School Project. Brainstorming Help.

[BP-Revo]

Alkaline. That's another requirement.

That worm gear box looks pretty good as well.

Thanks for the idea guys. Keep them coming. I have to go to this specific class right now, so I'll respond more in depth when I get back.

[lincpimp]

Originally Posted by simplechamp

The rules he posted says it has to be either RWD or 4WD.

Are the batteries going to be alkaline or NiMH?

No fun. I guess rwd will be easier to make the 4wd... With just 1 motor that is. Or use the tamiya worm box and split it off to 2 live axles with 1/4 elliptical springs for location. You can use the high lift springs and cut them in half. I can't imagine you want this to weigh much...

[TexasSP]

www.RC4WD.com also has a nice selection of solid axle kits with just axles. They also have transmissions and such.

[What's_nitro?]

Just remember the motor he has to use is much smaller than a 540. So most of those crawler axles are way too heavy.

[JThiessen]

Hmmm....do rear wheel drive, and drive it backwards....

[Overdriven]

Fwd will be hunting for traction in the pulling and hillclimb tests, even with weight over the front axle. I agree with the straight axle idea for simplicity. A solid axle with a worm gear drive, or a wheel driving a wheel would be best also. Either would give more ground clearance, since you have only a 1/4 inch from the center of your wheels to the "bumps" you have to drive over.

If you have to have a suspension though, be careful of axle steer. Some link designs have a tendancy to steer the axle when one side is lifted. Not an issue if you hit the "bumps" slow and perfectly perpendicular, but I doubt that's going to happen every time.

Can you take measurements of the course? Particularly "hill valley" so you know what your ground clearance needs to be in the center? Personally, I'd go for maximum wheelbase allowed for the sake of stability over the bumps. Steering settings will also be more forgiving, 1 degree off, a shorter car will steer for the wall faster than a longer one.

[whitrzac]

have you tried asking the professor what he thinks would be the best idea? maybe he can show you a few wining designs from previous years

[nitrostarter]

In the weight pull competition, are the weights on wheels? If not, I just can't see something that small and weak to be able to break friction to move the weight. Also can you add weights to your vehicle for added traction?

[BP-Revo]

Alright, so just yesterday I ordered a bunch of stuff from Tower for the project.

I bought 2 Tamiya "6-speed" transmissions. You build them and can choose out of 6 different gear ratio's when putting them together (it's not on the fly adjustable). I'm planning to hook both together so I can adjust to as high as a 1692340:1 for the pull, and adjust it back down for the other events.

The other main things I got were a set of Axial AX10 Solid axles.

We also bought a bunch of rod ends. I'm going to buy some threaded rod stock and cut that down to appropriate lengths for linkages, and with some T-Maxx shocks I have (which I ordered slash springs for so they are softer), we plan on making a multilink suspension, very much like a crawler. I played around on Solidworks and found some pretty good geometries.

I also ordered some Jato axles which I'll "make work" to connect the "tranny" to the diffs. I would have gotten the Axial shafts but they were out of stock.

[TexasSP]

The axial shafts are junk and I replaced mine with stampede shafts anyway so you are better off. Other than that the axial stuff is top notch.

[BP-Revo]

Originally Posted by TexasSP

The axial shafts are junk and I replaced mine with stampede shafts anyway so you are better off. Other than that the axial stuff is top notch.

That's nice to know.

And nitrostarter, yes you are allowed to add weights for the pull contest.

I plan to pull and do the hill climb in 4wd, but do everything else in 2wd.