Helpful Hints For Air Ducts and Control Horns

Installation instructions for the Dale Built air ducts:

Most pilots prefer their duct to be painted the same or a contracting colorto the cowl.  We recommend you paint the inside of the duct before mountingit in the cowl (after step 5).  No wax was used in releasing the part fromthe mold but wet sanding always promotes better paint adhesion.

If you have no visual access to the needles of the carburetor it will not hurt to drill a 1/2" hole to the left of the crankcase about the middle of the bottom of the duct.  With a flashlight it is possible to see the needles through this hole.

1.  This duct is universal and is made for both left and right cylinder forward engines. Extend the rear line of the duct in the direction to mark-off the side you wish to remove.  Cut the excess off using an old pair of scissors or a Dremel cutter.

2.  Most cowls are not flat at the front and tend to be rounded at the ends. Sand the front of the duct until it touches the inside of the cowl all the way around.

3.  Tape the duct into the cowl and check that the exit lines up with the center of the cylinders.  If it does not reduce the top or bottom of the front of the duct accordingly.  Check there is some clearance between the duct and the cylinder fins.  If not remove material from the rear of the duct.

4. Rough sand the inside of the cowl where the duct will be positioned.

5.  Rough sand about 1/2" around the outside of the front periphery of theduct.

6. Tape the duct at each end and the top and apply a few spots of thick CA to temporarily secure it.

7. Liberally apply slow drying epoxy ( I use "West" epoxy ) about 1/2" wide on either side of the joint between the airduct and the cowl on the inside of the cowl. Lay-in a 1" wide strip of 6 - 8oz. glass cloth along the joint. To do this; cut the strip approximately 4" lengths, with enough to do the entire periphery of the duct.

DaleBuilt Horns: Installation Instructions:

Each horn consists of two parts which need to be located in perfect alignment and securely installed in the moving surfaces of the aircraft.

1. Determine the width of your chosen ball link. The instruction example is the DuBro heavy duty link and the width of the ball plus one tapered standoff is 0.3125" or 5/16"

2. Determine the thickness of the leading edge of the skinned foam surface before the leading edge is applied. In the case of the 40% Carden 260-330 this is: Aileron (root horn) 1.70 with a 7 degree back angle, Elevator 1.94 with a 4 degree back angle and the rudder 2.50 with a 4 degree back angle.

3. Cut a separator block from bass wood or light-ply the width of your ball link plus standoff, in this case 5/16" by 3/4" deep and the thickness of the appropriate surface leading edge, in this case 1 at 2.5, 2 at 1.94 and 4 at 1.70. Sand the appropriate surface back angle on the block.

4. Install a ball link in each pair of horn sides (hole is drilled to accept a 4-40 bolt) and using 5 minute epoxy glue the separator block between the sides and tighten the bolt. Clamp until dry.

5. The horn assembly is ready for mounting in the surface.

6. After determining the position of the aileron and elevator horns cut a slot 3/4" deep and 7/16" wide in the leading edge of the skinned surface. In the case of the rudder, the slot needs to be deep enough to allow the curve of the horn end to be inserted per step 7. Install the leading edge and shape it. Finish sanding the surface.

7. Drill two or three anchoring holes in the front of the separator block to enhance adhesion and then epoxy the horn in the slot ensuring that the distance from the hinge centerline to the centerline of the ball link is what you want.

8. For an even stronger mounting of the horn; just prior to step 6 apply a 2" by 2" patch of 1/4 ounce glass cloth with thin CA to the top and bottom of the surface before cutting the slot to reinforce the horn mount.

Note: If more technical information is required fegarding this product and its installation please contact: Gerry Dale at DaleBuilt, gdale@earthlink.net, or Tel: 352.237.2908.

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