Firestone tailwheel ?????

flyingfool · Post by **flyingfool** » Sun Jun 14, 2009 22:52

gusc thaks for the part #

DC Krog: What is the proper tire pressure for an 8 inch pnumatic?

MikeB · Post by **MikeB** » Tue Jul 07, 2009 21:46

Success (maybe) with my Maule tailwheel. I fiddled around with different spring combinations (tension, compression, etc.) Finally settled on going back to the original Maule compression spring combination, light left, heavy right with a slight preload, 20# air pressure as recommended by Maule. Pivot angle is correct (caster). New tail spring. Landed on grass tonight and "no shimmy". Has a good tight feeling with the rudder pedals. Landing on blacktop will tell the story, I suppose.

For whatever it's worth: loose Maule spring combinations seemed to cause a shimmy condition as did too tight. The tension spring setup seemed to give a "soft" feel to the rudder pedals on ground handling.
I do like the larger Maule wheel as the look over the nose is better than the smaller hard rubber (Firestone) tailwheel set up. Also, better riding on grass.

Will let you know more after I try it on hard surface.

Mike

DC Krog · Post by **DC Krog** » Sat Jul 11, 2009 07:53

Technical note: When you replace the Maule tailweel bushing you need to know the diameter of the shaft. The old style is 3/4" and newer style is 7/8" and yes they are cheap. If you have shimmy problems I really recommend a solid tail wheel (maule or scott) These planes we origionally equipped with soild tailwheels from Middletown.

DC Krog

gusc · Post by **gusc** » Sat Jul 11, 2009 23:29

DC,

I would never consider going back to solid tailwheels. I have a couple hanging on the wall now that I will never use.

I fly out of my pasture and once I experienced the pneumatic tire I never looked back.

I presume they had solid TWs originally because they were cheaper.

My Stinson had a solid wheel and it wasn't up to the task because the Stinson tail is pretty heavy.

Harry Fenton · Post by **Harry Fenton** » Mon Jul 20, 2009 11:29

FYI, I really wrestled with my Maule tailwheel on my 7AC and the final solutions were fairly simple.

First, I bought a NEW tailwheel spring from Univair. The arch was gone out of my old spring and the new one pulled the pivot point forward abpout 2". HUGE difference right away.

Next, the Maule anti-shimmy springs were installed- correctly, as per the Maule instructions. Another significant benefit.

The next step was to install some AN-44 eye bolts in both the rudder horn and the tailwheel steering arm. I shimmed the eyebolts with washers to get the pull point from the rudder horn to the tailwheel horn level. When the spring is pulled, all of the fulcrums from the rudder horn to the tailwheel are aligned and the steering force and dampening stays constant under all loads. The original configuration had the springs pulling at an angle and the loading for dampening was not linear when steering or under springing loads. Another benefit of the eyebolts is that the eyebolt becomes the sacrificial wear point for the spring connection- not the expensive rudder horn or tailwheel steering arm. When the spring wears the eyebolt hole, it is a cpouple dallar parts replacement.

Another problem which contributes to tailwheel shimmy is the vertical alignment of the tailwheel. Many Aeroncas have had the main gear cluster where the oleo drag links attach to the bottom center of the fuselage wiped out during groundloops. If ths part is welded just a bit off, then the cumulative stack up of error will result in the airplane sitting with one wing low when parked level. This wing low problem is often misdiagnosed as an oleo or spring problem.

I keep tailwheel tire pressure at 20 psi. With the tailhweel slightly soft, it will dampen the tailwheel from hunting to find a center track.

The new tailwheel spring, correctly installed anti-shimmy springs, and 20 psi pressure solve all of my shimmy issues.

Harry Fenton

gusc · Post by **gusc** » Thu Jul 23, 2009 00:25

Harry,

A new spring solved a lot of my problems too.

My old spring was even missing one leaf on addition to being flat.

I keep my pressure at 25-30psi, seems to work better for me.

I fly from my pasture and sometimes don't see any asphalt for quite a while since there are so many nice grass strips around here.

Post by **joea** » Thu Jul 23, 2009 00:44

gusc wrote:DC,

I would never consider going back to solid tailwheels. I have a couple hanging on the wall now that I will never use.

I fly out of my pasture and once I experienced the pneumatic tire I never looked back.

My feelings exactly. It might cost me a pound or two in UL but for me its worth it.

flyingfool · Post by **flyingfool** » Thu Jul 23, 2009 13:53

Does anybody know off hand what type and lengths of bolts that hold the tailwheel spring clamp on?

I noticed my Chief only has what looks like a bicycle inner tube tire rubber between the spring and the fuselage longerons. The drawings shows a 15/64" thick (1/4") thick rubber pad here. However if I put this thickness in, the existing bolts I do not believe are long enough. Mine appear to be I believe 1-1/2"long grip length. I would need at least 1/3/4" by my estimate. Looking for the real dimension of the bolt.

I'd like to pick these up at Oshkosh!

Thanks,

TomD

gusc · Post by **gusc** » Sat Jul 25, 2009 00:53

Tom,

Use whatever length it takes, it all depends on your situation.