Gear Cover

Step 4 LANDING GEAR COVER

I started the gear cover per plans with duct tape on the recess and pieces of PVC cut and fitted to make up the basic overall shape. I epoxied some extra layers of 3/8" PVC on the ends, on the inside, to make it easier to shape the gear cover (on the sides near where the gear legs come out) without having to bend the foam.

Another shot of the gear cover when still in foam blank state.

Here's a closer shot of the layers of 3/8" PVC I used to make up the brake. In hind sight, I wished I had made this out of thicker foam, but hey, I had the 3/8" laying around and I would have had to wait if I had ordered thicker foam from Wicks.

I used my router with a roundover bit to round the edges of the foam for later when I have to do a layup on the inside of the brake.

My Stanley Shurform plane works great for shaping foam parts like this. Some foams are real easy to sand and not bother with carving, but PVC is sort of rubbery and the plane does a good job of it, and quicker, too.

Here's the gear cover after installing the outside layups. Not too big of a deal, although the corners on the inside of the NACA scoop were pretty tricky.

Installing the boards on top of the gear cover. Again I used hot melt. Quicker and less stinky as compared to bondo.

Here's the gear cover after sanding all the sharp corners round. You can see the micro stripes that revealed themselves after sanding the inside to shape. I used the micro to join the extra layers of foam.

To get a pretty nice edge on the gear cover around the gear legs, I used a contour gage. I know that this intersection gets a fairing later, but, I wanted to make the edges pretty decent anyway.

Here's the intersection of the gear cover and gear legs after final contouring. It's a pretty small gap but it's on the underside of the gear so any hard landing-induced flexing of the main gear legs should move the gear away from the gear cover, not toward it. As I write this though I realize I may need more room on the other side - the side between the fuselage and the gear leg - for just that reason.

Cling wrap installed in the hole in preparation for the inside layup of the gear cover. I used the wide stuff and therefore didn't have to piecemeal this together out of smaller sheets. Don't use stiffer plastic, the cling wrap will need to stretch a bit over all those awkward corners and shapes to enable the gear cover to fit into place properly.

Given the gear cover is non-structural, I decided to use up some fiberglass scraps to make it. If you do this sort of thing right, you can't see that the layup is not made up from one piece of BID per layer. Sure, the purists out there say just buy more glass, but I can't resist being frugal on non-structural parts.

Here's the strips of wetted out glass for the edges of the gear cover. This is where I used the scraps mentioned above. These sort of strips have a tendency to pull apart more easily when made from scraps, of course, but if you make them on wax paper or plastic that's a trivial issue when you install them on the part.

Gear cover, inside layup complete, installed over the cling wrap and weighted down in place. Wait 24 hours and we'll have a gear cover!

After the inside layup cured, it was time to drill holes for the aluminum inserts. No mystery here, mark, check your dimensions, then drill and hope for the best.

Here's a close up of the gear cover, marked and ready for drilling. The MGS epoxy makes a layup that is fairly clear so finding the exact location of the inserts is pretty easy. I still used a square and a ruler to find the exact center of them, however.

Drilling the aluminum inserts for the gear cover screws.

I had one insert that was fairly close to the edge of the bulkhead it was mounted in. To prevent the tap from cracking the insert, breaking the glass or something else bad, I clamped a piece of aluminum against the insert then tapped it. It worked well and I was able to tap the insert without causing any other damage.

After drilling and tapping the holes in the inserts, drilling and counter-sinking the holes in the gear cover, I installed the cover once with all its screws. Really cleans up the bottom of the airplane, doesn't it.

One final shot of the bottom of the plane with the gear cover installed. I think this setup has a lot less drag than with the gear cover not installed!

The landing gear cover is now complete. Axles and brakes are next, but I've only just started on those - click here for that page. The landing brake I have started on click here.