by Terry Flynn
Bushings and Bearings for
possible use on RiggenHO (and other brass) chassis'
----- comments and feedback welcome...
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Installation of Axle Bushings
by Terry Flynn
This installment covers the installation of front and rear axle bushing. These may be done together or separate to accomplish an individual’s goals. The purpose of a front bushing is to allow the use of small diameter axles found on most independent front end sets offered by Wizzard, Scale Auto, JW’s Speed Parts and similar vendors.
The rear axle bushings may be one of the most useful mods a hobbyist can perform on a Riggen. It allows the use of a .059 diameter drill blank rear axle. Coupled with quality gears from Wizzard or Scale Auto, the results are usually a smooth and precise chassis.
The general parts you will need are:
1) A good quality soldering pencil, silver solder, and flux paste.
2) Brush barrels out of a Mabuchi or Johnson can motor
3) Brass tubing that is .096” OD.
4) .059 drill blank rear axle
5) 2.5 mm (.096”) size drill bit to drill the rear chassis holes
6) .061” size drill bit to drill out the brush barrels.
7) Dremel with a cut-off wheel
1 – Drill out the brush barrels. Having a small set of pliers helps hold
the part while drilling. The finished inside diameter should be just large enough
for axle drill blank to pass through.
2 – Drill out the rear stock axle holes wit the 2.5 mm bit. The barrels are metric so you need the metric drill bit.
3 – Fit the barrels to the chassis and use a .059 axle to hold the parts
in alignment. Use a toothpick to apply a small amount of flux to the inside
of the chassis axle upright around the barrel. Melt the solder into a small
drop on the iron’s tip. Touch that to the inside to the upright and barrel
till the solder flows to the outside and around the barrel flange.
4 - Trim right side boss back about half its original length. Trim left side
(Crown gear side) back such that it leaves an amount equal to the outside of
the upright. ‘Chase’ the new bushing bosses with the .061 drill
bit for a perfect alignment. This results in a one 1,000ths clearance around
the .059 axle blank. Cut the axle drill blank to a standard width.
5 – For the front, trim the brass tubing to a slight friction fit between
the two front axle bosses. Insert the independent front axle blank to insure
alignment. I would try this solder operation without flux. Try bridging the
drop of solder over the tubing and the boss. Using too much flux or improperly
will result in solder flowing into the inside of the brass tube and onto the
axle blank. That is not a fun fix – been there… .
Other possibilities....
These are BSRT bushings...very hard to find but for all we know there are stacks
of them somewhere on a shelf at Scale Auto!!!!
Two sizes.
Here is an unknown bushing I found that works very well on the striated Tyco axle. It is flanged on both sides which may reduce wheel clearance. The outer flange can prob be shaved down...
Here is an unlabelled bushing I found that works well. It appears a little longer than the BSRT version. I have maybe 5 pairs of these.
This is the Terry Flynn modification.
This is an actual ball bearing, 1.5mm (available at Wizzard HO) with flange. They also have an unflanged version....This was crudely adapted to a stock chassis by simply reaming the rear uprights to fit. I did not attach but should be an easy solder job. The uprights are certainly alilttle weaker but the axle spins very nicely....
