Building MonsterTruck of a Mini ATV Quad.... ?!

[vectrex]

HI there ....
since i have no luck getting a 1:4 scale Monstertruck for years i stumbled across a posting in another RC forum ....
Modifying a 49ccm Mini ATV Quad to be Remote Controlled ..... anyone ever thought about this ?
Any member on here got any experience with such a mod ???
greetings thomas

[Mike Casey]

I saw a post about doing that on RCU. Interesting idea. I think it would be a pretty basic project. You could use a Tone servo for steering and one for the gas/brake. You would need to make a body because I bet the standard 1/4 scale ones would not fit. Those ATV's are cheap and I think its worth the small investment to try it out.

[vectrex]

yes they sell for 60 euro on ebay here ... 1 meter long ... so maybe also there s a chance for a body ....
you have the link to the posting you mentioned ?
greetings thomas

[M.R. Ogle]

Here's one that looks promising...
Item number: 150023851846
You know, it would be worth the 300 or so bucks just for the engine, wheels, tires, disc brake system, and hardware alone...
Just think how fast and rugged these things are, and for what we'd be doing with them... relieving them of 100-plus pounds of weight, they'd probably fly!
You might really be onto something here.

[vectrex]

yeah check this out: 250017084831
realy cheap i think its worth a try ... just need some BIG steering servo(s)

[Marccom]

Hi,
this idea ist amazing!!!
I think i will try it.
I,ve spotted some ATVs on ebay that maybe will run out not too expensive.
The completed weight of one special model is 30 kg.
- Well, we have to cut off some parts of the frame,
- we don´t need the bodyparts,
- no handlebars,
- no seats,
- i think we have to change the wheelbase (shorter) [?]
...that should have an effect of minus 5 to 10 kilos.

- roundabout 1kg will come back as servos, batteries, failsafe and RC-box
- roundabout 300 to 400g for a nice Quarterscale-Body (f.e. MCD HUMVEE 1 with wheelbase 650mm)
- max 500g for gas/brake steering and additionalities for wheel steering
- maybe 1Kg for possible 4WD (only additional chain and 3 chainwheels towards front axle)
to say it shorter:
this operation should end at a weight of a little bit less than 30kg...and i think for an RC QuarterScale Monster is this not too much. (Compare New Era Monster...f.e.)
An vehicle like this could mean real fun
Let´s see what we can do
Greets
Marc
P.S. for years im dreaming about a selfmade QuarterScale...but was afraid about the costs (one concept already done in 2004, but calculated costs were about 2000 EUR [2600$])
THANKS FOR THIS GREAT HINT!!!

[Marccom]

Hi,
now i only want to tell that this project is on its way.
i have an ATV now and just began to think, work and to order spareparts.
Watch some pictures below.
- the frame will be modified (just began)
- the rc-car will get an 5-HP-49ccm-Engine (on way to me)
- 4WD is possible an will be done
- the steering will be done by an electric-engine of a car-windshield-wiper (very strong)
- the suspension will be 4 shock-absorbers from a washing machine with individual industrial shock-absorber springs (don´t worry...all pretty cheap)
datas:
length: 1010 mm
width: 580 mm
height: 420 mm (at moment)
wheelbase: 700 mm
trackwidth: 500 mm
wheel diameter: 250 mm
max. ground clearance: 142 mm
min. ground clearance: 75 mm (chain wheel)
weight: 22 Kg (at moment)
Greets
Marc

[Mike Casey]

WOW! good for you. Looks like you have a good handle on the project. What is wrong with the engine thats in it?

[Marccom]

Hi,
thank you very much.
the engine in is a 49ccm-engine too, but with 3.4HP...well, that is not too weak, but i have problems with starting. First there were problems with ignition...that works now, but the engine ddoesnt want to start anyway.
Because of the low revolution of about 8500-9000rpm I planned an tunig-cylinder in any case for later. But now an completely new tuning engine was cheaper...and so i hit two birds with one stone: no more starting problems (i hope so) and a strong engine with higher revolution (12000-14000rpm, i think)
Greets
Marc

[Lovedr]

can you please post pictures of the shocks you plan on using. or a link to one.
thanks

[Marccom]

Yes,
look here
But time has changed and i have other plans now. I found a way to use original shocks and to get softer springs that fit.
that means: the washing-machine-shocks will not be used.
Greets
Marc

[vectrex]

COOL ! i hope you keep us updated on the progress of the project .. thanks !

[Marccom]

Thanks a lot....oh yes i will.
Für die deutschsprachigen Leser hier könte auch der Thread im www.rcindependent.com interessant sein.
Da steht alles im Detail.
Greets Marc

[Marccom]

some Progress:
on 09/17/06 I finished the modification of the back axle.
last week i finished and testet a curcuit for the steering. An old servo device combined with a 12V-sweeper over relais and diodes. Works good.
today I finished the suspension of the front axle.
Greets
Marc

[Marccom]

Hi,
just want to keep you informed, that the project has changed.
I collected very interesting informations and got new experiences and ideas.
So i decide to build a completely new car but will use several parts of the Quad.
Two weeks ago i bought a milling machine and i am going to collect the accessory.
Since a few days i am designing the modell via CAD-Program. But i have a problem with the number of parts you can collect to one assembly, because the program is a free version of ALIBRE DESIGN. The full version is about 1200$.
The decision to build a new car comes out of realization that some things are ddifficult to make on the original frame of the Quad.
- the frame is very inexact...so it is difficult to get additional parts on it in precise way
- the target to get 4WD on this is difficult cause of the first point an the ways of the drivechains would get too long
- the weight of the frame is unnecessary high. The planned RC-Car shall not be builded to cary persons. So an alu-chassis-plate-config is enough ...or much better, i guess.
-...
here are some pics out CAD... i am much further (all quad and planned for using parts [all in all 23 parts and 6 assemblies til yet] are ready, but cannot show because of the partcollecting problem.
Greets from Germany
Marc