2020 Muscle Car Class

edited 2/8/2020

This class will run with the same rules as Stock Class with the following exceptions.

BODIES
The only bodies allowed will be American sedans or coupes.  These shall not be any cars that could be considered sports cars such as Corvettes, Ford GT, or any other exotic car.  This class is for cars such as Mustangs, Chevelles, Javalins, Chargers, Cameros, GTOs, Rivieras, etc....  any car that could be thought of as a muscle car.

PICKUP SHOES
1. Original pickup shoes or at least pick up shoes with the larger step in them are required.  No Wizzard or similar shoes which have a reduced step are allowed.

HUBS AND TIRES
1. Only original plastic Aurora hubs are allowed.
2. Tires can be of silicon and must fit the original hubs.
3. Only akinny tires are allowed.  If the tire takes up the entire width of the hub it is not legal.
3a. At The "Dirt" wider tires are allowed on the original Aurora hubs as long as they are silicone and fit the hubs.

 Muscle Car Class
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.  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. The only bodies allowed will be American sedans or coupes.  These shall not be any cars that could be considered sports cars such as Corvettes, Ford GT, or any other exotic car.  This class is for cars such as Mustangs, Chevelles, Javalins, Chargers, Cameros, GTOs, Rivieras, etc....  any car that could be thought of as a muscle car.
6. Bodies must be readily available for anyone to purchase.
7. Body must be fastened to chassis using two screws.
8. Fender wells may not be trimmed in any fashion.
9. 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.
10. 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.
11. Split screw post may be repaired using plastic, or a sleeve of some kind.
12. Screw post may be replaced with plastic replacements only and must be positioned in the original location.
13. 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.
14. Fenders may not be flared, unless originally manufactured as such.
15. No body openings other than the side windows and front grills are allowed.
16. Body shape may not be altered from original molding unless a specific class used by a track owner has body rules that allow different.
17. 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 #6 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 #14)
5. Original pickup shoes, or at least pick up shoes with the larger step associated with the original Aurora pickup shoes in them, are required.  No Wizzard or similar shoes which have a reduced step are allowed.
6. 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.
7. Pickup shoe travel may not be restricted.
8. Pickup shoes cannot be weighted.
9. Shunt wires or other soldering is not permitted.
10. Guide pins must be original design, any color plastic.  No rear or swivel guide pins are permitted.
11. Guide pins may be glued to chassis but two mounting screws must be used.  (See rule #7 under BODIES).
12. guide pin may not be countersunk to allow lowering of the front screw.
13. Gear plate clamp may be bent or dimpled but may not be cut.
14. Gear plate rails may be trimmed to allow for lowering of the body.
15. 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.

TIRES/RIMS/AXLES
1. Only silicone or original rubber tires may be used.
2. All tires shall be equal to or greater than 0.350" diameter.
3. Tires shall only be width of original tires.  RT-HO and other similar tires are too wide.
4. Wheels must be stock original Aurora wheels.
5. Only stock 7/8" axles are allowed.  No tungstem axles permitted.
6. 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.
7. Rear and front hubs with tires must pass freely through a 1 1/8" tech block.
8. All four wheels must touch the track.
9. 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.

2020 Stock Class Rules

STOCK  updated 1-7-2020
These rules are the same as they were in 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 that 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.

2020 Modified Rules

At this point the Modified Class is a catch all class for any non-magnatraction cars which do not meet the specifications in the Stock Class Rules.  These cars will have to meet certain rules specifications which will be not as stringent as the rules in the Stock Class.  At some point in the future there may be a Super Stock Class for modifications to T-Jets and possibly another class for other cars with only dimensional restrictions along with basic body rules.  For now these rules will be for T-Jets, T-Jet clones (without magnatraction), and AFX (non-magnatraction).  If a Super Stock Class is formed these rules will be deemed out of date or modified to reflect a new class to go along with the Super Stock Class.  The Stock Class would remain the same.

BODIES
1. The car must have a body on it that represents a car of an actual car of some kind.
2. Bodies must be made out of hard plastic resin.
3. Bodies in 2020 may not be lexan
4. Fray style bodies are allowed
5. Bodies must be securely mounted to the chassis by front and rear screws.
6. Windshield and windows glass may be removed.
7. Fenders may be cut or flared as needed or desired.
8. Plastic may be removed from the body for weight reduction as long as the car remains appearing similar to the car it is modeled after.
9. Bodies must be readily available for purchase and not be one off moldings.
10. Body/car must pass freely through a 1 3/8" tech block.

CHASSIS
1. Chassis may be any 1/64 scale commercially available chassis using a pancake style motor.
2. Chassis shall not use magnets for traction.  This includes the chassis known as AFX Magnatraction.  These are chassis which have a magnet visable from the bottom of the car.  Auto World T-Jet clones or any other T-Jet clone must have the magnet removed from the bottom of the chassis if there is one present.
3. Due to the strength of magnets being used and the transference of the magnetic field through the chassis rules will be made later concerning how much down force is allowed due to armature magnets.
4. Bearings, bushings, spacers, and shims are permitted.
5. Add on weights are permitted, handling pans are not permitted.
6. Pick up shoe modifications are allowed as long as the connection to the chassis remains the same as the original chassis set up.
7. Chassis may be cut, sanded, or drilled.
8. Top plates may be changed or replaced by high performance parts as long as the parts are readily available to purchase.  Top plates may be modified.
9. Guide pins do not have to be the original guide pins but they must be of the original design for the given chassis.  Example, T-Jet chassis cannot be fitted with the snap in guide pins of the AFX chassis.  T-Jet guide pins with beveled holes for mounting are allowed as are flat head screws.
10. On T-Jets and T-Jet clones the guide pin may be glued to the chassis instead of using screws providing the body is securely mounted in some other fashion.
11. Gear plate clamp must be in place, but may be cut, dimpled, or altered in any fashion as long as it still performs the job of holding the top plate to the chassis.
12. Four gear chassis are allowed.  These are pancake style chassis which have 4 gears on the top plate instead of 3.

MAGNETS
1. Stock magnets are not required.
2. Magnets must be the stock shape and measurements of motor magnets in a pancake style motor and must be readily available.  No magnets are allowed that require changing the chassis for them to fit.
3. Magnets may be shimmed to fit in the chassis.  Magnets may be slightly sanded to fit properly.
4. Magnets may be matched.
5. No traction magnets are allowed.  A traction magnet shall be considered any magnet which is visible from the under side of the chassis.
6. Due to the strength of magnets being used and the transference of the magnetic field through the chassis rules will be made later concerning how much down force is allowed due to armature magnets.

ARMATURES
1. Armatures must be of a pancake motor style.
2. Armatures may be modified by rewinding, balancing, or truing.
3. Armatures must be readily available for purchase in their unmodified forms.
4. Armature spacers and shims are allowed.

COMMUTATOR BRUSHES
1. Brushes must be readily available for purchase.
2. Brushes may be modified from their original form.

GEARS
1. All gears must be readily available for purchase.
2. There are no restrictions on gear sizes or gear ratios.
3. Gears may be soldered or glued to their respective shafts.
4. Gears may be lapped and polished.
5. Gears may be drilled, beveled, or lightened in any form.

TIRES/RIMS/AXLES
1. Tires shall e large enough in diameter so light is seen between the chassis and a piece of test track.
2. Any commercially available axles may be used as long as the car passes through a 1 3/8" tech block.
3. Tungsten axles are allowed.
4. O-Ring tires are allowed.
5. Double flange rims are allowed.
6. Front wheels may rotate independent of each other.
7. Front axle weights are allowed.
8. Front tire/axle may be allowed to float from side to side.  Lateral movement may not exceed 1/32".
9. No additives are permitted on tire surfaces other than for cleaning purposes.  Tires must be "Dry" when placed on the track.

Snow Ball 200

On January 1st, 2020 The "Dirt" will be hosting the Snow Ball 200.  The "Dirt" was inspired by dirt tracks my Father took me to as a child.  This race will be a look at an old dirt track race program.  It will consist of Time Trials, a Trophy Dash, Heat Races, a Consolation Race, and finally the Snow Ball 200.  This race program will not be your normal rotational slot car race.  It will be a lap based race where everyone will be racing to the checkered flag for positions.  The starts will take place with the power already on and you have the capability of "jumping" the start.  If you do "jump" the start there will be a penalty assigned and the race will restart.

Time trials will consist of 1 minute on any lane you wish to run on.  Your fastest lap will count as your qualifying time.  The fastest qualifier will get an automatic place in the Snow Ball 200.

The Trophy Dash will be a 10 lap race to the checkered flags.  The four fastest qualifiers will take part in the Trophy Dash.  The lanes will be selected in an inverted process.  Number four qualifier gets first choice of lanes and first qualifier gets last choice.  Ten laps to win a trophy, don't make a single mistake!!!

The Heat Races will be with the even number qualifiers in Heat #1 and the odd qualifiers in Heat #2.  The fastest qualifier doesn't participate in the heat races.  The winner of each heat will earn a spot in the Snow Ball 200.  The heat races will be 25 laps on a single lane with the fastest qualifiers choosing their lane first.

The Consolation Race will be the first rotational race of the day.  It will consist of all the racers who have not qualified for the Snow Ball 200.  The Consolation Race will be 30 laps per rotation with a European rotation format.  The winner of the Consolation Race will qualify for the Snow Ball 200.

The Snow Ball 200 will be four rotations of 50 lap races.  The fastest qualifier will choose what lane they want first followed by the two Heat Race winners then the Consolation Race winner starts on the left over lane.

All races will be live start and will start at the start finish line.  On rotational races all rotations will be lap based with each rotation starting at the start finish line.  The rotational races will count the number of laps for the winner and the number of laps finished plus a fractional amount of your last lap based upon when you cross the finish line.  These fractional laps will be totaled by the computer for race results.  If the winner won all four rotations He would have 200 laps.  However, the winner could feasibly have 197.212 laps.

This race will be using the 2020 Dirt Stock Rules.  The only difference in these rules and the 2019 rules is that skinny tires must be run instead of wide tires.  The Dirt Stock class will follow H.O.R.M. Stock rules except for body rules.

This will be an exciting time of racing based on old school dirt track racing.  Oh, one more point.  In a 200 lap dirt track race the cars usually would not have enough fuel to run the whole race and would have to make a pit stop.......In the Snow Ball 200 you will have to make at least one pit stop.  The computer will show your fuel level, if you run out of fuel the computer will stop counting your laps until you make a pit stop.  You make a pit stop by stopping under the light bridge over the photo cell for at least one second.  The computer will then recognize you are making a pit stop and will refuel your car.  You can watch the fuel bar and leave at any time you choose.  Just make sure you have enough fuel to finish the race.

The track will open for practice at 11:00 and the qualifying will begin at 1:00

H.O.R.M. Modified Rules

At this point the Modified Class is a catch all class for any non-magnatraction cars which do not meet the specifications in the Stock Class Rules.  These cars will have to meet certain rules specifications which will be not as stringent as the rules in the Stock Class.  At some point in the future there may be a Super Stock Class for modifications to T-Jets and possibly another class for other cars with only dimensional restrictions along with basic body rules.  For now these rules will be for T-Jets, T-Jet clones (without magnatraction), and AFX (non-magnatraction).  If a Super Stock Class is formed these rules will be deemed out of date or modified to reflect a new class to go along with the Super Stock Class.  The Stock Class would remain the same.

BODIES
1. The car must have a body on it that represents a car of an actual car of some kind.
2. Bodies may be made out of hard plastic resin or vacuum formed lexan.
3. Bodies must be securely mounted to the chassis in some fashion.
4. Windshield and windows glass may be removed.
5. Fenders may be cut or flared as needed or desired.
6. Plastic may be removed from the body for weight reduction as long as the car remains appearing similar to the car it is modeled after.
7. Bodies must be readily available for purchase and not be one off moldings.
8. Body/car must pass freely through a 1 3/8" tech block.

CHASSIS
1. Chassis may be any 1/64 scale commercially available chassis using a pancake style motor.
2. Chassis shall not use magnets for traction.  This includes the chassis known as AFX Magnatraction.  These are chassis which have a magnet visable from the bottom of the car.  Auto World T-Jet clones or any other T-Jet clone must have the magnet removed from the bottom of the chassis if there is one present.
3. Bearings, bushings, spacers, and shims are permitted.
4. Add on weights are permitted, handling pans are not permitted.
5. Pick up shoe modifications are allowed as long as the connection to the chassis remains the same as the original chassis set up.
6. Chassis may be cut, sanded, or drilled.
7. Top plates may be changed or replaced by high performance parts as long as the parts are readily available to purchase.  Top plates may be modified.
8. Guide pins do not have to be the original guide pins but they must be of the original design for the given chassis.  Example, T-Jet chassis cannot be fitted with the snap in guide pins of the AFX chassis.  T-Jet guide pins with beveled holes for mounting are allowed as are flat head screws.
9. On T-Jets and T-Jet clones the guide pin may be glued to the chassis instead of using screws providing the body is securely mounted in some other fashion.
10. Gear plate clamp must be in place, but may be cut, dimpled, or altered in any fashion as long as it still performs the job of holding the top plate to the chassis.
11. Four gear chassis are allowed.  These are pancake style chassis which have 4 gears on the top plate instead of 3.

MAGNETS
1. Stock magnets are not required.
2. Magnets must be the stock shape and measurements of motor magnets in a pancake style motor and must be readily available.  No magnets are allowed that require changing the chassis for them to fit.
3. Magnets may be shimmed to fit in the chassis.  Magnets may be slightly sanded to fit properly.
4. Magnets may be matched.
5. No traction magnets are allowed.  A traction magnet shall be considered any magnet which is visible from the under side of the chassis.

ARMATURES
1. Armatures must be of a pancake motor style.
2. Armatures may be modified by rewinding, balancing, or truing.
3. Armatures must be readily available for purchase in their unmodified forms.
4. Armature spacers and shims are allowed.

cOMMUTATOR BRUSHES
1. Brushes must be readily available for purchase.
2. Brushes may be modified from their original form.

GEARS
1. All gears must be readily available for purchase.
2. There are no restrictions on gear sizes or gear ratios.
3. Gears may be soldered or glued to their respective shafts.
4. Gears may be lapped and polished.
5. Gears may be drilled, beveled, or lightened in any form.

TIRES/RIMS/AXLES
1. Tires shall e large enough in diameter so light is seen between the chassis and a piece of test track.
2. Any commercially available axles may be used as long as the car passes through a 1 3/8" tech block.
3. Tungsten axles are allowed.
4. O-Ring tires are allowed.
5. Double flange rims are allowed.
6. Front wheels may rotate independent of each other.
7. Front axle weights are allowed.
8. Front tire/axle may be allowed to float from side to side.  Lateral movement may not exceed 1/32".
9. No additives are permitted on tire surfaces other than for cleaning purposes.  Tires must be "Dry" when placed on the track.

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.

Rebuilding a T-Jet

 

Bobby and I recently made a trip to Huntsville, AL to learn more about building T-Jets.  The people with North Alabama Slotcar Association (N.A.S.A.) are way ahead of where we are in knowing how to do this.  The person we learned from has competed in some of the largest HO races in the nation.  While we were there they were in discussions about a race in Ferndale, CA they will be going to in March of next year.  The "Fray" is probably more prestigious than the H.O.P.R.A. National Championships.  These guys are serious racers and serious car builders.  We were extremely fortunate to have Kevin Riggs spend about 8 hours instructing us on how to do it right.

Rebuilding a car the way they do may take 6-8 hours or more, not the 30 minutes you may think it takes. You have to use specific tools to do the things we did under the guidance of an expert.  I tried to compile a list of tools we used and price them out.  My head was spinning by the time I finished.  To my count we used more than $1,500 worth of tools to rebuild these cars.  Mind you, that amount does not have to be spent on tools.  As I said these people are in a different league than us.  They build cars which can be competitive in any race in the nation.  They also have the know how and experience to use these tools properly.  Bobby and I were just stumbling along trying to follow instructions, our cars did not come out nearly as fast as what they can build.  But we did learn what it takes to do the job if you have the tools and the experience to do it right.  I repeat, you do not have to buy all these tools to enjoy HO racing and working on your cars, but it does take it to another level of enjoyment.  Who can argue that you can luck upon a car that is fast right our of the box.  Just look at Bobby's stock T-Jet, it is blistering fast and he did none of the stuff we learned to it.

The tools we used... Lets start this way, we didn't even know what most of them were when we started.  . Then Kevin pulled out an extensive quantity of parts, and a few donor cars to be used in the build of one car. TOOLS - A quality gear puller plus attachments to protect the chassis plate when you use it, A quality piece to peen the gears for when you put them back on the shafts and all the anchors they use for the different size gears A quality gear press, the lucky Bob's we have been using is not good enough. Various grits of sandpaper to sand every gear surface smooth and polished. You need a gauge to measure the flatness of an armature (this is not balancing). You need a tool to repair loose shaft holes such as armature, and pinion shafts, plus your axle holes. You need a Dyno or a replacement for one and an amp meter to measure your amp draw. You need good set up blocks which are perfectly flat and have something representing the rails measured to the rail height you are using. A gauge that measures tension when you rotate a gear. A gauss meter. Appropriately shaped pliers with flat jaws to adjust pick up shoes. Exacto knives and dental floss to repair brush springs. Proper oil including Dielectric oil for the arm hole by the brushes. A quality surface to check the flatness of chassis. A high quality set up to check for arms being out of balance. A device to clean and polish comms that goes way beyond what we have been doing. And a plate to set your chassis up with that is exactly true so your chassis is not crooked in aspect to the alignment of your axles. Now.....you have to know how to use each of these tools and when to use them.

I will try to explain the steps we went through. First you disassemble several cars to get a stock pile of part to build one car with. Every part has to be taken apart. Gears off shafts and everything removed except the copper plates on the bottom of the car. Find the chassis which seems to be the flattest with the best brush springs. Discard the rest of the chassis. Clean the chassis thoroughly. A little grit left where the magnets go could disrupt the handling of the car. Clean the copper completely. Straighten the chassis the best you can to get it exactly flat. This can be done by using a boiling plate and boiling the chassis for it to reset or by flexing the chassis until it comes back to its original shape. This takes a while and is very detail oriented. Once you have the chassis sitting flat check with an alignment tool to see if the axles may not be touching at all four corners. Once this is done you can start trying to adjust the brush springs. We learned the brushes have to sit up higher than we thought before.

Next select a top plate that fits the chassis the best. You want it tight but not binding. If the plate fits check it for flatness. Twist and bend the plate until it starts moving back to its original shape. Once it is flat according to a quality flat surface check again for fit. If it binds find another plate and start working again until you get one flat and fitting properly. Discard the rest of the top plates. The symmetry of the poles of the arm is what you are looking for. This is more important than having a low ohm rating. Once you have selected your best arm check using a run out gauge to see if the plates of the arm are all the same height. If not, loosen the clamps holding you lamanations together and squeeze together to get the right height then tighten it back down (this is not balancing an arm). You now have the arm you will be using, discard the rest.

Thoroughly clean your magnets. See if they fit in the chassis without binding. If they do, check for dirt in the chassis or get another pair. Find all the pairs of magnets you can that fit into the chassis properly. Check these magnets with a gauss meter to find the best matched magnets. Discard the rest of your magnets.

Inspect all your gears, look for spurs, bent or worn teeth, look for abrupt edges where the gears were stamped. Discard the bent or worn gears. Clean the remaining gears completely. Sand the gears smooth. Use a wire brush in the teeth of the gears to make sure they are clean. Polish the gears.

Check all the shafts gears will be on for pitting or dirty surfaces. Clean them and remove any tarnishing. Check axles for straightness. Discard any bad shafts or axles including the arm if necessary.

Look at your chassis and evaluate the hole that shafts and axles pass through. If any are loose you must tighten the holes up. Use a tool to pinch the hole in from both sides of the plastic and test the shaft for play. Remove as much play as you can without creating resistance.

Now you are ready to begin assembly. Install your pick up shoes and springs. Oil the hole in the bottom of the chassis for the arm to fit in and the hole in the top plate. Install you brushes. Drop your arm into the chassis. Install your top plate and clamp. Test the motor on a Dyno using an amp meter. Make not of the amp draw and how fast the arm is turning. Take the top plate off and find the idler gear that fits the shaft with the least amount of play while not binding. Discard the rest of your idler gears.

Now you are ready to start installing gears. Find your best armature gear. Use the peening tool on both sides of the gear (you don't want to spin a gear after everything is together). Using a GOOD gear press install the armature gear so it has as little gap between the shoulder of the shaft and the plate as possible without causing restriction. Put the plate back on the chassis with the arm attached and clamp it down. Test the speed and the amp draw of the motor again. If the amps have gone up a little it is ok. If the amp draw goes up considerably remove the gear and start over.

Once you are happy with your amp draw and the arm gear remove the top clamp, oil and install your idler gear. Use your tension gauge at this point to see how much tension it takes to move the idler gear. Change out the idler gear to each good one you have and test. Pick out the best one you have and discard the rest.

Disassemble your chassis again and find the shaft you have that best fits for your pinion gear. Discard the rest. Peen your pinion top and bottom (you do not want to spin a pinion gear in a race). Find your best driven gear (the one above the pinion) and peen it top and bottom. Using a high quality press put the driven gear onto the shaft until the shaft crowns slightly in the hole. Drop the shaft into the top plate and assemble the entire chassis again. Check for speed and amp draw again. If it goes up significantly find another gear and start over. Once you are comfortable with the gear you have chosen discard the rest of the driven gears.

Disassemble your chassis again and install your peeened pinion gear leaving as little gap between the gear and the plate as possible. Reassemble and test for speed and ampls again. If there is a big jump remove the pinion and start over.

Once you are comfortable with your pinion gear. Find you best rear axle and your best crown gear. Install your axle and crown gear. check once again for speed and amp draw. If there is a large amp draw go to another gear or axle until you are happy.

Once you have done all this you are ready to install your tires and check your shoes for contact. We spent an hour on this process. The shoe should have the most contact possible with the rail. Bend it until it works right.  I came away with the opinion all of the above helps, but what is more important than anything is how the pick up shoe meets the track.  You need as much contact as possible.