For any production hinges a tolerance is required between diameter of the orifice and diameter of the pin in order to avoid having to reject lots of parts that have too much friction. For this reason, the amount of play in Carbinge vs aluminum is likely to be similar. In either case, you can substitute different size pins in order to diminish the play.
A major and important difference between the two is that with aluminum hinges I don’t think you can avoid corrosive wear of the inside diameter of the hinge over time. Therefore aluminum hinges will always become looser over time and will tend to develop the play being discussed even if during installation the parts are match fit to avoid play.
Carbinge in our tests does not wear over time. The fit at installation should remain the same.
In either case, the pin itself can corrode. This will usually result in the pin being more difficult to remove because of rust deposits on the pin. It is good with Carbinge applications to occasionally remove the pins and clean them with Scotchbrite before re-inserting. Stainless Steel pins can decrease this concern but they tend to be more brittle and can fail due to breakage in some applications.
Regards,
John Barrett
Leading Edge Composites
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of marv@lancair.net
Sent: Friday, November 25, 2011 6:11 AM
To: lml@lancaironline.net
Subject: [LML] Re: Legacy vibrations resolved
Posted for "Bill Wade" <super_chipmunk@roadrunner.com>:
I agree. I’m using Carbinges on my IV-P MG doors and I thought they had too
much play. I think the stock pins are suitable when you’re attaching cowlings
or other curved surfaces but I wanted a tighter fit for use as a hinge,
especially if they’d be used for trim tabs.
I found a source for precision ground VAR stainless
http://www.smallparts.com/stainless-precision-ground-straightened-vacuum-arc/dp/B003R50276/ref=sr_1_1?sr=1-1&qid=1322133332&filterBy.material_browse=16414
. I tried a range of diameters and found 0.083 was a good fit. –Bill Wade
From: Chris Zavatson
Sent: Wednesday, November 23, 2011 10:05 PM
To: lml@lancaironline.net
Subject: [Norton AntiSpam][LML] Re: Legacy
vibrations resolved
The elevator trim tab is perhaps the most neglected control surface that can
really ruin your day. The goal for us should be to remove all play from the
trim tab system. There are many ADs and service bulletins written against
certified planes specifying the acceptable limits. We don't have the luxury
of such a guidance and thus only find the limits through experiences conveyed
by others that have stumbled across the edge. Unfortunately the inherent play
in Carbinge is similar to that of stock MS hinge material and will not improve
the situation described in Steve's post.
I think Randy's post is also referring to the spherical bearings used in the
tail of the 320/360 MkII and the Legacy in addition to the trim tab hinge
(Randy, correct me if I am wrong). The spherical bearing can be upgraded to
some
made to tighter tolerances and with better alloys.
Chris Zavatson
N91CZ
360std
www.N91CZ.net