On Jun 30, 5:52*am, Dan wrote:
Brian Whatcott wrote:
bildan wrote:
On Jun 24, 10:28 pm, cavelamb wrote:
Dan wrote:
Drew Dalgleish wrote:
On Wed, 24 Jun 2009 08:13:28 -0500, Dan wrote:
* I'm looking for a simple design for nose wheel steering for
retractable gear. Any ideas?
Dan, U.S. Air Force, retired
Have you considered just having a castering nosewheel? That's what I
have on my floats and it works pretty well steering with the brakes..
* Yes, differential braking is probably the simplest method. I'm not
discarding it, just poking around at options.
Dan, U.S. Air Force, retired
Thisis an interesting pic.

http://www.infinityaerospace.com/Oriion_TS_gear.jpg
Not a lot of detail there, but the steerable strut seems to poke thru
the top
and would meet with a steering link (tiller/thingie) there.

I keep thinking about the "T-Bar" idea. *If the rudder pedals had
control horns extending below the pedals hinge line with push rods
attached that extended forward to ball bearing rollers that pushed on
the right and left of the "T-Bar", that would provide the reverse
action to make the steering work right.

A push on the right pedal would pull back the push rod and roller
attached to it and the left pedal would push it's pushrod and roller
forward to turn the "T-Bar" to the right. *When the gear was
retracted, the pushrods wouldn't have anything to push on.

If the nose gear strut was directly below the pedals, the pedals could
just have "spurs" with rollers on them.

Here's my fantasy design. Two tiny motorbike master cylinders, one on
each rudder pedal, and one slave cylinder on a horn each side of the
nose wheel.
*Then the wheel could rotate and retract, and the hose pipes from brake
flexibles, would just flex. (Difficult to make this light enough, I
imagine.)

Brian W

* *I had considered that as I mentioned elsewhere in this thread. The
problems I can't get past is how to cut it out when retracted to reduce
rudder pedal effort and how to not interfere with differential braking.
I would think a castering nose wheel would be best with differential
braking, but one that's being steered could make for some interesting
effects.

Dan, U.S. Air Force, retired

I'm not sure I understand your concern. If the nose gear steering "T-
Bar" is above the nose strut pivot point, it will swing forward away
from the rollers as the nose gear retracts aft. There 'shouldn't' be
any residual extra effort from the pushrods since they wouldn't be
pushing against anything with the gear retracted.

I used to fly a Grumman Tiger with a castering nose wheel. It worked
OK but a long taxi in a crosswind would really heat up the downwind
brake - so much so that maneuvering in the runup area could be
problematic. Brake pads didn't last very long.