Side by Side Lego ATV

[AndyCW]

2 RC Buggy Motors

2 Rechargeable Batteries

2 V2 IR receivers

1 PF servo

Independant front suspension

Live axle rear suspension

5:1 Rear wheel drive(no differential)

Better bodywork than my previous submissions. The front battle bumper is the key.

The performance is outstanding. It can carry a tire and spin its tires on pavement. This is version two. The first one was an abject failure. Popping gears and not enough power. Redesigned drivetrain and the new receivers changed all that. Will take it out tonight for some offroad action and another video to demonstrate performance.

This combination of parts will be going into another trial truck soon. Hopeully, the new receivers and servo will improve the performance I was able to get on earlier submissions.

[z3_2drive]

sweet, sad that I only have one buggy motor...and those rechargable batteries are so pricy. looks great

[AndyCW]

Thinking about reducing the gear reduction and seeing if it still has enough torque. I now see the use of the new axles on 9398. The axles I am using try to back out of the reduction hubs and there is not enough room for some retainers with the wheels I am using. The train controller may be in my future to control this with a little more finesse.

[z3_2drive]

yes it does seem a bit slow, can you post pictures of the underside or suspension without wheels on? I'd like to see the front especially because I always have trouble with steering systems...thanks!

[AndyCW]

Having trouble embedding pics

link to pic

front suspension without wheel

I used the spindles from 8448.

Edited August 18, 2012 by AndyCW

[z3_2drive]

Thank you, nice model, I like the use of the different wheel hubs, do they have less friction than these?

Edited August 18, 2012 by z3_2drive

[AndyCW]

I don't know about less friction, but they allow a narrower track width and put the pivot point more towards the center of the wheel. The downsides are that they are rarer and do not have as secure of a connection to the wheel.

[AndyCW]

Just reduced the axle ratio to 3:1 and lubricated the drivetrain. Wow!!! There is still enough torque. It can still carry a wheel and spin its tires. The increased speed is causing the 8448 spindles and wheels to separate and the gear train is starting to pop. The next step will be to reduce to 2.78:1. This may also correct the popping in the portal hubs. I may have to go to the newer front spindle design to retain the wheels at speed. When it accelerates forward, it really "plants" the tires. It only is popping going forward and not when going backward. You can see the rear of the ATV rise up as the geometry of the rear swingarm tries to push the tires into the ground. Without porportional control, some steering imputs can cause the vehicle to roll over becasue of the soft springs. This MOC needs some serious work.

Version one of this vehicle had the old receivers and 4.2:1 reduction. This configuration was weak. It was not worth posting. The new receivers really do wake up the RC Buggy motors. Can't wait for someone with some electrical engineering background to quantify the improvement these new receivers are providing.

Edited August 19, 2012 by AndyCW

[DLuders]

@ AndyCW: To get your two Imageshack pictures to appear, I clicked on the (smaller, resized) image to get another (larger) image, then right-clicked on that image to select the "Properties". After you copying that image's URL and pasting it into the "Insert Image" button on your Eurobricks "Reply" screen, you see these:

[z3_2drive]

As I've shown before, I almost always use this custom rechargeable battery my father made:

And we plan to buy another v2 receiver as a test one, because whenever I used the regular receiver with buggy motor it got extremely hot and a couple weeks ago stopped working, and our battery even has a regulator so it doesnt give over approx. 9 volts. The v2 receiver doesnt even get warm so we'll try to remove regulator-giving about 1-2 more volts, and if everything works, all motors will be given more power and release their full potential