pic: West Coast Drive: Spokane Style

Actually, after reading over what you said, let's see how many iterations of the West Coast Drive there are out there! If you've got one designed, put the render up on www.tinypic.com and throw it up here!

[s_forbes]

Nice design, that kind of set up has been proven to work tons of times. What kind of guts do you have in the transmissions? Are they completely stock components (minus sideplates), or do some of the shafts/gears need machining?

Originally Posted by AdamHeard

2 CIMs geared for 10fps doesn't seem traction limited (assuming roughtop/wedgetop tread).

It certainly isn't, the traction limit for roughtop or wedgetop drivetrains (2 CIMS) is closer to 6.5 ft/sec for a full weight robot. Still, we ran wedgetop tread on our single speed robot last year at about 11 ft/sec and didn't have any problems. Of course, we didn't have to push anyone either...

Originally Posted by CraigHickman

Actually, after reading over what you said, let's see how many iterations of the West Coast Drive there are out there! If you've got one designed, put the render up on www.tinypic.com and throw it up here!

I made one a little while ago that's similar to yours in that it is just a small single speed drive base, but uses cantilevered dead axles instead of live axles. Not really west coast, but still... Comes in to about the same weight as yours, too, about 35 lbs with chain (says inventor). The transmissions are about as itty bitty as they can be.

[=Martin=Taylor=]

Originally Posted by CraigHickman

Actually, after reading over what you said, let's see how many iterations of the West Coast Drive there are out there! If you've got one designed, put the render up on www.tinypic.com and throw it up here!

Ourselves and team 368 built one with 80/20 (or Bosch). Team 100. Team 368. 368's actually had a really cool pneumatic break that shot into a hole in one of their drive sprockets.

Why is cantilevered better than non-cantilevered? Beats me. We won't be doing this again.

Originally Posted by Hachiban VIII

Why is cantilevered better than non-cantilevered? Beats me. We won't be doing this again.

Chassis weight. You need less chassis material for a cantilevered drive base. There's no need for an outer frame rail, which definitely takes weight down.

[Akash Rastogi]

Originally Posted by CraigHickman

Chassis weight. You need less chassis material for a cantilevered drive base. There's no need for an outer frame rail, which definitely takes weight down.

Hate to be uninformed, but what exactly is a cantilevered wheel/frame? Pics of specifics would greatly help.

[MrForbes]

Cantilevered means the axle is supported at one end or a the center, non-cantilevered the axle is supported on both sides of the wheel.

[Akash Rastogi]

Originally Posted by squirrel

Cantilevered means the axle is supported at one end or a the center, non-cantilevered the axle is supported on both sides of the wheel.

Thank you very much

[Brandon Holley]

Originally Posted by lilstogi11

Thank you very much

just to clarify a little more for you akash...

If you look at pics of our bot last year that is a good example of non-cantilevered....254/968 are a good example of cantilevered

[Joe Finkel]

I don't think you will climb anything over 20 degr. with bumpers mounts in front of the wheels.

Originally Posted by Joe Finkel

I don't think you will climb anything over 20 degr. with bumpers mounts in front of the wheels.

You're assuming that this is the complete assembly for climbing. It was mentioned that some small changes in the event of climbing being required are easily doable on this design. One gear change per box, and 6 inch wheel instead of 4 inchers. Or, I could leave one side open and put a roller on the front, much akin the 254 during raising the bar (I think theirs was to stop them from rolling over balls, but a few small mods and it would work for ramp climbing).

EDIT: I never sleep.... I need to stop forum lurking....

[jwancura]

ok, so I've been looking at these West Coast drives forever, but I still can't figure out where the bearing blocks for the wheels come from. Are they an off the shelf part you can get from mcmaster by any chance? My team has no milling whatsoever so I'm stuck with finding parts from a store.

[sdcantrell56]

In all of the west coast designs I know of and all of the ones I have designed, the bearing blocks are custom machined parts. There really aren't any good off the shelf parts that I know of to accomplish this. You could always look around for a machine shop to donate some machine time. Many shops are very receptive to robotics stuff. You could also use some of the bearing blocks from team 221 although I don't know if they would work for what you want to do.

[billbo911]

Originally Posted by jwancura

ok, so I've been looking at these West Coast drives forever, but I still can't figure out where the bearing blocks for the wheels come from. Are they an off the shelf part you can get from mcmaster by any chance? My team has no milling whatsoever so I'm stuck with finding parts from a store.

There are options for teams with limited machining capabilities. This link will take you to one option from Robot Market Place.

I am not advising either way with these. There are many more options like these, but it might get you headed in the right direction. A pair of these per axle should do the trick.

[s_forbes]

Originally Posted by jwancura

ok, so I've been looking at these West Coast drives forever, but I still can't figure out where the bearing blocks for the wheels come from. Are they an off the shelf part you can get from mcmaster by any chance? My team has no milling whatsoever so I'm stuck with finding parts from a store.

The best off the shelf bearing block I have found is this one (top of the page) used for front hubs on jr. dragsters. The bearings are a little big, but the assembly looks like it could work for wheel axles. I haven't gotten to play with one... I've only seen them online. They are probably way bigger in real life than they look in the picture.

[AdamHeard]

Originally Posted by jwancura

ok, so I've been looking at these West Coast drives forever, but I still can't figure out where the bearing blocks for the wheels come from. Are they an off the shelf part you can get from mcmaster by any chance? My team has no milling whatsoever so I'm stuck with finding parts from a store.

If your team has no machining resources a West Coast Drive is not a good option. If you have even basic manual mills available, it can be done very easily and simply; but if you don't have that, it will be much more difficult than other possible base designs.

I'd suggest looking into using the KOP frame (it really is awesome) if you have no resources, or try finding some resources. Opening a phonebook/google maps and calling machine shops will surprise you with the results. You'll see that there are both more local shops than you probably think, and more are more willing to help than you probably think.