Problem with Technic 8289 build...?

[Richard Dower]

Built this set a few days ago....but i have found that while using one function, such as turning the turntable would effect the other function....raising and lowering the boom.

is this a design flaw?....or did i built the parts too tight and turning one function is affecting the other?

In this vid you can see when he is raising the boom the turntable moves a bit....but mine is much worse.

[Anio]

This set is crap. Very poorly engineered.

Buy a 8292 and forget that 8289 forever.

For your information, the 2 functions are not totally independant because of the worm gear going through the turntable. When the turntable rotates, the worm gear rotates too, so the arm may go up/down. And vice versa, if you rise or lower the arm, it may rotate the turntable.

Same problem with many sets : 8446, 8071 but not as problematic as 8289.

You can also see a very similar problem with sets such as 8271.

[Erik Leppen]

Nothing wrong with the set. The problem you're describing is a consequence of running an axle through a turntable. However, the faster the axle turns, the less this effect is.

[Kman860]

I've actually never had that problem with this set, however while this topic is up, has anyone experienced something similiar with 42009? When I run most (maybe even all), of the functions, it extends the boom. Has anyone else had that problem?

[Anio]

Has anyone else had that problem?

Yes, especially if the arm is horizontal (which in reality you are not supposed to do ; you must raise it first, and then extend the arm or use the cable). Maybe you can rebuild it. During the building process, try not to tighten the parts too much. They have to rotate as freely as possible.

[GoldVillage]

Its a result from keep turning the knob after the crane has reached its highest point - something must give away and in this case the crane will start turn because the axle going through the turn table, so nothing wrong here.