Let's Make Robots!

My first omniwheeler

 

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Update: Hmm.. I found that it pulls a trailer really well.. Hmm.. And the Omni's are really easy to navigate. Hmmm :)


I was waiting for my omni wheels to arrive, because I wanted to see if they where not the right thing for my main project.

While waiting and working on other small stuff, I got interested in making my own Mecanum Wheels.

After making that proof of concept, I decided to make 4 stable ones, and put them on a test-platform.

I got some triangled wood, drilled holes in it, and cut it in 64 pieces..

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Double sided tape on;

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Marked up 4 CD's:

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Metal sticks in the holes, wheels on..

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Till I had 4 wheels - of the homemade "Mecanum Wheels" - type:

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Made 4 continous servos, and glued the wheels up on them:

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...

 

 

And THEN I got mail:

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WHAM! To hell with homemade wheels, I am back on testing for my main project :)

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Really fast made, as you can tell, I stuck new wheels and some sensors and an old picaxe 28A board on the simple frame.

Made some code very fast one evening (atached, read it, it's short compared to how complex it performs), to test how to navigate with the setup of these interesting wheels..

Result & what I learned:

Really fun & effective, wicked fun to code omni! - check code. Info: servo passive is at 135, not 150, because I set them up with another controller.First commands, "servo" is just to initiate servos, they are set for real by the "servopos" commands

I think I may have to make more tests (read: Have more fun with new wheels) before moving on with the project :) 

 

Sorry it's no fantastic robo-post, but it is & was my first omniwheeler, a simple robot, but I had to post it because the moves are new :D

(Have to clean up my workshop now, I know, a mess, must clean up!)

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I'm sure if Frits had got his hands on my old car he'd have come up with something a damn site better than Ford managed with their budget of millions.

Maybe the Start here robot should be called the Model T Frits?

You can have any color you want, as long as it's yellow...   drum machine

Recently, at my local Advanced Motorists group, we had a presentation from a chap affected by Thalidomide. I think he bought your Ford Escort! He told us that the steering modification made for him (he steers with his feet using a joystick as he has no arms or hands) "sometimes didn't work!" What a scary thought!

Nevertheless, you still MUST applaud fritzy's Blue Peter approach to sticky-back-plastic, safety pins, and whatever old nonsense he has lying around!!

Cool video!

I once had a Ford Escort that handled corners in much the same way.

At the same speed too.

Would stop and need turning back on for no reason, resulting in my bumbfounded "Huh?"

Frits, have you made this out of parts from my old car?

 

 

Nice home made omni wheels

 

I actually like the original omniwheel. Always nice home made stuff.

This bot is interesting for many reason.

- it realizes the cm ranges from the sensors are within numerical ranges of the servo commands.  therefore not a lot of manipulations are required to calculate servo movement.

- the more the left or right is constrained, the more that side moves.   a velocity profile in 1 IF statement.

- if I'm correct on this, only 1 side spins as it gets more constrained?   unlike regular 2 wheelers.

- the center of gravity appears damn perfect.

- and it all works because the omni allows the skid.

well done sir!

Thank you.

I think you are right with most of your very sharp observations, sire!

However, the trick in the very code is not the center of gravity, nor the omni wheels. I do believe that belt tracks would work fine, and that it just has to be able to turn.

In other words; the code could be easily adapted to any project that has 2 sensors, and 2+ continiously rotating servos for motion :)

that's some short code and it navigates awesome

THANK YOU! I am glad that someone could see that! :)

you're welcome and whats with you're picture