05-01-2010 09:50

billbo911

Re: pic: 2 Weeks Without Homework

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.

05-01-2010 13:00

Jamie Kalb

Re: pic: 2 Weeks Without Homework

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!

05-01-2010 13:22

Rion Atkinson

Re: pic: 2 Weeks Without Homework

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

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.

-Rion

05-01-2010 15:14

Peter Matteson

Re: pic: 2 Weeks Without Homework

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.

05-01-2010 17:09

,4lex S.

Re: pic: 2 Weeks Without Homework

Thanks for the input and comments.

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.

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 ) 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.

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.

05-01-2010 18:55

Eugene Fang

Re: pic: 2 Weeks Without Homework

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

05-01-2010 21:04

Stealth

Re: pic: 2 Weeks Without Homework

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?

05-01-2010 21:10

EricH

Re: pic: 2 Weeks Without Homework

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.

05-01-2010 21:11

Alan Anderson

Re: pic: 2 Weeks Without Homework

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.

05-01-2010 21:13

Rion Atkinson

Re: pic: 2 Weeks Without Homework

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.

05-01-2010 21:20

Akash Rastogi

Re: pic: 2 Weeks Without Homework

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.

05-01-2010 23:16

,4lex S.

Re: pic: 2 Weeks Without Homework

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.

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.

05-01-2010 23:28

LilianaMercedes

Re: pic: 2 Weeks Without Homework

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!

07-01-2010 15:53

,4lex S.

Re: pic: 2 Weeks Without Homework

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

08-01-2010 14:28

R.C.

Re: pic: 2 Weeks Without Homework

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

08-01-2010 15:14

,4lex S.

Re: pic: 2 Weeks Without Homework

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.