Offseason Development - Let's see it!

[sanddrag]

Whose doing offseason development of robot mechanisms and stuff? Let's see it!

[Veselin Kolev]

Lets see...

Two speed, 9 fps low, 15 fps high. Shift on the fly. 6 motors. 8 lbs per drive train. Red anodized. Dimensions (without motors): 2" wide, 2.75" tall, 6.75" long. Chain output directly to wheels. Be afraid?

Aaahhh... yet another X51 product for a bay area team. Guess which one.

Nah, I'm just messing with you. Woodside, team 100, will be running this transmission soon.

[sanddrag]

Very good. Sure looks a heck of a lot smaller than our HexaMax we made this year. Can I get a top view?

[santosh]

We are just trying to do a basic Crab Drive. We hope to also be able to come up with a CVT design that isn't friction based and is light weight.

[Paul H]

-2 speed Killer Bee style shifter...~10 fps high, ~5 fps low.
-Folded aluminum sideplates.
-6 wheel drive. (The center wheel is fixed to the output shaft of the gearbox, and the outside wheels are slaved off of it. I used 6 inch skyway wheels for the model because I had them on my computer, I don't know what will end up on the real thing.)

This is really just the basic idea of a design that I've been thinking about for awhile, I drew it on my car ride to DC for the fourth. I've still got a bunch of work to do, but it should be pretty lightweight, and cheap/easy to build. We'll probably build a prototype of it in the fall and use it for practice next season.

[Veselin Kolev]

As requested, an overhead view. Also a slightly tilted view so you can see all the gearing.

[sanddrag]

Thanks for the view. Looks a little complicated. What's the output rpms? I assume you plan to have additional sprocket and chain reduction. Also, the low gear seems kind of close in speed to the high gear, no?

Last, do I see a couple gears whose shaft is supported only on one end?

Anyhow, it looks good. I hope it actually makes it onto a robot.

[NoodleKnight]

Output RPMs are ~2000 in low, ~3300 in high. The gears are supported only one one end, sort of an unusual method but, the bearings are pressed into the gears and the shaft is pressed into the plates. Shaft collars hold the gears in place.

[sanddrag]

If the shafts are pressed into the plates (and straight) that should work fine. Your output speeds are quite high. Our HexaMAx was so large and heavy because we did all the reduction with gears in the box, and drove a 5.5" wheel straight off that. Our output speeds were theoretically about 600 rpm in high and 225 rpm in low.

Let's see some more designs!

[Cory]

Originally Posted by sanddrag

Also, the low gear seems kind of close in speed to the high gear, no?

No point in making it go, say 4 FPS when you can break traction at 10 as well. It seems as if recent games have turned more to speed anyways, and if you use that many motors, you can have speed and power even at such high speeds.

[NoodleKnight]

Originally Posted by sanddrag

If the shafts are pressed into the plates (and straight) that should work fine. Your output speeds are quite high. Our HexaMAx was so large and heavy because we did all the reduction with gears in the box, and drove a 5.5" wheel straight off that. Our output speeds were theoretically about 600 rpm in high and 225 rpm in low.

we have a pretty big sprocket reduction, haha.

[Veselin Kolev]

Originally Posted by sanddrag

Anyhow, it looks good. I hope it actually makes it onto a robot.

Look for the first of these gearboxes at Cal Games 2005. And if we still have the same motors next year, a similar version for 2006 FRC.