Oct 04, 2023     Seats       Category: Fuselage

Started with the original seat base that came with the airframe. I modified it by fabing anew seat back frame that was about 5” taller than the the original. I also enabled the seat back to be tilted forward with a release latch and pivot points.
Next thing was to cut a base from 1/4” plywood and a back from 1/8” plywood.
I cut 4” high density foam for the base and 2” med density foam for the back.
I got some remnant fabric from a fabric shop for a discounted price and covered the seats.
The fabric was attached with contact cement to the underside of the plywood base and back.
Same process used for the back seat.

  Sep 11, 2023     Rear sear       Category: Fuselage

I decided to start on some odd jobs that usually get left until last.
Rear seat is only 2 cross bars and a curved back bar. Time for some innovation.
Sorted through my surplus plywood and found some 1/4” birch big enough to become a seat bottom.

  Oct 06, 2022     Fabric coating       Category: Fuselage

Forgot to document the whole process with pics. This work was done in a couple of days in July, 22.
After glueing the fabric and trimming the excess, the shrinking process is done in two stages.
Next step is to apply the first coat of silver Hipec Sunbarrier with a firm foam roller (with vigor) to fill the weave completely and avoid pinholes.
After this 1st coat of silver, the inspection rings are placed while the coat is still sticky.
The product cures with humidity so spraying down the floor in advance not only keeps the dust down but speeds up the curing.
After inspecting for pinholes (and not finding any, fortunately), I proceeded with spraying on two cross coats of Sunbarrier. The rolled on coat was done in the morning and the spraying was done in the afternoon.
Next day cross coats of white were sprayed in the am, followed cross coats of yellow in the early pm. Done
Being my first try at covering and spraying, its got some flaws and blemishes but I think it will still fly.

  May 01, 2022     Fabric       Category: Fuselage

  May 01, 2022     Fabric       Category: Fuselage

Fuselage exterior, big job, big learning curve.
On the first side I attached the fabric along the bottom center stringer. That created a problem when wrapping the side and top.
Excess fabric appeared and some extra cuts and lap seams were needed to get a smooth cover.
The second side was better. I layed the fabric on the side of the fuselage and used clamps to position everything before starting to glue things down. Worked out much better. Had some help from my son for a day.

  May 01, 2022     Fabric       Category: Fuselage

Cabin interior fabric, lots of cutting and fitting

  Oct 10, 2021     Floor boards       Category: Fuselage

Second try to get the floor boards cut and fitted properly.
I used 1/4 birch G1s plywood for for the floor boards. Sides are 1/8” birch. Pictures are before staining and clear coating.
I will be doing fabric on the interior of the cabin (ahead of the baggage compartment). Still pondering if the sides should be hidden behind the fabric or installed after fabric to provide some protection. I'm leaning towards having them exposed to protect the fabric.

  Oct 10, 2021     Baggage compartment       Category: Fuselage

Floor is 1/4” plywood, sides are 1/8 “ birch. Light coloured stain and 3 coats of clear looks nice. I added a few tabs with nutserts in strategic location to secure and support the sides and bottom.

  Sep 26, 2021     Windshield base flange       Category: Fuselage

Aug 24– fabbing a windshield/boot cowl attach strip from fiberglass. Covered the windshield and boot cow with masking tape and also clear packing tape. Cut several strips of woven glass, starting with narrow and progressively wider until final strips were about 3-4” wide. I saturated the strips one at a time and layed them in position in multiple layers. The last layer was the wides and covered all the edges of the previous layers. I think I ended up with about 5 layers. After setup, it was removed and trimmed to the desired width and then the sanding, filling, sanding filling procedure started. Looks ok in the end, probably need some final prep before painting. Still need to drill for attachment screws into windshield and boot cowl.

  Aug 14, 2021     Windshield Category: Fuselage

August 2021. With the boot cowl finalized, now the windshield can be fitted. It does not extend far enough to attach at the front of the birdcage. A another channel is welded in place ahead of the front birdcage channel. This provides the support to attach the top of the windshield. Nut plates are plates installed. With windshield positioned in final location, attachment holes are marked along both sides and across the top. The holes are carefully drilled in the plexiglass using a step drill. The holes are drilled oversize for the #8 screws. This allows for expansion/contraction of the windshield as temperature changes. Nylon washers to be used under the washer-head screws to allow for movement.

  Aug 14, 2021     Firewall       Category: Fuselage

May 2021. Firewall will be fab'd out of .026 galvanized sheet steel sourced from the local sheet metal shop. I started with a piece of 3/4” MDF cut to shape and drilled to fit the engine mount holes of the fuselage. The sheet steel was cut 3/4” oversize around the perimeter and bolted to the MDF form, The firewall plan includes some stiffener ribs to provide some rigidity to the otherwise flimsy sheet. To form the ribs I cut grooves in the MDF with a router. With the sheet positioned and secured to the MDF, the ribs were formed with a 1/2” round pipe and a sizeable hammer applied with vigour.
Ear protection preferable for this procedure.
Next step is to bend a right angle flange around the perimeter of the firewall. This requires some relief notches at the corners to get around the curves. The corner notches were backed up with a 3/4” metal strip that was tin soldered in place on the inside of the corners.

  Aug 14, 2021     Boot cowl       Category: Fuselage

August 2021. Before final fitting of the windshield the boot cowl must be in place. The boot cowl will be made in 3 pieces, 2 that join at the top and go about 3/4 down each side, and 1 piece across the bottom and part way up each side. I started with oversize .030 aluminum sheet, it heavier than required but its what I have so it will work. I shaped it by using the oldest technology, brute force.
Lots of test fitting and adjustment, but with enough persistence it takes shape and looks acceptable in the end. Next is to measure, mark and drill for #8 screws. Last step is to install nut plates get on the firewall flange, the fuselage side channels, and the overlapping joints for the 3 peices.

  May 01, 2021     Throttle levers       Category: Fuselage

Now that I have a sea plane door on the left, the throttle levers have to find a new location. I used the existing levers and connecting link and mounted them lower so the top of the levers are about even with the bottom of the door. Mock-up of the location seems like it will be workable.

  Apr 10, 2021     Winshield       Category: Fuselage

With birdcage and stringer in place its time to tackle the windshield support structure.
I fabbed some z strips from .035 AL for the forward cabin post/upper door junction. The upper door will close against the inner flange, the windshield will be sandwiched to the outer flange. The z strip will be attached to the post with pull rivets.
I formed some 3/8” tube to take the shape of the leading edge, then welded them to the birdcage on top and the cabin post below. These will support the top part of the windshield curve. The windshield was test fitted and it looks like it will fit with a bit more adjustment.

  Apr 08, 2021     stringers       Category: Fuselage

with the birdcage in place now its time to work on the top and side stringers. I am using 1/2" AL tube for the stringers. It will be attached to the arches with a 1 inch long section of 1/2 round steel tube (sized to the OD of the AL tube) The 1/2 round bracket is tig brazed to the side and top arches and tig welded to the side of the fuse where there is more substantial tube to tig weld to. The AL tube will be attached to each bracket with a pulled rivit from the inside of the fuse. The arches were inplace when I got the fuse but some of them were less than perfectly aligned. I spent a lot of time trying to get things to line up and had to cut and adjust in a few places. One arch was completely re-made as it was beyond adjusting. In the end I was satified with the alignment overall, it should be acceptable with the fabric in place. The cut and fit method doesn't look very pretty but most of it is covered so I will live with it.

  Apr 08, 2021     bird cage       Category: Fuselage

with the wings in place, its time to tackle the birdcage structure over the cabin. I fabed up some 3/8 x3/8x3/8 channel from 22 ga CRS. Its a challenge to weld so I tried tig brazing which worked better. Got the structure lined up and tack brazed in place but the finish brazing will have to wait until the wings come off and I can rotate the fuse for better access for tig work.
I am planning for the upper structure to be a covered with tinted lexan. I plan to use clear lexan for covering the upper and lower doors as well as the side window.

  Mar 22, 2021     Doors       Category: Fuselage

Feb 2021 Using 3/4” square AL tube for door frames. Started with a AL tube added to the top door openning with a steel bracket welded on the front and rear uprights. Sections of piano hinge attached with pull rivits for top and bottom hinge.
Nylon inserts for the lower door latch pins to engage. Upper door closer engages the lower door.
AL welded using a spool gun, my first effort at AL welding. (If I was a better welder, I wouldn't be as good a grinder).
First design of latch handle was abandoned, 2nd design should be easier on the fabric where the latch touches when doors are left open.

  Jan 21, 2021     Trim system       Category: Fuselage

Dec 2020
With addition of seaplane door, now i need a different location for the elevator trim crank and indicater.
Cable was re routed to top of the cabin. This required two pulley brackets to guide the cable from the back to the front and a mount welded to the top x brace for the crank pulley.
April 2021 with the birdcage fabbed and mounted, now the top guide pulleys stick up above so thats not good.
I removed the original mount and rearranged it to a position below the top of the cage. I had to also move the crank pulley to the underside of the x brace, no problem with that. Next I had to relocate the intermediate set of guide pulleys to align with the upper guide pulleys. After all this the endless trim cable was too long. The only solution I could dream up was to add 2 to more pulleys in a z formation to take up the slack.
Later in April:
not happy with the trim, too much slippage even with the cable tighter than seems reasonable. New plan. I have one double groove pulley, and two single groove pulleys. I mounted the double groove pulley at the rear on the jack screw. I then mounted tthe single groove pulleys at the front on the crank. Now the cable is too short so its time to relocate the crank pulley rearward. This requires a tube welded in location between the top x-brace structure. Some mock-up effort required to find the correct location. A small idler pulley was added to direct the cable from the top groove to the bottom.
At the jack screw, an adjustable idler pulley was installed to allow for cable tension adjustment. The former z bracket was removed and a new piece was welded in to provide a bracket for the adjuster.
The system now works much better, and cable does not required excessive tension so cable stretch should not be an issue.

  Jan 21, 2021     Rear fuselage fittings       Category: Fuselage

Dec 2020
Tail post bottom bracket for tail spring attachment.
Elevator control access fittings for inspection cover
Trim cable tension pulley brackets
Grab handles on both sides of lower longeron

  Jan 21, 2021     Float fitting       Category: Fuselage

April 2020
Floats in south central Alberta? Probably just dreaming, (no water around these parts). Anyway its easy to do at this stage.
Some pics done later thats why they are primed.
Well if its going to be on floats might as well have a seaplane door.

  Jan 21, 2021     Wing mount brackets       Category: Fuselage

Nov 2020 Front wing spar mounting brackets positioned and tack welded.
Step one was to build a fitting that matched the spar mounts of the wings, it was then used to locate the front spar wing mount brackets. I will find out how accurate it is when it comes to mount the wing.

  Jan 21, 2021     Front X braces       Category: Fuselage

April 2020
Fitted the x brace from front top FW corners to cabin front corner, the cross tube at front of the cabin will be removed to make room for the instrument panel.
Fitted the x brace from FW corner to upper front spar cross tube corners.

  Jan 21, 2021     Top x brace       Category: Fuselage

April 2020
Front spar cross tube fitted, x brace between front and rear cross tube fitted,
All tack welded

  Jan 13, 2021     New tubes       Category: Fuselage

Aprill 2020: After removing the old upper structure i started with new tubes inserted into the structure at the rear spar, heat was applied and the new tubes bent down to parallel ( almost) the upper longeron ( which will be removed later for the door openning)
The front spar cross tube was fitted, then the corner uprights and the top x brace. These are all tack welded after much measuring and adjusting to get things squared up.

  Jan 13, 2021     Remove the bits and peices       Category: Fuselage

The airframe was fairly complete including all the controls brakes, rudder pedals, front seat, and floor boards.
All of these were removed to get it down to bare bones.

  Jan 13, 2021     Getting started       Category: Fuselage

Feb 2020: first thing is to get the airframe down from the ceiling. It has been here for several years quietly waiting its turn.
I built a crude but effective rotisserie on wheels to ease the work ahead. The airframe started as J3 but i am changing it by converting the upper structure to PA18 style with front spars attaching at outside of the upper structure rather than in the center as in J3.
The change involves a new front cross tube to attach the spars, new uprights at front corner of the cabin, an x brace in the top, an x brace from the top firewall back to the mid cabin front corners and a x brace from the top front cross tube to the top firewall corners.