quick question about Graupner speed 400 motors

[Wight]

Hi all,just a quick question for those using graupner speed 400 motors.
How do you think they compare to Heng Long motors for braking force?
What I mean is,would it be harder to turn the motor by hand?
Asking becuase my stug 3 does not want to turn going down hill as the track thats supposed to stop turning is not stopping.This is not because there is power stiil going to the motor but a lack of braking force from the stock metal gears and motor.
I am going to upgrade the gearboxes when I can to brass 3:1 ones,which I am hoping will add more braking anyway,but was curiuos about the effect of the graupner motors also.

Cheers.
Steve.

[Andy in Cheltenham]

I don't use these motors, but is there a chance the speedcontroller would help by means of the back EMF?

[971wright]

Hi I use speed 400 motors tried all of them ,best ones are the 7,2 v motors ,6v motors tend to draw more amps (and are a bit to fast)and I have burnt a couple of boards the 4,v motors way to fast and draw even more amps than the 6v motors.
Best set up is with standard gears 7,2 v motor in a Panzer 3 (stug) it may seem a little fast but acording to the gearbox calculator its spot on,my panzer 3 has full metal everything and runs very well.

regards pete

[Saxondog]

Really don't think the motor is the issue as much as the gearbox? I have a Tiger with Graupner speed 400 motors and they have been great but it is a totally different situation except for one thing,what pinion gear are you using? I have tried three with the 12 tooth being the best. Perhaps weight has an effect? But the motors if using a smaller pinion might effect braking?

Saxondog

[Wight]

Thanks for the replies guy's.
I'm not really expecting the motors to be a cure to this,just wanted to see if the motors may help a little.I know some motors will have stronger magnets than others which would help a bit with turning resistance.

Really don't think the motor is the issue as much as the gearbox? I have a Tiger with Graupner speed 400 motors and they have been great but it is a totally different situation except for one thing,what pinion gear are you using? I have tried three with the 12 tooth being the best. Perhaps weight has an effect? But the motors if using a smaller pinion might effect braking?

Saxondog

Sax I believe you are right in that the gears are the main issue here,geared down more the track would find it harder to turn the motor.Compared to the Heng long gearboxes in my panzer IV the ones in my Stug have less rolling resistance,it's a lot easier to turn the sprockets by hand on the stug even with the tracks off,they seem quite smooth really.

I don't use these motors, but is there a chance the speedcontroller would help by means of the back EMF?

You are right,an ESC with back EMF braking effect would be an answer,unfortunately the RX18 does not appear to support this.


Thanks for the help guy's,I think I may just get the 3:1 boxes first as this should be the cure.
By the way,I see there are 2 types of low profile gearboxes available.On has all brass gears whilst the other looks the same layout but with a couple of silver coloured gears.I think that one of them is Asiatam and the other is Mato,but I'm not sure.
Is there a difference other than a few quid in price?The ones with the all brass gears seem to be the more expensive of the two.

Cheers
Steve.

[Saxondog]

The steel gears were added because of a wear issue with the all brass set. Not sure but the all brass gearboxes in my King Tiger have worn badly, where the Asiatam metal gearbox in my Tiger are two years old and look brand new? Their seems to be a recent post about the brass boxes wearing down two gears, perhaps this will give you some insight. I am not impressed with the brass gearboxes,the only benefit I find is the appearance of the brass being more defined and attractive.

[wibblywobbly]

I have low ratio boxes in my Tiger and a PIII hull, the Tiger weighs almost 14lbs and will coast to a halt using the Elmod kit. I ran the gearboxes in using valve grinding paste, and they run very smoothly, there is also little or no resistance. I can almost spin the tracks by hand. I had a pinion come loose on one side and I didn't even notice because one motor was enough to drive both tracks.

It really does pay to run the gearboxes in, it staves off wear in the long run because all the teeth engage cleanly, and everything rotates freely. Noise is massively reduced too. Just a few dabs of valve compound, run the motors backwards and forwards a few times until they are nice a smooth, then remove the compound using WD40 or similar. Then grease the boxes.

Rob G