[rebel-builders] RE: And the saga continues...Rebel #56 Build
Posted: Sun Feb 19, 2012 8:54 pm
I used the same fuselage supports that I use for removing and servicing
the gear. Concrete blocks and wood or jacks under the cage. Actually I
like to put a 3 foot long wooden 2x3 on each side of the fuselage
stretching between the cage and the bulkhead that the rear drag strut
attaches to. Then I jack on each of those with the jacks an inch or two
behind the cage. Tail sits on something as well. As noted, the fuselage
will move a lot if you just leave it sitting on the wheels.
IMO one should not expect better than 0.2 degree repeatable accuracy out
of any electronic level that I've ever seen but that is good enough. I
would only use one level though. You've heard the saying that a man with
two watches never knows what time it is... If there is any doubt,
reverse the level (end for end) and see if the readings agree. Exacting
carpenters like to do that to confirm a level's accuracy. Frankly though
I don't think the dihedral is at all critical other than the control
horn attachments at the wing root will flex more if the dihedral is
excessive. Left and right roughly matching makes it a touch easier to
fly wings level I suppose ;)
Ken
On 8/25/2011 3:59 PM, Bruce Rose wrote:
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the gear. Concrete blocks and wood or jacks under the cage. Actually I
like to put a 3 foot long wooden 2x3 on each side of the fuselage
stretching between the cage and the bulkhead that the rear drag strut
attaches to. Then I jack on each of those with the jacks an inch or two
behind the cage. Tail sits on something as well. As noted, the fuselage
will move a lot if you just leave it sitting on the wheels.
IMO one should not expect better than 0.2 degree repeatable accuracy out
of any electronic level that I've ever seen but that is good enough. I
would only use one level though. You've heard the saying that a man with
two watches never knows what time it is... If there is any doubt,
reverse the level (end for end) and see if the readings agree. Exacting
carpenters like to do that to confirm a level's accuracy. Frankly though
I don't think the dihedral is at all critical other than the control
horn attachments at the wing root will flex more if the dihedral is
excessive. Left and right roughly matching makes it a touch easier to
fly wings level I suppose ;)
Ken
On 8/25/2011 3:59 PM, Bruce Rose wrote:
Roland: You have now identified your problem. It would be very difficult to
remove and attach the struts without some thing moving. I would remove the
gear and put the fuselage back on the table. level the table , then the
fuselage. I would then put the previous struts back on and remove the bolts
from one end. then set the wings at exactly 1 degree. Mark your fittings
through the previously drilled bolt holes and see what you have. It may be
possible to save the struts and two of the end fittings.
Bruce
----- Original Message -----
From: "Roland Kriening"<kriening@rogers.com>
To:<rebel-builders@dcsol.com>
Sent: Thursday, August 25, 2011 7:19 AM
Subject: RE: [rebel-builders] RE: And the saga continues...Rebel #56 Build
Main landing gear at front and sawhorse at back. Fuselage was within .1
degree of level, as measured off the front cage.
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of
Bruce
Rose
Sent: Thursday, August 25, 2011 9:01 AM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] RE: And the saga continues...Rebel #56 Build
Roland: What was supporting the fuselage during the levelling and
measuring?
Bruce
----- Original Message -----
From: "Roland Kriening"<kriening@rogers.com>
To:<rebel-builders@dcsol.com>
Sent: Wednesday, August 24, 2011 10:11 AM
Subject: [rebel-builders] RE: And the saga continues...Rebel #56 Build
In short form here is what I did...from what I can remember. It was as
per
the instructions.
1. wings on, supported at each end.
2. used digital level on the cage and came within .1 of true level
without
adjusting the fuselage on the gear. As the 36" level has an error range
of
+/- .1 degree I took this as my level point. Checked this a few times
with
two different levels. So I set the level on the forward cage and re-set
it
to 0. Now I was starting with the cage as my level point.
3. transferred the level to the top of the wing about five feet from the
root and on the main spar.
4. adjusted the end of the wing to achieve as close to 1 degree as I
could
get.
5. measured hole distance as per plans and cut strut as per plans
6. installed the struts and blocks and marked as per the plans
I think I may have been OK up to this point, now is where the mistakes
probably happened.
7. removed struts and marked as per the plans, lined up block on outside
of
strut and drilled single hole through end
8. marked and drilled remaining holes in block
9. lined up block on outside of strut again, pinned drilled hole and
drilled
out new holes
10. inserted block into strut and drilled holes all the way through
11. installed bolts and checked level still on top of the wing - still at
.9
12. removed support at end of wing and thought I had done well.
Went on to do the other side the same way. Once all bolts were in and
supports were removed I was surprised to see the first wing I did at 1.7
degrees and the second at 2.7 degrees. Double checked by taking my level
off
the forward cage (which was extremely close to true level anyway) and
setting the level in the exact spot I had it. I am most likely missing
something that should be very obvious, but my frustration level keeps me
from seeing it.
Ron's point about ensuring you have the correct angle on the blocks is so
very true. One of mine was off by a hair and translated into a 1/4 inch
variation at the other end.
Darryl will be sending me new parts $116 for the struts, and $85 for each
block. Expensive lesson, but critical parts.
Roland
R56
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of
Bruce
Rose
Sent: Wednesday, August 24, 2011 6:59 AM
To: rebel-builders@dcsol.com
Subject: Re: [Bulk] Re: [rebel-builders] And the saga continues...Rebel
#56
Build
Roland: You have to find out where you made the mistake before you try to
fix the problem or it may happen again. Can you write the exact procedure
that you used to line up the wings to the fuselage.
Bruce
----- Original Message -----
From: "Roland Kriening"<kriening@rogers.com>
To:<rebel-builders@dcsol.com>
Sent: Tuesday, August 23, 2011 2:22 PM
Subject: RE: [Bulk] Re: [rebel-builders] And the saga continues...Rebel
#56
Build
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