Ziroli p-47 92" blown up to 110"
03-20-2014, 12:21 AM
#76
Thanks, guys.
Chris,
See ya' in August.
Doug,
Your Alby looks great.
Mirce,
I always enjoy reading your build threads.
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Wings (cont)
Hinges:
I couldn't make a prototype fowler hinge work (at least not a complicated one) so I'm using my standard G10 hinge setup. My version don't slide backwards but they work very well and are sturdy, which is important on this size plane. I also like them as they are easy to remove for painting/maintenance.
The table saw made nice accurate cuts of the height of the G10 hinges. A drill press put a few holes in them to give the epoxy something to hold on to, the band saw did the detail cutting and the sander finished up the job.
The wing side gets a 1/8" thick aircraft ply piece sandwiched between two 1/16" thick G10. The flap/aileron side gets 1/8" thick G10.
Some 1/4" thick balsa supports the hinges. 4/40 screws used to connect the two hinges.
The hinge assembly epoxied to the first flap. Putting the hinges on while the flap is still attached to the wing insures everything is perfectly aligned.
After cutting the flap off, the LE of the flap and TE of the wing were trimmed/sanded to shape.
Last edited by samparfitt; 03-20-2014 at 12:39 AM.
03-20-2014, 02:02 PM
#79
Peter,
Yep, I've seen them. Kind of expensive but I'm happy with my hinge set up.
+++++++++++
Wings (cont)
Hinges (cont)
Right wing:
Installed the flap hinges and then did the same for the aileron.
Again, same procedure as with the flaps.
After the epoxy cooked, I cut away the aileron and sanded convex curves on the LE of the aileron and concave curves on the TE of the wing. With the hinge pin at the bottom of the aileron, there is limited UP movement but the concave in the wing's TE gives enough room for 1.5" throw, which is way more than I'll use.
While cutting the parts for the right aileron, I made duplicates for the left aileron so that install should go quickly.
Some 1/64" thick ply will be used to box in the wing's TE , plus 1/64" ply will cover the gaps between the wing and flaps/ailerons.
Last edited by samparfitt; 03-20-2014 at 02:07 PM.
03-21-2014, 04:49 PM
#81
Wings (cont)
Hinges:
Finished up the left aileron hinges.
Servo linkage to flaps.
HS-7955 (333 oz) servos are being used for the flaps. All dubro heavy duty ball links, 4/40 rod and brass tubing for anti-rod flexing.
Servo trays epoxied together using lite ply. 1/8" thick aircraft ply for control horn with 1/4" thick balsa sandwiched on each side of the control horn.
I've been using dubro's new dual arm servo arms but, since the servos came with metal arms, I'm using those.
The arm as well as the control horn is drilled/tapped to insure no slop.
The servo/control arm linkage is made perfectly aligned to insure no binding. The control arm was also placed in the same location on both flaps to insure both move proportionally together.
Some spruce 1/4"X1/2" stringers were epoxied between the ribs and to the upper sheeting and then some 1/8" thick aircraft ply epoxied to the stringers.
The transmitter was used to maximize flap deflection with the servo arm straight back to minimize servo stress for full down flaps.
My digital protractor says 56 degrees.
Not getting as much done with March madness going on!
03-22-2014, 07:29 AM
#82
Wings (cont)
Cardboard tube for wires:
Forgot to put these in before gluing rib W-1 to the wing so I cut almost through the tube every 4.5", bent the tube at the cuts and slid the tube in the rib holes; some CA on the cuts and some epoxy around the ribs and all's good.
Ailerons
Linkage setup:
Same as with the flaps, HS-7955's with all heavy duty ball linkage. Plenty of aileron throw: set at max throw with the transmitter but will be reduced, later.
Air cleaner:
My cost effective air cleaner works surprisingly well comprising of a good quality air furnace filter on a box fan!
Last edited by samparfitt; 03-22-2014 at 07:32 AM.
03-23-2014, 04:34 PM
#84
Wings (cont)
Sheer webbing:
Initially, I was going to use 1/16" thick ply but opted for the 1/32" thick; easier to cut with heavy duty scissors and should do the trick.
A forstner bit makes clean holes in the ply and will aid in routing any wires between areas. The ply is applied to the main and also the back spar up to where the outer rib holds the gear mount using epoxy. Full box webbing to both sides of the spars. The rest of the webbing to the tip will be 3/32" thick balsa sheet.
Wing to fuse mount plates:
Some 1/4" thick ply used on the bottom of the wing ribs. Four plates for four wing bolts.
Last edited by samparfitt; 03-23-2014 at 04:37 PM.
03-24-2014, 12:31 PM
#86
Wings (cont)
Gear door framing.
I used spruce 1/4"X1/2" to frame in the gear door opening. The one exception was 1/4" ply along the back curve where a wide piece of stock was needed. The 1/2" wide was used so a 1/4" wide gear door stop will be left when the bottom sheeting covers the other 1/4" remaining of the door framing.
The ribs along the oleo were notched so one long piece of spruce could be glued parallel to each side of the oleo.
The gear housing was also framed in for a cover hatch.
A triangular area was left open for the rotating landing gear light.
Last edited by samparfitt; 03-24-2014 at 12:34 PM.
03-25-2014, 12:24 PM
#88
Wings (cont)
Nav lights:
18" long drill bit used to route sullivan's blue nyrod blue tube from the nav light to the aileron servo area.
Guns (gotta' have guns!)
The guns will be removable (why it took all day!). They will be sticking out quite a distance from the wing's LE so they may have to be removed during transport to prevent hanger rash. Also, will make it easier to prime/sand the wing with the guns removed.
Initially, I was going to just mount them just past the sub-LE but that would not give them enough support against hanger rash.
Instead, two 1/4" square spruce sandwiched the center LE spruce spar, then a 1/2" wide piece of spruce was epoxied to the back of the 1/4" square spar. This gives enough meat to the area so the guns won't snap off due to hanger rash. Also, if any get damaged, they will be easy to replace (I might as well make up a few spares!).
The base for the guns are 15/32"X2" brass tubing with 1/2" thick ply (1" square) drilled half way through with a forstner bit and then drilled/tapped for a #6 bolt. The bolt was epoxied through the back of the ply and the 2" brass tubing was epoxied in the recess of the ply.
The guns are from 7/16"X.035 aluminum tubing. The thicker wall (.035) tubing looks better for guns. Some oak dowel was cut and epoxied in one end of each gun and then drilled/tapped to take a #6 size bolt. The guns will just be screwed into the #6 bolt at the base of the brass tubing.
On the P-47, the guns are parallel to the ground so a horizontal line was drawn on the wing's LE and four 1/2" diameter holes were drilled 1 3/8" apart. Holes a little larger than the brass tubing but it allows 'wiggle room' when aligning/epoxying the brass tubes to the wing. One gun is right in front of the gear mounting plate so the 1/2" thick ply had to be made very small to fit around the gear mount.
Sheeting prep:
The aileron servos were boxed in for hatch covers as well as around the compression screws.
Last edited by samparfitt; 03-25-2014 at 12:34 PM.
03-26-2014, 06:19 AM
#90
Wings (cont)
Bottom sheeting:
Carpenters glue used to make two each of two 3/32" X4"X36" sheets and two each of three 3/32"X4"X36" sheets. Changed the lengths from the tops 4' long sheets to the bottoms 3' long sheets to increase wing strength by not having both sides sheeting end at the same point.
I like to take several pictures of the 'guts' of the wings before sheeting for possible future reference.
Template:
The gear door area is a complex set of lines so some lite construction poster board was used to make a template of the gear area.
After taping the poster board to the wing, a straight pin works well to locate the end points of lines to transfer to the template.
The template gives me a nice accurate line leaving a lip around the entire gear area for the gear doors to rest on in the closed position.
Lots of pins, tape and carpenters glue and leave that sheeting cook for an hour or so.
03-26-2014, 03:43 PM
#91
Wings (cont)
Sheeting:
Did the TE and then the end of the right wing.
Pre-cut the flap/aileron hatch holes before the glue up and then sanded all the surfaces.
Guns for the left wing.
Had to get some more tubing before finishing up the remaining guns.
03-27-2014, 10:44 AM
#92
Wings (cont)
Guns:
Guns screwed on to check fit. With the LE still to be added, they should be about the right length.
Wing tips:
Used two 3/8" thick (outside) and two 1/4" thick (inside) balsa sheets to get the needed thickness of the wing tips. Some carpenters glue and clamps, spray stuck the wing tip form on the stack of sheeting and cut them out using a band saw.
Wing mounts:
Used some cherry 1" thick stock for the four wing mounts. Epoxied between two 1/8" thick aircraft ply so they should be good and secure, especially after I added a few wood screws from the side.
Sheeting:
Left wing:
Lucked out on the right poster board template working on the left wing; only a couple small changes were needed. Just flipped the template upside down.
Same procedure as done with the right wing.
With only able to use pins along the inside edges, I could just sheet the entire bottom of the wing at once with the three pieces of glued up sheeting.
Boxed in holes along the inner part of the wing to route wires/air lines.
Last edited by samparfitt; 03-27-2014 at 10:51 AM.
03-28-2014, 02:28 PM
#94
thanks, Tony.
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Club meeting:
Took her to 'show and tell'.
Wings (cont)
While I had the wing together from the club meeting, I figured I'd get a few things done.
I glue two 1/4" thick balsa sheets for the LE of the wing, planed and then sanded them smooth (I'm glad those guns are removable!).
Epoxied the wing tips on. Clamped the flaps and ailerons together so I could get an accurate outline for carving the wing tip. The master airscrew mini planer does a nice job of quickly removing excess balsa without a lot of dust.
Last edited by samparfitt; 03-28-2014 at 02:41 PM.
03-28-2014, 02:37 PM
#95
Wings (cont)
Mounting the wing to the fuse.
Put a plastic tack in the tail so I could align the wing to the fuse: Lucked out as the wing's center line was exactly in the center of the fuse center line.
The steel center strap was a little past the inner wing saddle so a couple notches were cut in the ply for clearance.
Using a 1/8" long bit for a pilot hole, the first hole was drilled, then 1/4" bit on the wing and 3/16" bit on the fuse wing block; tapped for a 1/4X20 bolt. Enlarging the wing hole, I only went in about 1/2 way and then went in from the other side to make sure the holes line up since there is just soft balsa as filler.
After the first hole was drilled/tapped and a bolt inserted, the diagonal hole was done, likewise. Once those two were in, the remaining two holes could be done at once.
Initially, I checked that the bolt head would be covered by the belly pan and had to move the tic marks in about a 1/4".
First nice day that I could work out in the detached shop. More room out there (plus I can make a mess with saw dust!).
Last edited by samparfitt; 03-28-2014 at 02:48 PM.
03-29-2014, 12:49 PM
#96
Fuse:
Inner cooler doors:
Cut those out and added some 1/4"X1/2" balsa around the opening. As with my precious P-47, I plan to have these functional.
Tail gear:
Since the gear mount ply is only butt glued to the formers, I added some extra bass wood support, above and below the mount.
A hatch will be needed to screw the gear to the mount so a hatch area was boxed in.
Gear doors:
Usual pre-set up. Used spruce to outline the door and door opening and used some 1/16" thick balsa as spacers between the doors and door opening. Some extra door formers were needed for the doors. Since the back of the doors are round, pieces of bass wood were shaped to fill in the entire back area, then it was sanded, The doors were removed and a scroll saw was used to cut the curve in the doors and the two waste pieces were epoxied to the fuse. Ready for sheeting.
03-29-2014, 06:09 PM
#97
Vertical fin:
Fuse angle transferred to rib R-1's angle.
Constructing the end ribs and LE allows easier placement of remaining ribs without distorting the LE and eliminates rib sanding for adjustments.
Holes for elevator linkage.
Corner brace cut with grain at 45 degrees to surfaces to maximize sheer strength.
Spruce spars and TE doublers added.
03-30-2014, 12:12 PM
#99
Mirce,
I'll be doing it in aluminum, as with my previous P-47. From now on, anything that flew in natural aluminum, I'm finishing the plane in aluminum.
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Vertical fin:
3/32" thick balsa sheet to cover one side of the fin.
3/32" thick balsa sheet used for the sheer webbing.