More Pictures F-Twister

LAST EDITED ON Nov-07-04 AT 09:22 PM (CDT)
 
The weight is now 37 ounces as it appears in the picture. I replaced the OS 25LA engine and stock muffler with an OS 40LA and tongue muffler. I trimmed a lot of weight off the airplane by removing more balsa. I added a little weight in the front. I copied the front of a Cessna. Not sure I like it. It seemed like a good idea at the time. It might look better after its finished. I might change it the 1/16" balsa will come right off with a razor knife. I can reduce the weight by another ounce maybe 2 ounces. Not sure how much weight the covering will add probably at least 1 ounce. I sure would like to have wing type landing gears but I worry it will add too much weight and cause wing damage during some of my fancy landings. Filling and sanding takes a lot of time it still needs some work. I painted the entire airplane with 1 coat of clear coat.

Looks great so far, I like those cheek cowls. Later, DOC

LAST EDITED ON Nov-08-04 AT 07:11 AM (CDT)
 
Did you remember to hollow out those tips? Your LE still looks a little sharp as well.

I like the nose though...

BIGS

" What constitutes the dignity of a craft is that it creates a fellowship, that it binds men together and fashions for them a common language. For there is but one problem - the problem of human relations."

>Did you remember to hollow out those tips? Your LE still
>looks a little sharp as well.
>
>I like the nose though...
>
>BIGS ]

I will hollow out the wing tips next. The larger engine made it a tiny bit nose heavy. Once I get the wing, elevator, stabilizer, fin covered and finished I will decide if I need to lighten the fuselage. I rotated the needle valve to the side now the fuel line won't connect without going around the fuel tank so I need to either make a new fuel tank or take apart the tank I have and change it.

Gary,
I am with Bigs. You really need to take the "point" off that leading edge. Round it off considerably.
Bill <><

LAST EDITED ON Nov-09-04 AT 09:21 AM (CDT)
 
I built a SIG Twister for the Sig Contest in Montezuma, in about 1990 or '91. Rules said "SIG KITS" and I built a Sig kit, turned out, I was the only virgin in the sorority house, but my conscience is clear.

I also started out with the idea of using an OS .25 and staying light. It did the pattern OK and I finished in about the top third. Fortunately, the wind was calm. It didn't have a chance in the wind.

I've gone through several engines, up to a Supertigre 40, and am now using a Fox .36 Mark V. The plane currently weighs 43.5 ounces, including tip and tail weights, paint, Monocote, and fuel soaking.

The problem with all these weight-saving schemes is they take it all off the back end, and you have to put it back to make the plane fly.

LAST EDITED ON Nov-09-04 AT 08:49 AM (CDT)
 
Several people have requested more pics of the cheeks. I am glad someone likes them I am thinking about removing them but probably won't until I finish the airplane to see how it looks. I cut a 1.5" radius from a 1/2" balsa piece. I cut a 1" radius out of the center of that piece and used both pieces. I glued the 1" radius piece next to LE. I glued the 1.5" radius half donut piece next to the nose. I wet a sheet of balsa on one side and in about 3 minutes I was able to bent it to fit the radius. I glued it in place wet with CA glue. The next day when it was dry I sanded the front round so it looks like the front end of a Cessna.

GW

The cowls are nice, the one on the engine side would appear to present a problem if you need to raise or lower the tank. Keep the nose ring in front of the engine and take off the rest. How did you fuel proof the inside of the cowl? How does air flow through the cowl, as constructed it would seem the air goes in the front and the only way out is around the engine.

Still need to round the edges of the plywood doublers, easily done with a dremel tool. The leading edge of the wing has what appears to be about a 1/16" radius, it should be around 1/4" or as large as you can make it and keep it straight. While a sharp leading edge works the wing stalls quicker than with a more rounded entry.

>The cowls are nice, the one on the engine side would appear
>to present a problem if you need to raise or lower the tank.
> Keep the nose ring in front of the engine and take off the
>rest.

>How did you fuel proof the inside of the cowl?

Several coats of clear coat.

>How
>does air flow through the cowl, as constructed it would seem
>the air goes in the front and the only way out is around the
>engine.

It doesn't, 1 way in, no way out, on the right side. On the engine side air will flow over the engine.

>
>Still need to round the edges of the plywood doublers,
>easily done with a dremel tool. The leading edge of the
>wing has what appears to be about a 1/16" radius, it should
>be around 1/4" or as large as you can make it and keep it
>straight. While a sharp leading edge works the wing stalls
>quicker than with a more rounded entry.

The weight is now 36 ounces. Going on a diet.

Gary

The cheek cowl is fine. It might not be the prettiest plane on the block but the inboard cowl is a very effective and light way of reinforcing the fuselage/wing joint.

Also, if you fly in hot conditions, put a couple of holes in the fuselage in convenient places to allow some airflow from the inboard cowl around the crankcase and out through the outboard side. At the temps we fly in Sydney summers, such measures are almost mandatory to ensure consistent engine runs.

It's looking good--run with it.

Weight is now 35.5 ounces with the 2nd coat of clear coat.