1) Only original Aurora Thunder Jet chassis
assemblies with non-plated copper electrical components are
allowed. Brush springs may be bent to alter brush tension.
Pickup shoe hanger plates may be slightly bent.
2) The rolling chassis’ axle and
armature holes may be slightly opened up for increased clearance. The
truck hole cannot be utilized in any way.
3) The rolling chassis assembly must
not be fitted with bushings.
4) The chassis may be trimmed slightly
(no more than .010”) to allow for crown gear tooth clearance.
5) Any original Aurora T-Jet pancake
gray armature with two laminations, with its original commutator, and
all of its original unmodified windings may be used. The armature
may be, (balanced, and trued)
6) Each armature pole is to be measure
across two separate commutator segments. The Average of all three poles
must be 16 ohms or greater. I.e. pole A measures @ 15.8 ohms, pole B
measures @ 16.2 ohms and pole C measures @ 16.0 ohms – This armature
is Legal. All measurements are to be taken at the current available room
(ambient) air temperature. The warming of either the commentator
or the armature is not allowed before and during measuring. (The
combined total ohm reading of all three armature poles must equal or
exceed 48 ohms)
7) Any original Aurora magnets or
Johnny lightning magnets must be used. Johnny Lightning magnets may be
sanded to fit the chassis. The distance between the magnets must be a
minimum of .700; no exaggerated sanding is allowed to close the arm gap.
This will be teched using our custom designed, specially fabricated
plug.
8)Magnet shims may be used. Shims must be
non-ferrous. No shims are allowed either under or on top of magnets.
9) Any flat top and bottom carbon/copper
motor brushes are allowed. Brushes may be scored with one score
line or an “X”. No exaggerated deep cuts or crevices allowed. This
will be checked at tech.
10) Any stock or commercially available stock
replacement 14 tooth brass armature pinion gears are allowed.
11) Any stock or commercially available
stock replacement 24 tooth brass idler and driven gears are allowed.
12) Any stock or commercially available stock
replacement 9 tooth brass pinion gears allowed.
13) Any stock or commercially available
stock replacement 15 tooth crown gears are allowed. The crown gear
boss may be trimmed or a spacer may be added to adjust for proper gear
mesh.
14) Only original Aurora drive gear shaft
must be used. The shaft may not be trimmed, cut, or, shortened.
15) Gear tooth friction surfaces may be
deburred by polishing, filling or sanding.
16) Gears may not be chamfered,
lightened or relieved.
17) Any front, rear wheel and, tire,
axle may be used, but the front tires cannot be smaller then.300
diameter. Maximum lateral movement in the front wheel assembly is 0.031.
18) Front and rear axle shim washers or
spacers are allowed. Front axel, shim washers or spacers must be on the
outside of the frame rails. Refer to Chassis Rule #13 for adding spacers
around crown gear.
19) Any stock or stock replacement
pickup shoe must be used. These shoes must have a factory formed step,
and the step must be unaltered except to allow flat pickup shoe contact
with the track rail. Replacement shoes can be American line shoes.
Thunder shoes BSRT #504, are allowed. The radius bend on front of the
pick-up shoe below the slot may not be altered in anyway.
20) The
“ step” in the pick-shoe must remain intact and be unaltered, except
that only the first bend in the step (Bend #2)
may be changed slightly so that proper “pick-up shoe “ to” rail”
contact can be achieved. NO attempts to “flatten” the “step” are
allowed. The area between bend 1 and 2 may “flattened” to achieved
better contact with the “rail”. The front, vertical, slotted portion
of the pick-up shoe may be bent to limit shoe travel. The rear, hook
portion of the pick-up shoe may be bent to limit shoe travel and shoe
tension.
21) The pickup shoe spring may be cut,
stretched, shimmed, or compressed.
22) Any amount of the vertical gear
plate rails above the upper horizontal plane may be removed. No
amount of material may be removed from the gear plate at or below the
upper horizontal plane. The serial/patent numbers and letters must also
remain intact.
23) Guide pins must be plastic and must
be of a design essentially similar to the original Aurora black plastic
front guide pins. Guide pin may be, trimmed or bent. Countersinking
screw hole on front guide pin is allowed.
24) Glue may be used on a rolling chassis
assembly only for the purposes of attaching gears, guide pin or axles.
Solder may be used to attach metal gears to their metal shafts.