Hey people! It's a long time since I appeared on this forum. Well...I used to come a couple of times but I didn't get a chance to post. Anyways I am back and I am bring a new project, "Monster Ambulance"!



Monster Ambulance is one of the project's built by Jesse andhis team on the show Monster Garage on the Discovery Channel.
Check out the link:- Monster Garage

On my birthday, I was given a present from my friend. He knew I was fond for RC's so he decided to pick up this one!

So. what's this thread about...Well, opening the car and gutting out all the parts I found out the this car was capable of some serious modding!

Here the project starts.....

Here are some pictures:-
*Flickr*:- http://www.flickr.com/mpjs

There are many pictures so I thought this will work out!

so what exactly are you going to do, or is it going to be a SUPRISE?

with all of the battery weight in the back like that it shouldn't be too much of a problem getting it to pull wheelies. looks like a fun project!

Nope, well I tried but the car doesn't have enough torque to just pull it's wheels up.
Welll, today instead of the 7.2v batteries I added a 9.6v battery. The motor gets very hot so I am goinfg to add a heatsink and the board, there is some kind of thing on it with heatsinks and that is the only thing that get's hot.

P.S:- Why is this forum very active. I see that people rarely post in the threads!

There is a huge volume of information archived that people find in searches.

Adding more voltage may not be what you need to do here. 7.2 volts should be more than enough to flip that thing over if done right. The board on it will restrict the power to the motor so you don't burn out the motor. You'll need a motor with more torque, probably some lower gears, and most likely you'll need to stack the FETs on your board. The FETs are probably the part that is heating up.

Update:- Today while turning on the car the car didn't go front but when I pressed reverse it went back. Turning was well and everything was working fine until there was an explosion on the circuit board... ... got a bit burnt but no biggies.

After some while I thought of an ideo to swap the electronics from my 1/10th Hummer to this car. With the power of 9.6 volts and no heating issues, it works fine.

Testing:- I charged the battery, hooked it up and whoa it screams....Well, it's got some guts but when I palce it on the ground it seems as if it's strippind the gears..I don't know why, can someone help me out?

Sorry about your electronics, most little cars like these won't handle over 7.2 volts. When your car stopped going forward, it was because you burnt out your forward FET (field effect transistor) There are also FETs for your turning and your reverse. I won't go into that too much since you've already replaced the electrics.

it looks like your motor is mounted vertically, I don't know what your gearbox looks like so I really can't help you there. I doubt they put a LSD or an open differential in there, but if they did you might have to lock it to get it to pull wheelies.

I haven't got time to check that out but after some time I will surely!

I have to open the gearbox to see if I stripped the gears and to cut some stuff to put the custom heatsink! And about the motor it's mounted horizontally!

whats this in the picture? I thought it was the motor.
[attachmentid=22670]

i was gonna say that that was a steering motor until i saw it in the front, maybe it's under the electronics and that motor does something else.

if it's not driving the car and it's not steering it, then you have some weight you can trim out. The more weight you have forward of the rear axel, the harder it's going to be to do a wheely.

is it related to the large cylinder beside it?

perhaps a hopper,or siren based thing...
take it aprt and find out! inquiring minds want to know now...

Looks like a speaker to me...

It's a wheelie bar! Well...actually it's a mechanism based stuff, when you press the button the remote, 2 shock absorbing wheelie bar pop up till the desired height you press it! It was stupid and it weighed half the car's weight, so I took it apart! I am going to put a real wheelie by by some modifications to the same wheelie bar!

Update:- Still the clicking sound, opened it up to see that nothing's wrong except the spur gear stripped up a bit. I don't think that would affect it a lot and my berother was telling me that when you added the 9.6, the motor get's enough torque so it starts stripping the gears.
I took out the wheelie bar motor and check it out and saw that it had 9 teeth on it's pinion gear. If I put that would it fix it?

And I also added the heatsink by a lot of cutting and calculations. Again got burnt today and it hurt a lot!

I will get the pictures in a moment.....

So here are the pictures!

Mods up till now:-
1. 9.6v PCB swap from 7.2v
2. Lightened Chassis
3. Lightened Body

And some other stuff still coming up!

Chassis with electronics. Notice the duck tape...well couldn't find my velcro I just kept it here somewhere.
http://farm2.static.flickr.com/1231/119855...ac5f9f046_o.jpg

Stock motor(top) compared to wheelie bar motor(below)!
http://farm2.static.flickr.com/1041/119769...5338429fe_o.jpg

The windshield...Notice the reflection of the game juice on the windshield. I saw on instructables that toothpaste can remove scratches and polish the surface. Welll..I trie that and voila!
http://farm2.static.flickr.com/1313/119853...e9a8ae6fb_o.jpg

The rear wheels. It has no differential and some strange kind of mechanism?
http://farm2.static.flickr.com/1403/119851...ea8c2781f_o.jpg

My Weller soldering station! It's heling me a lot in this project, thank you weller!
http://farm2.static.flickr.com/1065/119766...01592753e_o.jpg

you defeated all the weight savings by droping your battery pack in the bottom of the tub. You need the weight of the pack behind the rear axel or you won't lift your chassis. Also, you don't need that many batteries to run one 280 motor. If those are brass pinions on the motors you didn't strip them on a plastic spur gear.

No...the spur gear is getting stripped not the brass pinion gear!
And for the batteries, I will put the 7.2 volt compartment back and see how much power can the pcb feed into the motor!

And....if I put all the weight behind, do you think it will pop wheelies?

would it be too much to ask for you to resize your pics?
remember 400 pix limit.

thanks.

but, this build seems to be going well, i can't wait to see it get to the fab stage.

is the axel one solid bar inside of that plastic? It looks like some kind of extendable sleeve for shifting to a lower gear set or something. Anyway... if you move the batery pack to the back, pull out the motor and mechanism from the center of the chassis, use an upgraded electronics that can run a 280 motor, that thing will flip on 7.2 volts. If it's busting teeth on your spur gear you're going to have to replace it. Repairing it is real hard and I wouldn't recommend it with a drive gear. a servo gear isn't as crucial, but a drive gear is going to get worn too much for a patch job.

They sell little gear box kits at the hobby store and at some electronic stores. They're made by tamaya and you can get high and low gear sets, and sets that have modular pieces for adjusting your gearing to whatever you want. They usually are in the craft area with the do it yourself robots and science kit stuff.

Okay, I will just link them. It's in the flickr account and these are private!

thanks dude, but I am just starting now to put on the battery compartment. Let's see how it goes on!

Yes, it's a solid rod. I have a couple of gears from old broken rc's and I think I can fit them in. Oh yeah, the wheels can be removed too!

One more question, can a rc car do wheelies if it has no suspension? Because this car doesn't have!

In a wheely, the last thing you want is to have the lift created by the rear wheel's torque converted to compression of a rear suspension.

A wheely is a lot easier to do without a suspension. If you did have a suspension it would have to be really firm.

Today I tested it and it doesn't wheelie. I put all the weight behind. I tried 7.2 volts and 9.6 volts but both failed. But it's damn fast and when it's accelerating and I turn it, it still goes forward and doesn't turn. That means I need more grip.

Anyways I tried pressing the back a little to see if it ries to wheelie. It pops up instantly but I don't know how much weight would be required! Wopuld lead weights work?

yes, putting weight in the back will help.. thats why the battery pack is so far back. if you set up a weight on a really loose spring, it will slam to the back when you accellerate popping your wheely. when driving at constant speeds, the spring will pull the weight back forward to give you better steering control. any weight you add will have to be BEHIND the rear axel, so push that battery pack back as far as you possibly can to allow room for your extra weight to shift into.

edit... attempt at illustrating what I'm talking about.

the green thing is a weight on a stand. the fulcrum it pivots on is behind the rear wheel. The weight is in front of the wheel at rest and at constant speed. When you accellerate the weight shifts back behind the rear wheel, causing a wheely to occur. The tension spring then pulls the weight forward again and drops the front of the chassis back to the ground.
[attachmentid=22682]

Hey thanks a lot baratacus! I owe you something!

Today, I put some lead weights behind with 6 batteries and a 9.6v pack behind. I turned it on, the battery pack wasn't fully charged as I was just checking to see if it worked because a cat attacked my car! ....

It worked and when I press the acceleration button it tried to raise itself up but it could do it only a little. Then I pressed reverse and accelerated it. It popped wheelies and was so cool!

I will get some pictures tomorrow because it's 3:05am at night and I need to go to sleep.

Well..thanks a bundle baratacus! Oh yeah, the project isn't still finished!

any time. That would be really cool if you got it working so it popped wheelies whenever you punched the throttle. Lots of people try to make their R.C. cars wheely but can never get enough power. They don't realize that its all about weight distribution. I hope I was some help to you.