[f-AA] Maule tail wheel

[Tom Boyle]

I think this came up recently as a thread, but I can not remember the conclusions.

 

I have had on and off shimmy problems with different solutions.  Now I've got the shimmy again and noting is working to get rid of it.  Being cheap, I don't want to buy a new one, yet.  I have found that both springs are loose.  I have the springs with different spring rates.  Are these springs supposed to have tension in them as installed?  They each have about 1/8 inch of play in them.

 

I know, I should have paid more attention.

 

T²

[Mark Peterson]

Shimmy:
Use Compression springs, not the screen door type.
Springs tight with different spring rates installed on correct side (I forget) as per Maule manual.
Tailwheel pivot is vertical when loaded.

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From: tomb...@charter.net
To: aer...@westmont.edu
Date: Thu, 26 Apr 2012 17:16:28 -0500
Subject: [f-AA] Maule tail wheel

_______________________________________________ Aeronca mailing list Aer...@westmont.edu http://mail.westmont.edu/mailman/listinfo/aeronca

[jay curtis]

Tom, a Champ I had previuos had equal set of compression springs and chains were slightly loose with a maule and never bothered. Current one had tension springs and worked perfect,but I removed them and went with equal compression type springs and the way the links worked out have quite loose chains, this Champ has a scott tail wheel and have not encountered shimmy either. Lots of past posts have talked about proper spring arch perhaps the trouble lies there. I remember on first plane the past owner actually balanced the wheel by trial and error holding it to a belt sander to spin it fast and getting it right with adding washers to a bolt on rim (tire and tube type) If hard type wheel don't know how ,or are bearings good and tight?  A final thought or question  ,is it  not better for wear and tear to have compression springs slightly loose so there is not pressure on rudder pins all the time ?

----- Original Message -----

From: Tom Boyle

To: fAA

Sent: Thursday, April 26, 2012 6:16 PM

Subject: [f-AA] Maule tail wheel

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[Victor]

IMHO Bear in mind that if they have 1/8” of slack now, when you get on board they will have even more. Have someone climb in and tighten them up snug & see if things change.

 

From: Tom Boyle

Sent: Thursday, April 26, 2012 6:16 PM

To: fAA

Subject: [f-AA] Maule tail wheel

 

[Cy Galley]

The biggest thing that causes shimmy is the position of the vertical pivot UNDER load.  If the bottom of the pivot is behind the top under load. It will shimmy.

 

A couple other things are a loose spring or mount. Out of round tire. Out of balanced tire. Cupped tire. Under inflated tire. Tail wheel not inline with the Rudder.

 

 

Cy Galley - Chair, AirVenture Emergency Aircraft Repair

A service project of EAA Chapter 75 since 1963

www.eaa75.com

 

 

 

From: aeronca...@westmont.edu [mailto:aeronca...@westmont.edu] On Behalf Of Tom Boyle
Sent: Thursday, April 26, 2012 5:16 PM
To: fAA
Subject: [f-AA] Maule tail wheel

 

I think this came up recently as a thread, but I can not remember the conclusions.

[Dale P. Jewett]

Tom,

 

Since you have a Maule tailwheel, I feel inspired to respond.

 

In my opinion, the Maule is an excellent tailwheel if properly maintained and installed. However, that also goes for other brands of tailwheels.

 

I had a Maule on my 1939 Stinson HW-75, and over a several year period only had one instance of shimmy that turned out to have been caused by a ridge in the blacktop along the center of the runway. No other shimmy in hundreds of landings, both on grass and pavement. Now, I have a Maule on my 1946 Chief 11AC that I replaced a damaged original Scott. In more than a year of flying, mostly patterns and landings on both grass and pavement, it has never shimmyed.

 

I think the key is to have the correct caster, good maintenance, good alignment, and correct air pressure. On both of the Maules I have had, the caster was set very slightly forward when the aircraft was fully loaded(see the attached two commentaries about this setting). One commentary is by Cy Galley, and I don't know where the other one came from. These caster diagrams and explaination are excellent. Cy's comments apply to the Scott, but the same caster also applies to the Maule. Also important is to have the correct alignment with the rudder, and a proper amount of pre-tension in the two compression springs (different spring rates). (See the attached Maule installation procedure).

 

On my Chief, because of the short distance between the rudder horns and the tailwheel steering arms, I had to use both styles of attachment clips. (See the attached photo for a shot of the Maule installed on my Chief).  

 

I think that if you get the correct caster, spring pre-tension and alignment, you will correct the shimmy problem.

 

Keep us posted.

 

Dale Jewett

----- Original Message -----

From: Tom Boyle

To: fAA

Sent: Thursday, April 26, 2012 5:16 PM

Subject: [f-AA] Maule tail wheel

[Tom Boyle]

Many thanks, Everyone.  I will be working on the springs and castor tomorrow.  I will let you know how it works out.

 

Tom

[Tom Boyle]

Changing the castor worked

 

I made several changes to get the caster right.  If the springs keep sagging, all I have left to adjust will be to rebend the springs or make new ones.

 

Thanks again, everyone.

 

T²

[Dale P. Jewett]

Excellent, glad it worked.

 

Dale Jewett

----- Original Message -----

From: Tom Boyle

To: aer...@westmont.edu

Sent: Monday, May 14, 2012 6:49 PM

Subject: Re: [f-AA] Maule tail wheel