Electric flaperons
Posted: Sun Feb 19, 2012 11:04 am
[Steve W. and I continued some discussions about electric flaperon
control, replacing the teleflex cable, off list. I thought I'd bring the
whole thread (bottom up) back on list as others may be interested.]
-----
That's good news Steve. Query: what is the total up/down travel of the
mixer arm at the forward side of the retainers between your limit
switches as you have it? You're plenty clear that it's less than 2", but
I'm curious what the actual travel is to get the range of flaps you've
got. If you get a chance to measure that, do let me know.
I believe you're using the Danaher Electrak 1 Model S12-17A8-02 (see p.
14-15 of their "Industrial Linear Actuators Catalog Section" at
http://tinyurl.com/q4hrp) which has internal limit switches, and you've
added the one external microswitch to keep total arm travel to less than
the full 2". A major virtue of the Electrak 1 you have is that it's only
1.58" thick, so you were able to mount it just aft of the door, between
the aileron control tubes and the fuse with no interference -- very slick.
I think I'm going to try a slightly different model, Danaher's Electrak
E050 Model DE12-17W41-02FPMHN (at p. 9-10 of the PDF catalog). It also
has the two internal limit switches, and in addition, an internal
position sensing potentiometer which I hope to use with a remote
controller/indicator. The idea is to use the internal sensing
potentiometer and both of the internal limit switches -- without more
external active parts. The E050 also has environmental sealing to the
"IP-56" standard, whatever that's worth.
The main drawback I see so far is the E050 is thicker (2.47") so I'll
have to mount it further aft, at a <90 deg. angle to the mixer arm,
instead of directly perpendicular as you have it, in order to get the
actuator itself away from the vertical flaperon control tubes. A short
extension rod off the actuator tube will easily fit behind those, of
course. Perpendicular to the mixer arm as you have it would probably be
best, but I'm thinking if it's only set further aft enough to make
perhaps a 70 deg. angle to the mixer arm it should be fine...? A bonus
_might_ turn out to be that, if it's back a ways, at an acute angle to
the arm, it may even use up more of the available 2" travel in the
actuator for the same mixer arm travel, and if so, the internal limit
switches will hopefully be all I need. Hmmm. I better try to get my
college-bound math whiz daughter to check the geometry for me. :-)
That's the current plan anyway. At a 110 lb. rating, the E050 should
have oodles of ooomph (technical term) -- maybe even too much. Yikes.
Will have to be EXTRA sure to get any flaperon gust locks taken off
before cranking it up! :-)
Other than having to design the actuator mounting in a different area,
do you see any significant problems with this plan right off the bat?
FWIW, from Ralph at the Richards Co. (http://richardscompany.com/) I got
a quote of $202 for the one you have, and $232 for the E050 model.
Ron
254R
http://n254mr.com
steve whitenect wrote:
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control, replacing the teleflex cable, off list. I thought I'd bring the
whole thread (bottom up) back on list as others may be interested.]
-----
That's good news Steve. Query: what is the total up/down travel of the
mixer arm at the forward side of the retainers between your limit
switches as you have it? You're plenty clear that it's less than 2", but
I'm curious what the actual travel is to get the range of flaps you've
got. If you get a chance to measure that, do let me know.
I believe you're using the Danaher Electrak 1 Model S12-17A8-02 (see p.
14-15 of their "Industrial Linear Actuators Catalog Section" at
http://tinyurl.com/q4hrp) which has internal limit switches, and you've
added the one external microswitch to keep total arm travel to less than
the full 2". A major virtue of the Electrak 1 you have is that it's only
1.58" thick, so you were able to mount it just aft of the door, between
the aileron control tubes and the fuse with no interference -- very slick.
I think I'm going to try a slightly different model, Danaher's Electrak
E050 Model DE12-17W41-02FPMHN (at p. 9-10 of the PDF catalog). It also
has the two internal limit switches, and in addition, an internal
position sensing potentiometer which I hope to use with a remote
controller/indicator. The idea is to use the internal sensing
potentiometer and both of the internal limit switches -- without more
external active parts. The E050 also has environmental sealing to the
"IP-56" standard, whatever that's worth.
The main drawback I see so far is the E050 is thicker (2.47") so I'll
have to mount it further aft, at a <90 deg. angle to the mixer arm,
instead of directly perpendicular as you have it, in order to get the
actuator itself away from the vertical flaperon control tubes. A short
extension rod off the actuator tube will easily fit behind those, of
course. Perpendicular to the mixer arm as you have it would probably be
best, but I'm thinking if it's only set further aft enough to make
perhaps a 70 deg. angle to the mixer arm it should be fine...? A bonus
_might_ turn out to be that, if it's back a ways, at an acute angle to
the arm, it may even use up more of the available 2" travel in the
actuator for the same mixer arm travel, and if so, the internal limit
switches will hopefully be all I need. Hmmm. I better try to get my
college-bound math whiz daughter to check the geometry for me. :-)
That's the current plan anyway. At a 110 lb. rating, the E050 should
have oodles of ooomph (technical term) -- maybe even too much. Yikes.
Will have to be EXTRA sure to get any flaperon gust locks taken off
before cranking it up! :-)
Other than having to design the actuator mounting in a different area,
do you see any significant problems with this plan right off the bat?
FWIW, from Ralph at the Richards Co. (http://richardscompany.com/) I got
a quote of $202 for the one you have, and $232 for the E050 model.
Ron
254R
http://n254mr.com
steve whitenect wrote:
...Ron, u won't be short. I was way to long to get the required -5 + 20
flaperons and had to put in the limiter switches. I put both in, but
the up internal switch was in the right place to stop at the -5 reflex
position. I have a spare with me in case the bottom one goes south. I
could get 40* without the limiter switch which, of course, is way too much.
Steve
From: Ron Shannon <rshannon@cruzcom.com>
To: steve whitenect <srwhitenect@hotmail.com>
Subject: Re: Electric flaps
Date: Wed, 09 Aug 2006 12:11:33 -0700
From the current (3/2/06) control systems manual doc., Ch. 20, steps
17-22, and Fig. 20.5.14, it looks like the retainers are 6", with 1"
spacers on each end. The mixer arm itself must be close to 2" wide. That
would leave only about 2" of available travel for it in total, so
perhaps Jim's install is correct after all, and the pic was built to
some other measurement. In the pic it looks like that top spacer is
maybe 1/2", if that. Hmmm. So I'm wondering A) what the total possible
travel is of your actuator model itself "in free air" and B) what total
travel you might have available for the mixer arm between your retainer
spacers. I'm leaning to the 2" travel actuator, but don't want to be
short. I'll have the one with the built-in potentiometer, with external
micro limit switches on both ends.
Ron Shannon wrote:Steve,
Is your flap actuator model the one with 2" total travel, or 4" total
travel?
Amazingly, I came away
from
your plane without pictures of the mixer arm, micro switches, etc.,
which were the main thing I was interested in.
Hope all is well there. Really enjoyed meeting you, and hope to keep in
touch.
Ron
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