--------->QUADROCKER Micro: An ATV Mod w/ Controllable Figure

[joywrex]

I’m relatively new to R/C in general. I have built up a Venom Creeper that was an impulse purchase and with a little help from the great people in the RCC forums it can climb just about anything now. Link to my build thread. For my next project I wanted to add a new challenge to the mix. I have been working on this project for a while now. I figured it was time for you guys to see it. This post is very picture heavy (and word heavy) I wanted to also explain my thinking and my process. I do things a little differently because I don’t have a big shop and usually design for mass production. I’m eager to know if anyone else wants to quadrock a rig! -Noah









Quadrocker, a controllable figure add-on for the RC crawler.

Concept:

The idea is that controlling a truck is fun, but if you could somehow lean as if you were on a lightweight atv than it would be even more fun! Compared with R/C Helicopters and Airplanes, R/C Crawling uses fewer channels and requires you to think about less at once. That was one of the reasons I like it more than racing rc cars. Now, don’t take offense, I know once you start channel mixing with digs and all that it gets more complicated. I like the simplicity and intuitiveness of no dig, but being able to force the weight of the vehicle to change in some way.

Sure it has a higher center of gravity which makes it more difficult. I know, but screw it, it’s really fun.

It’s 2012, Motor on axle crawlers have made ridiculous things climbable. Nonetheless, lots of people are into scale crawlers which includes adding unnecessary weight onto the trucks center. As with the other car types: sportsman, super, mini, etc, This driving would be in a different class that is yet to be defined. I am calling this class Quadrocker. I imagine that it will look a lot less ‘scale’, if you could call it that just as competition crawlers have lost much of their truck-like appearance. For v1 I have tried to make it look relatively real so people get the concept. I could see making it very untruck-like or very scale depending on personal preference.

[joywrex]

Here is a compilation of crawling videos. You can get the idea but it obviously needs a lot of work. The head should be able to pitch at a greater angle, a wider stance, more weight in the wheels, etc.

Quadrocker Micro Crawling R/C Controllable ATV - YouTube


If anyone besides me wants to pursue this folly, here are a couple of the hypothetical rules.

Competition Rules:
An agreed on amount of weight must be mounted to the chassis midpoint. This mass can be controlled in any way.
The mass center must be in the center + or - 1cm
The mass must have the same length width and height + or - 1cm (no long things)
The mass must be an agreed on height from the center of the wheels
Here is an example image:





But I digress, There is no competition when there is only one of these out there.

Even before people were RC crawling I wanted to have an atv with a rollcage that I could crawl with . It would be 4 Wheeling and atv combined. Or, Trials Biking with 4 wheels and a motor. The rig could be tweaked with your body weight. The issue is opposite of the micro rc version. The rig would weigh too much vs your body weight.
I’ts possible I will try to build a 1:1 scale in the future. A superlight 4x4. Also with a roll cage because I will flip it. That would require a lot of funding. I was thinking kickstarter but that would require a lot of work.
One of the inspirations for this concept was the genre of videogame that use lean forward/lean back game mechanic. Games like excite bike (NES), Trials HD (Xbox Arcade), Exite Truck (Wii), Toy Stunt Bike (iphone), MX Mayhem (iphone) to name a few.

These are screen grabs from Trials HD:

centered:


forward:


back:

[joywrex]

I figured I could use two servos to control the body and have a lead filled head at the top.












At first I used parts from my other RC build Joywrex's Creeper Build (First RC ever). I realized that if the servos were bigger than micro sized then their weight would require me to add a lot more weight to the head and so i decided to avoid that by building the first prototype with the smallest car possible. A Mini RC size would probably be better in the long run, the micro itself is too light.





Enter the Losi Micro Crawler. This specimen was sold on RCCrawler to me by SNCrawler

Now I know that ATV’s don’t usually have straight axles for the front and rear suspension. Maybe they should. Body weight counts, just as much as much as I’d like. The grizzly is close; power steering, 4 wheel drive.

[joywrex]

Taking the time to learn about what electronics I would need was bringing me down so I went to toys’r’us and found just what I needed to start thinking about sizing.







After removing all of the extraneous parts I was left with this.





Naked Micro. About to get a lot heavier...

Shout out to hotglue. I love it. It is great for mocking things up quickly. Also, having a large (electric) and small (butane) heatgun makes it easy to adjust or remove bits.



The Micro has a reveiver esc combo board which was not good for me because I am adding two channels to control the rider.





Iteration 1 of the torso yoke. It’s good have cad skills. I recommend solidworks. It’s really intuitive. At least compared to others. I order the prints online. It’s pretty cheap considering I don’t kneed a machine shop or even a garage. I have used lots of services. Shapeway’s is a good one. They can print or otherwise form a large selections of materials. Check it Shapeways - Customize and create 3D printed products. Welcome to the Future of Stuff.

It’s worth getting their sample pack of materials if your interested. It’s $30 though.

These two parts were $15





Head on a spike

[joywrex]

Servo housing v1





Torso yoke v2 and
Servo housing v2



Torso yoke v3



I made a platform for the servos to sit on using shapelock. I heat it up with my trusty heat gun then sculpt it with my burning fingers. It’s like shapeable hotglue to make hard parts out of.

You can get a sample from their website. SHAPELOCK FREE Sample Offer It’s $5 for shipping



These videos are the first movements while the servo chassis is mounted on the actual micro. “It’s Alive!”

Quadrocker Micro- torso yoke v3 leaf spring test - YouTube

Quadrocker Micro - torso yoke v3 shocks test - YouTube

Quadrocker Micro - torso yoke v3 shocks test2 - YouTube

Quadrocker Micro - Final Weight Wiggle Test.MOV - YouTube

[joywrex]

I got some 2S lipo packs to give it more power than the NiMh it came with. Here is a video to understand the difference.

Losi Micro NiMH vs. Lipo batteries - YouTube

Obligatory articulation pictures (not that their any good)







Heavy legs. They should be vacuformed in the future.

Does anyone know where I can get lighter legs?



The smallest receiver I could find. OrangeRX. It works with DSM2. Therefore I am getting a Spektrum 5-channel. (DX5e)



I am using the stock motor and transmission.





Servo housing v3







I am unhappy with the shocks the Losi came with and with the head weight you can kinda slouch off of obstacles. I decided that a leaf spring style chassis would spring back more readily. It would feel a little more like an atv. I ordered the DP Torsion Chassis to try out. It is not designed for much heavier midsection so its as good as it can be. I would like to machine out my own design someday.



Possible receiver placement







These tires are worn out.



This project has given me control issues. The only one that is not specifically for this project is the flysky gt3b.



Weight testing








It’s looking good so far.

[Hydro-Tank]

Only one word can describe this.....wow.

Great job man!!

[joywrex]

First iteration of a hollow jacket in place of a body. I suck at sewing.



And then I filled his head full of lead.





Once it was filled i covered the lead shot with hot glue to seal it in the helmet.


Torso yoke v4



Second attempt at a jacket.

[joywrex]

I got some Miniqlo Miclaw tires and weighted them with bb’s. No foam. The are a bit big. Maybe I should switch to the trail trekker tires or lengthen the links. (kinda hard to lengthen the links with the shockless chassis though)








I painted the wheel weights. The paint scratches easily because I didn’t prime the surface in any way. It’s going to look pretty cool once they get all scratched up IMO. I love this picture. Reminds me of a ring wraith from Lord of the Rings.



The quadrocker component is surprisingly durable. I am using Tower Power MG90S servos and they haven’t broken. This video is a fall onto carpet from 42”. The only damage was one of the ball end links popped off and the hot glue bond connecting the servo chassis to the driveline broke.

Quadrocker Micro - surpisingly durable - YouTube

[joywrex]

After many Rx placements I finally settled on mounted to the server chassis. I updated the cad to make it fit just right.





Again, hot glue is awesome. I added some material to the rear body part and drilled a hole for the body pins.





I picked up some aluminium spindles, just because...







Added the on off switch to the fender





Torso yoke v5
I switched to ball and socket style rod end rather than tie rod style. They are lighter and can pop off in a bad crash. The flat side of the yoke is for the screw that mounts it onto the driveline (universal joint)



Servo chassis v4
Here you can see the front where the body pin screws into and the receiver covers









I removed the little gas cap and put the body pin through that hole.

[joywrex]

To make the body as light as possible I made a tube from fabric and used thin wire to create the skeleton.









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So there you have it. A new thing to do to your crawler. Granted it will make it harder to crawl. I can imagine a snap on version that could easily come off for standard crawling.
I’d like to make a version for a larger crawler in the future.

Please comment and answer the poll question!





Quadrocker Micro Crawling R/C Controllable ATV - YouTube

[Hydro-Tank]

Freakin sweet man! Very cool.

[chevy55]

Way to think outside the box!

One of the coolest micro creations I have seen!

When he leans forward & the rig hooks up , that shyte is priceless

[munsterman]

that's sic but it does look a little creepy lol a bigger version would look awesome

[gopher]

very well done!

[eborgie]

I think if you got used to it enough, you could eventually do wheelies on flat land.

[8695Beaters]

That is so weird looking, but awesome. Great job!

[brandonwalsh420]

very nice

[coryshad]

Very cool, And creative. Nice work.

Sent from my SPH-D700 using Tapatalk

[THX_138]

You are either an engineer by career, or seriously need to change jobs!

I know I'm lazy (the wife confirms it all the time).... But the amount of work in that tiny thing is above and beyond my ambition level. Great work!!!!!

I really dig the weighted head to get the realism on driving. Can't wait for a video