On today’s episode Ian Lee visits the studio with his newly created C.A.T.T. Bot - “Computer Aided T-Shirt Tosser”
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Awesome job, @ Greg! I had a blast that day. Looking forward to my next visit. Thanks!
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@ ianlee74 - This was a fun video to make. Thank you for taking time and helping out 
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@ ianlee74 - Where did you get such large wheels?
Fortunately, I caught them on sale for about half the current price. 
@ ianlee74 - Wow for that price, you should have 3d printed them.
Yea… And I’d just about now be done. I’ll admit I definitely paid a lot more for this robot than is necessary for someone with more time. Given my time constraints, I made the decision to buy off the shelf as many components as possible so that I could have some time to focus on software. Unfortunately, even with that sacrifice there was still little time to do much with the software. This is still very much a WIP and not the last time you’ll see it around. I have many big ideas for it that will come to fruition throughout the year. Stay tuned!
Love the wheels. Those are what I used on my Chitty CHitty Bang Bang car. A little noisy but work awesome. Everyone is always amazed on how those wheels work.
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@ skeller - I’m curious how you ended up controlling your car. Did you end up creating a custom controller to take full advantage of the capabilities of the mecanum wheels or were you able to find an R/C controller capable of doing everything necessary? The wheels are definitely worth the investment. They get more attention and questions than any other part of the bot. Noisy is good when you’re trying to attract attention 
@ ianlee74 - Your C.A.T.T. Bot is awesome. What functions did the Pi provide?
For now we are using the mecanum R/C controller from AndyMark. ([url]http://www.andymark.com/product-p/am-2715.htm[/url])
We are using two R/C controllers total. 1 for driving the car, the second to control the elevation, decorative wheels and wings of the car. This frees the operator that is driving to focus only on driving. Since it is on stage carrying and interacting with the actors it’s better to stay focus on the driving and leave the fancy stuff to someone else. ( Video from one of the theaters that rented the car: [url]Chitty Chitty Bang Bang - car movement - YouTube)
I would like move away from the the AndyMark controller to something embedded. I would like some ability to modify the control algorithm.
I used AndyMark gear boxes that take the 3 CIM motors. Those add a lot to the noise. I would like to switch to ClearPath servos and quieter gear boxes. ([url] https://www.teknic.com/products/clearpath-brushless-dc-servo-motors/[/url]) From what I can tell the ClearPath servos will take the standard R/C servo signal.
Here is the base only video: [url]Dropbox - 2015-07-16 21.03.53.mp4 - Simplify your life
Some of the movement: [url]Dropbox - 2015-11-10 15.30.19.mp4 - Simplify your life
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[quote=“skeller”]
@ ianlee74 - For now we are using the mecanum R/C controller from AndyMark. (http://www.andymark.com/product-p/am-2715.htm)[/quote]
How did I miss that? I’ve actually been thinking of making & selling that exact thing since I couldn’t find one anywhere. Does this give you full mobility (strafe in every direction)? What limitations have you found? One feature I would like to have, though, is automatic heading control so I don’t have to try and twist my mind as it gets turned around. So, I may still end up creating my own. But, in the meantime this looks like something I’ll add to the bot.
I essentially have the same problem. If you noticed the big blue switch… That is for switching the driving from RC to computer automated driving (not currently implemented). For just playing around with a crowd and moving the bot around, I need the RC mode. However, eventually, it will have several self driving/navigating modes where the Raspberry Pi will need to take over control of driving.
Oh man, I’m glad I didn’t see those ClearPath motors a couple months ago. Those are sweet! I may still consider getting one to try and replace the catapult motor with. Servo control simplifies so many things. I’m using the Toughbox Micro gearboxes. They are loud. I’m not really impressed with the tolerances of their gearboxes. I believe that’s the main source of the noise. During the lubeless burn in, I was really concerned that with all four going it would be totally unacceptable. They get a little better once grease is applied and once you’re distracted by the mecanum wheels you hardly notice it.
[quote=“ianlee74”]
How did I miss that? I’ve actually been thinking of making & selling that exact thing since I couldn’t find one anywhere. Does this give you full mobility (strafe in every direction)? What limitations have you found? [/quote]
yes it allows control in all directions. One of the issues I think we have is that the controller assumes a perfectly square platform with the wheels at each corner. Because the platform is long it makes some of the moves a little tricky. However, the operators catch on pretty quick. I probably will leave “well enough” alone since there is benefit in the simplicity of the control setup.
I agree once everyone sees how it moves the noise usually isn’t an issue. In my case, there is almost alway music playing while the car is moving.
She (i.e. Chitty) is actively being rented around the country to different theaters. I think she is going out 4 times this year. If the rental business continues we might consider re-building the frame out of aluminum to make it lighter and adding better motors and gearboxes.
While I love the AndyMark wheels I would like to find a supplier (preferably USA based) that had heavier duty wheels with machined hubs versus the stamped plates AndyMark uses. As flexible as the mecanum wheels are you would think they would be more popular.
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@ ianlee74 - Nice bot. If you don’t mind me asking, how much would you say you have invested in it?
Well, if I ever get around to my drop-in replacement consider yourself the first to receive one for beta testing. I wouldn’t wait for it, though. This year is already fairly booked. 
[quote]I agree once everyone sees how it moves the noise usually isn’t an issue. In my case, there is almost alway music playing while the car is moving.
She (i.e. Chitty) is actively being rented around the country to different theaters. I think she is going out 4 times this year. If the rental business continues we might consider re-building the frame out of aluminum to make it lighter and adding better motors and gearboxes.[/quote]
That’s awesome and a business idea that I never would have dreamed existed.
AndyMark serves its community very well. Unfortunately, their community is high school & college students that are building competition bots that only need to work for one season of competition at a reasonable price. I don’t mean to suggest that their parts are low quality because they definitely are not but they are far from industrial quality. They’re a great source of parts for PoC projects. My biggest gripe is that they only supply 12V motors. I guess that’s a requirement for FIRST? I really would have liked to have gone with 24V or 36V motors which would have saved a lot of money in motor controllers and eased wiring.
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In case my wife is listening…probably close to $11111010000. My BOM fell behind somewhere around $010111011100
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Zoiks! Well, it’s not every build that gets you a speaking slot at Codemash.
Hopefully, its not the only one either. Lots of topics and talks planned to be built around this platform. Expect to hear a lot of C.A.T.T. bot talk from me in the future.
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There’d better be, if you want to demonstrate ROI so that you are allowed to make more toys in the future…
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You do realise those numbers look worse Waaaaaaay worse ! Perhaps $7D0 and $5DC would have attracted less attention
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devhammer,
Leave it up to us nerds to use terms like ROI to justify our hobbies
Also, you have a good point.
Tandy
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