Lynxmotion Tech Support

Hi, I have started working on a hexapod project because I find multi-legged creatures more interesting than bipeds. I saw the A-Pod, Phoenix and the other hexapods on the lynxmotion site and I thought why not, I'll make one as well.

I have uploaded pictures of one of the legs of the robot, all the parts that make that leg and I will shortly be uploading a short video of two of the legs sort of working.

Thanks for looking!

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

Here is the video of the two legs moving.



What does everyone think so far? It's not much, but it's a start.

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

Its looking really cool! I like the design of your legs. Ill keep an eye on how your project is coming along

Thanks. I've currently got 4 legs assembled but my router broke down so I haven't been able to make the body. . However, it gives me time to work on the code for making it walk and do other things and the body should be ready in a few days (I'll be using a friends router).

Thank you for showing interest!

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

Ok I've got another problem. I know this is supposed to be my project but I require some help (just a little bit). I have some code here which I got from a Biped BRAT tutuorial and I wan't to know what the "TOINT" part meant and also what the numbers in the brackets next to the aServoOffsets mean/stand for. Here is the chunk of code:



Thank you for the help!

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

This is a conversion from floating point (real numbers) to integers. This version of the brat program is probably using floating point math to do the calculations. For example StepsPerDegree may be defined like 166.6

Note: that in many of the programs some of us try to avoid floating point math as the underlying hardware has no support for floating points. So we often do our math with fixed point where we may keep our values like positions or angles in something like 10ths of a degree or maybe 100ths... So instead of:

You may see something like:
Where the 1 at the end of the variable is a reminder to us that the value is 1 decimal place...

Hope that helps.

Kurt

P.S. - Don't worry, all of us with our own projects often ask for help.

Thank you, I think I understand it. I am trying to write the code for the hexapod for only a Basic Atom Pro (and not using the PS2 remote controller or other boards in conjuction with the Bot Board II).

Here is an update on the project so far:

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

Ok, here we go - the completed quadrapod (WAHEY)!

I'll be working on the code during the next few days and I should have it working by the weekend or Monday at the latest (provided nothing unexpected happens).

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

I've started programming it with simple commands and so far I have got it to sway from side to side - I've named it the "Spider Dance". (Okay it's missing four legs but the "Quadrapod Dance" doesn't sound very nice).

Here is a photo of the quadrapod with new shiny black legs (the other red ones were quite flimsy but the new ones are much stronger). I'll upload a video of it shortly. How's it looking so far?

P.S. I was bored so I wrote my name in Arabic (that's as much as I can do in the language).

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

It doesn't look like your legs can move very far forward or backward. You might need to cut some of the body out to get a full range of motion. Other than than, cool project! Keep it up!

_________________
Curiously enough, the only thing that went through the mind
of the bowl of petunias as it fell was "Oh no, not again."

James "Don't call me Jim" Frye
Lynxmotion, Inc
http://www.lynxmotion.com

Um yeah, I was hoping no-one would notice that. I realised that about an hour after I cut it out and I currently have a new more efficient design which I will be cutting out soon.

Thank you for the comment!

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

I'm sorry to be the bearer of bad news, but I just noticed the servos you are using are HS-422. The really long femurs are going to be too much for them. The femurs on our 3DOF legs are much shorter and they require 485 servos as the minimum. I would recommend scaling it way down, or getting more powerful servos.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Oh ... Ok. I'll buy some more powerful servos and then it should be good to go (well, good enough for some basic movement).

Thank you for the tip.

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk

Also, it's easier to make a hexapod walk then a quadruped. Read the threads.

Alan KM6VV

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Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/

Ok. I am going to buy some more powerful servos but I am unsure of which ones to purchase. I was thinking of purchasing HS-5485HB High Torque Digital servos but does anyone suggest anything else? The dimensions of the quadrapod are:

length = 24cm
width = 50cm (end of one fully extended leg to the other on the opposite side)

I hope they are of some use.
Thank you for the help!

P.S. Could someone post some information on good high current battery packs (something with about 4-5A) and with roughly 6-7.2V. Thank you again!

_________________
ROBOTS FTW! ^____^
http://kaizoku-robots.co.uk