Offseason 2012 chassis

As an offseason project, our team is going to prototype a new chassis for future years. this is what i came up with. it takes ideas from all of our best chassis, and best of all it does not require machining at our sponsers. Do you guys have any ideas that could make it better. The wheels will sit on purchased pillow blocks, and the chain from the CimpleBoxes will run directly down to the center wheel

PS. if someone can please load the picture into the forum that would be great.
Thanks

ThadsChassis.pdf (91.7 KB)
ThadsChassis2.pdf (64.8 KB)
ThadsChassis3.pdf (88 KB)


ThadsChassis.pdf (91.7 KB)
ThadsChassis2.pdf (64.8 KB)
ThadsChassis3.pdf (88 KB)

You mention that best of all it does not require machining from your sponsors. My question is, if you have the sponsors and they will/have work with you, why not take advantage of the services and machining that they offer?

Just because you have machining resources, doesn’t mean you should make a design to incorporate those machining options. I bet this design would be driving by the middle of week 1 because you can avoid machine time.

The design looks nice and simple. Is there a reason for CIMple boxes instead of toughboxes?

Keep at it, looks like a decent start. Add in some supports for your gearboxes though.

We used toughbox mini’s this year, and would have liked speed insted of torque. Because the mounting holes are very similar between the 2, it can be switched at any time. and support for the transmissons will be the bars the come with them the go between the 2.

Probably because CIMple boxes gets you on Einstein. :slight_smile:

Really? Witch team used them?

Team 1503 Spartonics.

What kind of pillow blocks, and where can someone get these?

We would either buy them from mcmaster or ace, or if we have the time we could get them machined by our sponsor. because they are separate from the main chassis, we can work on the chassis at the same time, so we do not lose time with the chassis either way. it all depends on if we can find the right ones for sale.

Yeah, they powered our drivetrain.

We had a secondary sprocket reduction from the gearbox to the wheels though, to make our drivetrain have a theoretical top speed of 11.14 fps. :stuck_out_tongue:

-Nick

We used CIMple boxes this year for Maccanums … but they dont have enough torque to turn the wheels for straifing (spelled that wrong). And i believe it would be alot better if you had more torque over speed, because if a team gets in your way it would be easy to push through them, unlike if you only have speed, then you can’t.

And Nick did you use 1 transmission per side or 1 per wheel??

I dont beleive we will use CIMple boxes for drive again, but instead use 2-speed Gen 2’s, then we have speed or torque depending on what we need :slight_smile:

It’s not a matter of what gearbox you use. It’s a matter of what gear ratio you use and what kind of drivetrain you use. You can’t just say “CIMple Boxes are bad” when one of you is talking about an 8 inch mecanum drive and another person is talking about a chain-reduced 4" 6WD.

The CIMple Box is a good gearbox for people not interested in direct driving wheels. It packs a lot of reduction into a single gear stage so that you can “finish the job” with your chain reduction.

We used one per side.

-Nick

Im not saying that CIMple boxes are bad, i’m just saying that they weren’t good enough for maccanum drive. They need more torque for what we were using them for (it was just our fault for picking the transmissions)

Did you have an additional reduction after the Cimple Box? Were you using 6" or 8" Mecanums?

If you properly designed it they would be part of a geartrain that had plenty of torque for a Mecanum drive, your wording of “weren’t good enough” blames the gearboxes, not the person that improperly used them. I apologize if I sound harsh but you need to go some research.

I suggest you go look at JVN’s mechanical design calculator and learn how many options there truly are ratio wise between a motor and wheel.

unfortunatly we were direct driving them. this was the first year we tried maccanums, we never even tested with them before. And we were using 6". Another team in Pittsburgh was using 8" Maccanums and they could do everythign fine :blush:

This… is why we do the math.

Does anyone know a good gear ratio for speed and 6 inch wheels. i would like to know what kind of reduction i would need in the chain, or if i should just move to toughbox mini’s and reduce the ration inside of them to get more speed.

What’s speed are you aiming for?

816 ran TB’s (Tough Boxes) with 6" wheels from '08-'10 with a 25:22 reduction (25 tooth sprocket on trans, 22 tooth on wheel) and it worked well for us. Floor speed was somewhere around 11/12 fps.