Rudder Pedal Deflection

OGee · #1 08-31-2015, 03:08 PM

RV-8 with ground adjustable pedals. Rear seat pedals deflect the rudder to the stops - no problem. Front seat pedals do not. However, if I disconnect the brake cylinder from the pedal I get full deflection to the stops. So, I surmise a problem with the cylinders and/or the way I've installed them. Sent pics to Vans - no help. Hopefully one of you will see the error.

Deflection should be 2" from elevator - more like 4" with brake cylinders attached.

Help!

R. Daniels · #2 09-01-2015, 02:40 PM

Hi John, the rudder deflection should be measured in degrees from neutral. The rudder stops are cut down until you reach the specified deflection. Next, it looks like you have the rudder pedals installed in a very far position and have some long links connecting the rudder cables to the rudder pedals. You must be at least 6'4" tall?
You will most likely need to shorten the links by around 1/2". That will make quite a difference in your ability to achieve full rudder deflection.

Rex

Scott Hersha · #3 09-01-2015, 04:20 PM

Your rudder needs to be able to hit the stops (adjusted per specs), to ensure positive stall/spin recovery. In the picture, your rudder isn't near the stops yet. Rudder pedals need to move aft if the rider pedal/master cylinder assembly hits the firewall. If your rudder pedal location that allows full rudder deflection without interfering with the firewall is uncomfortable for you because of your height, consider the 'tall man' conversion to your seat back support. It gives you a couple more inches aft - behind your back, at the expense of your rear seat passenger...... hopefully someone shorter.

DanH · #4 09-01-2015, 04:53 PM

A few moments with a chain saw file will open the necessary clearance in the slot on the master cylinder.

OGee · #5 09-03-2015, 10:59 PM

Since I couldn't apply the brakes without hitting the firewall I moved the pedals aft a notch, drilled holes in the cable linkage to lengthen it a bit and now have full deflection. Only potential problem is with full rudder deflection and full braking (same pedal) I hit the firewall. Hopefully, the brake cylinders will not be depressed that far with fluid in them. If not I'll take the chain saw to the pedals and use the boat anchor. Thanks for the responses.