Hi Tankers,

I've been unable to play for the first few months of the year so have not been able to try the 8 tooth pinions on my tank untill recently as suggested by Swathdiver. Now my problems are resolved, or nearly so, I have been able to get back to tank driving.

I hope this information will be of help to anybody purchasing a Heng Long Tiger 1 and a KV-1 and want them to run at scale speed. Fitting the 8 tooth pinion was not as straightforward as I thought, it required modifying the gearbox cage. The 8 tooth is of course is a smaller diameter than the standard 10 tooth so won't make contact with the drive cog. I chose the screw hole furthest from the drive cog centre and elongated it by about 3mm. I also had to file away about 1mm at lower edge of the large hole that accomodates the motor's shoulder. This allows the motor to swivel on the second fixing hole. Just like the fanbelt adjustment on the car. When locking the motor in place, adjust untill it rotates as smooth as possible.

The result of this is that my HL Tiger with Mabuchi silver cap motors, standard metal gears, 8 tooth pinion driving plastic tracks has a top road speed of  1.40 mph or a scale speed of 22.5 mph. which is pretty close to the quoted top speed of 24mph. I wonder if the real thing was measured empty or fully loaded?

The KV-1 has a quoted speed of 22mph but that is for the original 1939 model. The Heng Long KV-1 is the e version that has four and a half tons of aplique armour added. After a lot of research I have found a source that quotes this model as 18mph top speed. As the KV-2 was only 15mph and all these models had no upgrades to the engine I would say that this sounds about right.

I first tried the 8 tooth conversion as on the Tiger, this produced a scale speed of 24mph. After trying a couple of different motors without much success I purchased the metal 3/1 reduction gears with black capped motors. This moves the KV-1 at a top speed of about 1.12 mph or 18mph. Spot on!

My next project is to get the turrets to rotate at the correct speed. They both run through the nearly 360 decrees at about 16 seconds when it should be nearer 30 seconds. Has anybody tried this?

Regards