fin attach revisited: 2008
Posted: Sun Feb 19, 2012 5:07 pm
Hi everyone, and happy new year!
I am running into a previously reported problem with the assembly of the fin
with respect to distance to solid bulkhead (fus 36) and FUS 31. When the
tail cone is flat on the table and in line with the fin-post, and with fus 31
installed appropriately, the forward fin attach bracket does not reach the fus
36/43 bulkhead (at least a 1/4" gap...probably colser to 0.5"). I know that
adjusting the angle of fus 36 has been widely suggested as the fix for this,
but the fus 29s (and fuse 22) in my case are already drilled and trimmed. I've
looked through the archives and the following suggestions appear as fixes.
Can I get your opinions on best options? I have not yet approached MAM
with this query.
1. In a 1998 post to this list, Del Schmucker added a spacer to the forward
fin attach bracket with 4 bolts replacing the 9 rivets (apparently with MAM's
blessing). I liked this until I read a more recent post by Bob P apparently
discouraging this solution...why?
2. Ken Lehman recently noted that not all fus 30 installations are "flat" on
flying rebels, suggesting that the fin be attached with the exisiting parts (and
resulting angles) and fus 30 angled and adjusted to fit. In my case, to get
the fin to attach at both fus 31 and fus 36 attach points would raise the
bottom of the post about 4 inches. I didn't think that was a "fudge-able"
distance.
3. Someone suggested that fus 31 be "shortened" by cutting the rear tab on
fus 31 and bending a new one after some trimming (or adding a second "fus
31 fin doubler"). I really like this idea and it would be really easy. Only
question is strength. For reference purposes, the length of my FUS 31
bulkhead is 22 1/16".
4. Completely redo fus 29s (as others have done) and adjust the angle of fus
36 to suit fin-post distance, while leaving fus 31 intact. Obviously not my
favorite solution but will do it if that's what's recommended. FUS 36 is indeed
slightly out of alignment when measured against bulkheads D and C and could
come conceivably come backwards to meet the forward fin attach bracket.
(Fortunately I purchased a big roll of 0.020 stock for just such an occasion!)
Many thanks!
Rob
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I am running into a previously reported problem with the assembly of the fin
with respect to distance to solid bulkhead (fus 36) and FUS 31. When the
tail cone is flat on the table and in line with the fin-post, and with fus 31
installed appropriately, the forward fin attach bracket does not reach the fus
36/43 bulkhead (at least a 1/4" gap...probably colser to 0.5"). I know that
adjusting the angle of fus 36 has been widely suggested as the fix for this,
but the fus 29s (and fuse 22) in my case are already drilled and trimmed. I've
looked through the archives and the following suggestions appear as fixes.
Can I get your opinions on best options? I have not yet approached MAM
with this query.
1. In a 1998 post to this list, Del Schmucker added a spacer to the forward
fin attach bracket with 4 bolts replacing the 9 rivets (apparently with MAM's
blessing). I liked this until I read a more recent post by Bob P apparently
discouraging this solution...why?
2. Ken Lehman recently noted that not all fus 30 installations are "flat" on
flying rebels, suggesting that the fin be attached with the exisiting parts (and
resulting angles) and fus 30 angled and adjusted to fit. In my case, to get
the fin to attach at both fus 31 and fus 36 attach points would raise the
bottom of the post about 4 inches. I didn't think that was a "fudge-able"
distance.
3. Someone suggested that fus 31 be "shortened" by cutting the rear tab on
fus 31 and bending a new one after some trimming (or adding a second "fus
31 fin doubler"). I really like this idea and it would be really easy. Only
question is strength. For reference purposes, the length of my FUS 31
bulkhead is 22 1/16".
4. Completely redo fus 29s (as others have done) and adjust the angle of fus
36 to suit fin-post distance, while leaving fus 31 intact. Obviously not my
favorite solution but will do it if that's what's recommended. FUS 36 is indeed
slightly out of alignment when measured against bulkheads D and C and could
come conceivably come backwards to meet the forward fin attach bracket.
(Fortunately I purchased a big roll of 0.020 stock for just such an occasion!)
Many thanks!
Rob
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username "rebel" password "builder"
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