[MOC] Rock Crawler

[timslegos]

Hello,

Today I present to you my rc Rock Crawler. This machine is almost two years in the making, and it has gone through many revisions over time.

The crawler features:

1. two buggy motors for propulsion
   
2. two speed gearbox (remotely switched)
   
3. independent front and rear steering
   
4. linked pendular suspension
   

The body is very similar to a trophy truck, though it is not based off any real life truck. Bodywork is not my favorite, so it took the longest!

In order to go around the limits set by the pf recievers, the buggy motors are attached to switches that are then directly attached to the battery boxes. The servo motor shown is used to turn the switch, causing the truck to go forwards or backwards. I stole this clever design from efferman, so all credits got to him.

The two speed gearbox takes advantage of both outputs on the buggy motors, with the low speed coming from the slower of the two motor outputs. Though it works well indoors, the high speed does not have enough power to work well outdoors. Below you can see the switching mechanism as well as the gearbox itself.

The best part about the crawler is the two axles. Designing the axles was the most challenging part of the build, as I wanted to have a solid base for the rest of the model. In order to slow down the buggy motors, a lot of reduction occurs in the middle of the axle. The process was made significantly easier when I got the new portal axles from the 41999 BOSS Set. In this photo you can also see the turntables. With all the space taken up by the gears, it was difficult to fit in the steering. The linked pendular suspension was achieved by connected the two turntables via a differential. While one side goes up, the other goes down. This setup has the advantage of not needing linkages or suspension, as well as greater travel.

Here is the video, with plenty of driving out in the snow!

Follow me on facebook for the latest updates and photos! https://www.facebook.com/timslegos

More HIGH RESOLUTION photos can be found here.

http://www.brickshel...ry.cgi?f=538172

I would appreciate feedback, this is only my second studless creation .

tim

Edited January 3, 2014 by timslegos

[Alasdair Ryan]

I like it,you made a good job of it.

It drives very well in the video too.

[MrNumbskull13]

Awesome MOC!!! Great performance and cool features. I haven't seen any crawlers in a while but I really like this one!

P.s: your front left tire was on backwards during the video. ;)

[Junpei]

That linked pendular suspension is genius!

Awesome job, very cool!

TLH

[HorcikDesigns]

That's nice crawler. I like the axles and front bumper. :)

[timslegos]

Thank you for the nice words!

That linked pendular suspension is genius!

I agree, it works VERY well.

P.s: your front left tire was on backwards during the video. ;)

Shoot, knew i missed something .

tim

[piterx]

it has some really nince performances!

well done :)

[Gee]

Second studless MOC?! That's awesome!

[TinkerBrick]

Good job! Great performance. Way better than the 9398.

[Boxerlego]

Looks great. Steering looks very strong. I like the fact that both front and back steering are independently controlled.

[Rishab N]

Great crawler and performs really well!

[timslegos]

Steering looks very strong.

Keeping the steering from self destructing was definitely a challenge! The tires are so grippy that it was difficult to build a strong enough mechanism.

tim

[legomuppet9]

Beautifully engineered model great job! And I agree, the willpower it takes for me to make body work for my models is huge. I hate it

[Foggy]

Well done! Drives very well, you did an outstanding job!!

[timslegos]

Thanks again! Studless building does not come easy to me.

tim

[Lakop]

Great crawler with good performance. It has a good ground clearance and I love the features.

Well done.

H

[TimH]

Very nice crawler, I like the independently controlled steering.

[Edwin Korstanje]

This is one of your best MOC's you made so far