H.O.R.M. Stock Class Rules

STOCK  updated 6-23-2019
The Stock Class is for Aurora Thunderjet 500 cars.  The purpose of this class is a starting point to bring HO racing to the area.  Any T-Jet clones will be put into a modified class as they usually have different gears, brushes, and while their armatures may have the same ohm ratings their armature lamenations and balancing are usually different.  These cars are usually faster than the stock T-Jets but do not handle as well.  This makes them prime candidates for the modified class to be discussed later.  Any body built of hard resin with mounting post for T-Jets will be allowed providing they follow the rules set forth in the body section of these rules.

The rules here-in will include specific rules theat must be followed concerning Bodies, Chassis, Armatures, Magnets, Tires and Hubs, and Gears.  If the car does not meet any of the listed rules it will have to run in a class we shall call "Modified" at this time.  Future classes may include varying degrees of modifications on T-Jets and magnet traction cars.

Bodies:
1. Body must completely cover the chassis when viewed from above except for legal openings (i.e. windows and vents) unless a specific class used by a track owner has body rules that allow different.
2. Bodies must be of the hard shell variety. (No vacuum formed bodies)
3. Bodies must be complete with windows, bumpers, drivers or roll bars as originally manufactured unless a specific class used by a track owner has body rules that allow different.  New resin bodies with molded in bumpers are allowed.
4. Bodies must be originally manufactured with two screw posts specifically for mounting to a Thunderjet chassis; Aurora, Model Motoring, MEV, Playing Mantis, etc. and easily identified as such.  No AFX, Tyco, LifeLike, G-Plus, etc.  Bodies must have original windshields if included.  No wide specially formed Fray type bodies allowed.
5. Bodies must be readily available for anyone to purchase.
6. Body must be fastened to chassis using two screws.
7. Fender wells may not be trimmed in any fashion unless a specific class used by a track owner has body rules that allow different.
8. Bodies may be lowered by trimming back the mounting post, but may not be lightened by removing material other than the height of the post.
9. The body may be trimmed slightly if the body restricts the movement of the pickup shoes. This trimming can only be for the purpose of making the pickup shoes movement operate properly.  Any excessive trimming will deem the body illegal.
10. Split screw post may be repaired using plastic, or a sleeve of some kind.
11. Screw post may be replaced with plastic replacements only and must be positioned in the original location.
12. Front and rear glass is required if it was on the original bady as it was manufactured.  Side windows and excess "glass" inside the roof area may be removed.
13. Fenders may not be flared, unless originally manufactured as such.
14. No body openings other than the side windows and front grills are allowed.
15. Body shape may not be altered from original molding unless a specific class used by a track owner has body rules that allow different.
16. Body msut pass freely through a 1 1/8" tech block.

Chassis:
1. Chassis must be original stock Aurora Thunderjet with all copper components.  A lighted Aurora Thunderjet chassis may be used only if all lighted components, including the wires, light, solder, and brass clip are removed.
2. Bearings, bushing, spacers, and shims are not permitted (exceot as noted in #5 in TIRES)
3. Weights and handling pans are not permitted.
4. Chassis cannot be cut, sanded or drilled in any way except for trimming the rails on the gear plate for body clearance (See rule #15)
5. Pickup shoes shall be stepped shoes only (e.g. Aurora, Model Motoring, American Line, BSRT (model 504 only), Slottech, Wizzard, Dash, etc).  "Ski" shoes or other pickup shoes without steps are not permitted.
6. Any readily available pick up shoe spring is acceptable.
7. Pickup shoes may be bent to allow better surface contact with the rails but must remain stepped.  The pickup shoe may only be slightly flattened.  The contact point of the shoe may not be lengthened.
8. Pickup shoe travel may be restricted either by bending the rear hook where it connects to the chassis, folding the front hook where it meets the front chassis tab, or by installing a non-metallic restrictor ring at the top/front of the shoe.
9. Pickup shoes cannot be weighted.
10. Shunt wires or other soldering is not permitted.
11. Guide pins must be original design, any color plastic.  No rear or swivel guide pins are permitted.
12. Guide pins may be glued to chassis but two mounting screws must be used.  (See rule #6 under BODIES).
13. guide pin may not be countersunk to allow lowering of the front screw.
14. Gear plate clamp may be bent or dimpled but may not be cut.
15. Gear plate rails may be trimmed to allow for lowering of the body.
16. Lowering of the body is only allowed by trimming the body mounting post.

MAGNETS:
1. Magnets must be stock Thunderjet as originally manufactured.  Original color combinations were green/orange, green/white, green/red, white/red, and black.
2. Magnets may be shimmed using mon-metallic and mon-magnetic material only.  Magnets may only be shimmed on their back side, not the side facing the armature.  Chassis cannot be cut to allow re-positioning of the magnets.
3. Magnets may not be sanded or cut.
4. Magnets may be matched.
5. No traction magnets are allowed.

ARMATURES
1. Armatures must be stock Thunderjet.  T-jet armatures are typically painted gray and have green, red, or gold windings, or a combination of these colors.
2. Armatures must measure 16 ohms or higher when measured from pole to pole.
3. Armatures may not be balanced.
4. Armatures may not be rewound or de-wound and soldered tabs may not be altered.
5. Armature spacers are not permitted.
6. Armatures may not be shimmed.
7. Armature lamenations may not be trued, shaved or cut.
8. Commutator plates may be polished but may not be shaved, trued or altered.

COMMUTATOR BRUSHES
1. Commutator brushes must be copper/carbon compound.
2. Brushes must be flat surfaced top and bottom.  Brushes may be lightly scored on the bottom to prevent spinning.
3. Any readily available aftermarket brush is acceptable.

GEARS
1. Armature pinion, idler, and driven gear must be stock brass gears.
2. Armature pinion gear must be 13tooth.
3. Idler gear and driven gear must be 24 tooth.
4. Final pinion gear must be original 9 thooth.
5. Crown gear must be 15 tooth nylon gear.
6. Gears may be soldered or glued to their respective shafts.
7. Gears may be tapped and polished.
8. Gears may not be drilled or lightened in any form.
9. Gears may not be beveled.
10. Smaller diameter or "specialty chassis" crown gears will not be permitted.
11. Identical replacement gears are permitted and must be made of the same material as the stock parts.  No CNC machined aftermarket gears will be allowed.  Unless a track allows this under their rules.

TIRES/RIMS/AXLES
1. Any tire is allowed, provided it is a readily available part and is manufactured to fit the stock rims.  Tires may not exceed standard replacemant width for acceptable after market narrow tires.  No O-Ring front tires are allowed.
2. All tires shall be equal to or greater than 0.350" diameter.
3. Wheels must be stock original wheels or aftermarket equivilant.
4. Double flange "skinny tire" rims are allowed.
5. Rims must be constructed of plastic only.  Metal rims are not permitted.
6. Only stock 7/8" axles are allowed.  No tungstem axles permitted.
7. Front tire/axle may be allowed to float from side to side.  Lateral movement may not exceed 1/32".  Non-metallic spacers may be used to extend width to a maximum of 1 1/8" with tires.
8. Rear and front hubs with tires must pass freely through a 1 1/8" tech block.
9. All four wheels must touch the track.
10. No additives are permited on the tire surfaces.

QUESTIONABLE MODIFICATIONS
1. If you don't know if it is legal, it probably isn't.
2 Don't cheat and you won't be embarrassed by being caught.