Negative Offset Crown Gear

[Retro Racer 44]

Hello to all the 1/43 racers out there.

I have a quick question.

Does anyone make a negative offset crown gear. What do I mean? When a 1/32 company like Slot.it makes an offset pod, the axle is higher than the motor shaft to lower the CG. A negative offset would have the axle below the centreline of the motor, there by allowing the use of a larger motor and smaller wheels.

A standard crown gear could maybe be filed or cut to run smoothly below the pinion, but if such a product is out there it would solve my problem.

I have three cars I wish to build in 1/32 scale that would still look small on a 1/43 track. One is a standard Austin Mini with scale wheels in the 10-12 inch range. It is presently mounted on a 1/43 Immense Miniatures 3D chassis, but is on 13" BWA wheel and Paul Gage tires that are just a little too big. The other two at Arii Japanese Kei cars, a Mazda 360 and a Subaru 360. These cars are even smaller than the Mini.

I figured if anyone knew of such a product, it would be the 1/43 racers, eh?

Keith

[Arkay]

I don´t think that this is made somewhere. The reason to make offset gears is to lower the c.o.g. or using flat motors, I´ve never heard of someone wanting to raise it. What motors do you use ? 13 D ?

An alternative is to mount the motor in an angle that is centered to the axle.

Arkay

[Retro Racer 44]

Basically, I want to use a BWA or M/T FF-050 motor with 10-12" scale wheels, with the motor flat to the floor of the chassis for low CG. I agree I might have to angle the motor to do it, but if such a crown was available it could work. I might only need 1/16 or so of an inch. I suspect I will have to file the teeth of a standard crown at an angle to get what I need. I'll start with a worn one, because I am sure I will ruin a couple before I get it right.

[Florida_Slotter]

Keith,

Well if you were to turn over the Slot.It gear, it would be a negative offset gear now wouldn't it?

Recently I upgraded a Sebring chassis for my "Super Cooper". It has the FF50 motor in it. I installed some real bushings from Slot Car Corner, a Slot.It axle and I tried several Slot.It gears. None worked well, so I resorted to something I have used in the past - custom building my own "offset gear".

First thing I did was to shim the FF50's 1.5 mm motor shaft with a piece of tubing that allows you to use 2 mm gears on this motor. I installed a Slot.It 9 tooth inline pinion. The first thing that this increase in motor shaft diameter does is properly align the crown gear with the pinion and then keeps it in alignment. In my opinion, the 1.5 mm motor shaft allows too much play in the gear mesh.

The mesh was quite tight. I set my bench power supply to 4.0 volts and let the motor run with it engaged with the crown gear. Current draw was about 350 milliamps - high. Then I got out my Radio Shack Micro-Torch and started the heat the PINION gear. Use caution here as it is very simple to get too much heat into the crown gear. As the gear started to get soft, it started to mesh properly with the pinion. I saw the current draw go down to 35 milliamps - yes a 10 to 1 reduction! Just imagine how much quicker and faster that car is now!

I've done this many times and the results are always the same - a very smooth running drive train.

I hope this helps.

[ElSecundo]

[pfuetze]

What is the outside diameter of the wheels you want to use?
The Scaley Mini (1/32nd) has an FF050 motor, 16mm OD tires and a standard gear set. The slotdevil micro chassis is using a FF050 motor and 15mm wheels with 24 tooth slot.it gears. Be aware of the outside diameter of the crown gear you want to use, it will limit your choice more that you have to worry about the offset wheel.

there is no offset crown in 1/43rd available.

Peter