Rock crawling, Where to start?

[oldfordguy]

O/k, going to give this a second try. Heres what I have planned. I want to build a really great slow rock crawler. Something with great suspention articulation, and ability to climb seemingly impossible obstacles. I have considered building a lazer or top force with big wheels and tires, and locked diffs for this. Other considerations are Tamiya txt1, Jugg2(with semi truck tranny as suggested bySnollan), 3 spd truck, Kyosho pathfinder/pajero/4runner, Tamiya cross country. What about the older Kyosho 4wd monster trucks,, any good for real rock crawling? Havent considered emax yet, as they are pretty common, and I want something different. What about the hpi electric mt? Yokomo mr4t(? Seems to me that one should be able to lock either or both diffs.

[retro]

I think a monster truck would be the best starting point. You want a really low gear ratio, but if you start with a buggy it will be difficult to gear it down enough, then putting big wheels on it will make things worse.

Which truck you choose depends on how big and what type of suspension setup you want. Real rock crawlers mostly use solid axle setups, but many r/c trucks use full independent suspension. Looking for the truck with the most suspension travel and ground clearence would be a good start.

[WillyChang]

You can get gear reduction units that just bolt on, not a problem.

You starting point really depends on what you want your finished product to be like. If you want something that looks pretty scale & real then your only real contender is the XC or Pajero XB, if a Bruiser is not on option. Kyosho also has their own XC-style (slightly larger too) with room for twin motors too, but these are harder to find than Tamiya's.

Clods & TXTs aren't really built with a low centre of gravity in mind. T/E-Maxxes are good and low with huge wheels and great articulation but they aren't very realistic... have yet to see anything of that proportions parked outside Tescos.

[oldfordguy]

Not concerned with scale looks. Just looking for the best way up and over some big gnarly bolders.

[WillyChang]

Sounds like bigger = better then! []

Any aversion to gas cars?

There's quite a few huge trucks these days eg Kyosho Megaforce etc and others that are based on 1/8th scale buggies. All are gas engined kits but if you're gonna go custom anyway it shouldn't be too hard to retrofit a big tranny and electric motor into it.

[oldfordguy]

Yes, I agree with the bigger is better theme. I must do more research and see whats out there.

[Rossco(2)]

you won't go wrong with either an emaxx or a modified clodbuster, TXT's are capable and look good but not really tough enough....especially when running hot motors!

have a look at my showroom

http://www.tamiyaclub.com/showroom.asp?id=567

[raemin]

The clod buster is a nice base for such project : the very simple suspension setup offers some incredible posibilities of reuse (you will need though a huge lot of ball ends ...).

A nice way to get you started would be to give a look at Nasa's modified versions (ask space center for pics), I was personnally absolutely amazed by the final result given the "relatively moderate" level of modifications they made : slightly larger alloy wheels whith soft imex tires, enhanced suspension setup, a few reinforced aluminium parts, solar captors, and there we are with an almost "out-of-the-box-ready-fly-to-mars" RC kit. Another advantage of the clod buster is its heavy but bullet proof transmission that can resist almost all sort of abuse. Last but not least a decent donor won't cost you as much as a TMaxx.

As for the gear ratio, you can consider electric airplanes engines with built in gear reduction.

[walawala_com]

In my opinion, it depends very much on what budget you have.

An excellent Rock Crawler has to be a modified Clod. But the price is kind of scary. A modified Clod will obtain a very low CG since the batteries & motors are being put at the bottom, unlike Jugg & TXT-1. But always has power loss due to 2 trannies driven by 2 different motors.

Jugg & txt-1 can have a shift fun with TTR Maxx tranny conversion.

Straight axle monster trucks will have a better ability in rock crawling but cannot handle jumps very good. While trucks with independent suspension system will have the other way around.

Joaquim

[walawala_com]

In my opinion, it depends very much on what budget you have.

An excellent Rock Crawler has to be a modified Clod. But the price is kind of scary. A modified Clod will obtain a very low CG since the batteries & motors are being put at the bottom, unlike Jugg & TXT-1. But always has power loss due to 2 trannies driven by 2 different motors.

Jugg & txt-1 can have a shift fun with TTR Maxx tranny conversion.

Straight axle monster trucks will have a better ability in rock crawling but cannot handle jumps very good. While trucks with independent suspension system will have the other way around.

Joaquim

[oldfordguy]

Clod seems to be a great way to start. I like the idea of a seperate motor mounted low on each axle.