Lift Duct Construction
I cut a piece of ply at 22 deg. to help set the lift duct at the perfect angle. Remember if you use an engine in front, the most you can go is 22 deg.
If you are building to plans with one engine you will want a 30 degree slant on the lift duct.
I used the 4' T square, (without the T) to measure down to the deck and determine whether the duct was positioned properly before foaming in place.
As you can see the rear of the lift duct is tapered back to provide more airflow to the rear.
I placed extra 2" pieces of foam around the lift duct and spray foamed them in place. This is not on the plans. I liked it for several reasons. Sound, Strength, & attachment point for top..
This shows metal motor mounts with wood main supports. After the first season I cut out the wood and used 1" aluminum tubing. I mounted the motor directly to the aluminum. I ran the gas down one tube and the electrical wires down another. It is a much cleaner installation. I will attempt to get pictures up ASAP.
Using wood disk to center the motor.
The cut out of the upper left motor mount is for the exhaust. I had to add a piece of metal to the exhaust to divert it down so it would not blacken the fiberglass of the duct.
Plans call for an all wood 2X4 about 3 ' long and very flat. I stuck some #40 grit self sticking sandpaper to it and leveled off all the surfaces. Then I epoxied a top layer of 2" foam to it.
See the cabin construction section
May 2001. The following pictures are of a change I made to the airflow to the front intake lift. I wanted to reduce turbulence to the front lift fan. I cut out the area shown, beefed up my new front motor supports, filled in the area with foam then made a larger radius on the leading edge. This is supposed to provide a laminar flow and reduce turbulence.
