[HELP] Propulsion by L Motor and XL Motor

[T Lego]

Hi everyone,

I am making a new lego technic supercar, but I have a question.

For my propulsion system I want to use 2 XL and 2 L motors. Since the XL and L motor have different rpm (XL 110 and L 195), I don't know what the best way is to conect them. If I have done the Maths correct the L motor should be geared down by 1:1.77. I am trying to connect them in that gearratio but the best option I have found so far is to gear the L motor down by 1:1.66t (using the 20 tooth and 12 tooth gear). Other suggestions are welcome! When powering the motor the sound is just a little bit different, but I dont know if I am damaging the motors and getting all of the torque..... 

Edited August 10, 2017 by T Lego

[BusterHaus]

You can use an adder mechanism based around a differential, although I'm not sure if it will give you much benefit. 

 

[T Lego]

Thanks for your reply!

 I think an adder mechansim is not the ideal way to do it.... It is quite big and you lose torque, beceause of the diffs. 

[Beck]

Truthfully, I would just use 2 XL motors. An adder or subtractor are your only practical options if you wanted to mix motors, so I would simply opt for 2 (or 3 if you are very stubborn) XL motors. Besides, 2L and 2XL motors with an adder may add unnecessary complexity to your model. I can think of only a few circumstances when you would need to have more than 2 XLs.  

Edited August 11, 2017 by Beck

[nerdsforprez]

Not only would an adder not add much power due to loss of torque......but the added weight would also add to the inefficiency, not to mention you would have to add the extra battery box.

[Leonardo da Bricki]

Two XL-motors is usually fine for almost any model. Using an adder just complicates the whole system and is unnecessary in most cases. What scale are you hoping to build in?

[T Lego]

4 hours ago, Leonardo da Bricki said:

Two XL-motors is usually fine for almost any model. Using an adder just complicates the whole system and is unnecessary in most cases. What scale are you hoping to build in?

I am building in scale 1:8. putting in 2 battery boxes is no problem beceause there is enough space. The reason why a wanted to add two extra L motors is beceause I have geared te XL motor up by 3:1. just like brunojj1's Ferrari red Spider. That car uses 2 XL motors geared the same way. Since my model is bigger and heavier, I dont think it wil be powerfull enough. With the added 2 L motors I think it will.

[TechnicSummse]

22 minutes ago, T Lego said:

I am building in scale 1:8. putting in 2 battery boxes is no problem beceause there is enough space. The reason why a wanted to add two extra L motors is beceause I have geared te XL motor up by 3:1. just like brunojj1's Ferrari red Spider. That car uses 2 XL motors geared the same way. Since my model is bigger and heavier, I dont think it wil be powerfull enough. With the added 2 L motors I think it will.

If you need to gear up the XL-motors... would'nt it be better to use only L-motors?

L-motors are almost as strong as the XL-motors if you compare them at the same rpm. But if you need upgearing, you can take directly the higher rpm L-motors. Use 3 L-motors instead of 2 XL-motors and you should have more torque at the same space, and you loose less torque from gearing. 

[mocbuild101]

I don't really have much to add here, maybe one of these topics will help: