Wednesday, August 16, 2017

RC12R6 Front End Build Notes Part 1

Ok, ok. I had some Yokomo blue turnbukles!

I am a little picky about front end build. For me it is one of the most important as the consistency of the way the car drives is very dependant on it's accuracy.

Lower Wishbones

First, something to get right. The front carbon lower wishbones are NOT symmetrical. There is no Left/Right to worry about but there is a front and back. This is not obvious from the manual.

Here is the manual pic below. Notice the inner mounting hole lower in the picture is more "meaty". This will be towards the front of the car. The thinner part is towards the rear. If you run it the other way around then you will have a longer wheel base than the kit setup.

We are running the kit setting here. Meaty/fatter bit forward. We are also running the kit setting for a narrow front track using the 3 dot insert as shown.

Orientate these correctly!

Thinner part to REAR of car

Fatter part to FRONT of car

Tight Ball Syndrome?
Next I feel that the lower ball carrier is too tight in the wishbone (tolerances will vary). Insert the ball and feel that it is free in the carrier. It's a nice fit and all is well but.... when I then inset this into the wishbone, the carrier is compressed and the ball becomes tight.

You don't want "tight ball syndrome" in your undercarriage, it will restrict your shaft movement later :-) Seriously. The king pin angle changes under spring compression in a reactive castor front end and this ball has to move to allow it. If the ball is restricted, it binds the king pin.

So I open it up a little with a file till the carrier is snug but not overly tight. Free your balls!

There is no way I am using the O ring supplied in the kit to secure the call carrier in place, it will move around. Follow the "racer tip" in the manual and glue it in there. I just dab a little super glue onto the flange (this is the lower side). It will capillary around and into the material joins.

At this point (before gluing!) really make sure you have orientated your wishbones so you know your left from right and top from bottom otherwise you are going to glue something in wrongly that is not coming out again without damage.

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