Bungee (modified) Gear Thoughts
Posted: Sat Feb 18, 2012 11:24 am
G'day Wayne & Everyone ...
I would like to hear your, (and others), opinion on "fixing" our
Rebel
As you already know, I stuffed up big time - trying to win a spot
landing competition .... never again ! :o(
Anyway,... when I dumped the flap, (from FULL to negative - in 1/2 a
second) - just as I got hit by a big gust / rotor (strong quartering ON
headwind - along a strip lined with big trees) - and she lifted and
then FELL heavily, ... the thing that let go was the "drag link" - as I
call it ... the square tube piece that goes from between the floor
channels / carry throughs, down to the "X brace" - which is the joiner
between the strut down to the wheel on both legs & back up to the floor
on either side.
I made a set of legs - similar to your own design - copied from a Super
Cub plan set - obviously out of chrome moly. I also fitted a pair of
Carr McMaster Heavy duty compression springs - in place of the bungee
cords - (looks much neater, less air drag & work very well). The legs
are undamaged in ANY way - despite being punched up through the floor
when the other tyre dug in as the plane slid & turned !
Obviously I'm going to replace tha sqaure aluminium "drag link" tube
with chrome moly (which was the only piece of the original U/C set that
I used) , as I rebuild her .... but my question is:
WHAT would you do - (other than not let me fly it), to stop this
happening again ?
I have thought of some sort of heavy duty rubber "stop" - that might
compress as the coil spring bottoms out .... but then I wonder - am I
just expecting too much here .... ?
(I realise that at some point, a BAD enough landing is going to have
some repocussions - no matter what we do to beef things up - but I'm
just trying to think of ways to back up / remove this single point
failure from causing the same outcome in any future BAD landing)
BTW - I could not install the steel cable back up in the U/C - as is
called for with the aluminium bungee gear leags - as I had made the
"inner tube" of the sliding leg rather heavy walled - and there was no
room to fit a backup cable down the middle ....
Perhaps I could fit a cable - parrallel - down the back of the leg
assembly - outside the tubes ...( but it would look crappy I think)
Can you think of another way to make a "failsafe" / backup for this kind
of failure ???
AS always - yours, Bob's & other opinions are gratefully received !
Rick Harper
541R - under reconstruction :o(
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I would like to hear your, (and others), opinion on "fixing" our
Rebel
As you already know, I stuffed up big time - trying to win a spot
landing competition .... never again ! :o(
Anyway,... when I dumped the flap, (from FULL to negative - in 1/2 a
second) - just as I got hit by a big gust / rotor (strong quartering ON
headwind - along a strip lined with big trees) - and she lifted and
then FELL heavily, ... the thing that let go was the "drag link" - as I
call it ... the square tube piece that goes from between the floor
channels / carry throughs, down to the "X brace" - which is the joiner
between the strut down to the wheel on both legs & back up to the floor
on either side.
I made a set of legs - similar to your own design - copied from a Super
Cub plan set - obviously out of chrome moly. I also fitted a pair of
Carr McMaster Heavy duty compression springs - in place of the bungee
cords - (looks much neater, less air drag & work very well). The legs
are undamaged in ANY way - despite being punched up through the floor
when the other tyre dug in as the plane slid & turned !
Obviously I'm going to replace tha sqaure aluminium "drag link" tube
with chrome moly (which was the only piece of the original U/C set that
I used) , as I rebuild her .... but my question is:
WHAT would you do - (other than not let me fly it), to stop this
happening again ?
I have thought of some sort of heavy duty rubber "stop" - that might
compress as the coil spring bottoms out .... but then I wonder - am I
just expecting too much here .... ?
(I realise that at some point, a BAD enough landing is going to have
some repocussions - no matter what we do to beef things up - but I'm
just trying to think of ways to back up / remove this single point
failure from causing the same outcome in any future BAD landing)
BTW - I could not install the steel cable back up in the U/C - as is
called for with the aluminium bungee gear leags - as I had made the
"inner tube" of the sliding leg rather heavy walled - and there was no
room to fit a backup cable down the middle ....
Perhaps I could fit a cable - parrallel - down the back of the leg
assembly - outside the tubes ...( but it would look crappy I think)
Can you think of another way to make a "failsafe" / backup for this kind
of failure ???
AS always - yours, Bob's & other opinions are gratefully received !
Rick Harper
541R - under reconstruction :o(
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