- General Building Car Tips -

David Spashett currently holds 3 World Championships, 13 European Championships and 22 BRCA National Championships. He competes in one tenth electric, one twelfth electric, one eighth gas and one tenth gas. He was part of the team who initially developed the XXX-S and has driven it successfully to the present day. No one better then to advise on building the car.

Building and Car Assembly Tips

Although these tips are aimed at the Losi range of cars, most are universal and can apply to a lot of other cars and types.

Screwing into untapped plastic/graphite chassis.

Always try to pre-tap the holes before assembly, especially holes that have a countersunk head and consequently use a small hex wrench.
Look out for the depth of the hole, never bottom out the screw, itís a sure way to snap the head off.

When first tapping the hole use a little drop of oil or grease, use a cap head screw so you can use a larger size driver, and remember for every half a turn in, do quarter of a turn out.

Tie-rods and ball joints.

Initially set up the lengths off the car as itĎs easier to be accurate when the rod is in you hand rather than on the car.

When initially setting them up turn the turnbuckle deeper into the balljoint than is needed and then screw them back out to the correct length. This will pay dividends when you come to adjust the rod on the car, if there is no thread in the ball joint the force needed to cut the new thread will try to force the cup off the ball and possible open up the cup and leave them vulnerable to popping of in accidents.

Never turn a tie rod into the ball joint so deep that it bottoms out, this will weaken the cup and leave it in a position to bend in incidents.

If the ball joint cup is tight on the ball stud, try to pinch the plastic around the ball joint when it is in place, this usually loosens the joint, do not squash it off of the ball and damage the plastic.

Battery slots.

In moulded or machined chassis the edge of the battery slots can be sharp, this will lead the heat shrink on your battery pack to be damaged and split with constant use as the battery rubs against the edge. This can lead in the worse case to a very expensive breakdown, i.e shorting of your cells and possible damage to the chassis as well.
It is simply prevented by chamfering or radiusing the edge of the battery slot with a small file or dremel, but make sure you do not cut the slot wider so as to allow the cells to protrude further out side the bottom of the chassis which could lead to damage over rough ground.
Finally when you have finished filing the slots drip a little thin super glue on to a piece of dowel and rub it along the slot, this will insulate and strengthen the edges.

Drive belts.

Run them in. It doesnít hurt to initially run in the belt to allow it to become supple without weakening it. this is best done on a variable voltage power supply set at about 2-3 volts or by charging up a old pack of cells. Build up the chassis but do not fit the drive shafts, (there is no point in just spinning them for the sake if it) solder two leads with croc clips onto an old motor and then connect to the power supply for 10-15 mins. If you donít have a power supply charge up an old pack of cells and connect the motor across two cells at a time, cells 1 and 2 first then cells 3 and 4 and finally 5 and 6. By doing this youíll get a good long run-in at 2 to 3 volts.

Wheel bearings

If it appears that when you fit the wheel bearings and put the axles through them they do not spin correctly, the chances are there are tight spots in the plastic housing squashing the bearings. To relieve this pressure do not deremel of file the complete hub , try just chamfering the edge of the hole as it can very often be flashing from the moulding process that causes the pinching. What you want to end up with are bearings that fit snuggly in the housing and do not bind, but at the same do not spin in the hub as this will just lead to premature slop.