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Upper wishbone
8smokingbarrels - 11/7/03 at 11:39 PM

A couple of questions about this much loved component!

Firstly - I was thinking of using an audi track rod end instead of a transit one. One of the reasons for doing so is that camber adjustment would be a v.easy as the audi rod end screws into a separate threaded bar. The other end of this then screws into the trackrod itself. The threaded bar has both left and right hand threads and is simply turned to change track. My main concern with using this is that the threaded bar is only 1/2 inch thick and im not sure if it would be strong enough. Just wondering if anyone had opinions on this?

Secondly- was studying 'the book' plans for the top wishbone and noticed the greater angle that one arm has from the centre line (ie wishbone isnt symetrical). This of course relates to the castor angle. What puzzles me is why it wouldnt have been simpler to make the wishbone symetrical (angle of both arms equal to centre line) and move the brackets of the upper wishbone further back to take account of the castor angle.

Can anyone explain this why this isnt the case- Im still trying to get my head round this suspension theory!!

chris


Rorty - 12/7/03 at 02:01 AM

8smokingbarrels:

quote:

...the threaded bar is only 1/2 inch thick and im not sure if it would be strong enough.

If it's OK for a tank-like Audi, it'll be OK for a puny locost. It's probably made of half-decent german carbon steel.



quote:

...was studying 'the book' plans....What puzzles me is why it wouldnt have been simpler to make the wishbone symetrical (angle of both arms equal to centre line) and move the brackets of the upper wishbone further back to take account of the castor angle.

The only parts of the RC chassis I understand are the flexy brake pipe tabs!


Hornet - 14/7/03 at 08:54 AM

Lo dood, if you move the brackets further back... the are hanging in mid air as LA and LB are needed to attach to. hope this helps


Mark Allanson - 14/7/03 at 05:18 PM

Do a search on 'accurate front suspension' and 'more accurate front suspension', almost everything is explained in these (very long) threads. Also a current tread 'mistakes in book' is good reading


Mark Allanson - 14/7/03 at 05:28 PM

I ended up making these upper wishbones Rescued attachment UpperWishbonesFast.gif
Rescued attachment UpperWishbonesFast.gif


8smokingbarrels - 15/7/03 at 11:47 PM

Thx guys for the replies

Hornet- I had a suspicion that the reason that the upper wishbone wasnt symmetrical was for some space reason- thx for confirming. Im not building a book chassis- so hopefully may be able to put the brackets further back and keep the wishbone symmetrical- just for ease of making

Mark- I will check the thread u suggest- like everyone else, im trying to learn a great deal of complicated suspension theory in a short period of time- it isnt easy!

Thx again

chris