I ordered a Sig 1/4 scale clipped wing kit from LHS today, 86" WS.
Anyone have thoughts on a good engine? Im thinking 120 4 stroke or so, I just got my 1st 4 stroke for my 4 star 120, a Saito 150, and I love it.
Also, this kit comes with a plastic cowl, should I trash it for fiberglass, which one? This is my 1st scale project, any pointers sure be appreciated.

Thanks Roger
RB

Any 1.20 Four stroker will do just fiine, you could order a fiberglass cowling, but I'll give you a little secret Get a 2 oz. or so fiberglass cloth, and after the cowling is put together, on the inside and brushing pure acetone, glue the fiberglass to the surface, apply a little bit of pressure with the brush, use an acid brush, they're short and stiff and cheap, in areas were the cowling is curved, cut the cloth in strips for easier placement, be careful not to brush too much acetone at once and ruin the plastic, nor apply so much at once that it runs all over the place, it will leave marks. You first apply the cloth and then brush the acetone over it, pressing it down, this reinforcement adds tremendous strength to plastic parts, it can also be used inside wheelpants. When painting the cowling later, spray a little bit inside too.
It is important the way the cowling attaches to the fuselage, I've found out that having the hardwood blocks touch the plastic is best, position the cowling, drill the holes, remove the cowling, enlarge the holes in the hardwood mounting blocks and insert a 4/40 T nut to screw the bolts into. Enlarge the holes on the cowling just enough so you can pass a short piece of fuel tubing (silicone), for each bolt cut about 1/8 long piece of tubing, insert the bolt through it and then attach through the cowl, you must use a small flat washer with each bolt, to stop the tubing from sliding out of the hole, this way the cowling material is not under direct pressure, and the bolts do not have to be tightened down all the way, no cracked cowling.
And all you asked was if the cowling should be trashed?

Thank you Walter!
Exactly the kind of information Im looking for. Ive built 4 models so far, however, none have been scale nor have I used a cowl yet.
Ive done a little research on cub kits and Sig advises the 1/4 scale clipped wing is for advanced builders. Most folks say the Great Planes version is simpler, but, I still dont know what aspect of the build theyre refering to. I guess it doesnt matter, Ive already ordered the kit and should receive it next wed.
LHS owner says the Sig is built stronger than the Great Planes and since hes seen all the planes Ive built so far, he says Ill have no trouble, I hope hes right, Id like to have this one flying by 1st of spring.
Of coarse Ill be covering this with fabrick, which I like very much compared to Monocote, I used it on my 4 star 120 and it turned out great. What I didnt like was the paint and clear i used which was Lustercote. Im thinking this time ill go with automotive paint, I just havnt been able to find a great deal of assistance anywhere when it comes to painting fabrick, I REALLY want this to be a perfect job, Im going to duplicate Hazel Sigs paint scheme on her full scale cub.
As always, thanks for assistance.
Roger

If you want a nice scale engine for the cub call Balsa USA they have 1/4 scale plastic engines kits not the cheap vacuformed type. Jugs with chromed heads. The jugs look like the ones Willams Bros. sell. Also in 1/3 size

A OS 1.60 twin would be nice and look pretty scale with the vavle covers sticking out. No fake engine and great 4-stroke twin sound. Only problem is coughing up the dough.

Cub really need that much umph? I am almost done the GP cub, 90 inch wingspan, building heavy I think but it seems really strong with all the reinforcing i have done.

Any links on fabric covering, how to, what products? never used it, sounds interesting.


Mill

I am currently building this kit. It already comes with some nice dummy jugs. I won't be using them however as I am going to use the 160 twin that Joe B. is talking about.

One piece of bad news for you. This is NOT a simple kit.
They are refering to things like this for example...

The fuselage formers are not die-cut. You get a piece of plywood that is cut to size, then you must notch it and add balsa strips to complete them. (See pic)

Also, things like the wing tips are made by laminating several balsa strips around a plywood form, and then sanding to shape. This is what's known as a "Builders Kit". I was very dissapointed that a company with Sig's reputation still makes these things. I don't mind building a "Builders Kit" But I already had one on the workbench, and thought I'd "Throw together" a Cub for my dad. Now I have TWO big projects this winter!

(It IS going to be sweet with that OS 160 twin though!)

Old Mill, Try 21st Century Fabric covering. Easy to use and already painted.

http://www.coverite.com/covering/covq0301.html

http://www2.towerhobbies.com/cgi-bin...?&I=LL5672&P=1

I used a OS 120 twin with a 16x6 apc in my 1/4 Sig Clipped wing and it was wonderful. Plenty of power and great sound. Used Robarts landing gear which is also very nice.

Think I will have any problems then with an OS 91 4 in my cub? Went with the upper engine range, but I am a silly newb. Or is this just a plane where you have a huge engine range?


Mill

No Problem, You're building the GP 60 size right? A 91 is plenty of power for that. We are referring to the SIG 1.4 scale Cub, a much larger plane.

PS, Old Mill, you may want to consider chopping off your wingtips, then removing the last 2 rib bays, and then gluing the tips back on. Every cub I've ever seen with the full sized wing has a tendency to have adverse yaw in turns, It's like the wing is too big for the plane. That's why the "Clipped Wing" version is so popular. And the clipped wing is certainly no more difficult to fly. If anything, it's easier due to the lack of adverse yaw.

Hmm, then the sig at wingspan of 86 inches is clipped? no wonder. I thought mine at 90 inches was a bigger plane, why I was confused.The GP cub has the clipped wing version instructions too, but I didn't know about adverse yaw, I wanted a big plane with tons of lift, this will be primarily a winter plane with floats(need something to fly for the next few months!!) and I figured big wing = more lift.

So much to learn in this hobby. Thanks for all the input, will see alot of questions from Mill the newb in months to come.

I figure I am two weeks from covering stage, and then I guess we shall see!!

Thanks again,

mill

The cub will have plenty of lift with the clipped wing. The original Cub (full scale) was meant to be the Volks Wagon of the air. It had a small engine and therefore it needed the big wing. Somewhere around the 40's a better engine came along, and after a while a lot of full scale Cub owners clipped their wings. So, model wise, if you have a 90" Cub and wanted it to fly like the Original, you could probably get by with a .60 4-stroke. Since you have that nice 91 Surpass, I think you'll find that clipping the wings will give you a much more enjoyable airplane

WHHEEEWWWW!!!!
A builders kit doesnt sound bad at all if thats the worst of it.
Ive been out to Lowes this am checking prices on scroll saws ect.. I have nearly a complete machine shop at home, however, elec. wood tools limited to drill press, belt sander, dremmells, jig saw and some hand tools.
Im getting real excited about this plane and have decided to install nav. lights and anti collision strobes as well as a smoke system.
Ive decided to use my Saito 150 on the Cub and purchase an OS 160 to reinstall on my 4* 120.(WAY after Christmas)
Wheel pants for cubs are sharp on cubs too, I think Ill start looking for info. there too.
Thanks for feedback everyone!
Roger

The Sato 150 will be way tooooo much engine....But you can always fly at 1/2 throttle...
I had built the Balsa USA 1/4 scale...did a little extra reinforcing where I thought it needed it...covered it with colortex and painted it with Rustoleum, a lil' heavy, a club member wanted it and sold it with a Enya 120, Not enough motor for him, so I sold him a Sato 150....
Ala, inverted flat spins, short hovers...and whole lot of other things it wasn't supposed to do....
But it stayed together....
Next one will have a G38 or a RCS 180F.....

Just two cents worth....

Flap,

A 120 4 stroke will work just fine. I have the full wing Sig version that I recovered from an old timer who put in the trees on landing. I built a new wing kit and repaired the fuse. It is not the most simple kit, but far from totally difficult.

The old guy has a OS 1.08 two stroke on it. It did everything it was asked to do.

As far as covering is concerned, I used the 21st century fabric, Cub yellow of course. This stuff works great! I would recommend the use of the Balsarite Fabric formula preparation. It really made the fabric stick.

I also used the plastic cowling. It is made from ABS. The suggestion of using the extra cloth and acetone is a good one. I would use MEK as opposed to acetone simply because it evaporates slower and will really bite into the ABS.

Good luck, you will have alot of fun with this one.

Be aware that MEK is deadly!!!! Please don't dispose of carelessly, you may ruin all the wells downstream of your dump site!!! MEK gives off a heavy gas and will seek the lowest point, so get the boys out of the oil change pit before you open the jug.

How are you getting MEK anyway?

AAAAHHHHH.........What IS MEK?

Methyl Ethyl Ketone, I believe is the right name, it is a liquid like acetone used to glue different materials to plastic , it softens the plastic, kind of melting it, thus the other part sticks to it, it evaporates extremely fast, it glues almost as fast as cyanocrilate (e.g. Hot Stuff), it works very well when gluing plastic cowlings or wheel pants halves, just hold the parts together, run just a little of the liquid on the joint and presto, it is a very strong solvent, like acetone, these should be used in well ventilated areas as most other glues. Pure acetone works the same way, they even smell alike, neither one should be trusted as safe chemicals. (Could they be the same stuff?)