[HELP] Custom Universial Joints

[Dans lego]

Hello , I believe I'm among many technic builders that are having trouble with universal joints snapping and/or breaking , hase anyone found a reasonable solution to this problem ?

Cheers-Dan

[weavil]

Here might be a good design for you. http://www.eurobricks.com/forum/index.php?showtopic

[Rockbrick]

I like Zblj's idea, with a large enough wheel and deep offset then centre point steering would be possible

[Gee]

Sariel also has a neat solution for a strong custom UJ. Can't put my finger on pictures right now, but sure you will be able to find it with google.

[nicjasno]

If only small angles are required, pulley wheels connected with pins are the best sollution. Usually this works best in HD driveshafts and on the diff side of halfaxles.

[KAKTyC]

Sulution^ but it has friction:

[Milan]

This driveshaft with custom UJoints worked pretty good in this truck.

The central part is THIS.

Cant remember where I saw it first, but in works really nice in my Scania, even with crane section mounted.

Edited January 15, 2014 by Milan

[Dans lego]

Thank-you all , I am currently trying a few ideas , including some of the ones mentioned above

[nicjasno]

Milan: i broke all designs exept the pulley wheels sollution in the mustang.

[Boxerlego]

There are sever areas a U-joint can break at. I've seen various approaches on how to strengthen the U joint, tho I never tested any of these method out for myself. My favorite is using heat shrink tubing.

[jesse66058]

There are sever areas a U-joint can break at. I've seen various approaches on how to strengthen the U joint, tho I never tested any of these method out for myself. My favorite is using heat shrink tubing.

I've experimented with modifying the u-joints in many ways. It is very effective if you strenghten the ends, as you mentioned as example with heat shrinking tubing. I tried it with rope and some hard glue and it behaved quite good. But you don't need to expect the u-joints will hold up in any extreme-torsion setup. Strenghtening the u-joints with copperwire behaved worse than expected, but all slack was gone and the axle was harder to come lose in steering designs.

The best way might be to modify the cv-joints since they have only 1 bar, and not crossed bars like the u-joint has.

The failed modification:

[Lakop]

I've not had one break on me yet, but then I've not built a large moc as yet, but I have known them to crack as you insert an axle. This topic will serve as a good reference in the future.

H

[z3_2drive]

I used notched nail sections and hot glue to replace the center piece...this works good but eventually it comes apart if it's not perfect. for the outer parts heat shrink tape is good but the center piece is still vulnerable. The large u joint with pulley wheels is indeed the strongest but only good for huge models.

[Milan]

Milan: i broke all designs exept the pulley wheels sollution in the mustang.

Probably because you used lpe, in Scania i used 2XLs, the whole truck was more than 6kg, but very slow. It never broke that way.