Chapter 9 - Step 6

This step involved the building of the landing brake in the bottom of the fuselage. Mine will be different by making use of Wayne Lanza's electric landing brake motor in place of the manual system outlined in the plans.

Removal of brake May 21, 2001. Here I have just removed the landing brake from the bottom of the fuselage. This step was easier for me because I cut the glass around the brake when I glassed the bottom of the fuselage while it was still wet. You can also see duct tape covering the foam. This extra tape helped ensure I didn't glue the edge of the brake down with excess epoxy while doing the bottom.

Foam Removed for LB-19 May 23, 2001. Here is the landing brake after removing the foam to accomodate LB-19 and the hinge. The forward edge has also been trimmed so it doesn't cover the hinge pin.

LB-23 and LB-19 May 23, 2001. LB-23 and LB-19 are glued to the hinge. The slugs are in position on LB-23. One has been removed as a reminder to move all of them. After all was put together I realized that the slugs needed to be moved closer toward the edge of LB-23. In the location described in the plans, the screws through the hinge would have been at the edge of the slugs instead of in the middle. No big deal to rip them off and reglue them in a better position. At least I checked that fit before LB-23 was glued into the fuselage bottom.

Per the FAQ, I made LB-19 1/2" wider to accomidate the wider spacing of the LB-18s. As it turns out I should have made it 1" wider toward the outside. It appears the new mount moves the brakets even further toward the outside.

LB-23 and LB-19 May 23, 2001. Here is another shot of LB-23 and LB-19 glued to the hinge. Following the FAQ I used 3 layers of Duct Tape instead of the 1" square thin Aluminum called for in the plans. Worked just fine.

LB-23 Slot May 23, 2001. At first I couldn't quite get a grasp of how the slot for LB-23 was to be cut out. After rereading the plans for the tenth time I started to put all the geometry together. The first thing I did was ignore the part about drilling two holes 2 1/4" aft of the front seat. I looked back in chapter 6 and was reminded that the front edge of the brake was 2" from the front seat. This easily gave me the location of the hinge pin without drilling holes and sticking nails in them. Next I dug out the Dremel tool and set it on a 45° support and routed out the foam. I had a perfect fit for LB-23, the spacer, and the hinge. I made the extra grooves for the slugs. Later I realized that the hinge was mostly imbedded in the same slot so I cut away more foam aft of the slot so I could get to the hinge. Now I realize I could have cut away much less foam and glass for the slugs. Oh well.

LB-23 and LB-19 in Position May 23, 2001. After all that work getting the slot just right I finally positioned LB-23 in position. The top (or is it the bottom) of LB-23 is flush with the glass around it (which is slightly depressed from the fuselage bottom).

Depression After 1/8 inch May 24, 2001. It took way too long and made quite the mess making the 1/8" depression in the landing brake area. One issue I had to deal with was the fact that the yellow foam has a layer of micro on it from chapter 6. This made sanding very difficult so I resorted to more serious methods. I used a router (big mess - sent foam dust everywhere) where I could. Then I used a Dremel with the router like attachment. Finally I used sanding block and paper to finish it all. After all the areas where made 1/8" deeper I used a sanding wheel on the Dremel to round the fiberglass edges. I think I will be shaking foam dust of my clothes, hair and inner ears for a while. At least I wore a mask and goggles.

Gluing LB-23 May 26, 2001. Here is the brake after gluing LB-23 into the fuselage bottom. The boards are hot glued to the brake to ensure it is even with the fuselage bottom.

Note: I did all that routing and sanding before gluing this in place. Not a great idea because this made it harder to ensure the brake is positioned correctly. I should be OK but it would have been more obvious had I glued this in place before removing the 1/8". Gee, that is the order stated in the plans. Duh! Actually I did it this way because of time and the fact that I needed to clean my epoxy pump and get fresh epoxy after my eight month hiatus.

Initial hole for brake May 27, 2001. Since I am using Wayne Lanza's electric landing brake mechanism the plans dimensions for the slot in the fuselage bottom don't apply. I spent a few hours figuring out the best location to mount the actuator and how big and where the slot needs to be. I did this three times. Each time I discovered I had some critical dimensions wrong. One I had the right dimensions I drew the locations of: hinge, LB-18 mounting hole, seatback, map pocket, seat back brace, fuselage bottom. I drew where LB-18 would be closed, at 60°, and at 70°. I drew an 8.25" arc from the closed location (actuator at its shortest) and 12.25" arcs from the 60 and 70 degree locations. Where the arcs intersected would be locations to mount the actuator. I decided to go with the 60° location. I figure this is plenty of brake and it puts the mounting location of the actuator in a better place. I also made sure I wouldn't be mounting this in the map pocket. It's close but just below it. Lastly I figured out the size and location of the slot.

Final hole for brake May 27, 2001. After all the calculations were made I figured the slot needed to be 2.5" long and 1" wide. The forward edge is about 3.5" aft of the hinge center. The edge closest to the fuselage centerline is 0.75" from the seat back brace. I cut this out using the Dremel (Above picture). After this I figured I needed to cut the foam out in a 1" perimeter around the slot. After that I angled the foam back a bit as directed in the plans (As shown in this picture). After test fitting everything I decided I needed to widen the aft half of the slot to fit more of the actuator. Everything is now ready to be glassed.

Glassing the Brake June 2, 2001. Here is the landing brake all glassed with three plies of BID. The peel ply is where the LB-18s will go. It's hard to tell but if you look at the hinge you can see the corner has been rounded a bit. This is a result of making clearance after glassing the brake depression in the fuselage bottom.

Brake settting up June 2, 2001. It only took about 2.5 ~ 3 hours until I needed to knife trim. Here is the brake screwed into place in the fuselage with some boards ensuring nothing is sticking above the bottom surface of the fuselage.

Completed Brake - Forward June 5, 2001. This was the final installation of the landing brake.

Completed Brake - Aft June 5, 2001. The brake is in its fully open position. This worked out to be 60° I'm hoping that is enough. Getting much more than that required the actuator to be mounted in a less than ideal location.

After getting all this installed and working I went to the house and made my wife come out and see the first moving part on the plane. She seemed to be thrilled but I'm sure she was just making me happy. :)

After she left I took it all apart and set it all away until the plane is ready to be finished.

Actuator Arm June 5, 2001. A close-up of the actuator arm and its mounting to the brake. I made LB-19 to be 0.5" wider as suggested in the FAQ. That was barely enough. You can see that one of the LB-18s is right at the edge. I recommend making LB-19 1" wider on the side of the actuator to be sure.

And no, that is not a dent in the arm. It's just the flash reflecting off of it.

Actuator Mount - Right June 5, 2001. Here is the actuator mounted to the seat back brace. I added a four ply BID layup under the bracket to add some strength. I also mounted the bracket to be more perpendicular to the actuator as opposed to parallel to the fuselage bottom. The main reason is the latter would have caused interference with the map pocket.

By the way - I found testing was made easy by using a standard 9V transistor radio battery to power the actuator. No need to run a bunch of wire to the car battery. I wonder if I could rig up the little battery as a backup in case of real electrical failure during flight someday?

Actuator Mount - Left June 5, 2001. Here is the other side of the seat back brake. I also added the four ply BID reinforcement to this side as well.