John, First I'm really glad you weren't hurt. My comments about the drive are that I have seen the Marcotte, and the gears at least looked more than adaquate for a 13B. Powersport buillt a similar reduction drive which is very successful, but used straight cut (spur) gears, where the Marcotte uses helical. The trouble with a helical gear set is obvious in that there is a axial load generated by the helix angle. This has been a problem in several reduction drives. The Ross drives needed a double thrust bearing installed to hold together. Tracy's drive was better set up for thrust but he has had some seals have some trouble on some drives. MY feeling there is seal trouble rather than the drive, as parts do vary. Mistral's planetary was custom made and used spur gears also, haven't heard if they have had any seal trouble. Does your drive actually show signs of overheating? Have you had the time or desire to remove it and do a full tear-down? Any info you could supply the group would be very helpful. Glad YOU are safe, hope you can make repairs.
-----Original Message-----
From: John <downing.j@sbcglobal.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, Jul 12, 2010 5:38 am
Subject: [FlyRotary] Flight Test
The airplane went over and the right wing spar broke, tail post is bent at top about 3 inches, it takes less than a second and a skid of 60 feet to be out of the plane. The 80W was burning inside the SS exhaust shield and on the 40 inches of .016 SS x 11 x 1 inch formed channel that I had on the bottom of the fuselage over the muffler which I assume kept the fabric from catching on fire. There is also 1/8" fibrefrax between the SS and the fabric. The prop and spinner is history. You sure do love the high wing aircraft to protect the ole bones.
The article in the Contact Magazine told about all the problems that one fellow had to fix and also on a RV builders site with a Sube engine was an article about the problems of the Marcotte. The input seat was driven in and bent, then covered with permetex which hardened and was leaking and had to be replaced. A machinist friend has a buddy who is a retired gearbox engineer who said that the aluminun housing with overheated gears would soon expand and let the seal fall out, they are going to tear down the gearbox to see what it looks like inside. Selling aircraft parts to be field tested isn't the most intelligent idea in my mind. Buyer beware.
The rotary is one smooth engine, with the exhaust exit from the Hushpower II behind you and with ear plugs and a noise cancelling headset it's like the sound and vibration of a sewing machine at 190 mph. JohnD