pic: 2 Weeks Without Homework



This is what I did over christmas break to keep my CAD skills sharp. After four years of putting together robot drivetrain designs, I finally got everything I was hoping to unleash in '09 (Lunacy somewhat nixed this option from my team’s perspective) down in CAD. The outer black frame is welded while the interior frame members, including the red drive rails, are combo rivetted/bolted. I owe credit to 1114, 148, 968, 254, 233, and 217 for their inspirational designs, as well as AndyMark and Autodesk for some of the CAD models I used. I can’t wait to find out why this design is obsolete on saturday!

4lex S,
Considering where you drew your inspiration from, I am not surprised that this design turned out so beautiful! I really like this and will definitely ask my students to consider using something very similar, if the game lends it’s self to this design.
Again, based on the game, I might suggest some mods, but over all, this looks extremely well thought out.

Overall, very nice! Looks solid and efficient.

One quick question: How do you tension the drive chains? Sliding blocks like 254/968?

Keep up the good work!

Looks very nice! You put a lot of thought into this. It turned out very well. :smiley:

Few questions.

Whats the weight?

Is that plexi-glass that the electronics are mounted on?

What type of gearbox? (Sorry, I can’t really tell from the picture.)

Overall, I love it. :smiley:

-Rion

I have to say I like the nice clean bumper mount rails with the cantelievered wheels. the AndyMark hex bearings make this a super simple design to build eliminating any need to turn the Hex shafts if you plan it right.

Thanks for the input and comments.

How do you tension the drive chains? Sliding blocks like 254/968?

The tensioning system is very similar to that of the Universal Chassis by Team 221 LLC. Essentially the floating block is moved back and forth by a cap screw and threaded hole in the block. I can take a wireframe picture later if clarification is needed.

Few questions.

Whats the weight?

Is that plexi-glass that the electronics are mounted on?

What type of gearbox? (Sorry, I can’t really tell from the picture.)

I am currently unsure of the weight, as I don’t exactly trust the 42 lbs Inventor spit out. Once I am done the BOM (if I ever finish :rolleyes: ) I should have a better estimate. The frame is pretty light compared to others I have worked on though.

The electronics are mounted on a thin plexi layered on thin aluminium sheet metal (which is not visible). The reason for this was mostly electrical isolation for the control system.

The gearboxes are modified AM Supershifters with the black covers removed, standoffs installed, and a custom long output shaft to interface with the AM performance wheels.

I have to say I like the nice clean bumper mount rails…

That was an almost direct reverse engineer of the 2009 254/968 bumper mount system. Whoever came up with that design deserves a cookie for saving West Coast Drive.

Nice CAD! Why are the gearboxes turned 90-degrees from each other?

I think he means the cim motors. And yeah I have the same question. Is it just to reverse the direction of the wheels without programming?

It may just be an oversight, or a space consideration. Looks more like an oversight; I’d say those gearboxes could go in either way, as long as the chain worked.

But it isn’t to reverse the direction of the wheels without programming. He’d have one gearbox out over the bumper area with both pointing the same direction if that was the goal.

The Supershifter output shaft is not in the center. Direct-driving the center wheel, the gearboxes would have to be mounted with one forward of the other if they weren’t turned. The way they’re mounted in this design puts them directly opposite one another.

Actually. I have a different theory. If you look. One AM SS is shifted by pneumatics, the other via a servo. I think it is to show that both could be used, and the best space saving way to mount them.

Just a theory.

-Rion

EDIT: I forgot about what Mr. Anderson said, he is right, I designed a chassis with these over the summer, I did the same thing.

EDIT2: Scratch that. They are both pneumatics. I would delete this… but I can’t find how. :smiley:

Woot, cool to see a more completed design than what RC and I have been talking about.

http://picasaweb.google.com/rcthekid1323/CAD#5418103106851444610

I love the use of the rivets as our team has been looking at similar designs due to lack of trained welders. Great stuff! Hope you actually get to use it this year though.

The gearboxes were placed in the way they are for space savings, and to shift the CG to the rear (I assumed the robot would run mostly on its rear wheels, the gearboxes could easily flip for a front-heavy robot). The other reasoning for this is that I wasn’t sure how the AM SS kit shipped, so in this design, no matter which way the gearbox is assembled, it still works (You only need one spare gearbox). They are both pneumatic, as this seems to be what AndyMark recommends.

Woot, cool to see a more completed design than what RC and I have been talking about.

http://picasaweb.google.com/rcthekid...03106851444610

I love the use of the rivets as our team has been looking at similar designs due to lack of trained welders. Great stuff! Hope you actually get to use it this year though.

We rivetted everything but the kitbot last year, and it worked out well, I would highly recommend it. Its nice to see this kind of parallel design work. It gives me confidence I am thinking soundly. Sadly you won’t see this design on the field from 1006, I have graduated and my team has been temporarily disbanded. Hopefully this helps generate some ideas for the new game though, for anyone browsing CD.

Wow, this looks really intense. Its my first year on my robotics team and i can’t wait to see what competition is like! This is very thought out and looks great! keep up the good work!
:slight_smile:

billbo911,

The PM system is not allowing me to reply to your message, so if you would like a response could you please send an e-mail to awstrong@engmail.uwaterloo.ca.

Thank you

Alex,

One Suggestion Nick (FRC254) gave me was to stand up the battery, it gives you more room for electronics. The render Akash links to shows the battery stood up.

-RC

One Suggestion Nick (FRC254) gave me was to stand up the battery, it gives you more room for electronics. The render Akash links to shows the battery stood up.

-RC

I agree somewhat, though there are good justifications for both standing it and laying it flat. Mechanically I have always preferred a flat battery, as it shifts around less and lowers the CG more (I am a mech guy). But if I was to add a compressor and all the primary electronics, this design should either have a standing battery as you suggest, or a dual level control board. My electrical friends would always harass us about not standing up the battery, so mabye appeasing the controls group is a good enough reason to stand it up…

Iteration 2 --> Someday.