid aluminum gorilla mech on RX-64's would be like? Like $6k expensive.

Maybe one day.

DresnerRobotics
12-18-2008, 09:08 PM
It would be one mean mother ;)

You could probably get away with RX-28s without issue as long as you didn't have too much additional payload. Those are about 550 oz-in of torque each, double that of the AX-12s. Save money on the brackets by getting your own machined too, I used the drawings provided by Robotis to design my own and am having Big Blue Saw (http://www.bigbluesaw.com) machine them for me.

Sigma X
12-19-2008, 12:21 PM
robotis provide drawings of their parts or brackets?
also I kinda need a bit of help and that's where to get
transparent colored plastic

lnxfergy
12-19-2008, 12:37 PM
robotis provide drawings of their parts or brackets?
also I kinda need a bit of help and that's where to get
transparent colored plastic

I order most of my plastics from http://interstateplastics.com/
Price is quite good if you are ordering in quantity (I ordered about $75 of EPVC last month that would have run about $125 any where else I found), but if you only need a small piece you will want to go elsewhere.

-Fergs

DresnerRobotics
12-19-2008, 12:40 PM
robotis provide drawings of their parts or brackets?
also I kinda need a bit of help and that's where to get
transparent colored plastic

http://www.robotis.com/zbxe/dynamixel_en

Should all be listed there, they even provide their brackets in a 3D cad format, but it doesn't import very well into Inventor, and I wanted to redesign them for simplicity anyway.

Sigma X
12-19-2008, 01:37 PM
Thanks for the link this will be helpful
now all I need are some color transparent plastics

Adrenalynn
12-19-2008, 02:17 PM
Stop by your local TAP Plastics - assuming you're in the US - they have locations all over the place, but also online sales. http://www.tapplastics.com/shop/product.php?pid=341&

If you need other colors, I can recommend some other online sellers, like USPlastics. Lots of color and transparency options available in Acrylic.

DresnerRobotics
12-19-2008, 02:31 PM
Thanks for the link this will be helpful
now all I need are some color transparent plastics

I wouldn't recommend making brackets out of plastic. To be honest I doubt you can make them any stronger than the stock Bioloid brackets, and for anything stronger than an AX-12 you need to be using industrial plastic or aluminum, the latter being much easier to make brackets from.

Obscene
12-19-2008, 04:57 PM
Metal is just cooler anyway! The Bioloid kit is great, but I think I'll eventually go all RX-64's and metal brackets.

Here's my configuration with the new squash ball fists and feet:

http://forums.trossenrobotics.com/gallery/files/2/4/8/9/dsc02352sm.jpg

Sigma X
12-22-2008, 02:14 PM
@Adrenalynn: thanks i've been looking for somthing like this for months
plus they have great prices and they sell carbon fiber

@Tyberius: actually it's not for the brackets the
plastics are for custom body shells but now that you bring up industrial plastic
what's the difference between indurstrial and engineering plastics

@Obscene: man that's a bot it looks like it's going to smash the camera guy
in it's primal fury!!