Cabin Doors and Windows
Initial Cabin Cover Flange Trim
The doors come with four alignment holes around the windows and two in the lower part of the door for alignment to the fuselage. In theory, you drill the holes on the two door halves and when joined, the doors will be properly aligned. Problem is that when the two door halves are brought together, none of the alignment holes align. Apparently there is quite a bit of slop between the two door halves. I used the two lower alignment holes which were pretty close to matching and then set the two halves together from there. I brought the door halves together during cabin cover install(sec 43) to facilitate my trimming of the cabin cover door flange. This was done with the cover off of the airplane to keep the dust away.
Rear Window Install
The work shown in the following table was performed during cabin cover install in section 43. I drilled the hinges early so I could close off the interior area where the bolts project through. See the Cabin Cover Modification page for details of the close out. I installed the rear windows with the cabin cover off so I could use gravity as my helper since I did not have any assistance. I tilted the cover up on its side so a weight could be applied to the window. I masked the interior and exterior areas of the cover and the entire window inside and out except for where the adhesive needed to be applied. I roughed the window with 400 sandpaper and the cover with 60. I only cleaned with a tack cloth and did not use any chemical cleaners. I mixed the Weld-On in a zip lock bag, cut the corner and then spread a bead around the mounting flange. I placed the window on the goo and weighted it down. I wiped off what little excess there was that squeezed out and then duct taped the window in place to cure. I waited about a half hour and then removed the interior tape. I did not have enough adhesive ooze out to make a good interior bead so I will need to apply more with a syringe. The one kit of weld-on was slightly too little and I was left with a small gap in one area. I plan on filling this with a syringe once the other window is installed.
Left Window fitting.
After glue set.
Door gluing is absolutely a two person job. I used a total of 20 pumps which is about 16 oz of epoxy - more than the 10 oz that Vans
calls out in the plans. Remember that most of the flange is going to be cut off in door trimming so you only need to epoxy the inner
portion of the door and window flanges. The procedure I used is as follows:
- Person1 mixes 2 pumps and gives to person2 for wetting bonding areas
- Person1 mixes 4 pumps and wets the parabeam
- Person1 mixes 4 pumps in one container and 4 pumps in another container for Cab-o-sil mixing.
- Person2 mixes remaining wetting epoxy with 2 more pumps for Cab-o-sil mixing
- Person1 is spreading cab-o-sil on bonding areas
- Both people place door halves together and cleco/clamp to airplane
- Clean up excess with Acetone
Clamped for Gluing.
After Initial Trim.
With the door held in place by just the fore and aft cleco, I used an edgefinder tool I made to trace an outline of the door frame on the outside of the
door. I then used a cutoff wheel to get me within about 1/4" of that line. The rest was taken off with a belt sander. I used a sanding block to
make a 45 deg angle on both the cabin top and door edge. The angle was set using a gauge that I made from wood. The door was trimmed from the top down.
As I made progress in seating the door,
the cabin top door flange would have to be relieved
in some areas. In essence, you are hand carving the door and cabin opening. The entire trial and error process takes about 10 hours per door.
I stopped before doing the bottom edge and installed the hinges. Then I completed the bottom edge.
After the door would seat pretty flush, I moved
on to the frustrating task of installing the latch and pin mechanism. The pins have to be precisely bent to the contour of the door to prevent
binding either against the door or in the pin blocks. I found at least one pin too short and I will have to make a longer replacement. I also
installed bronze bushings in the door pin blocks for smoother operation.
The next stage of door fitting was to match drill the door latch pins to the fuselage. Once this was done, the doors pulled in a little
more and I had to re-trim the interior flange. Then I took the flange in a little more to allow for door covering that I will be adding
later. The total time on this section from start to having doors that can close and be latched with a proper gap is 95 hrs. I still have
about 10 hours of exterior build up work to do for a consistent exterior fit.
45 deg Gauge.
After Initial Trim.
The locks I used are exterior rated and are available from McMaster Carr as part number 13105A75. The locks can be set for 90 deg or 180 deg
action and come with three different lenghts of cam latch. The hole is 0.625" tall by 0.750" wide.
I made a reinforcement plate from 0.060" sheet and bent the end up so it would butt up against he lock mechanism. That helps prevent rotation
when a locked door is attempted to be opened. The reinforcement/anti-rotation plate is also blind flush riveted in place. That provides a
pretty strong foundation for the lock. The bolts holding the lock are a temporary fastener. I eventually replaced them with a flat head screw
and a fiberglass stainless washer on the exterior of the door. It was pointed out to me that I have the nut plates mounted backwards. They should
protrude into the latch mechanism(outboard), not inboard.
Door Open Unlocked
Door Closed, Locked
Gas Struts and Door Windows
I had Thanksgiving week off and put in about 35 hours on the project. The Gas Struts were installed after modification of the upper bracket to
lower the piston pivot point. The window install was the same as the cabin side windows and I used the recommended weld-on. I had no problems. When
the glue cured, I covered the seams in fiberglass strip and then went over that with Super-fill. Another feature I added to the doors is a limit switch
to sense the rear door pin. This is different than the sensor that comes with the kit in that it's sensitivity is adjustable and it does not have a
magnet to confuse the ships compass and magnemometer. I fabricated cover plates for the latch pocket, pin blocks and hinge pockets. The interior lip
of the doors have been painted. The last thing I have to do is fabric cover the door interiors and then I will be done.
Door Pin Sensor
Final Fit Check
Finished Door Interior
The windshield install is being defered to a later time. I am going to wait until I have some panel work done before I install the
upper forward cockpit.
This section of the plans took longer than building the wings or the tail kit. These doors are the most BLEEP design I have ever BLEEP seen. I would
like to meet the BLEEP that designed them and BLEEP his BLEEP. BLEEEEEP. BLEEEEP. At least it is over and there is no more fiberglass work to
do...well except for the cowl, spinner, windshield install, gear pants and gear leg fairings.