I put this section on hold for a long time before returning - I don't quite remember why. I think I wanted to wait until the rudder is in place with its cables connected to the front, before taking this section on...
For me, there are two parts in this section - 1) mounting the master brake cylinder to the rudder pedals and 2) link the rudder cables to the rudder pedals. As I mentioned prior, my rudder pedal design uses the Velocity's hanging pedal concept - with some deviations.
Mounting the Rudder Cables |
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Here's another view of the mounting hardware attached to my rudder pedals. |
[Hindsight]
Jamie got a chance to see my design and gave me a B grade |
Combining Turnbuckle To Rudder Cable Attachment |
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I used a similar concept (above) to engage the master cylinder. However, our pedal design requires us to engage the rudder cable first before the brake cylinders. Since my hanging pedals are of different design than plan, I have to figure a way to do the same as well. Calculations for the amount of pedal travel (to activate my rudders and master cylinders) are discussed in Chapter 16 - Section 6 Rudder Stops and Brakes).
My master cylinder mounting hardware includes: - a 5/8" square bar with 2 through slots at one end and a threaded hole at the other end. The long slot is for the foot pedal to slip through. The short slot is for guiding a steel pin. The threaded hole (at the other end) is for connecting the bar to the master cylinder; - a round bushing & guide pin that fit inside the third hole (from top) of the foot pedal - providing a 2.42 mechanical advantage (Matco recommends 2.5 ma); - an anchoring bracket for the end of the master cylinder. I made the bracket out of an aluminum U channel. |
Once the pedal reaches the vertical position, the steel pin will reach the end of its travel along the (short) slot and will push against the square bar, which in turn pushes against the master cylinder, thus starting the brake engagement. The threaded hole at the end of the square bar provides fine length adjustment for brake engagement position. The long slot, which is designed to accommodate the foot pedal body, will provide enough travel for the full travel of the brake cylinder (~1.5"). Per Cozy archive and my prior testing, the master cylinder should need less than 1/2" of travel for hard braking...My current setting provides ~.75" of travel. |
With the hanging rudders, a slot is cut on the outer tube to allow for the swing of the pedal arm that is attached to the inner tube. The challenge here is that if the slot is too long, it will weaken the outer tube, thus the infamous 'twisting' of the rudder tubing. On the other hand, if the slot is too short, it will limit the pedal arm movements in the event more brake travel is needed.
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The 1/8" clearance turned out OK. It allowed me to lengthen or shorten the turnbuckle and/or the master cylinder contact point. Thus, providing fine adjustments for activation points for both the rudders and brake cylinders. |
Master Cylinder Attach Hard Points |
I decided to build up a foam/glass 'faceplate' and glassed it against F-5 as shown. Note that the initial 'faceplate' was a bit wide (vertically) such that I can test out the optimal position of the attach points. In addition, I made a 45o support for the face plate. |
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Between the turnbuckle and the threaded post of the master cylinder, I got a relative range for positioning the rudder pedals. |