Lets do it

Want one bad enough? Could be done with some tapered roller bearings affixed to the gear leg and inserted into a modified mount in the fuselage. Make a linkage from the pedals to the gear leg, then change the fork a bit so that there's proper caster.
 
billpilot1 said:
Has anyone done (or know of) a modification that has a steerable nose wheel on an RV?
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I'd be very surprised if anyone has done that. No motivation or need for it. Rudder is enough when taxiing, and will accommodate most taxiway turns. The only time brakes are needed during taxiing is during very sharp turns. "Poking" the brakes is sometimes needed when taxiing in strong crosswinds, creating a ground track resembling a serrated knife edge pattern. You don't want to ride the brake continuously in this situation - it may torch.
 
mrt890 said:
The yellow RV-12 has one.

MRT890
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Yep and they dumped it on the production version.

IMHO it will add too much weight and complexity. In addition, it might add a good bit aerodynamic drag as it would have to come straight down from the firewall with a big round strut, not stick forward on a spring strut as the current gear leg does.

However, these are experimental aircraft and you are free to experiment with them. By all means, design and install one and report back your results.

(Notice how I refrained from saying something about they have one, they just moved it to the tail.)
 
I think it can be done

Before I finally decided to go TW I toyed around with the idea of a NW steering setup. I believe it could be implemented without too much pain as follows:

At the bottom of the gear leg, on the vertical portion, a stationary cross-shaft would be installed with a small pulley on each end.

Then on each side of the fork near the aft end, a stud protrudes out the side a short distance (the end of the stud and the corresponding pulley are at the same "left-right" distance from the A/C centerline).

There would be one steering cable for each side. The cable attaches to the stud, runs forward to the pulley, then wraps around the pulley through greater than 90 degrees and runs up the gearleg (probably through some eyelets) to the rudder pedals. The connections would be crossed (LEFT steering cable to RIGHT rudder pedal and vice versa).

When the rudder pedal is pushed, the opposite pedal comes back, pulling the cable. The cable shortens the distance between the pulley and stud, turning the wheel in that direction.

You would probably need some springs in the system to keep the cables tensioned and allow the gearleg to move normally.
 
JHines said:
You would probably need some springs in the system to keep the cables tensioned and allow the gearleg to move normally.
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I think it's done this way in the C172 - cables pull springs attached to wheel. It makes the steering a little bit indirect, but it also dumps shimmy a little bit and save your feet from kickbacks when you ride on rough surface.
 
JHines said:
Before I finally decided to go TW I toyed around with the idea of a NW steering setup. I believe it could be implemented without too much pain as follows:

(snip)
When the rudder pedal is pushed, the opposite pedal comes back, pulling the cable. The cable shortens the distance between the pulley and stud, turning the wheel in that direction (snip).
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And what happens when you are on final about to flare compensating for a strong crosswind with wing low and opposite rudder? That would put the nose wheel headed downwind at nose wheel touchdown.
 
Sure it would. No different than in any other aircraft with a steerable nosewheel.

In a Piper the NW angle is rigid to the rudder deflection; in a Cessna there is a spring-loading so the NW can move indepdently of the pedal input. With the NW axle being substantially aft of the pivot point in an RV, the spring load would probably be mandatory.
 
Cessna Nosewheel Centering

On a Cessna strut, when there's no weight on it the nose wheel will self center. So, when you're in the air the nose wheel is always straight. That's the reason for the springs. In the air the wheel is straight, the springs pull the pedals back to center. It'd be hard to do this on a Van's without major mods to the fork and gear leg.

On a crosswind landing you should be okay though. The nose wheel would be off the ground allowing rudder to align with runway center. You might get a slight jerk in the pedals when the nose wheel touches down....
 
I'll admit it took some getting used to after flying Cessnas so much. It seems strange that throttle setting has an effect on how fast you're turning. And you have to get used to using the brakes a little at a time. Like someone said, holding one brake while moving can be costly.
 
Low n Slow said:
Fewer brake fires?
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Funny :D.

But I think the occasional brake fire is due to poor technique or misinstalled master cylinders (leaving some pressure on the disc). I feel the need to use my brakes only a very small amount while taxing.

(Hi Tom - I'm Kevin from KSQL)
 
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