Recently MRRC brought out two more of the
Chaparral 2Fs (No. 4 and 66). The number 66 appears to be the one
people want and so I bought two of them. Usually this is done to
make one a runner and the other a shelf queen, but in this case I was going
to make one a runner and the other a chassis donor. The body is going
to a friend who likes models, but could care less about slot cars. The
donor chassis is going into my Lola T160.
Cincyslots (Bruce Yeomans) has been selling old Strombecker
Lola T160 bodiess for $5 a piece. As of this writing Bruce still
has three. My objective is to make this car into a good looking and
fine running slot car. This will never happen if the original Strombecker
chassis is used. There were several chassis options open to me.
One was to scratch build a chassis and the other was to adapt a one from
a RTR car. The problem is that the Lola is a very small car.
The 1:1 car only had a 94" wheelbase and the Strombecker body is spot on
the mark in this regard. The MRRC chassis was chosen as the donor
for several reasons. The first was that it is adjustable enough in
both wheelbase and track to fit the body. Also it uses the Mabuchi FF-50
form factor motor. These are powerful, small and plentiful. They
can be found in all sorts of devices from toys to computer CD drives.
Recently, Scalextric and MRRC have been using them in their slot cars.
In this first picture the body was placed on the chassis to see how it
looked and fit. With a simple adjustment and a little trimming of
one tab the thing slid under the body with room to spare. There were several
things I noted at this stage. The first was that the wheels did not
look right on the car and so I decided to go with SlotIt rims and some
inserts I got from Dan Wilson a long time ago. The problem that then emerged
was that the MRRC wheels are tightly stuck on the axles. Because
the wheels and body are going to a friend I did not want to run the risk
of damaging them. The solution was obvious, change the whole assembly.
Now the problem was to get a spare crown gear from MRRC. The next
day an email was sent off to them and early the next morning came their
reply. They advised me that spares would not be available until next year.
I read on the web that the new SlotIt hypoid gears had the same offset
as the MRRC gears and so during a visit to Fastlane Hobbies two hypoid
crown gears were purchased. Since I am cheap and was out of SlotIt axles,
a polished 3/32" rod that had been scavenged from an old floppy drive was
used. The wheels and bearings were taken from a dead SlotIt Audi
R8. When assembled the axle spun beautifully in the chassis with
the 28 tooth crown gear on it! The problem that next emerged was
that the MRRC pinion did not mesh well with the SlotIt gear even though
the offset was right. The pinion was just too big. SlotIt does not
make pinions for these small motors, but Slot Car Heroes does. I
have had a stack of the eight tooth variety for several months and so this
was the perfect opportunity to use one of them. Off came the MRRC pinion
gear and on went Tim's little purple gear. The resulting ratio would be
3.5:1. The gear sort of meshed well, but the teeth were not long
enough to stay engaged with the play that the SlotIt crown gear allowed.
This is not a fault of either gear but results from using two gears that
were not deigned for each other. The crown gear was designed for
an armature with a larger diameter and so it allowed the axle to move to
much horizontally. The solution was to put a spacer between the gear
and the right side bearing to remove the play. A collar from an RC
airplane was used as the spacer as it was exactly the right length and
had a set screw to hold it in place. Once this last step was done everything
was perfect.
The axle was then cut to the right length and the
SlotIt rims were mounted. The gear mesh was just fabulous. This new
gear train seemed to allow the motor to rev higher because the friction
from the bad gear mesh was gone. The coolest thing from an aesthetic
standpoint was that the fat tires on the back looked right. Now "all"
I have to do is make an interior with driver, exhaust pipes, injector stacks,
and duct work for the brake vents, and of course sand, paint, decal, and
mount the body. Oh, I forgot I still need to find front wheels and
tires. Then of course run the daylights out of the thing.