Elite Fin Spar/Rudder Horn Clearance
Posted: Fri Feb 17, 2012 9:02 pm
Hi Folks
I have been having an off line discussion with one of our group about a few Elite things and one
point has come up that I think is worth sharing with the whole group (we have been mostly
sociable off line).
In our early Elite, 583 and also the other one #714, the rear spar of the fin requires a notch to
clear the lower hinge/rudder horn of the rudder, this was not mentioned in the manual version we
were using at the time nor does it appear to be in the later version that came with #714. MAM
responded that the rudder must have a travel of between 25 and 35 degrees each way but were
unable to specify how deep the spar must be notched to achieve this. They did however say that
the notch is incorporated in "later" production parts (whatever that means....).
In our case, by notching the spar by about .46" we got the required travel. You can double check
this by measuring from the front face of the spar to the bottom of the notch which will be about
.5". Be careful that you have the same travel in both directions because in our case one leg of
the channel which comprises the rear spar was longer than the other by a measurable amount so if
you just measure how deep you make the notch you could wind up with more travel in one direction
than the other.
The other thing to keep in mind is that it is a good idea to put a (large OD) nylon washer
between the two halves of the rudder hinges to act as a thrust washer (carrying the weight of the
rudder) avoiding the galling that aluminum on aluminum could experience as the hinge moves. I
would put one at each hinge. I don't recall the correct part number but I do know these can be
had from a company here in Canada called Spaenaur for a reasonable price. I am sure any god
fastener supply house could source them as well.
OK, that is about it, I wanted to pass this along since I it looks like the spar cut out seem to
be an issue with more kits than I had thought. Question, is this also an issue with the SRs?
Dave R.
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I have been having an off line discussion with one of our group about a few Elite things and one
point has come up that I think is worth sharing with the whole group (we have been mostly
sociable off line).
In our early Elite, 583 and also the other one #714, the rear spar of the fin requires a notch to
clear the lower hinge/rudder horn of the rudder, this was not mentioned in the manual version we
were using at the time nor does it appear to be in the later version that came with #714. MAM
responded that the rudder must have a travel of between 25 and 35 degrees each way but were
unable to specify how deep the spar must be notched to achieve this. They did however say that
the notch is incorporated in "later" production parts (whatever that means....).
In our case, by notching the spar by about .46" we got the required travel. You can double check
this by measuring from the front face of the spar to the bottom of the notch which will be about
.5". Be careful that you have the same travel in both directions because in our case one leg of
the channel which comprises the rear spar was longer than the other by a measurable amount so if
you just measure how deep you make the notch you could wind up with more travel in one direction
than the other.
The other thing to keep in mind is that it is a good idea to put a (large OD) nylon washer
between the two halves of the rudder hinges to act as a thrust washer (carrying the weight of the
rudder) avoiding the galling that aluminum on aluminum could experience as the hinge moves. I
would put one at each hinge. I don't recall the correct part number but I do know these can be
had from a company here in Canada called Spaenaur for a reasonable price. I am sure any god
fastener supply house could source them as well.
OK, that is about it, I wanted to pass this along since I it looks like the spar cut out seem to
be an issue with more kits than I had thought. Question, is this also an issue with the SRs?
Dave R.
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
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