Platinum_Racing

Check this out guys. It's a large scale R/C Project destined for greatness.

The specs can be found on our webpage, but for the most part it's a large scale (1/2 to be exact) 2WD, 2 speed, 4 stroke R/C monster.

No more small talk, here's the page with the goods. Let us know what you think!

www.TeamPlatinumRacing.com/TPRXL2.html[link]http://www.TeamPlatinumRacing.com/TPRXL2.html[/link]

bigger the better

WOW.[X(]

And I was scared to hit the dog with my MT.
Cool project, can't wait to see what you do for a body.

J_D

looks like a ride-on mower

rchertz

wheres the farmer ?

Platinum_Racing

He's on brake right now, he'll probably be back tomorrow afternoon.

Seriously though, the front and rear axles are modified greatly from a ride on mower. The heavy modifications will make them more practical for use in such a vehicle.

highspeeddirt

My Feedback: (1)

Nce looking project you've got there. I'd hate to have to carry that to the local park to run it. But it would be funny to see the looks you'd get at the local track with it. Keep up the good work and good luck.

Platinum_Racing

Yeah, we are going to use my truck to get it places. Needless to say, we're going to need some throttle return springs, some neutral springs (To shift the tranny to neutral if the servos go limp), some failsafes (To engage full brake in case of a problem), and some other safety devices before we run it. Something this big running away will hurt more than just itself. Forget the T-MAXX running into the street and causing a car accident, this thing will run into the street and need to be CLASSIFIED as a car accident. Property damage would be immense if this thing ran away and hit the leg of a porch, some outdoor furnature, a house, a car, or (What I'm most afraid of) my pool!

So the list of safety features we're planning so far are as follows:

Failsafe on the throttle and brake servos - Return to full brake in emergencies
Throttle and brake return spring - Zero throttle and full brake if the servos go limp
Shifter return springs - Returns shift servo to a neutral if the servo goes limp

Anything else from the large scale world I can use to keep this thing and the people around it safe?

D0G

My Feedback: (1)

What about a seatbelt for the sorry soul whos gonna ride on it..lol
Thats a MUST have saftey feature.


Thats to funny...well said.

highspeeddirt

My Feedback: (1)

An ignition kill switch wired to the coil might be a good idea. It could be set up so that if you loose power to the receiver or get a radio glitch it would kill the power going to the spark plug, and kill the motor. Just some thing you might want to consider. Once again good luck, and keep us posted on your progress.

J_D

be cool if u had a sepeate reciever and transmitter just to contorl the kill switch, like ur mate just has the killswitch radio in his hand while ur having fun, if something happens he just pulls the throttle on his radio or something, and it kills the engine,

so its a completely seperate system, which might be more safe

Platinum_Racing

Possibly, but we have to share radios and recievers between the cars we have now!

I do like the kill switch idea. We could just ground the ignition wire to the chassis and it would kill the engine! To be honest, that hadn't really crossed my mind! Thanks!

hndaman1

My Feedback: (6)

are you running gears out of a riding lawn mower then?then it isn't going too be really fast, or are you building a rock crawler?cause the gears from a riding mower are geared so low the highest gear probally is only 10-15mph?

J_D

could fit a 4 speed and a 2 litre engine on that thing :P

mayhem272

LOL!! that is true!
at first it seemed like a onroad go kart, but then i said, rc? man this would be the next big thing to hit the market
but i dont want to know the price lol. that engine is prolly $500+ itself!
but hey its a 4 stroker! you got that nice low sound and no mixing! but that with a 2 speed? i really really wonder how that would sound!
well ill keep lookin at it to see if they come into production!

hndaman1

My Feedback: (6)

it might even be out before the BAJA B5[sm=spinnyeyes.gif]

Platinum_Racing

Well with the 2 speed it will go alright... it's just the idler shaft we need to put on it. We are still considering the possibilities of using the torque converter from a Go-Kart or Mo-Ped.

The ratio of the clutchbell to the bottom idler pulley (Which we have designed and most of the parts for) and the ratio of the top idler pulley to the drive pulley are going to determine how fast this thing will go. The clutch will bog the engine before it dies, so we don't have to worry about damaging stuff while we tinker with gear ratios.

If all else fails, we have a gear driven 6 speed lawn mower tranny too. Most new lawn tractors have one solid speed in the tranny, then a big belt driven torque converter system that adjusts to different belt tensions. It's complicated, but cheaper for the big guys to manufacture than 2-6 independant gears with sliders and bearings.

The original engine was a 6.75 HP flathead Tecumseh, but we kind of ruined it... It still runs, but not very well. When we got it we already needed to put in a new head gasket because the original one had a huge hole in it, but we didn't know the problems would continue from there. We did have it going good, but then we modified the exhaust to make it run better at higher RPM's, which it did. Then we designed a supercharger shroud to push air into a modified filter box on the carb. The shroud took the left over boost from the cooling flywheel and directed it into a custom cut channel into the carb. Then we modified the governer to allow the engine to spool up higher. This thing was blowin flames like a freakin' dragon, and (NO KIDDING) it sounded like a Harley when it idled. The extra boost did nothing at all at idle, or even up to about 3 thousand RPM... but we figured that when it hit 3,600 (Where the governer was supposed to limit the RPM's) it started to get a bit more kick. From there, all the way to about 5 grand was an instant scream out of the single cylinder flathead mill..... yank the throttle and you were met with a scream of 11 HP of pure 4 stroke fury (We did the math with the stock HP and torque, then factored the higher RPM and gave it another small adjustment to figure in our mods to get the 11HP figure, Horsepower is Torque X RPM (At which you want to find the HP) / 5,252.)

So yeah, the engine just sorta... pooped out.

Now we have this engine. We were thinking of tearing out the 18HP opposed twin Briggsy out of MY personal lawn tractor for the build, but upon finding out a new engine from Briggs & Stratton was in the $7-800 dollar range, I changed my mind!

Platinum_Racing

Hey, if you guys want larger pics you can right click on the ones on the page and select View Image.

Either that or copy the image location into the adress bar and hit enter... that'll give you some larger pics.

wayneuk

why dont u just make a trailer with a seat ..drive yourself there

Platinum_Racing

Yeah... or we could weld on a lawn chair and ride it around! That would work too.....

When it's done we just might have to get this beast inspected!!! Hope it passes emissions!!!

Platinum_Racing

We updated the page. We need information about the steering. Our hydraulic idea might work, but we still need more opinions.....

So, hydraulid, or mechanical (4X 1/4 scale servos W/5:1 reduction)

Read the new info and let me know what you think.....
[link]http://www.TeamPlatinumRacing.com/TPRXL2.html[/link]

hndaman1

My Feedback: (6)

do you have any newer pics of the updates? look like the same pics

slaphead

As they say only in America! Can anyone possibly explain the point of this exercise, surely if your going to build something 1/2 scale you may as well sit on it and drive it yourself?[sm=confused.gif]

Platinum_Racing

Being an American, I can only say............

Because I can.

What bettter way to waste money than to buy raw steel, more gas, and a whole lotta welding wire?????? Jeez... you Brits... so practical all the time!

Pics may be on the way... We are still looking for some hydraulic rams for the steering... any ideas? They should be reasonably priced, yet still able to finish the job. Used pieces are fine... just as long as it's got the power, speed, and durability to turn the wheels.

fz1

I hope you have fun. I have seen this post from the beginning. I give you guys more credit for trying more than the guy who just
buys a rtr and thinks he knows everything. Designing things is not easy sometimes. Especially with limited equipment to work with.
Just be carefull running it.

quarterscalelegends

A tone 5,000 oz servo will handle the job. They run about $500 and work great. I have them on my monstertrucks and one servo will turn 4 16" tall tires while the truck is stopped.

If you want to get real trick you could get CNC servo motors with a CNC controller and limit switches. You could make something really awesome with that.

If you want to go the hydraulic route you can use air cylinders. They have them in a 2 way configuration and they only run about $40 each. You can run hydraulic fluid in them or air. The problem is getting the hydraulics to move smoothly and at the right speed, not to mention holding power.