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(From CP30, Page 6, October, 1981)
Ref: Section 1 Page 9-2 and 9-3
Attaching axles to the main gear strut: CAUTION! You must set the toe-in parallel to the WL, not 90 degrees to the strut as several builders have tried to do. The main gear strut should be mounted on the fuselage. A good idea at this point is to stretch a tight wire down the fuselage centerline, at the level of the axle centers. This assumes your fuselage is upside down, with the main gear strut sticking up. Using a rasp or a course file, trim the faces of the strut where the axles will be mounted to roughly give you the correct toe-in. Try the brake plates on, to be sure that they seat flat onto the axle flanges. You may have to file a small radius into the brake plate to get it to seat properly. Now, position the axles on the gear, the flat machined areas on the axle flanges should be oriented close to vertical, and the bottom of the flanges should be approximately 1/2 inch up from the bottom of the gear strut. The brake caliper must be oriented forward and the top (with the airplane upright) of the caliper will be level with the top longerons or W.L. With these parameters, there is only one way that you can install the axle/brake plate/caliper assembly. When you cut the main gear strut to clear the caliper, be absolutely certain that there is a minimum of 1/16" between the caliper and the strut. The caliper must not be able to touch the strut at all, or you can have an intermittent or failed brake. Now, lay-up 3 plies of BID both sides of each strut and mount the axles using clamps to position the axles such that you can place a 24 inch steel carpenters square on the axles as shown on page 9-3 (section I). With the square held In position on the axle, measure from the forward tip of the square to the tight wire, (1/2 of dim.A) and from the heel of the square to the tight wire (1/2 of dim. B.). The difference between these dimensions, (1/2 dim B) minus (1/2 dim A) should be a minimum of 0.1" to a maximum of 0.2". The smaller dimension is better, this is approximately 1/4 degree of toe-in, and will give excellent tire wear. M26MS was done this way and now has over 500 landings on the original set of tires.
Ref: Section I, Chapter 6.
When you assemble your fuselage sides to the bulkheads, be sure to install the firewall first, then the aft seat bulkhead, the forward seat bulkhead, the instrument panel, F22 bulkhead and then F28. If it is done in this order you will have little trouble bending the sides. There may be a tendency for the foam to crack in the area of the aft seat bulkhead. To avoid this possibility, particularly when working in a cool or cold shop, apply local heat with a hairdryer, to the foam. This will greatly reduce any possibility of cracking foam.
Long-EZ Elevator Templates:
Ref: Section I, Page 11-1, step I
A few builders have reported that they have cut the templates accurately, and still ended up with oversize foam cores after hot-wiring the elevators. It appears that perhaps we allowed a little too much allowance for the hot wire burn-down. So when you make your elevator templates, go ahead and clamp them together, and sand down not just to the line, but you should sand virtually all of the line off. Check your templates carefully against the full size drawing on page 11-5. Remember that 2 plies of UND (the skin) will add only .018" to the size of the foam core. Be absolutely certain your foam cores are perfect before you glass the skins.
Long-EZ Pitot tube.
Ref: Section I, page 13-10, step 6
Install the pitot tube so that it runs uphill continuously from the tip of the nose to the airspeed indicator. The easiest way is to run it aft through NG31, then over against the left side, and all the way uphill to the airspeed indicator. The tube can be attached to the fuselage side with a few narrow strips of BID.
Homebuilt fuel/baggage strakes
Ref: Section I page 21-7.
Builders have reported that they built the fuel strakes without installing the wings and when they came to installing the foam block between the wing root and the diagonal rib (O.D.) the top of the strake was too high to fair in nicely with the wing. When you are ready to install the top cover on the fuel strakes, install the wing, and check with a straight edge that you will have a nice fit to the wing. If necessary, trim the O.D. rib down before installing the tank top.
Hot wire templates.
When making identical templates, (canard, elevators, etc.) clamp them together, and use your Disston abrader to sand them to exactly the same shape. This is also valid for canard jigs.
Hot wire cutting the canard
Ref: Section I page 101 step 1.
An excellent suggestion for hot
wire cutting the four foam cores for the canard is to use the outboard templates (no spar
trough) only, to cut all four cores. Then use the inboard templates to cut the spar
troughs on the two inboard cores. Caution: If you use this method you must leave
the cores in the blocks weighted onto your table during the trough cuts. Otherwise, if the
cores warp, the trough depth will vary incorrectly along the span.
This method makes certain that all four cores are identical, and also lets you cut well-defined spar troughs, with no wire lag in the corners.
Paul Burch had improved his balance by gluing a Sears line and surface utility level (around $3) to the beam. This allows you to see when you are getting close with the hardener, and also makes certain that the whole balance is level. Parallax errors are also eliminated.
Worm/Worm-gear retract mechanism.
Some builders have experienced "chatter when extending the nose-gear while static on the ground. While this has never been a problem in the air, due to air loads, it is possible to minimize this by checking alignment of worm and worm-gear and also backlash between worm and worm-gear. If you have fore-aft movement of the worm, add a washer to shim it snug. This will eliminate the chatter.
Wiring from the Wing to the Center-section
Cut a 2" dia. hole in the
outboard bulkheads in the center-section spar, opposite the point where the wiring comes
Inboard through the hot wired holes in the wing cores. Mike bought some pin male and
female plugs and sockets from Radio Shack and wired nav. lights and strobe lights through
these plugs and sockets, breaking the wiring bundle a few inches inside the
center-section spar. This enables you to reach in through the hole in the bottom of the
center-section spar, and pull the wiring bundle down and out so that it may be
disconnected in order to remove a wing. The comm. antenna(s) should of course also have a
BNC connector at the same location. Mike ran his Nav/strobe light wiring bundle out
through the wing, together with the comm antenna coax and has no perceptible interference.
All this wiring is now brought inboard through a hole cut in the CS6 and CS7 bulkheads (a
1" dia hole is fine), and then inboard to just inside the fuselage sides, at which
point you can drill up to a 1/2" dia. hole in the forward bottom of the spar
box, and run the wiring down through these holes into the area aft of the back seat
CAUTION! Do not drill through the lower spar cap.
The transponder antenna can be mounted under the front seat thigh support, and this is where quite a lot of builders have located it. However, Jim Weir of Radio Systems Technology has cautioned that it may be possible that high-powered microwave energy may be radiating in very close proximity to a rather sensitive part of the pilots anatomy. To put it bluntly, it may be a little like sticking your fanny into a microwave oven! In any event, no qualified person to our knowledge has tested this, so it may be prudent to laminate a sheet of aluminum foil under the thigh support. Microwave energy will not penetrate the thinnest of metallic foils.
Now have brushable
"Spray-Latt" canopy protective material in stock. They also carry the full line
of VDO instruments and still have the Whelen strobe/nay light system (single flash) for
Prefab 500 x 5 wheel pants, are now available from Aircraft Spruce and Wicks Aircraft. Hardware kits to install these wheel pants are also in stock. Instructions for installation of the 500 x 5 wheel pants are essentially the same as for the 3.40 x 5 wheel pants, except that 16 K1000-3 nut plates should be installed evenly spaced on the flange, instead of 11. .062 thick 2024-T3 aluminum is substituted for .032 for the mounting bracket. See CP 28, page 10 for these instructions.