April Fool's day has passed, so it's time to get serious. After building my large speed chassis with the new hubs, I was so eager to build I disassembled it right away I think I have a video, but not completely sure, because I deleted some... Anyway after a couple days of messing around with various ideas I came up with a solid prototype. Features are: 4 link connections, gear reduction 1:9-using a nifty reduction right before the 5x7 frame(which has knob wheels so I don't break any bevel gears), a telescopic driveshaft which I got from a youtube video-not sure who it was by; new 8t gears, and to top it off, my 1.9 Rok Lox tires Photos:

I guess I will build a chassis then the front axle. This crawler will probably use buggy motors considering the reduction.

I might be wrong in saying this but you might be better making a custom universal joint using half toggle joints,I believe it would be stronger.

I love the look of those tires, they certainly give you more clearance as well. I would try to not use the nob gears though, they drive rather irregularly.

tim

looks pretty strong

I might be wrong in saying this but you might be better making a custom universal joint using half toggle joints,I believe it would be stronger.

I love the look of those tires, they certainly give you more clearance as well. I would try to not use the nob gears though, they drive rather irregularly. tim

Alasdair, I might just do the custom u joint but I'll make the chassis first to see if it would fit, because it would change the geometry I currently have, and Tim, yes I love them too but their size can put a little bit of stress on the axle when going over obstacles, and if this crawler gets fully built, I will decide whether knob wheels will be necessary (torque-wise)

I might be wrong in saying this but you might be better making a custom universal joint using half toggle joints,I believe it would be stronger.

Excuse me... What's a half toggle joint? Do you have a bricklink URL? And how would you build that to be more stable?

Edited April 3, 201311 yr by deckard9

It will work even better if you mounted those shock absorbers closer to the wheelhubs Then the axle itself won't bend so much when compressed, and you take friction out of the equation

Excuse me... What's a half toggle joint? Do you have a bricklink URL? And how would you build that to be more stable?

Here is a custom universal joint.....

There are two types of toggle joint smooth and toothed.

Thank's for the info!

Here is a custom universal joint.....

I don't understand how it works. I see that it blends in one direction, but how does it blend in the other direction?

I don't understand how it works. I see that it blends in one direction, but how does it blend in the other direction?

I don't think it does bend in the other direction...

I don't understand how it works. I see that it blends in one direction, but how does it blend in the other direction?

wait, i thought i couldn't blend,but will it blend?

i think it might just be 1 degree of freedom..

Edited April 3, 201311 yr by Someonenamedjon

If you need it to pivot the other way just add another section to it.

Edited April 3, 201311 yr by Alasdair Ryan

If you need it to pivot the other way just add another section to it.

it might be a bit big then though

Edited April 3, 201311 yr by Someonenamedjon

It would be 5 studs long...so not that big,I don't build off-roaders so I can't say for sure that a reinforced universal joint will help performance.

It would be 5 studs long...so not that big,I don't build off-roaders so I can't say for sure that a reinforced universal joint will help performance.

why not just build u joint?

why not just build u joint?

I don't need a universal joint?

Edited April 3, 201311 yr by Alasdair Ryan

I don't need a universal joint?

now im confused

Looks overcomplicated to me. You could use a 36 and 12 tooth gear, therebye elimenate the inefficient knob gears and the offset.

Looks overcomplicated to me. You could use a 36 and 12 tooth gear, therebye elimenate the inefficient knob gears and the offset.

yes I agree, I was just messing around with ideas because i've used the 12/36 combo in the past, but my building skills and parts inventory have improved since then, so here is version 2 which I built yesterday:

^need more 3x5 thin liftarms to make the other side

^heavy duty u-joints take up too much space, sorry.

^these pieces keep the 12t in place by reinforcing the axle it sits on.

^these keep the bottom link mounts from popping off, I will figure out some to do the same for the top link mounts.

The improved one looks even better!

ok so I've been thinking...I want some extra gearing so in the chassis I think I'll use a 12t/20t combination, but do you guys know if installing....lets say a 2 speed gearbox... will be worth it? or having one ratio with high torque?

I think a high torque one and a high speed one would be best.

Well, some time has passed and I played around with some ideas and eventually decided on using the output selector gearbox by Sariel. So after building yesterday evening and this morning I finally got a half-chassis connected to the rear axle, along with a fully remote controlled shifter using mini LA's. pics:

I have a modified version of Sariel's gearbox that takes advantage of the high power and high speed outputs on the buggy motors. Here take a look:

tim