RC Tank Warfare community hobby forum

Hello. I have noticed that rctank.de is selling 7:! gearboxes from Taigen.
https://www.rctank.de/7-1-gearbox-made- ... eopard-2A6

I have posted a link for the one I was looking at for my Panther which is currently using the 4:1 gearbox from Taigen that came with it. As anybody tried them yet? If so, what do you think?

Hmmm, I can't see where they get the 7:1 from, there's only six gear trains

The 76 to 1 gear ratio is very desirable, and if those motors can handle that ratio better than the so called 5:1 boxes handle their ratio in a much lighter tank, especially with stock MFU's, they may be on to a winner here.

Thanks for bringing these to our attention

Son of a gun-ner wrote:Hmmm, I can't see where they get the 7:1 from, there's only six gear trains

The 79 to 1 gear ratio is very desirable, and if those motors can handle that ratio better than the so called 5:1 boxes handle their ratio in a much lighter tank, especially with stock MFU's, they may be on to a winner here.

Thanks for bringing these to our attention

Yeah, no problem. From what I was reading on another store the 7:1 is slightly faster than the 4:! but much slower than the 3:1. I'm not sure about torque though and I know very little about gearboxes lol. I am learning though.

Well, with this gear ratio, the motor torque is multiplied 76 times, therefore the sprocket drive shaft receives 76 times the motor torque. BUT, that is providing the motor has enough torque at the start to handle such a large multiplier.
With standard Heng Long gearboxes, it's only a 39 to 1 gear ratio, and therefore, the sprocket is only receiving 39 times the motor torque.
A larger gearbox torque than standard does need stronger motors, which in turn need more amps from the MFU, which may mean a standard MFU could struggle and overheat.

Now I'm not so sure about these new boxes. I'm not surprised they will run faster than the Taigen 4:1 boxes which are an actual 90 to 1 gear ratio, but only has a top motor speed of 18 000 rpm, where these new boxes have a full 10 000 rpm more, and running through a smaller gear ratio.

Edit, to add that forgebear is also selling them.

Gearboxes
https://www.forgebeartanks.com/store/c32/Gearboxes.html

This is the reason gearboxes need to be rated by their actual final gear ratio and/or final shaft rotation speed. This arbitrary 3:1, 4:1, 5:1, 7:1 nonsense confuses people. The motor manufacturers give you the RPM specs by RPM per volts - not some arbitrary RPM number with no voltage reference. Running a 12V rated motor at 18000 RPM would be 1500RPM/V. The same motor would be 11100 RPM at 7.4V. Take the RPMs of the motor and divide them by the actual ratio 39:1, 56:1, or 90:1 and you get your final shaft rotation speed. Much less confusing using the industry standards.

So that delivers 200 revs on the 4.1 at the output shaft or 360 revs at the output shaft on the 7.1. That's much faster, regardless of torque. What we need is a good, proportional ESC in the mfu so the motor/ gearbox combos can be controlled smoothly.

Mr tankme, this is so true. With the Taigen "4:1" boxes for example, it's stated 18 000 rpm, but is that at 7.2volts, 7.4volts or something that the motor manufacturer has stated for the maximum volts these motors are rated for?
Same with these new 28 000rpm motors.

Heng Long has actually realized people aren't dumb with the CNC gearboxes and actually has the gear ratio printed on them as 39:1 or 56:1. The 18000rpm and 28000rpm motor could be the same motor just measured at different voltage for all we know.