See my friend Wesley's RC car

Here's my latest project: TANK

Chainsaw Engine Powered R.C. car

I was thinking about building a radio controlled car from scratch and using a chainsaw engine for power now for some time. It took me a while but I eventually did it and it's pretty cool. And when you see and hear it, it's more cool. There's too much power and it's a little hard to control but that's okay, it's supposed to be extreme. Here's how it went.

After you read this, see version two. I rebuilt most of the car a second time making a bunch of improvements over this initial design. The picture below is of the current version.


Video clips

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Watch the tires try and spin off the rim and a straight shot down the driveway


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Pulling a wheelie in this shot. 


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Top end speed in a parking lot...The lot could be bigger though because I never actually hit top end.


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Just having some more fun in the baseball diamond...and getting sideways.


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I'm patting it to make it happy and's rip-roaring time in a baseball diamond. 


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New tires! This is the latest version of the car.


And now, on with the build...



Here is a photo of the basic but somewhat stripped chainsaw. The air filter cover is off so you can see the carb and the muffler is also off which resides to the left of the clutch.


Here is the other side of the motor. It's pretty clean and the compression seems good. No broken parts as far as I can tell. I'll still rebuild the motor however.


Here is the clutch that comes on it. The dumb chainsaw chain makes this set-up useless. I'll have to buy something or get dad to rig something for me.


I bought the rear bushing drive at the hardware store for $19.00 and it should work fine. Nice and solid!


Here's just another angle. You can see how the chain will go and if I get brave I'll put shocks on the back somehow. I have to be able to control this thing otherwise Brian (my cousin) will crush me.


I'm going to make the frame out of this aluminum square tube. It's strong and nice and light and looks cool. I will probably have some sort of platform though because otherwise the frame may be kind of bendable.


On day two I rebuilt and cleaned the engine. I had every nut and bolt off of the thing. I decided to replace the rings since they looked a little worn.


Here's the motor all reassembled and it lost some baggage from the previous day. Notice the mounting plates on each side.


Since I stripped off the outer casing I'm left with a problem of figuring out a way to start this thing. I'm thinking about using a drill...(you'll see)


This was the part that scared me the most since I needed to find a sprocket assembly small enough for this. Plus the clutch had weird teeth on it. Thankfully my dad does tool and die for a living.


This is a close-up of the custom parts my dad made. The sprocket is is from a bicycle and the hub is custom tool and die work by my dad. He also got a small sprocket welded onto the clutch. Worries are over.


Since day 1 I have redesigned the drive axel. Firstly I moved from a steel axel to an aluminum one and I also decided to go with bearings instead of bushings.


She begins to take shape. The frame is made of aluminum and bolted together with stainless steel nuts and bolts. I built this part of the frame twice because I first used too thick of aluminum square tube. Now it's much lighter


Figuring out the best way to mount the engine was hard. I spent days just looking things over and finally decided on this design. It's close to the rear and still close to the ground. Figuring out those mounting plates was a challenge


Here's a view from the other side. I'm hoping to start the motor somehow using the axel that the flywheel is mounted to.


Maybe I didn't need another shot of the same thing but this gives me a chance to say hi.


I put the tires on and am starting to see this thing take shape. I know it will be a little high off the ground but that's ok. Maybe it will be more of a monster truck. Since I don't have any suspension it may not be wise to go too fast anyhow.


Oh yea - these tires are not the ones I'm going to use. I have some monster truck tires on order from the hobby shop They are 6" high and 4" wide. I also have a heavy duty servo ordered and just bought the receiver today.


OK folks - I've got some 6" high USA-1 tires and rims for this thing. They've got a unique mounting set-up that should be very solid. They're not quite as stiff as I'd like but they'll do.


The tire has a hex pattern molded into the rim that fits snug over this part my dad made which slides over the axel and is secured with a cotter pin. Once bolted down Those tires are going nowhere.


Here's what it looks like with the tires mounted. It sits a little high but that's good because it means MUD BOGGING! The grip these tires get is amazing especially with the POSI rear end.


Here you can see that the chain is on and the set-up is rock-solid. Better than I even imagined. I was having trouble with the clutch self-tightening against my mounting plate so my dad made that part that sticks over the end and holds the shaft in place.


The muffler is another sticky part to this project. Again, my dad made this custom part that allows clearance for the chain yet accommodates the large pipe - plus it's made of lightweight aluminum.


Yet another problem area. This is the chamber pressure unlock key. You pull this pin out and it makes the flywheel easy to turn and and the motor starts easier. It works like a charm and I'm a genius for actually figuring this one out.


And since you're curious I'm starting this beast with a plain old drill. I've got a socket attachment that just slides over this nut. You fire the drill and the flywheel spins.. it actually starts. You'll have to wait to see those pictures :)


And once it's started I've got this handy kill switch to put it out. I'm not sure if this is the best spot for the switch but for now it works fine. Do you like the HI-TECH sticker on the back? At the American Science Center they have these aluminum stickers for less than a penny a piece.


Front suspension and steering time. The conception was harder than the actual building of it. I got this idea from looking at a full size go-cart. The block you see rotates and glides up and down creating the "suspension". Of course my dad built the block and tapped the holes for me.


Here's a picture of the oversize 1/4 scale servo (133 sq oz of torque). I originally bought a $75 servo that ended up breaking so I found this stronger one and bigger one for only $30...I could kick myself for not finding it sooner. You can also see the receiver mounted on top of the servo in this picture.


Here's looking at the front of the car where you can see the servo with servo-saver and the tie rods attached to it. I slipped stainless steel tubing over the rods because they were too flimsy and bent easily.


Just another shot of the steering mechanism from a different angle. The ground clearance in the front could be better but I have options for that if I need to adjust it.


A top view of the steering and associated structure. I've had problems running into objects and bending it. So, as long as I don't crash this set-up should work perfect.


On day 6 I'm just adding the finishing touches but some of these proved to be the most troublesome and time consuming. Here is what I figured out for an air filter - just a piece of square aluminum from the carb and a foam filter zipped to the end.


Finding a gas tank was/is difficult. This one is used for model airplanes. It's not the right kind since I need one that has a actual screw on cap not one of these pressurized jobs. But it works fine so until I find something better I'm sticking with it.


The throttle after two re-works now works perfectly. It's quick and responsive and seems very solid. You can also see the on/off switch for the servos in this shot.


The other side of the servo cable ends here at the carburetor where the throttle is controlled with precision and no static or glitches in performance.


I may have mentioned this before but I was having trouble with the clutch spinning off the threads so my dad built this little stopper. Works like magic.



To prevent this bad boy from flipping over and doing wheelies I built this wheelie bar. Attached to it is the roll cage. Which looks pretty cool too :)


Well folks it's all done and my oh my does it look good. However, I have a biased opinion so you may think differently. 


Just in case you're interested in seeing what it looks like from the bottom here it is. It gets a little dirty but not too bad. The solid plate across the bottom does it's job pretty well.