RV-3 Plans - 'Clarifications'
I have suggested to Paul Dye that we start this thread as a 'sticky'. It is intended as a summary of significant errors / omissions / areas needing clarification in an RV-3(B) build. Paul's seems to like the idea :eek:
To keep it separate from the ever expanding "advice" topics, we suspect it will need "moderating" according to a set of rules, which as a first guess might be:
RV-3 SB going slowly
PS I'll kick off with a sample on Flaps...
Flaps - FL-303
Root Rib needs moving inboard
Randy's site info from Dan Benua
[Andy Hill April 2010] We have built the Flaps with FL-303 moved inboard by 7/8". Will update in ? months/years when we fit to the fuselage
Great Idea Andy.
I have already have a section of my build site devoted to this. I have collated all of Paul's relevant posts onto this page in my site and I will be updating it as and when an appropriate post or piece of information comes my way. Here is a list of Paul's posts, that fall under your criteria:
Error on Quick Build Wing
Aileron Gap rivet question
F-303 Center Section Build-up
Lower Forward Stringers in the Fuselage
F-336 “Wall Outlet” SNAFU….
Send me a mail if this is okay, and if Paul wants to expand on these topics later I will edit this post out.
Flaps - Too long?
Flap parts longer than Plans?
DWG 9 shows a distance of 10 1/2" from the Flap TE to the Hinge CL with reference to the fuselage datum. Trig that to the vertical displacement and you get ~10 19/32" as the length measured directly from TE to the Hinge CL.
Putting the (supplied) FL-302 (Spar) and FL-303 (Outboard Rib) into FL-301 (Skin), and adding the hinge as per Plans gave a distance about 5/32" more'. Paul Dye seems to have come across supporting evidence of this RV-3B - Fiddling with Flaps
Request(s) for Info: Can others let me know / post here and I'll edit into this post, this measurement for their Flaps, esp QB ones.
[Andy Hill Apr 2010] We have built the Flaps with the direct distance of Flap TE to Hinge CL = 10 20/32". Will update when Flaps/Ailerons/Wings all fitted as to how TEs line up :confused:
Mount aileron's first
I'm not sure what the QB guys are facing, but for a SB wing the
procedure is straight forward. Mount the ailerons first and use
an airfoil template to be sure they are exactly in trail. Build
the flaps next, and drill the hinge to them. You don't have much
flexibility on the distance from the flap spar to trailing edge unless
you modify the shape of the end ribs. Finally, trim the trailing edge
of the lower skin so that the flap and aileron trailing edges are
in line when the other half of the hinge is drilled. The flap brace is f
abricated an mounted after the skin edge is trimmed.
You should considered the dimensions on the plans to be only
advisory. On this airplane, nearly everything is "trim to fit".
You always have to be thinking about which dimensions are
not adjustable, and then adjusting everything else to make
- Dan Benua
Rear Deck Access/Lightening Holes
When fabricating the rear fuselage deck, I laid out the holes (forward round one, middle "pear-shaped, aft rectangle) per the drawings, and it just didn't look right - the rectangular hole at the back looked too far aft by about an inch. These holes are located on the drawing by measuring incrementally from the front of the deck, and I discovered that the "8 inches" seemed to be the error - it put the pear-shaped and rectangular holes an inch too far back. I laid it out again replacing the "8" with a "7", and everything fit much better.
Treat this as a "potential" plans issue - I'll report further if I have created a new problem by changing the locations.
HS rear spar rivet spacing
When constructing the rear spar of the horizantal stabilizer, pay close attention to the rivet spacing in the area where the fuselage - HS attachment bars will be bolted on. You must leave plenty of space between rivets in order for these bars to sit flush.
When drilling the rivets for the rear deck access plate, pay close attention to the rivet locations in the area that the front horizantal stabalizer angle bracket will be attached. The rivets holding down the rear access plate could interfere with the front spar hold down angle.
F-337 Pushrod Length
Quick summary - 48 1/2" worked for me.
The plans leave a lot to be desired when it comes to fabricating the elevator pushrods. The forward one (F-337) that links the stick to the bell crank is shown on Drawing 22 with a cut tube length of 49 1/2 inches "To be determined in assembly". Well, it's good that they warn you, and also that the 49 1/2 inches is extremely generous - it's much easier to trim more off than it is to add it back on.
The exact length is dependent on the final position of the stick mixer assembly and the bellcrank - neither of which positions can be determined from drawings (they are shown but not dimensioned). I centered the bellcrank between the F-306 and F-307 bulkheads and positioned the mixer bearings where they seemed to fall given the mounting angle length. I then cut the pushrod to the specified length and did a test fit. Clearly, it was too long, as the stick and bellcranks were at their full deflection with the rod ends screwed all the way in.
I shortened the tube in small increments, and finally got to the point where the bellcrank was mid-travel with the stick in about the middle of it's range. most importantly, I can get full stick travel and full bellcrank travel. This is still with the rod end bearing screwed almost all the way in. This occurred with the tube cut to 48 1/2" - one inch shorter than specified. Seems like a large deviation, but I can always screw the rod ends back out to get almost an inch back if I need it later.
I couldn't find anything in the instructions or drawing that give rigging instructions, so I am going with the idea of mid-range for the stick should be mid-range for the bellcrank, We'll see if that works when I mount the elevator.
DWG 9 - 'Wingwalk' (Left Wing)
DWG 9 details the Wingwalk reinforcement, and states sheet required 10"x24". Also states "Left Wing only".
Kit provides a sheet 10"x48"... and you might be forgiven for thinking they gave you enough for 2 e.g. in case you built a slider canopy and wanted one RHS as well.
Unless I have got it wrong I found the sheet required to be trimmed to ~9.5" x ~25" - so suggest do not cut the sheet in half / to the stated dimensions - carefully measure the ribs/spars and cut/trim accordingly (pretty good advice for the RV-3 all round ;) )
DWG 16 - Rudder
Not an "error", but definitely a well laid trap :)
The Build Manual and the main Rudder drawing all seem clear - bottom rib rivets to Rudder skin, been there, done that a few times before. So we'll drill, dimple, prime and rivet.
Before doing this, I had a think ahead - how do we attach the Fibreglass Rudder bottom? Study drawing, takes me to Section E-E, look at that, and lo and behold, see it requires a ~1" wide strip of 0.032" to be riveted with the above on the inside of the rib.
Looking at the RV-3 build websites, and some "completed" rudders, not much evidence seen of these strips :confused: So presumably some rebuilds going on at the end as the tips get fitted :mad:
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