Balance a Chassis

Words: Mark Payne
(Mark Payne's 1:12th Scale RC Notes)

Tweaking out the chassis for predictable handling on a 1:12th car is going to be dependant on a good static balance from left to right as a starting point.

Start with a flat surface which is level on your workbench. I use a piece of safety glass (pop down to your local glazing company for an off cut). Level the glass out with a spirit level.

The chassis will need indentations or small holes at the front and back on the centre line of the car to allow the correct location of balancing pins. The rear hole needs to be located on the back cord of the rear pod. I cannot remember if the CRC rear bottom plate has this hole and the front definitely does not.

Use a set of calipers referenced off the inner edge of the rear wheels to find the centre line of the rear pod, the whole pod is off centre so this is the only reference that makes sense. The centre line at the front is easier to scribe from the edges of the chassis.

Now comes the balancing bit

Set the car up with all your gear, wheels/tyres on and set for correct ride height and rear pod droop (more on this later). Batteries in, pinion on and wiring all plugged up ready to go. Just don’t stick any of your electronics in yet.

The variable items that can be moved around will be the speedo, radio receiver, RX battery pack (if you use one) and Personal Transponder (PT). I place the PT last to fine tune the chassis balance by moving it between the steering blocks at the front.

I have made a pair of alloy balancing pins which locate into the holes made earlier in this discussion. HUDY make these things if you have need.

Place the car on the pins and use a spirit level over the back tyres to locate the car parallel to your flat surface. Now when you remove the sprit level, the car will obviously fall over on the heavy side. You can now move your electronics around until the car balances perfectly on the pins.

Finally locate all your gear and stick it down. You are now ready to move on the next part of the chassis setup.