Reset elevator trim pointer

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

Post Reply
User avatar
johnsunday
Posts: 54
Joined: Tue Oct 09, 2007 4:08 pm

Reset elevator trim pointer

Post by johnsunday »

During the last annual on the old Alaska Bush Plane we found a cracked horizontal bulkhead just under the horiz stab which required a disassembly of the aft end control surfaces. The elevator trim wheel indicator now points to a position aft of the old position. All angles on the trim tab are correct when the wheel is moved to its forward and aft limits, it's just the pointer doesn't point to the "green band" it use to point to. How is this pointer repositioned?
bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: Reset elevator trim pointer

Post by bagarre »

I just took mine apart and it's so simple, it's genius.

The side of the wheel has a spiral groove cut in it (I always thought they were decorative circles) The trim indicator thingy rides in this groove.

To adjust it, Set the trim neutral on the tail and take out the 5 screws that hold the side of the trim wheel plate on.
Remove the side plate, adjust the trim indicator thingy to the position you want and put the thing back together being careful to get the indicator in the groove.

Before doing this, make sure you have enough links on the trim chain for full travel. If the needle is off, you might not be centered on the chain.
trim.jpg
wheel.jpg
User avatar
gfeher
Posts: 571
Joined: Fri Sep 26, 2014 9:19 pm

Re: Reset elevator trim pointer

Post by gfeher »

That's slick. I love it when something isn't over-engineered.
Gene Feher
Argyle (1C3), NY
'52 170B N2315D s/n 20467 C-145-2
Experimental J3 Cub Copy N7GW O-200
bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: Reset elevator trim pointer

Post by bagarre »

Before taking it apart, I couldn't fathom how it worked.
As soon as I took the cover off, it was a revelation.
User avatar
GAHorn
Posts: 20968
Joined: Fri Apr 12, 2002 8:45 pm

Re: Reset elevator trim pointer

Post by GAHorn »

As Goldie used to say.... Grooovey... :P
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
Post Reply