Unofficial Coolbank M5A1 Stuart 1/16 Scale Light Tank Discussion Thread

[Houtje24]

I've ordered the 1/16 Stuart and the loose receiver board and transmitter in order to make a 1/6 scale Stuart working with that. The 1/6 is running now with a old Robbe Promars transmitter with a mixer on one stick that controls two Robbe Navy 540 compacts. I hope I can get these working with the new receiver board.

[MaverickTank]

SMOKE!!! It does smoke after all. I was doing range tests this evening and noticed wispy smoke curling out from under the rear deck. 😁

But, I definitely have radio problems. At 20' the signal is spotty at best.

Does anyone know how the steering works for this tank, since it has a single drive motor?

[tank_me]

SMOKE!!! It does smoke after all. I was doing range tests this evening and noticed wispy smoke curling out from under the rear deck. 😁

But, I definitely have radio problems. At 20' the signal is spotty at best.

Does anyone know how the steering works for this tank, since it has a single drive motor?

It's apparently two motors. The other is under the plastic from what I've heard. The one you see is the steering motor. The drive motor is in the enclosure.

[MaverickTank]

It's apparently two motors. The other is under the plastic from what I've heard. The one you see is the steering motor. The drive motor is in the enclosure.

Hmm. I wonder if the steering motor slides spur gears across worm gears or something. If so, that certainly affects how aggressive I will drive it.

[RichJohnson]

It’s a cross drive or dynamic transmission. They have many names but one motor drives it the other engages clutches for steering. The Henglong 7.1 system can be changed to a mode to run this type of transmission.

[Sureshot]

Kind of like my early Tamiya Sherman only with a motor doing the clutches instead of servos.

[MaverickTank]

Wow. Read about how the Tamiya version worked DECADES ago. If this works in a similar fashion then we should be treating it with care. That system wasn't very resilient.

[tank_me]

Wow. Read about how the Tamiya version worked DECADES ago. If this works in a similar fashion then we should be treating it with care. That system wasn't very resilient.

It's not like the single motor Tamiya clutch system. It's a dual motor system, but the motors are two different sizes. It uses a differential drive system and not servos like the Tamiya setup. It's like the PDGBS or the HL "dual current" gearbox. The large motor controls both tracks at once either forward or reverse. The smaller motor engages to stop or reverse a track making a turn. When you turn one gear manually by hand, the other gear turns in the opposite direction.

[MaverickTank]

It's not like the single motor Tamiya clutch system. It's a dual motor system, but the motors are two different sizes. It uses a differential drive system and not servos like the Tamiya setup. It's like the PDGBS or the HL "dual current" gearbox. The large motor controls both tracks at once either forward or reverse. The smaller motor engages to stop or reverse a track making a turn. When you turn one gear manually by hand, the other gear turns in the opposite direction.

That makes sense- a differential. Thanks for explaining.

[keilau]

It's not like the single motor Tamiya clutch system. It's a dual motor system, but the motors are two different sizes. It uses a differential drive system and not servos like the Tamiya setup. It's like the PDGBS or the HL "dual current" gearbox. The large motor controls both tracks at once either forward or reverse. The smaller motor engages to stop or reverse a track making a turn. When you turn one gear manually by hand, the other gear turns in the opposite direction.

From your description, the Coolbank M5A1 Stuart RC tank does not have proportional drive control. It can turn left or right, but not running in larger diameter circle? The control is discrete only?

[tank_me]

It's proportional.

[keilau]

It's proportional.

Is it done electronically? Or mechanically like the CVT? No matter how they do it. It is very, very impressive to have proportional steering without the cost of Heng Long "dual current" gearbox or Tongde's.

At US$127, it is an excellent value. (7/2 price. It may go up and down a few dollars everyday.)

https://www.banggood.com/COOLBANK-M5A1-1-or-16-2_4G-RC-Tank-Sound-Recoil-Shooting-Simulated-Vehicles-Models-RTR-Toys-p-2013149.html?warehouse=CN&poa=POA10747076&rmmds=fe ed-brand-topProducts&cur_warehouse=CN&ID=6291567

[RichJohnson]

It is the same design as the dual current named transmission. They have many names but they are all the same. Tamiya leo 2, Abrams, type 10, DKlM, Henglong coolbank m5, all the same design different name. One more drives and the other somehow mechanically speeds up one side or slows down the other to turn.
the DKlM product is amazing. Rubiocon put one in an M60 and wow does it have control

[keilau]

It is the same design as the dual current named transmission. They have many names but they are all the same. Tamiya leo 2, Abrams, type 10, DKLM, Henglong coolbank m5, all the same design different name. One more drives and the other somehow mechanically speeds up one side or slows down the other to turn.
the DKLM product is amazing. Rubiocon put one in an M60 and wow does it have control

I presume that you are referring to the PDSGB from DKLMRC.com.

https://www.dklmrc.com/product/dk-fmpdsgb

The biggest holdback is its price. It costs twice as much as the CoolBank Stuart M5A1 tank.

The CoolBank Propulsion Dynamic Plastic Gear Box is priced at about $13. It is physically too small to fit any Heng Long tank.

https://www.banggood.com/COOLBANK-M5A1-1-or-16-Dual-Flow-Drive-Main-Gearbox-RC-Car-Tank-Spare-Parts-p-2016021.html?warehouse=CN&poa=SKUK67732&rmmds=feed-brand-topProducts&cur_warehouse=CN

[RichJohnson]

Right, it’s small and plastic to fit into the small light weight m5.
the DKlM unit is super impressive and the fine control and slow crawl it offfers is amazing but yes it’s costly.

[DavidN]

I received my M5 yesterday. It was fun driving it.

[DavidN]

[MaverickTank]

Love this tank. I may get another and cut off the skirts.

[keilau]

Back in 2022, tank_me started a thread on the merit of the PDSGB. The many posts touch on other types of gearbox too. Very interesting read on the topic.

https://www.hobbysquawk.com/forum/rc-cars-tanks-trucks-and-more/rc-tanks/359451-pdsgb-propulsion-dynamics-steel-gearbox-and-hl-dual-current-gearbox-discussion

The major obstacle was cost then as is now.

[MaverickTank]

Back in 2022, tank_me started a thread on the merit of the PDSGB. The many posts touch on other types of gearbox too. Very interesting read on the topic.

https://www.hobbysquawk.com/forum/rc-cars-tanks-trucks-and-more/rc-tanks/359451-pdsgb-propulsion-dynamics-steel-gearbox-and-hl-dual-current-gearbox-discussion

The major obstacle was cost then as is now.

Will read. Thanks for posting.

Looks like the output shafts for the gearbox on the Stuart are nylon?