ARXD

Yes I know, found out the hard way :) I gear it up (higher RPM) on the expense of torque (safer that way)

the pic is just a test model - not the real RC car. I am building 4x4, nothing crazy - just for fun around the house. at the moment the RC car drive fine with one XL motor, and I was wondering if it will perform better with 2 XL motors. It is a lot of fun pushing the limits, so I was also wondering if I can make a 2x4 to 4x4 gear box, and in the 2x4 state, gear it up slightly... yes I know I am pushing it, but like I said, that is the fun part :)

Your opinion please! 2 XL motors must be better then 1 XL right? so, on RC car, which configuration will perform better? A. Hard-Coupling 2 XL motors on rear axle (rear only) OR B. one XL for each axle (rear and front) ??? My guess is B, but I didn't had the chance to test it out yet, and I'm wondering if anyone ever tried it. Thanks.

2 speed gear box!? and what's up with the elastic bands?! that is new... I wonder what's is for... The blue pins really ruining it for me... why not in black!? What is that new crawler in the background? another new set!? edit* YES it is - 42055 !!!! nice :)

If this car will come in white, I will buy it in a heartbeat!!! This set in white will be perfect as a set donor for my custom MOCs :)

WOW Amazing!!! so much details!!!

I will buy this part even if it is not made by LTG, perfect in any way.

What about 3D printing for that damaged gear?

YES, I HAVE , but with old motors styles, not the PF ones.

I have that book, this is the BEST book on LEGO Technic on the market!

It is not that hard, just follow these steps: 1. Find the right angles, (from rear axle canter) 2. Follow this design for steering: 3. Measure \ test the angle.

Yes, this is a real issue. All motors has some differences in tolerances and spec PLUS it's own footprint of wear and tear (How it was used/played history) No motor is exactly the same, and when you coupled motors you need to take that to account, especially large motors (XL or RC) Hope it's helps.

They are not equivalent. In hard Coupling, one motor is attached directly to the second motor, any speed variation will put strain on both motors. In adders, any difference between speed inputs will be equalized by the system of the differential’s inner gears. The output will be driven by the sum of the inputs’ torques and the average of their speeds.

YES and NO It depend HOW you do it, "Hard-Coupling" is a simple solution, this is good for M or L Motors, but can be harmful for motors with heavy load/torque The safest way is to use Adders, but that also add friction, wight and take space in a design adder makes use of a differential in order to equalize the differences between two (or more) inputs and to drive a single output. I like to build powerful designs so for safety I always use adders.

Well, I was experimenting last night with the 2 XL Motors on a very basic experimental vehicle, - Empty and with heavy wight on it. and here is what I have found so far: - Two XL Motors are always better the one XL motors, that extra torque is significant. - Reduction Gear Box for two XL motors is NOT what I need for my next creation! In 1:1.4 ratio test, Motor connected directly to rear differential (20T to 28T differential) the motors are VERY POWERFUL and VERY SLOW, this is great for constructions models like my old Bulldozer or for a 4x4 Crawler, BUT not suited for my next RC FATH (Fun Around The House) model. In 1.19:1 ratio test, Motor pass through 1.6 Multiplier gear box to rear differential (20T to 12T, 20T to 28T differential) The experimental vehicle drive in fair speed and still have a A LOT of torque to spare! I will continue to experiment in the next few days, coming up: 1.985:1 Multiplier gear box, (20T to 12T, 20T to 12T, 20T to 28T differential) 2.143:1 Multiplier gear box, (36T to 12T, 20T to 28T differential) And for the fun of it , I will also try: 6.429:1 Multiplier gear box, (36T to 12T, 36T to 12T, 20T to 28T differential) - I will video-tape this one :) I really want a good gear box, possibly with "Gear Adder", witch will also open up others Multiplier gear box ratio like 1:1, 1.98:1, and 2.78:1 Will updated as I progress. *edit: I have uploaded a video of my testing last night for your amusement (and some pics of the experimental vehicle) My Experimental Vehicle: