Simple Rock Crawler for extreme terrain (PF RC)

[Tamas Juhasz]

Hello!

I present my latest crawler:

http://www.brickshel...ry.cgi?f=538333

I wanted to make something totally new crawler construction. During the last months, some variation was made (little upgrades), this wast he first:

My goal was to made a very simple and reliable crawler, which is able to take apart in competitions. It was succesful in Malug crawler races. Crawlers are relatively free-made, so the bodywork isn't made after a picture from reality. One important thing: you may noticed, it has a relatively large wheel base. To have the good wheelbase/ground clearance ratio, I also increased ground clearance. All depends on the terrain, it can be as good as short wheelbase. With a long one, it's more stable against falling backwards.

It has "no" suspension, the chassis is strong enough but felxible to give articulation for the axles:

(this makes it simplier)

The next varation (V2) was made with longitudinal strenghtening to prevent the decreasing of ground clearance in the middle:

The non Lego tyres: RC4WD 1,9" rock crusher XT.

The chassis shows the innovation:

It's driven with two XL motors (in the axles), on M motor steers. The additional M motor and ship weight in the front axle is only for weight, they have no functions. More weight on the front axle helps a lot in terrain.

The bodywork in not too strong, but who cares with that in a crawler. Lightweight construction was important. In the video below, you can see some high-speed recording about a falling of a piece from the body.

More pictures:

In competition:

http://www.brickshel...ler-No2/019.jpg

http://www.brickshel...ler-No2/020.jpg

http://www.brickshel...ler-No2/021.jpg

Video:

This is totally different than my previous videos. Was made with 30 fps (instead of 10) and 1080p HD resolution. I don't say, I will make every video in this way (requires a lot HDD space, sometimes unnecessary), but the more important or bigger mocs will be recorded similar. So the video:

Hope you like it.

Edited January 5, 2014 by Mbmc

[Doc_Brown]

WOW, you actually went up stone stairs! Amazing.

I can't think of any other moc that has done that, great job! :thumbup:

[Kronos]

WOW, you actually went up stone stairs! Amazing.

I can't think of any other moc that has done that, great job! :thumbup:

I just fell on some concrete stairs and broke two ribs...does that count?

[Doc_Brown]

I just fell on some concrete stairs and broke two ribs...does that count?

OMG! I'm very sorry to hear that, TC.

[HorcikDesigns]

It could be shorter (for better design, in my opinion), but with this lenghth it seems to climb better... ;)

[Tamas Juhasz]

@Doc_Brown:

Thanks. I even surprised when it passed the stairs. For a long time, it was me the impossible terrain section..

@Gzzig:

Thanks to share your opinion. If it seems climb better with longer wheelbase (without that I don't think, the stairs section can be passed), then why you suggest the short wheelbase? Nobody can proove, why it's good, and I tell the reason: it's not better or worse. There are simply long and short wheelbases. There are terrains/sections where long or short wheelbase is better. But I wrote one reason for the long wheelbase: "With a long one, it's more stable against falling backwards."

We are allowed to think outside of the box.

RC crawlers have short wheelbase, because:

- they have relatively low ground clearance for better center of gravity--> with short w.b. their abilities are better

- to get better turning circle

--> my crawler is light, don't need a lower center of gravity --> big ground clearance can be made --> long wheelbase also

Turning circle: I don't care much about it, but the front wheels can be steered in big angle, so I had no problem with it.

( I would be happy, if this topic wouldn't turn into fight against long/short wheelbases... )

Edited January 6, 2014 by Mbmc

[VKTechnic]

WOW, you actually went up stone stairs! Amazing.

I can't think of any other moc that has done that, great job! :thumbup:

Wouldn't be possible without third party tires ;)

Mbmc great moc! Interesting use of a flexible chassis for suspension, I like it

[Tamas Juhasz]

Thanks! I think the stairs would be possible also with PP tyres, you just need more ground clearance, a bit different geometry, and more weight on the front axle. If the tyres becaome dusty, then there are only a little difference between custom tyres and PP tyres. We prooved this in our last crawler race. There was nearly nothing difference between the climbing of a PP wheeled crawler and a custom wheeled one (rc4wd tyres). Maybe I'll make this crawler. Until now, this PP crawler was made: http://www.eurobrick...showtopic=72950

Anyway, I don't understand why my crawlers have this lack of interest. If they aren't good, feel free to tell me. Should I made the pictures or the video in different way?

Edited January 7, 2014 by Mbmc

[AndroTech]

Nice crawler .... simple and effective .... love the third party tires ..... good work ......

[Gee]

Highly innovative. I really like the simplicity of the chassis and how you have used the flexibility of liftarms to your benefit. Makes sense to use the material characteristics of the LEGO as an advantage rather than trying to mitigate against it and then add suspension. The performance of this vehicle speaks for itself.

I think that it's not more popular because it's not got a fancy 4 link suspension system or some realistic bodywork, but if you're a fan of form follows function like me, this hits the spot. Ironically, I just made a post in my newbie thread about off-roader suspension systems in LEGO and why they are always highly complex.

[Junpei]

Awesome crawler! I almost missed this thread somehow. Very innovative design, and the first crawler I've seen climb up stairs

Regarding the lack of interest- I'm really not sure. If there's one thing you're missing, it's this.

TLH

[RCS]

That is a good use of the 'stick' type chassis for rock crawlers which was pioneered several years ago in the hobby grade R/C world. I have never seen that idea tried with LEGO. Very interesting.