pic: WCD Practice 2



-1"x 2"x 1/8" aluminum tubing
-center travel block w/ threaded hole for tensioning
-1/2" hex shafts
-5/8" slot for tensioning slide
-All 1/4 20 hardware
-Estimated mass as is (without transmissions and hardware) ~ 19 lbs
-Best guess with hardware is 20-21 lbs

Im currious as to what type of bearings you plant to use, unless it is a dead axle system?

How do you execute dead axle cantilevered wheels?

Run the chain outside of the chassis next to the wheels.

Because the sprocket and wheel have the tube between them, I’m going to guess this is live axle.

THis is a live axle setup. I designed this around the AM hex bearings(the heavy duty ones)](http://www.andymark.com/product-p/am-0692.htm).

This picture is without the wheel, shaft, bearing mount and bearing. I did this to show the innards of the design. Any critiques, more questions, or input? I am very interested in what CD has to say about this.

With a cantilevered wheel, it’s probably safer to use 1/2" hex.

But Chris, I am using 1/2" hex shafts. that hole is just a clearance hole for the shaft when it rotates. The bearing blocks are connected to that inside block, as you can see in both of the other pictures.

If you are using .5 hex shafts I might consider turning them down to round where it goes through the tube, or making the slot 3/4 of an inch wide. As it is now, you have about 1/32 of an inch clearance between the slot and the axle when a flat is perpendicular to the slot, if your blocks are even slightly off, or if you powder coat, the axle might start rubbing on the tube.

Edit:
The link you posted is for the 3/8 hex bearing on andymark, I think that is why Chris assumed you were using 3/8 hex shafts,

You are correct about the bearing. I meant the 1/2 in ones here.

That is a good idea about the shaft. That is not a big problem either. Anything else?

I don’t know if you have Caded the bolts for the assembly, but currently it looks like they will interfere with the bolts holding your wheel together. You might want to move them farther apart, or make the bolt circle on your wheel smaller, threading outer bearing block is also an option, but it will make your setup more complex.

I am a bit confused as to what you mean by bolts holding the wheel together. The mounting holes on the performance wheels are for sprockets and gears and the such, which I am not using. There will be no bolts in those holes. But even if there were, the bearing mounts are counter-bore so the heads of the bolts are flush with the top of the bearing mounts.

My next step is to put all of the bolts in place.

that answers my question. i was wondering if you were using something like Placticons and a hub, with the performance wheels though there is no hub.

Exactly. Just a hex bore. I will probably use snap rings and some spacers to keep everything tight.

I also think so.

Reported.