SIG Banshee CG Location?

I've been away from models for almost 30 years, but my interest has recently been rekindled. So, I'm resurrecting an old (OLD) SIG Banshee that I've managed to (mostly) preserve all these years. It seems sound, but I had to do a few repairs and I'm guessing that I've altered the CG. For some reason, I recall it being right on the spar, but I've slept (a lot) since then. How far back from the LE should it be?

Cheers,

Kim Elmore

LAST EDITED ON Oct-08-04 AT 02:27 AM (CDT)
 
Gee - another Elmore!

I'm Tony Elmore,

My dad is Ken Elmore.

Tony

Plans call for c/g to be on forward half of spar. Hopes this helps.
Lee TGD

Thanks! I appear to be way tail heavy, which is OK since I can remove weight from the tail and the less weight, the better.

Thank, again. It will be fun rediscovering CL models!

Kim (yet another) Elmore

Wow! A tail heavy Banshee!? Have you shortened the nose?

Yep, another Elmore! I've seen your site; very nice! I'm told that Elmore is a common surname, but I don't run into that many.

Dad is Robert Elmore; he introduced me to models but doesn't fly 'em.

Cheers!

Kim

Paul Smith

I cannot imagine a tail-heavy Sig Banshee, unless you use an OS 15.

I shortened the nose when I built mine and then about 2 or 3 more times before I could get it to turn.

I general, I start out at a CG of 20-25 of chord and move aft until it won't fly level.

Paul,

Exactly how much did you shorten the nose the first time ?
Tribal knowlege has it that 1-1/2" is the norm. So, considering this, exactly how much did you take off altogether?

DAVE

LAST EDITED ON Oct-08-04 AT 09:14 PM (CDT)
 
Oh yes, the nose is shortened on this one, too. I think it's 1 1/2 inches, more or less. It still needed weight in the tail, so I get to remove some of that. Woo-hoo!

I was a kid when I flew CL, and I never had a chance to appreciate the nuances of the different designs and how well they flew (or didn't). Here's how experienced I was (and still am): the Banshee was the best flying airplane I ever had. I got to where I could do a fair bit of the pattern including the 4-leaf clover, but I don't think I ever got through the triangular loops or the hourglass; never had the guts to pull that 120 degree turn to level at the bottom, 6 ft off the ground. As a kid, airplanes came at a dear price and when one ate dirt, I was out of the air for awhile. I may have taken a stab at overhead 8s, but I never competed.

This will be fun!

Kim

Hey Kim,
The Banshee has been one of my favorites also. I have 2 flyers and 2 still in the box. If you build another one, try moving the wing forward 1 1/2" instead of shortening the nose. I like the way it handles and the looks better that way. I didn't have to do any balancing acts on either one. They both have Fox 35's.
Hope to see you again sometime, its been around 30 years now since we have flown at the same field. I sold my cycle shop in January, but still work there. You can find me at the TGD flying field on any Sunday.
Lee TGD

Hi Lee!

How do you move the wing forward 1.5"? Do you need to cut a new fuselage?

I'll try to be out there on a Sunday. For some reason, Saturdays often work out better for me, but with two little kids, each day is an adventure in ad lib.

It'll be fun tpo hook up again!

Kim

Hi Kim,
I just cut out a rectangle around the wing cutout about 2 inches longer on the front part. After that was remove, I cut 1 1/2" off the front and placed it at the rear of the wing slot. Then glue all back in place and you have it. Also it help to exten the engine mounts back as far you can. This helps to eliminate vibes.
Lee TGD

Very pretty planes, Lee!

I think I got it, but I'll have you explain it to me when we meet.

Cheers,

Kim

Paul Smith

I can't remember exact dimenisons, but my procedure is always the same.

In any kit, extend the hardwood motor mounts all the way back to the wing. This makes the front end stronger and gives you plenty of room to move the engine.

I would assume that the Banshee was designed for a Fox 35 stunt with no muffler. Any heavier engine with a muffler and a bigger gas tank would make the model very nose-heavy.

My current Sig Twister is the same way. I believe I shorted it one inch for starters. Then, later on, I marched the engine back one bolt-spacing at a time. This allowed me the option of going back to the last positon and plugging the new holes.

If you run out of front-end, add tail weight.

LAST EDITED ON Oct-09-04 AT 08:11 PM (CDT)
 
Well, I've got a Fox 35 on the front and a 4 oz uniflow tank using Brodak's adjustable, soldered-on mounts (yep, I used silver solder).
I yanked a bit over 1 oz off of the tail -- getting rid of those old DuBro wheels made a huge dfference.

The airplane weighs in at 32-33 oz dry weight according to our cooking scale. I didn't build the wing; it was given to me built and covered.

I'm mildly concerned about the motor mount, as the engine mount screws are only about 1/16" - 1/32" from the inside of the hardwood bearer on the upper mount. I obviously flew it that way, so I was OK with it before. The inside of the hardwood bearer also feels a bit soft by one of the screws, so I might have some oil-soaking problems there. Despite this, the engine seems very solidly mounted; nothing moves or gives as I wrench on it. I'm not sure how to rebuild the nose of a profile fuselage with the wing mounted. This may not be a problem anyway, because the airplane may not survive many flights with me at the handle.

Anyway, it'll be fun until I get my Stunt Sticks here and together. I'm told they are nearly indestructible. But then, they didn't test 'em with me...

Kim

Paul Smith

I found the actual piece that I cut off the front end on my Twister in 1990. It was 1.75" and that was for an OS 25. I ended up cutting off more when I went to a 36. As i recall, the Twister and Banshee are pretty much the same.

It did the pattern pretty well on the OS 25, but only in calm wind.