Building and finishing my 2+2/PA 14

Gerry,
Did you make your own blocks? I got these from Wag; the top seeks a little thin for a grease fitting. I came up with a real nice fit but grease would be nice down the line.
Marty

Marty57 said:

Gerry,
Did you make your own blocks? I got these from Wag; the top seeks a little thin for a grease fitting. I came up with a real nice fit but grease would be nice down the line.
Marty

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1 drop of oil once a year is all you need

Glenn

My wife is camping this weekend with the Girl Scouts and I just picked up my fuel tanks ............ shop is getting pretty full ......... anybody think she will notice? They won't be staying long; guess they could be called guests, right? ;-)

Marty

Marty give us some better pictures of them babies. Show us whats under the blankets.

Here's a couple better pictures of the tanks. These were made to match the wood model I made that fits my tank bay. I went with custom tanks so I could run the cables in front of the tank rather than through the tank. I also eliminated the cross brace through the tank and built the wing with a sheer plate under the tank bay. Capacity should be between 16-17 gallons; I'll test fill to verify. The quality is amazing. The gentleman who built my tanks has been fabricating Indy Cars and top fuel dragsters since the 60's! His gas welded tanks are accepted by the NHRA. The large fittings were heili arc welded. The tanks are .062, A bit thicker than needed but it's what he likes to work with. The are about 12 lbs each. My cost was less than the stock tanks from Wag Aero and not shipping charge. Very happy with the decision to have these made.

Marty

Very nice, very very nice. I dont know if you ground your plane when filing gas, many dont. My Dakota tanks have a small ground lug welded to them for a jumper wire to complete the ground circuit to wherever you want to ground when filling. Again just an idea. I ground when i fill at home here but i made it real simple. a wire from the tank to the spar and then i have atlees tiedowns, there like a tab looking for something to be hooked to it so i do it.

Grounding is good. The Atlee Dodge tanks also have ground lugs for bonding to the airframe.

You can ground the tanks by eliminating the rubber hose connector tubing. Just use a long nipple on the tank with an elbow on the end connected directly to the aluminum tubing. The aluminum tubing is grounded to the airframe at the selector valve, the belly quick drains and the gascolator.

S/S external braid Aeroquip hose would do that also. I have both that and a grounding wire - belt and suspenders ;-)

Yes but how are you grounding the external braid to the tank and airframe? There still needs to be a connection.

The aluminum hose fittings make contact with the braid, and my installation includes a bulkhead fitting on the frame where the hose transitions to aluminum tubing. The fittings also make contact with the aluminum tubing and tank (which you already pointed out).


Edit: Tried to delete this post due to its being duplicated, but it didn't disappear!

The braid makes contact with the aluminum fittings. Those in turn make contact with tank and aluminum tubing. Additionally, in my installation where the Aeroquip transitions to aluminum tubing, it terminates with a bulkhead fitting on a tab that is welded to the frame. But like I mentioned, I also installed a bonding wire between tank and airframe. I doubt that it's possible to have "too good" a ground.

Got it. I thought that you only used the ss covered hose with a worm screw clamp.

Good questions and thoughts about grounding. Since I have a wood wing I will have to intentionally ground tank to fuselage. I will likely run a ground from the tank to the wing attach fitting; that should provide a good ground to fuselage. I need to make sure I have a paint free path for ground from tank to somewhere on the gear. Glad you guys brought this up, thanks.
Marty

And if you have a portable fueler, theres hose with groundwire molded in.

More progress to report. I have finished the upper baggage door. Like many other items, this is made of wood. The door will be covered in fabric with a weather striping gasket on the door frame. The door will overlap the fuselage skin.





I still have to enclose the upper baggage area but that should be easy. The latches I used are from the local RV store, one thumb latch and one lock. I'll swap them out, key up front and thumb in back. That way, if the thumb jiggles loose the corner of the door will not open into the slipstream.

Next is the doors. I've been working on these a while now; they proved to be pretty interesting to build. Again, I have chosen wood (Doug Fir is an alternative to steel shown in the plans). With no angles the same and all the compound angles it took some planning but they came out great and ate very strong and rigid. Next will be the skin. I'm going to sheet 1/8" plywood and than cover the door with fabric. The upper window will be sliding on both doors; tracks will be out of UMHW plastic that I will machine. I debated about covering the door with clear plexiglass but decided on the wood surface as I like the look of the solid door. I have the option of routing out the ply between the sections made by the diagonals if I decide I want a clear door. If I go that rout, I could inset the plexiglass inside the doors with 3-M tape. Right now, I'm leaning toward the solid door. Since there won't be any one flying from the back and not many back seat passengers the observation windows aren't that necessary in my case. The left door came in at 4lbs 14oz as it sits. Not sure how that compares to a steel frame door but it is what it is. Door handles will be a locking "T" handle on both sides. Some pictures:





Last bit of progress to show is the flap handle. I used a flap handle and ratchet from a Pacer. I needed to extend the handle but that was pretty easy. I'll be covering it in leather wrap (think steering wheel cover) to hide the tube extension.



The cable will run above the floor as shown, no room underneath. I'll build covers for all the exposed cables as I move along. Lots done but some long gaps in December and January with little work. I should be pretty steady at it now.

More to come soon,
Marty

Nice work Marty!! Looks like you could sleep in there.

Looking good Marty, Don't forget to place a small drain hole on the inside of the doors at the lower corners of each of those triangles. Moisture has a way of collecting in closed places.

Are those doors going to be conventional or seaplane style? If seaplane, they need a latch down near the bottom so they don't spring out in flight and make a wind noise or water leak if flying in the rain.

Perry,
The doors are seaplane style; piano hinge across the top of the door with a couple of gas springs. The latch system will be next. I plan on a couple of plunger type latches down low on the door. I've got some pictures of other set up that I'm going to work from. The skin for the door is first so I know what I'll be mounting "T" handle.

Marty

Two plungers is plenty if they're located properly. In your door I'd say triangle #1 and #3 (#1 being forward), if that makes sense. Mine are at the upper long. (3 and 9 o'clock) and the door would gap a bit at the bottom in flight. I made a simple rotating latch at the bottom that catches the door frame gusset. It is operated only from the inside so I was REALLY careful to design it so it couldn't become engaged by itself (as in locked out). My left window is a swing-out with plungers and my fat butt isn't going through the baggage door, so I'd be SOL in that situation! Looking good Marty.

Yep, two plungers on my top-hinged Crosswinds Cargo Door, one each fore and aft, about the middle or a little below that vertically. It does fine without a bottom latch. I've never checked to see if the bottom pulls out any in flight, but I've never been suspicious either. For whatever that might be worth - - -

Marty, just as an FYI I only used one gas spring on the door, at the front. No adverse issues. My door frame is 5/8 X .035 square 4130 tube per the Crosswinds STC. Again, for whatever it's worth - -

Gordon,
I have pictures of your doors (thank you) and will be doing the latch pretty much as on yours. The wood frame I built is really strong and rigid so the two side plungers like you have should be fine. As for my comment about a couple of gas springs, kind of thinking out loud about the order I'm placing for the two springs, one for each door. I'll set those up after I get the wood surface on the door and the hinge in place. Building the doors has been very challenging as there is very little in the plans, not even a hint to any kind of latch or handle. Sure am glad you guys post lots of pictures and that this site has a great search function. I made patterns tonight for the 1/8" plywood skin for the door. I'll temporarily attach and than build the latches. I feel like I at least have a firm plan now on finishing the doors.
Marty

Looks like I need some help here on these doors. I am working on the linkage and T handle's, I need some advice. I'm building this from what I can see in pictures of other seaplane doors, nothing in the plans so lots of guessing going on. I attached some pictures of where I'm at. I have a few issues that I need to clear up before I can move forward. First, the linkage rods. I am using 3/16" rods, threaded at the end, with clevis forks at the T handle. I will be drilling through the wood frame for the rod to pass through. The picture shows the intended direction. I will be placing a bushing in the wood frame for ware and support of the rod. I know I need a relatively snug fit through the bushing so the door will hold tight against a rubber seal. Is the rod size of 3/16" enough to be the plunger into the frame to hold the door closed? If so, what ID for the bushing? Is 1/4" ID close enough in size? I made a bushing at .194" as a test but that seems pretty tight. At the rear of the door I will be able to drill through the fuselage door jamb (frame) for the plunger; at the front I won't be able to drill through. There is a 7/8" tube under the fuselage door jamb at the front. I will be making a strike plate for the plunger to lock into and securing that to the door jam. I built the doors with a 1/4" gap between the door frame and the door jamb. The strike plate will only be about 1/4" deep unless I notch out the door frame some for a thicker strike plate; I can do that pretty easily. How deep should the strike plate be? In the pictures below, the front of the aircraft is to the right. If this seems like a bad idea all around I could surface mount the linkage with bushings attached to the fuselage door jambs for the rods to drop into. With the narrow width of the cockpit I don't want to have anything protruding into the cockpit that isn't necessary. I want to put a door panel over the linkage to keep arms and other things out. If necessary, the door panel could be made to cover a surface mounted system but it will take up some interior space. Kydex might work for door panels if I need to surface mount the linkage. I will go with either system. These doors will be covered on the outside with 1/8" ply and than covered with fabric. Upper section will be sliders, everything supported with one gas spring for each door and a piano hinge across the top. So ......... suggestions? It's easy to attach anything I need to the wood frame so all ideas are on the table. Thanks.

Marty

Marty I think you can harden that hole with some thin CA glue instead of a bushing. Drill the size you want and take the CA and soak the wood in the hole and redrill it? Try on a scrap first

Glenn

Marty, my plunger rods are 1/4" 4130 tube. They are split and pinned to the handle bellcrank with 1/16" cotter pins (per the STC), and have a solid nose welded into them where they penetrate the fuselage holes. No problem with stiffness or strength.

Gordon,
What does the plunger go into in the fuselage? On mine, I have a 7/8" tube at the front and I'm reluctant to drill into that tube for the plunger. At the rear, I can go into the fuselage frame about 3/8"; there is a 1/2" tube at that location so not a big issue. I could switch to 1/4" tube pretty easy and still use the clevis forks. I could also weld a 1/4" tube to the 3/16" rods for plunger. Thoughts?
Marty

Marty, I welded in cross tubes (transverse bushings) into the structural tubing after drilling oversize. By matching the structural tube wall thickness, that structural tube isn't compromised significantly. I don't recall right offhand what size those bushings were, but probably 5/16 or 3/8 O.D.? I'm away from home right now so can't go check.

In any case, those transverse "socket tubes" are sized to fit the plunger ends with enough clearance to allow free motion. The solid plunger ends can be reduced in diameter a little bit without hurting anything. Getting everything well aligned prior to and during welding was the hardest part. I expect to be back home tomorrow and can take some more detailed pics if that would help. Problem is, most of the airframe (not door) detail is now covered up.

Not sure I answered that very well - I'd be happy to take some close-up pics tomorrow.

Gordon,
That's what I figured you did. Unfortunately, nothing in the plans so I had no idea that was needed when I welded up the frame around the doors. No way that I can go back and recreate the socket tubes. Guess I'll have to rethink what I have been doing for latches. The pictures I have of your doors show how the plungers go in so no need for any pictures tomorrow. Now I know why every Wag Areo 2+2 has the doors done completely different. I'm stuck; going to have to do something completely different.

Marty

Marty57 said:

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Some random thoughts:
Piper used two 3/16" bolts for the door hinges. The pins are loaded in shear so should be strong enough. 1/4" would be stiffer and more resistant to bending.

The ends of the pins should be tapered to make them more easily slide tightly against the striker plate as the gasket is compressed.

Is there a detente, latch, over center position, springs or some other means of preventing the handle from being inadvertently rotated open in flight?

Should you decide to weld bushings into the 7/8" tube as Gordon suggests, drill completely through, insert a bushing and weld both ends leaving the bottom open. This will prevent pieces of sand from falling off your shoes and jamming in the hole leaving you to wonder why the door latch will not close completely. I don't know about you, but if it were mine this would happen.

The bushings should be large enough to allow some wobble with the travel of the rods. The geometry of the bell crank introduces some angular motion.

The forward rod could be bent with two bends to form an offset. This will keep most of it inside the door except for the end portion which goes against the striker plate. A bushing could then be welded to a flat plate which is screwed to the cabin side of the door. Alternatively in lieu of the bend you could parallel weld two pieces of rod for the offset.

Door seals change dimension over time. Give some thought to possible adjustments to compensate. This is a minor part of the puzzle.