RC Tank Warfare community hobby forum

I’ve modified one of my stock Heng Long gearboxes to low ratio, but found the Heng Long motors are too slow. So thinking of upgrading them, I’m considering these

Graupner Speed 400 6v
Nominal voltage 6V, Operating voltage range 2.4-7.2V
No-load rpm 18000, Current drain at max. efficiency 4A
Shaft diameter 2.3mm, Weight 73g

Graupner Speed 400 7.2v
Nominal voltage 7.2V, Operating voltage range 3.6-8.4V
No-load rpm 16400, Current drain at max. efficiency 3,3 A
Shaft diameter 2.3mm, Weight 73g

Using the gearbox calculator the stock HL motors gives 0.587mph, if I use the faster 6v motor this will increase to nearly 1mph or 16mph full scale speed. Also the gearboxes are in a full plastic Tiger (except drive sprocket & idler wheels) so the tank is light weight compared to metal versions so I don’t think that will over load the motor either and draw more current and damage the RX18 board.

Any thoughts?

Hi I don't know what these motors are like in a tank but I have used both motors in a small fast electric racing boat with a surface drive propellor and I found they worked well at high racing speeds but lacked torque at the lower end of there RPM's. My own experience of these motors was that at racing speeds I had to water cool them and using a 7.2V racing battery pack they could pull up to 16 amps and we could just get about a 6 minute running time, ( fast electric racing is a 5 minute race with the winner being who could get the most laps in ).
Don't know If this is any help.

Thanks for your comment. Just bought a pair of 6v ones this lunch time so will find out.
As for the speed these are going in a low ratio gearbox so that will provide the torque with the motor revving its nuts off so hopefully good combination.

Tankbear wrote: time so will find out.

Make that a long time. Managed to ruin a brand new motor even before showing it to my tank. Bent the shaft putting pinion gear on Man do things test me.

I need a new hobby something better for the stress levels. Candle making, how's that sound

Damn that sucks ..hope you get it all fixed soon.

On a plus point your spares are increasing

caddyshack wrote:Damn that sucks ..hope you get it all fixed soon.

On a plus point your spares are increasing

Yes the spare/bent/damaged parts boxes are pilling up

It's doubling annoying as I went into a model shop (mainly helicopters, airplane & boats) for the motors. Asked if he could remove pinion gear from old motors and put on new ones, as I thought he have the tools in back of the shop. He said no but told me how to do remove the old ones.

I then asked if he sold 10 tooth pinion gears with grub screw fixing and he just said no. What a helpful chappy.

So knowing how easy it is to bend the shaft, I now need to find suitable pinion gear with grub fixing. Any suggestions?

Visit here: http://www.etoarmour.com/products.php?ViewCategory=47" onclick="window.open(this.href);return false;

Cheers Pcomm1 for the link.

Is it 48 Pitch I need? is this also refered to as 48DP?