Q-talk 155 - Is This the Way You Do It?
- Category: Q-Talk Articles
- Published: Tuesday, 23 October 2012 16:23
- Written by Tim Mason
- Hits: 3588
by Tim Mason
[EDITOR'S NOTE: It seems to me that I read somewhere . . . perhaps even in the Tri-Q plans . . . that the main gear leg should be clamped to the bottom of the fuselage, but drilling 12 holes into a structural component will work too . . . At least I’m pretty sure.
Who cares if 1/8” and 1/4” plywood trays have been tested for thirty years in flying aircraft . . . If they seem inadequate to you, just use 1/2” plywood instead. What’s a “little extra weight” when your safety is concerned?
Also to fully test your set-up . . . just flip it right-side-up . . . and jump up and down inside the cockpit. That should more than adequately simulate dropping it in from 10 feet above the runway at max gross weight . . . sure!
You might also want to check out Mike Perry's comments about Confirmation Bias, and then with these thoughts in mind, please read the following submission from “Experimental” Dragonfly Restorer Tim Mason.]
I always admired the design of the Dragonfly but the idea of the tail dragger seemed a bit intimidating to me especially since I trained in a Cessna 150 tricycle configuration. I also liked the idea of seeing straight down the runway.
For a long time I dismissed the idea of a tricycle gear on the Dragonfly as I thought that it would be a lot of extra work and expense changing over to a the MK III configuration, but I went ahead and took the leap.
I tend not to be trusting when it comes to making changes like these and, quite honestly, it seemed to me that the framing available was quite inadequate. However, after talking to Richard Kaczmarek, I took some of his ideas and incorporated a little of my own and came up with this plywood tray idea for strength. Here are some pictures of the tray.
It is made of 1/2" birch plywood and covered with 3 layers of fiberglass. The floor below the tray I layed up with 4 layers of fiberglass, then I set the tray in and covered it with 1 layer of fiberglass. The bottom side I placed on each side of the gear 3/4" Balsa wood and sanded it to shape then covered it with 4 layers of fiberglass.
I drilled 12 holes through the bottom and inserted 12 5/16 stainless steel bolts with large fender washers. After doing all this it seemed very solid as I bounced it around and stood on the gear leg and jumped up and down on it.
The gear seemed very strong but it may have just it bit too much spring in it as it seem to flatten out slightly, but may not be a problem.