Issues with the vibration unit

[Mouton]

Last night I got my Knight running (no pun intended)...

Everything works fine but the vibration unit is causing some undesired effects. When it fires up the truck the motor running the vibration fly wheel moves outwards becaus of the centrifugal force. This creates a mechanical rattle noise that sounds like a klonk. The same goes for shutting it down.

When it idles it vibrates withous mechanical noise but when I rev the engine it starts to make that mechanical noise again.

I first removed the plastic cover for the fly wheel since I thought the fly wheel might have been hitting it from the inside. I then noticed that the motor axle moves about 1 mm outwards when the motor speed changes. After it has reached its new speed it settles and becomes quiet again.

Any advice? Can it be that it needs to be fixed more firmly in the truck? It is kept in place on its bracket hat is fixed by four screws. Would rubber bushings (i.e. a few mm of nitro fuel tubing on the skrews) help?

PS. I will post photos of it during the weekend in the gallery!

[monster_beetle]

I have no problems at all with the virbation unit in my liftie. But I should try to screw it more firmly, when you're going to use rubber bushes I think a lot of the vibration effect will go away in the rubber. And when it's firmly fastened you're sure it al is good in it's place. When it doesn't work by then, I don't know it anymore....

[chucky]

I had the same problem with my scania. it went away over tym. still happens now and then but not often. I just tell people its a oil pressure problem:willy_nilly:

[Mouton]

monter_beetle, it _is_ firmly fixed. I can lift the truck with it without experiencing any flex. That is not the issue. The problem is that its motor axle can move a millimeter or two outwards. Add the centrufugal force of the counterweight and you have a problem. As far as its vibrating power, it is set to lowest and has the small counterweight. It still makes the truck vibrate more than necessary. Thus, reducing it further might actually imporve the realism.

chucky, thanks for your input. That it might go away over time is of some comfort but it's definitely a dissapointment since I have gotten used to "First in Quality Around the World"...

One idea might be to install a pressure ball bearing on the inside of the vibration cover so that the counterweight and motor axle are fixed in that direction. Other thoughts or ideas are welcome!

[podfreak]

i did not have any problems in my globeliner at all....

[Thorsteenster]

Did it just start or has it been doing it from the get-go?

[Mouton]

It has done this since I first installed it. Oddly enough it does seem to rattle less now than during the first testruns. It still rattles and it is annoying.

However, installing a pressure ball bearing (of appropriate thickness) on the inside of the plastic cover is not that difficult and will pipe it down.

[podfreak]

do you think it may be a defective unit?

[Mouton]

I "stretched" the motor axle and pulled it out as long as I could when I installed the counter weight. That took out most of the play that was in the motor. The motor still worked as it should but some of the noise was still there.

I ran the truck and noticed that the bracket that holds the vibration unit flexes very much. It really rocks back and forth in spite of beeing firmly fixed with four screws. I simply used an extra screw that helped fix the vibration unit's plastic cover to the inner ceiling of the body (since mine is mounted there and not on the speaker box). Problem solved.

[The_Blue_Dragon]

I get this badly, infact so bad that Ive taken it out