- 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.
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
Always try to pre-tap the holes before assembly, especially holes
that have a countersunk head and consequently use a small hex
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
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
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
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.
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.
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.