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Tailwheel steering issue

jbDC9

jbDC9

Well Known Member
So my tailwheel steering is starting to get a bit funky. I've got the Bell fork and and 985 hrs TT on the ship; I'm on a regular schedule of every 75-100 hrs pull the fork to clean and relube everything, plus the occasional file or sandpaper on the pin to keep the burrs and snags away. I'm wondering though, if the spring under the pin can wear our or get soft?

The funkiness shows up while taxiing when I press left rudder; I get initial steering feedback, then click, it feels like the pin has retracted and I'm in full swivel mode. Pushing right rudder is fine, plenty of steering feel/feedback and the pin seems to hold properly. Any ideas? Would a new spring/pin assembly help? I will try to polish and smooth out the groove where the pin rides at extension, but I'm open to suggestions...

Thanks!
 
The steering arm

is likely worn out. I'm on my 3rd steering arm after 1300 hours. Vince's arm has a slightly deeper slot in the arm and that solved the problem.

On another subject, I have "slop" where the pin rests inside the slot in the Bell fork. It looks like the pin is wallering out the slot.

Bill
 
You might just need to file the slot in the arm a little deeper and dress the end of the pin to the blunt squared-off shape that's shown in Vince Frazier's website document.
http://www.flyboyaccessories.com/store/index.php?main_page=product_info&products_id=383

We had issues with the tailwheel unlocking and not re-locking like it should in my friend's RV-8 (newly-built aircraft) and once I reshaped the pin and filed the arm's slot a little bit deeper, it's been working great for a couple years now.
 
billgill said:
is likely worn out. I'm on my 3rd steering arm after 1300 hours. Vince's arm has a slightly deeper slot in the arm and that solved the problem.

On another subject, I have "slop" where the pin rests inside the slot in the Bell fork. It looks like the pin is wallering out the slot.

Bill
Click to expand...

Wow - I am still on my first arm at over 500 hours. Looks like new. 400 hours with the Bell fork.
 
Excellent; good stuff for me to check out. I usually focus on the pin... hadn't thought to check the slot in the steering arm, duhhh.
 
As others have posted we have fixed several including mine by increasing the depth of the slot in the arm. Larry
 
jbDC9 said:
Excellent; good stuff for me to check out. I usually focus on the pin... hadn't thought to check the slot in the steering arm, duhhh.
Click to expand...

I went through a couple of control arms before I switched to those from JDAIR - they seem to be harder, and the slot doesn't wear out as quickly. Look at the corners of the opening end of the slot for wear John - if you see any, that is a contributing factor.
 
Indeed we do cut our control arm notch a bit deeper than Van's does. And we changed the profile of the pin, as stated earlier, to give more edge to contact the control arm notch.

There is a LOT going on with the tailwheel. More than I can possibly type up here. I do recommend everyone getting a copy of our tailwheel tech sheets I think we've got a bit of info in them for most common problems. And it's free for the asking with no strings attached whatsoever.

One problem that no one has mentioned yet is that the Van's fork has a longer arm between the vertical pivot and the tire axle than the Bell fork or our Screaming Eagle fork do. That makes the Van's fork put a lot more load on the control arm and the locking pin, thus wearing them out. Actually, damaging them out might be a better description in many cases.

(The longer arm, and other geometry, of the Van's fork also make it steer harder and snag more obstacles, but that isn't really the topic we're discussing here.)

This will sound like a sales pitch, sorry for that, but I suspect that if there was a way to survey the folks who are using our fork and our control arm, you'd find very few locking problems. Doug Bell's fork should be similar if used with a control arm with a deepened notch.

IMHO, hardening parts isn't necessary when the parts are designed optimally as a complete system. You can do it if you like, but it's just masking the problem.

http://www.flyboyaccessories.com/store/index.php?main_page=index&cPath=66
 
Ironflight said:
I went through a couple of control arms before I switched to those from JDAIR - they seem to be harder, and the slot doesn't wear out as quickly. Look at the corners of the opening end of the slot for wear John - if you see any, that is a contributing factor.
Click to expand...

Thanks for posting Paul. Gave me just the right nudge to choose between the JDAir and Bell forks. I was leaning towards the JDAir anyway, but had not read many reviews of them. The Screaming Eagle seems to me like a pretty small improvement in clearance over Vans.
 
ColoRv said:
Thanks for posting Paul. Gave me just the right nudge to choose between the JDAir and Bell forks. I was leaning towards the JDAir anyway, but had not read many reviews of them. The Screaming Eagle seems to me like a pretty small improvement in clearance over Vans.
Click to expand...

The quality and design of the JDAIR parts are generally quite good - but note that in this case I was talking about the JDAIR Control Arm...not the fork. I haven't used the JDAIR fork, so I can't comment on it, good or bad.
 
ColoRv said:
The Screaming Eagle seems to me like a pretty small improvement in clearance over Vans.
Click to expand...

Bill, That is incorrect. The tire becomes the limiting factor, not the fork.

Adding more clearance will not make the tire roll over an obstacle that is taller than the axle line. Our tailwheel fork has clearance well above the axle line.

The Bell tailwheel fork, a very fine product, and ours are functionally identical. The only differences worth mentioning are that our fork is arguably more streamlined and you can, if you choose, put a tailwheel pant on ours and it will still full-swivel. However, doing that does reduce the clearance!

I have yet to talk to anyone who thought that our fork (or the Bell fork) was only a minor improvement over the stock Van's fork after they've tried it.

tailwheel%20comparison.JPG


http://www.vincesrocket.com/tailwheel comparison.JPG

You might also notice that our fork has a shorter arm between the pivot and the axle. This helps lighten the steering forces required, particularly when the plane is aft loaded, i.e. when you are in a tandem RV with a rear seat passenger, or any RV when fully loaded.
 
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JD Air Arms

Thanks Paul for the kind words. We have several hundred JD Air Parts arms out there and have not had any issues To date we have not had any issues with the arms. They are harder to more closely match the locking pin. With any arm assembly regular maintenance is required.

The JD Air Parts tailwheel fork is lighter than the stock Van's and raises the tail
1 3/8". This small difference makes a huge difference in visibility and clearing those occasional depressed tie down pits. You can get them in bare metal or powder coated.

All of the various after market tail products out there are excellent. Choose which meets your needs and use with confidence.
 
vfrazier said:
Bill, That is incorrect. The tire becomes the limiting factor, not the fork.

Adding more clearance will not make the tire roll over an obstacle that is taller than the axle line. Our tailwheel fork has clearance well above the axle line.
Click to expand...

I can't say I agree with you here, though I'm sure your fork is an improvement over stock. If I drop my tailwheel into a hole and the first thing to touch the other side is a vertical piece of metal, I cant see how that is better than a rolling rubber tire being first to contact. The rolling nature of the tire will tend to climb. At least that's how it has always worked off roading, where I've climbed countless objects that were taller than the axle both on two and four wheels. That's why bumpers are lifted up in the air on off road vehicles and rock climbers...to present the wheel to the object rather than the bumper. The wheel is also why motorcycles can perform the feats they do in trials competitions. If the the side of the hole has any slope at all, the tire has the advantage over a vertical piece of steel. A perfectly square edge may not, in theory, but the the stinger is pulling the tailwheel at an uphill angle which means even a vertical hole is not 90 degrees to the pulling force and would leave some relative slope angle for the rolling tire to climb out. Or so my aged engineering mind has come to believe, always admitting of course that I may be mistaken.

Again, you have enough support in here to convince me that your fork is certainly better than Vans and I'm not besmirching it....just having a discussion amoungst people of like interest.
 
I am using Vince's fork/wheel on my F1 Rocket and so far, with over 120 hours on it, I have had no problems with the locking mechanism. I have not seen any significant wear at this point.
 
Bill, I suppose that we're both mostly correct.

I guess I could argue that most guys don't do any rock climbing in their RV, so most any aftermarket tailwheel fork is head and shoulders better than the stock RV forks. Regardless of whose fork is back there, you still need to use due diligence so you don't taxi into a hole so deep that tailcone damage is inevitable!:eek:
 
A few things I noticed when I upgraded (Bell).

When I took off the Van's fork I noticed quite a few dings and scrapes. This was only after 100 hours. It was obvious that I had dropped off a runway edge or two on taxi. Good thing is the fork handled it and I did no real damage.

Although it only raises the tail an inch or a bit more, visibility over the nose was considerably improved. In the 6, probably the most limited RV for forward visibility, a little helps a lot.

There is some attitude change. It is not uncommon for me to hit the tail wheel first during a three point. That is not really a problem as the mains are really close to the runway, I am very near stall, and the gear handles it without a bounce. Something you should be aware of if you upgrade and may or may not be common to all models or even other 6's.

Again, I have had no issues with the locking mechanism or the arm which is Van's stock. (550 hours +)
 
Ahhh, that's better!

A few weeks ago I ordered a new steering arm along with a new pin/spring from Vince at Flyboy Accessories; I just got around to installing and flying it yesterday. Man, what a difference! Steering is back to being tight and responsive; it's funny how wear items like this can creep up on you slowly and you don't really notice until it just quits working... and then I focus on the pin/spring and completely dismiss the steering arm, duh.

The best part was getting this back in shape for only 30 bucks; try fixing the tailwheel on a Cessna 185 for that price! I see the Scott tailwheel arm at ACS is only $284...
 
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