24 Hrs – Ch 14 – Main Landing Gear Cover

LG Cover Foam ShapeThe shed is complete, and took far more work during a busy summer than I was expecting.  While I’m waiting for control bearings from the Cozy Girrrls, I decided to build the LG cover.  I decided to take the Wayne Hicks approach to building this, for two reasons.  I won’t have to worry about the slugs in the LG bulkheads, and it was a very nice transition from the fuselage to the cover.  Since the indentations for the cover recess was already built into the fuselage, I didn’t really get to take advantage of the latter.  I started by cutting 2″ Styrofoam to fit into the LG cavity.  One sheet wasn’t thick enough to cover the NACA scoop, so I used some pour foam to glue two pieces of foam together.  I hot glued some wood scraps inside the LG bulkheads to support the foam while sanding.  I sanded the NACA scoop to contour, and the protruding foam to the same level of the fuselage.  Removed the foam, and added 3 layers of duck tape to the edges to match the thickness, and for release of the fiberglass.

LG Cover 1st LayupLG Cover 2nd Layup

 

 

 

 

 

Micro’d the foam inside the NACA scoop and covered with 2 ply BID and peel ply.  After cure, I micro’d the rest of the foam, made flox corners, and covered with 2 ply BID and peel ply.

LG Cover with Wood Foam Keeping StructureUsed a hack saw blade to get between the fiberglass and the packing tape to release.  Left the peel ply on and hot glued boards across the piece on the peel ply to hold the shape.  Peeled back the peel ply along the edges to mark the cut line.  Removed from the opening and started removing foam to 3/8″ as Wayne Hicks calls for.  I had to trim the cover at the leg openings so the cover would fit once the gear was installed.  I started by installing the MLG and putting the cover on until it caught on the gear leg.  I set a compass to the same distance that the cover was protruding, and used it to transfer marks on the cover, using the pointy end to follow the gear leg.  Turned out to be a simple technique, but one that is difficult to describe.  Continuing with Wayne’s method, I removed 1″ all around and sanded the fiberglass in preparation for glassing.  Using the compass for marking the 1″ proved to work well too.  Finished the night by rounding the foam edges, and the piece is ready for glass.

LG Cover Back Side LayupAdded 2 layers of fiberglass to the inside of the LG cover by wetting two layers on plastic and transferring to the piece.  If I had it to do over, I would have applied each layer separately, since all of the compound curves and angles made it very hard to get 2 layers to lay down properly, without air bubbles.  After getting all the bubbles worked out, I added a 2 BID strip around the area where the screws will fasten to hold the cover in place.  I did not run this all the way to the edge, as I was worried how the extra thickness would affect how it seated in the joggles.  Peel plied the edges and left for cure.

Trimmed the layup, removed the forms, and double checked for fit.  Snug fit, but I think OK.  Removed the gear bow and reinstalled the cover.  Hot glued some Popsicle sticks to hold the cover on.

LG Cover Mounting LipTurned the fuselage over, and sanded the forward and aft LG bulkheads for glass.  Cut some 2″ pieces of 2 layer BID on plastic and added in the corners of the inside to create a lip for the LG cover to rest on.  3 strips on the front and back bulkhead edges, for 6 total layers on each.  Finished with peel ply.

 

 

LG Cover Flange with LG CutoutsRemoved peel ply, turned the fuselage over, removed the cover, and trimmed the layup to 1″ width.  Smoothed the edges and added the cutouts for the LG.  Started measuring for where the nut plates will be installed.

Drilled out all the holes for the LG cover, and all the rivet holes for the attaching the nut plates.  Have to wait for the countersink to come in the mail, as I need these rivets to be LG Cover Completeflush.  I was able to use the countersink I had on the LG cover for the screw holes.

Received the countersink and riveter in the mail.  Countersunk all the rivet holes and installed all the nut plates.  Tested the cover for fit.  A-OK…

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About Tarmac Grazer

I have recently purchased Cozy MK IV Plans #1627, and will be using this blog to log my build progress.
This entry was posted in 09. Main Gear & Landing Brake, Uncategorized and tagged . Bookmark the permalink.

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