Screaming Louder
by Brad Birdnow
This article is a follow up to my earlier article entitled
"Building a
Tjet Screamer". I thought you may find it interesting to hear some of the
other modifications I'm considering for my '67 Camaro Tjet. Some of these
are things I've done in the past to other Tjets, some are things I've seen
or heard of and would like to try and some are just ideas I've had.
I plan to use the Dremel cut off wheel to cut small slices from
some
computer hard drive magnets and super glue them to the upper side of the
pickup shoes. I used to do that when I was a kid but the magnets available
now are much stronger. Back then I would cut a Tjet pickup spring in half
to reduce the tension, stretch them a bit to make them reach and let the
magnets make up the difference. When AFXs came out I started using AFX
springs instead of cutting the Tjet springs. I'm guessing that with the
magnets nowadays I can eliminate the spring altogether. I'm thinking that
this may also help hold the inside of the car down on curves. I may have
to make a brass tube axle though, to keep the magnets from being attracted
to the Tjet steel axle.
Regarding the front axle, it may look goofy, but spacing the
wheels
out to the maximum that the tech rules of a racing class allow will help
the car corner more stably. I've seen Tyco 440X2 or Tomy axles & wheels
used for this. I was thinking of something a little more homemade. The
wheels can be made to be independently rotating if I take a steel pin (I
found some at an office supply store that are like a straight pin used in
sewing, only much larger) and grind it down to the size necessary to pass
through a standard Tjet wheel and fit into the end of a brass tube axle,
leaving a little room for the wheel to move left and right. In cornering,
a little side play will cut down on tire scuffing and therefore cut down on
the tendency of the Tjet rear end to skid out. So if you followed all
that, the idea is to cut a piece of brass tube the correct diameter for the
chassis front axle holes and place that through the holes. The length of
the brass tube will be something like one inch. A drop of superglue should
be enough to keep it centered. Once the tube is installed through the
front axle holes a pin stuck through a wheel will be inserted into each end
of the axle tube. The end result will be a widely spaced, independently
rotating front end with enough side play for the wheels to move left or
right a little in cornering. I'm shooting for an overall length of 1 3/8"
to match the rear slicks.
Regarding reducing friction in the chassis I was thinking about
sleeving both ends of the armature shaft with brass tube. I had also
thought about looking into the possibility of finding bearings in the right
size. This may be a problem on the bottom, though, as the brushes are so
close to the armature shaft on a Tjet. I have a set of the gold plated
Super II brush barrels, but I don't think I can get them to fit if I sleeve
the armature shaft. I don't want it arcing across the armature shaft
between the brushes!
The lower and lighter I can make the body, the better the car
will
handle. In addition to the mods detailed in the earlier article I'm also
thinking about a couple of other things. Removing the glass and gluing a
little bit of mosquito net in for a windscreen. Shaving the gearplate
rails off ahead of the armature shaft so I can shave the front post to drop
the front of the body a little more. Both of these things should help to
lower the center of gravity.
Another project that would combine the concepts of lowering the
center
of gravity and reducing friction would be redrilling the rear axle holes a
little higher to drop the rear of the chassis and then sleeving them with
brass tube (or perhaps bearings). This will also involve shaving the nub
on the bottom of the gearplate where the pinion shaft goes through and
raising the pinion gear on the shaft. If I do that I'll probably sleeve
this hole with brass tube as well as the hole in the chassis bottom that
positions the end of the shaft. An alternative to raising the pinion gear
would be to adapt an AFX gearplate to the Tjet chassis. That would also
reduce a little weight and save me the trouble shaving the front of the
gearplate rails down.
I'm a little shy to do some of these things for fear of ruining a
great running chassis. I'll probably wait on some of the sleeving until
wear and tear makes the holes a little too loose.
I have tried to find a way to gold plate some parts. I would love
to
have the electricals on this chassis gold plated, not to mention some
pickup shoes. The couple of plating companies in the yellow pages won't
even talk to a hobbyist like me. I work at an electronics factory and know
a few of the people in the plating department, but there is no provision
made to allow me to pay for the plating. I also have a good friend who is
a jeweler. I plan to ask him about plating.
Another thing I intend to ask the jeweler about is the
possibility of
getting a couple small sheets of silver and gold. I currently cut small
strips from .020" copper sheet to and solder them onto grooved old pickup
shoes. I was thinking that if I install the Super II brush barrels and
solder a strip of gold to the bottom of the shoes with a wire soldered
right to the barrels that would be about as good as it gets. Then the
plating would be unnecessary. I wonder where I can find some silver or
gold stranded wire...