QuickTalk 9 - QUICKIE HINTS
- Category: Q-Talk Articles
- Published: Saturday, 30 April 1983 07:11
- Written by Jim Masal
- Hits: 2246
From Don Larson, #198:
1. I took sound advice and put a suicide spring on my throttle arm. That very day, due to poor engineering, the throttle wire broke. Sure was nice to have it at full power instead of idle! At about 3500' over the strip I cut the switch and the fan stopped at about 80 MPH. Would be interested to know if anyone has tried restarting with airspeed. Due to a timid nature, I would prefer someone else try it and let me know!
From Harry Daymond, #461:
1. (Page 7-8) Be sure to keep your main waterline marked on the plane as you will need these measurements for building the aircraft and later to do weight and balances.
From Vic Schatz, #317:
1. The trailing edges of the flying surfaces will have a "ditch" which must be filled with dry micro. This is not brought out in the plans.
From Harold Little, #147:
1. (Page 10-6) It is required that one UNI and two BID be applied to the canard stiffener groove and that the stiffener by installed on top of the plies. As one UNI is 0.009" and two BID are 0.026", the glass will only be 0.035" thick. If the groove was cut with 0.035" diameter safety wire, then the burndown of the foam stiffener will be such that the foam will be well below the canard surface upon cure. As this area will be flexed considerably upon landing, it is not advisable to fill the area with micro, as it may fracture. Rather, build up the foam stiffener with scrap blue foam prior to the layup. The excess foam is readily sanded to contour with no excessive sanding.
2. (Page 9-1) The whole wing fabrication was a ridiculous exercise, especially turning the worktable over to glass the shear web. The problem occurs when constructing the wing shear web in the aileron-cutout area. The web, in a "U" shape, must make a 90-degree turn, forming a flanged rib outboard of the aileron. However, making that 90-degree turn causes the glass shear web tape to bunch up in the corners. Consider the following instead:
First, glass the shear web on the inboard wing foam cores separately and glass the rib on the inboard end of the outboard wing cores. (These pieces can be supported in any way the builder sees fit during glassing.) NOTE: The rib does not extend any closer to the trailing edge than 2" from the finish trim edge. The rib DOES extend to the maximum core thickness, or 2" beyond the shear web flange for construction purposes.
After cure, jig the wing in the supports and join the cores using the standard plans procedures. Add two 4" BID tapes to the vertical face of the shear web and rib.
Next, add two 8" BID 45-degree tapes over all butted faces (wraparound top and bottom). To ensure the required torsional stiffness, extend the "C" and "H" spar caps by 4" overall to allow an additional two inches outboard of the rib. This will reinforce the joint between the two flanges and maintain the original integrity.
From Fred Eckel, #1024-Can.:
1. Buy a Dremel type grinder before you start your project. You'll end up using one before you're finished and will probably kick yourself for trying to get along without it.
2. All builders near completion should advise new builders to peel-ply all areas that will need later bonding. Obviously, we all missed many spots at the start because we did not know enough about the project to determine where these spots were. A mission of mercy would be to identify all locations in their plans.
3. (Page 15-1) A recent challenge was to cut the canopy. The dimensions given in QPC #7 to supplement the plans were not even close for my canopy. Consider trying the following steps: Using an adjustable protractor or rafter square, determine the angle between the longerons and headrest. Invert the canopy bubble (on a carpet) and lay a board across the opening perpendicular to the sides. Place the protractor (set with the previously measured angle) on the board, with the blade pointed aft. Verify that your aft canopy bulkhead has the same profile as the seat back bulkhead. Place the aft canopy bulkhead inside the bubble with its straight edge along the board, the center bar aligned with the protractor blade and its circumference touching the bubble. Mark the arc where the circumference touches the bubble. This is the aft cut line and the final location of the aft canopy bulkhead. Tape and cut as per instructions. With the forward fuselage cover removed, place the cut bubble on the longerons and verify that the aft cut is correct. Trim as necessary. Remove the bubble and tape a stick across the open aft end for support. Put the forward fuselage cover back in place. Measure the vertical distance, at the location of the instrument bulkhead, from the top of the longerons to the top center surface of the cover. Invert the bubble as before and lay a board across the opening near the fron end. Mark the "nose" point (BLOO) at the spot where the distance from the board to the canopy equals "a". Turn the bubble right side up. Place the left canopy stiffener along the canopy border with one end of the stiffener even with the aft canopy cut. Mark the position of the other end on the canopy border. Repeat on the other side using the left stiffener again. Using a flexible ruler, join the side point with the "nose" point. This is the forward cut line. Tape and cut as per instructions. Cut off the side pieces at the canopy border as well. Proceed as per plans, mid page 15-1 "The canopy must be ft to your aircraft..."
From Robert Godbe, #397:
1. I recently flew to Mojave and got Gene Sheehan to go over my plane. He gave me several ideas on cooling and "cleaning it up". At his suggestion, I opened my cooling outlets quite a bit, but I'm still running hot, especially the left cylinder. Gene took one look at my exhaust pipes, marched into his hangar for a hacksaw and ten minutes later my pipes were 3" shorter. They now jut out of the cowling only about 1/2". This helped. On my way back home, I was about 1-2 MPH faster. My carb heat bump on the cowling had a flat frontal area. He had me round it for better flow. Next, be sure the cowling flairs nicely into the fuselage. If necessary, add glass to insure a smooth transition. For some reason, I had never filled the bottom trailing edge of my elevators. It still had the hot wire "lip" on it. He had me fill it up with micro. All totaled, I've gained about 5 MPH.
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