Dual 550 motor 4:1 steel gearbox for 1/16 Leopard 2A6?

[sclui56]

Am looking for replacement gearbox for my Taigen Leo 2 currently using the stock 4:1 - (90:1 ratio) using stock v3 MFU. Has anyone tried with success using the 550 like this? https://www.dklmrc.com/Dual_550_motor_4_1_steel_gearbox_for_116_Leopard_2 A6/p2389473_14664952.aspx

[Rubicon99]

Yes I have used it. The question would be through, what performance gains are you looking to achieve with this set up?

[sclui56]

Hi Rubi, the Taigen Leo 2 is using the same setup as in the KT, i.e. their 4:1 90.1 reduction, which is perfectly fine for WW2 tank in terms of speed, but not so much on the Leo. My Leo in its current form trails the HL Abrams w/ 390 red metal tracks/wheels/gear badly.

Taigen recommended their V3 gearboxes aka 7:1 - 76:1 reduction, that will increase the speed slightly. I am only looking for alternatives ATM. DKLMRC is not absolutely sure the 550 will work on the Taigen and with what mod (e.g. does it need to switch to HL sprockets?) Taigen indicated the setup s/b 58mm, but HL lists theirs at 59mm. Don;t want to get a replacement only for it to start throwing tracks.

Thanks.

[Rubicon99]

Hi Rubi, the Taigen Leo 2 is using the same setup as in the KT, i.e. their 4:1 90.1 reduction, which is perfectly fine for WW2 tank in terms of speed, but not so much on the Leo. My Leo in its current form trails the HL Abrams w/ 390 red metal tracks/wheels/gear badly.

Taigen recommended their V3 gearboxes aka 7:1 - 76:1 reduction, that will increase the speed slightly. I am only looking for alternatives ATM. DKLMRC is not absolutely sure the 550 will work on the Taigen and with what mod (e.g. does it need to switch to HL sprockets?) Taigen indicated the setup s/b 58mm, but HL lists theirs at 59mm. Don;t want to get a replacement only for it to start throwing tracks.

Thanks.

So I assuming you want it as fast or faster then the HL Abrams. In which case the 540 motors/gearboxes you are looking at will not achieve this.

The best way to achieve similar performance is with the HL or just to keep it simple Taigen 3:1 gearboxes paired with Taigen black 390 motors (higher RPMs then the Red motors) running at 8.4-9.6 volts. The higher voltage is like adding a light supercharger to the motors and this allows them to overcome the added Leopard weight quite easily. I run all my tanks on either 8.4 or 9.6 volts and have for years. The only caution is if you are using the Taigen control system. These do not like anything over 8.4v, unlike HL that is rated up to 12.6 volts.

HL and Taigen sprockets are interchangeable. Shafts being 1mm in difference in length especially on the Leopard will have no negative effect either way. That said the thickness of the Taigen shafts is slightly greater then the HL shafts and this can sometimes cause fit issues with some sprockets. Again easily overcome with a little sanding.

[sclui56]

It's interesting that you mentioned the 3:1, I actually asked Erik about using that w/ 390's since that's what my PZ4 came with, in that configuration the PZ4 was running way too fast, I ended up switching to a pair of Tami 380's and still have to step down the output from my Tx. BTW, here is what Erik said - "Yes you can use any 3:1 ratio gearbox (they are available in H/L and M/L configurations) just make sure to get the 58mm length variant as that is the one you need. The 3:1 is made in the V1 and V2 version gearboxes, however the V3 has its own motor configurations and is not the same as the previous generation gearboxes. The 3:1 isn't recommended honestly as the tank will lose a lot of low end capabilities. Those are the same ratios we put on our plastic tanks, not meant for the heavy ones. The V3 is a good compromise in middle ground while still keeping low end control. The faster you make your tank the more torque you lose as well as low speed control.".

I only run my v3 MFU up to 7.4 LiFe, but I think I may just try the Taigen v3 box first and if that doesn't work out, then back to the drawing board.

[Rubicon99]

The lack of low end torque he is referring to is made up by adding higher voltage. He works within a “set box of specs” and doesn’t really venture outside that box because he is worried about warranty returns. I find it funny that on another forum he also states he does not like the V3 gearboxes in modern tanks as much as the V2.

Respectfully I have totally disagree with his assessment about speed and low end control because you absolutely can have both these days. Maybe with the outdated systems that Taigen and Torro use he is correct, but not with the new 6.0+ HL, Tamiyas or Clark’s.

[sclui56]

I do remember he indicated his preference on the V2 over the V3 several times. If I were using HL MFU in this tank, then I would have gone straight to the PDSGB version, but I am keeping the Taigen MFU since I am using my Tx 7 Rx's (not ready to have so many active OEM Tx's around nor ready to speed several bills for after-market controllers for each). Decision decision....

Thanks again for your insight, really.

[sclui56]

Rubicon99 Would you mind elaborating why the 550's (in the 1st post) won't work. Dominique from RCtank.de also indicated loss of torque with the 3:1, and that the new 7:1 (v3) won't give me the proper speed for a Leo (i.e. not much better than the stock 4:1). May be I have to change controller...

[Rubicon99]

Rubicon99 Would you mind elaborating why the 550's (in the 1st post) won't work. Dominique from RCtank.de also indicated loss of torque with the 3:1, and that the new 7:1 (v3) won't give me the proper speed for a Leo (i.e. not much better than the stock 4:1). May be I have to change controller...

I have already recommended what to do. As others here can attest I am well know for my modern tanks top end scale speeds and excellent low end handling characteristics.

I have spent the time and money experimenting / learning first hand and making expensive mistakes. If you want scale top end speed and excellent low handling while keeping the complexities down you need 390 motors, 3:1 gearboxes, 9.6volts and one of the control system I mentioned prior. This will drive a modern heavy tank at -45mph scale top speed and provide the low end power needed for excellent off road handling in almost every terrain types.

There are issues and unseen variables in every tank. With modern tanks like the Leopard 2, Abrams and Challenger it is their length and if they are running rubber padded track. The rubber padded tracks have an extremely high coefficient of friction. Add this to a heavy modern tank and this can cause some issues with turning performance on concrete, asphalt, carpet and grass.

Now to answer you question. 550 motors at 7.2 volts under load are only producing roughly the equivalent power of a 390 motors at 9 volts (max RPMs for motors are typically shown for their max voltage rating usually 12v so the RPMs shown are often misleading) So simply changing the battery can greatly increase the performance of the 390 motors and the difference in price for a battery vs expensive new gearbox can be sizable. Next the gearbox is still a low gear ratio. So your net total at 7.2volts is more torque but not really any more speed over what you have now.

Now to run that 550 gearbox above 7.2v you need a control system rated for the voltage and much much higher amp draw. Here again you will need to replace the Taigen/Torro system with either a HL 6.1S or a Clark 80 series. Both these are rates to handle the higher voltage and amp draw of the twin 550 motors. Failing to change out the Taigen system WILL burn it out.


Side note: The HL 6.1S system is rated up to 12.6 volts and 20 amps per motor for use with up to 11.1 Lipos. It has two power settings, Low=7.2 volts and High up to 12.6 volts. This in effect is two speeds. Use the High power in high torque applications such as rough/soft terrain turning or high speed runs over open terrain when desired . Use the Low power for simple cruising around. This can all be controlled with the flick of a switch on the remote. Combined with 390 motors, 11.1 Lipo or Li-ion battery and a 3:1 gearbox it is an quite excellent combination. It’s also relatively cheep at around $60

Yoa can have the best of both worlds, both scale top end speeds and slow precision handling and it doesn’t need to be complicated or expensive. I have proved this time and time again.

If you want to see check out my Instagram @ fsttanks.

[RichJohnson]

Your big problem is limiting yourself with the taigen system which is little more than a toy.
the HL system is light years ahead and while a cheap feeling radio, the mFU is nearly hobby grade.
i fear the 550s will burn out the taigen system.
remeber this, more volts available means less current needs to be drawn to accomplish the same amount of work. Just make sure your mfu can handle the voltage level and current draw.
I run my Abrams at 12v with red motors on ultimate trannys, I have an old ibu in it.
it is just as fast as the tanks Rubicon has set up with 390s and 9.6v. Why, the voltage has not add it faster. He has better tracks and wheel sets and such, I am merely using less current to do the same work.

his advice in experience is valuable and weighted much heavier than that of taigen support who do not do this kind of driving.

You may make choices and decide you don’t like the results and will have to rethink your plan of attack. All of us have at times.

[sclui56]

My plan is to keep things simple and thank you for the clarification on the 550’s combo, now I understand why the difference is marginal since most video clips don’t go into specifics like you did.

I am back to running the metal Taigen tracks as I have very some minor slippage when using the padded tracks from DKLMRC (couldn’t get the Tami’s), the same padded tracks are perfectly fine on the HL Abrams, I suspect it may be the drive sprockets even though DKLM didn’t mention possible issues w/ Taigen sprockets. But that’s not critical ATM.

I think I will go ahead with the 3:1 390’s v2 box and look into transplanting the HL MFU. The parts are readily available but I need to figure out the rewiring for the upper hull. Would you know off-hand if my 6.0 or 7.0 Tx would bind with the 6.1s MFU?

Really appreciate your help and knowledge. Thanks!

[Rubicon99]

Your 6.0 TX will bind with a 6.1.

Wiring the turret is easy. You actually can dump the upper hull control board and go directly item by item to the 6.0+ systems.

[sclui56]

Your 6.0 TX will bind with a 6.1.

Wiring the turret is easy. You actually can dump the upper hull control board and go directly item by item to the 6.0+ systems.

Excellent! Thank you again....

[sclui56]

his advice in experience is valuable and weighted much heavier than that of taigen support who do not do this kind of driving.

You may make choices and decide you don’t like the results and will have to rethink your plan of attack. All of us have at times.

Rich, I am actually glad that both Rubicon and you chimed in on my question as I have been following both your threads with interest. I do value the opinions but only wanted to understand why the 550's were dismissed, which is now explained. I stay with the Taigen MFU's simply because they came with the tanks, and that I can bridge to my own Tx/Rx, purely for convenience and not because I thought they were better, especially since they did the hard-coded mixes for the MG & smoker.

Looks like the 3:1 & 6.1s MFU will be it for now. Thanks.

[RichJohnson]

I dont post here much or start new threads. I live over on rcuniverse which is where I post my long scale model build threads and crazy mechanical stuff. I have one project I started recently over there that is similar to what you are doing. I infact had two 540s in it and used an 8,4 battery and it was insanely fast, as well, I was using a tamiya MFU system which is rated up to 12v and high amp output. It ran for a few minutes until the MFU overheated and shut down on me for self protection. So back to the drawing board with my transmission design, and I mean drawing board and design. I dropped to 390s and started changing pinion gears around. But thats all very complicated with things I do. Your welcome to take a look at the stuff I do over there if you want.

[sclui56]

Rubicon & Rich, the 3:1 v2 boxes came in, only 2 of the mounting holes line up with the 3 on the Leo, so I had to add the 3rd hole, swapped over the 390's from the v2 4:1 originally boxes, pulled out the pinion gears a bit to line up with the 3:1 input gear, and I am happy with the speed improvement using Taigen's v3 MFU & 7.4v Li-ion, so I know I would be disappointed with the more expensive v3 boxes. Low-speed driveability is fine since I can modulate just like before with my own Tx.

Just waiting for the HL MFU, didn't want to pull one from another HL. BTW, the DKLMRC padded track slippage on the Leo I mentioned had nothing to do with the sprockets, that was caused by a couple of pads worked themselves outward, just enough to interfere with the teeth.

Thanks guys.