Hey guys,I just finished my Mini and was wondering whats the best way to balance right on front of lower wing?I had to add about 2oz to tail ,hope I did`nt over do it.I`m runing a Saito 72 in mine.

Nice model!

I balanced mine on the top wing, at the point indicated on the plan, and have found it very comfortable.

BTW I estimated my old (and rather heavy) OS 61 Four Stroke would make it nose heavy so placed the battery under the ockpit and Rx just behind the cockpit and servos, and thus needed no additional ballast to balance.

wow, ive been following this thread for a while, i finally traded my os 61 fs 4 stroke.im gonna use an os 46 fx.with a pitts muffler.i should receive my plane in about a week.so if any one has any tips tricks or pics then please let me know.also if anyone has a video then please post the link or post it up. i would love to see this beauty fly.
i will keep you all updated on my build and try to add pics.
thanks, matt

Did you use silk/dope or ultra coat on your Smith?

Thanks much for this thread. I just started my SMP a week ago, been sitting in it's box for over a year. A couple things I've learned, the hard way, that may help any one else building this kit.
Do not put the cockpit floor in before gluing up the 1/8" nose balsa. this is the only access to the formers from inside the fuse.
Do not glue in the 1/8" balsa nose bottom before fitting the cowl. Fortunately, I was planning to install a removeable hatch in this area, decided to glue up the cowl and test fit it first. The plans manual says " Careful shaping of the nose is necessary to achieve a good fit". What an understatement! Spent a couple hours carving and sanding the nose! Finally got a "good fit". The bottom would have had to come back out had I installed it first.
That's it for now. Just have to decide on a color scheme. Looks like I should have plenty of time to decide!

Here's a tip for when adding the top fuselage sheeting - prepare the cockpit cut-out in the sheeting before you glue it on - makes bending it into position much easier.

As my dear old grand pappy used to say, rest his soul, "Live and learn." I have also learned to pay closer attention to the pics in the thread! Could have saved me a bunch of time!!!!

Hi,

These are some GREAT looking planes guys! I'm thinking about building one,

Sig advertises 5.25 lbs, how light are yours?

Seems like with this kit a scroll saw, mitre saw and/or belt sander might be required accessories!

Jeff

I read the whole story and just could not resist to show mine

It took me over 6 months to build but at last I finished my Miniplane the other week.
It is powered by a Saito 56 with a Perry Pump. Covering is done with Oracover and matching Oracover paint for the pastic parts and struts (this paint is really great stuff to work with!).

Good job supaglo... where did you get the cockpit items

Do you think a magnum 50 4 strokes can haddle a smith? i fly at 7340 feet over sea level (mexico city).
i dont want a underpower model.
thaks
lalo

The instruments are 1/5 scale instruments which are supplied by several brands (same item, diffrent brands....) The ones I got came from R.E.M. but Robbe supplies the same (# 1-6156). The instrument on the right side is modified to a voltage gauge for the 2 receiver batteries.
The 2 red knobs on the left side are toggle switches which are cut to the right length for scale appearance. They operate the solid state receiver switches.
The throttle quadrant was scratch built after a part from the aircraft parts supplier Aircraft Spruce (http://www.aircraftspruce.com/catalo...hbthrquads.php). Once I have the time to hook up the cable to the throttle servo it will move too.
Most of the decals I used are scaled down previews from the internet site stated above and other inernet sites.

lalo,

I expect the 50 four stroke will fly it in a very scale like manner. However, i doubt that you will have a lot of extra power for aerobatics, which this plane is very capable of.

Truely a sweet flying little bird. Here is a pic of my 23 year old Smith MiniPlane. Not quite as nice as those pictured in here.

It'll fly it, but it will not perform, and that would be a shame since the SMP is really a very capable aerobatic mount.

Mine has an ancient OS 61 FS and I think it's ideal, not overpowered but climbs very well for a stall turn, and does not "run out of breath" when going for a very large Immelman.

Hi Guys. Sorry to butt in on this excellent thread but I have a SIG mini plane that I built in 1994 and only flew 2 - 3 times because I was relatively new to the game and only using an OS46 engine that flew her reasonable well. Anyway I have decided to get the model out of the loft and fit an OS70fs which I have laying around.

The only problem is I don't have a clue where the plans are and could do with a confirmation of the balance point. I understand it is just aft of the leading edge of the lower wing but could do with a measurement of how far "just aft" is (if it is there)

I'll pop a picture in later but the model has stored well except for the paint which has matured with a slight yellow tinge.

Hope someone can help.

Regards

JoLLy.

Jolly, I'll dig out the plans tomorrow and let you know.

Top Man, thank you for taking the time.

JoLLy

Mr Jolly,
Sig's plans show the balance point 1/4" behind the leading edge of the lower wing.

Good Luck with it[8D]

Very helpful thank you very much.

Nigel

I'm planning on putting an E-flite 46 with a 4S lipo into one, but would like to keep the AUW under 5 lbs. To those who have built this kit, if you were going to 'electrify' this plane, where would lighten up the airframe? Would replacing the wire N and cabane struts with ply also help? Any ideas would be appreciated.

I don't know a thing about the electric components and their weight. My Smith came in a little over 6lbs with an OS 45 FSR and muffler with extension. Also have a little lead in the nose.

My suggestion would be to try and loose a little weight in the tail. Maybe you could save some weight replacing the wire with plywood for cabanes and N-struts, but I wonder, would you loose the look as well?

Dustmaker,

I would not use plywood to replace the wire struts as I would hate to have the upper wing part company with the fuselage. A possible alterative would be carbon fiber tube or rod, much lighter and stronger than the plywood. As most Smiths need some nose weight, do what Dave suggested and lose tail weight. The wire struts are forward of the CG for the most part and the weight saved forward of the CG may need to be replaced with dead weight. I think a step up in motor/battery size may be a better choice and use the batteries to help balance.

I strongly recommend you do not change those elements of the construction.
They are desigend correctly for their intended purpose and the model's size, weight, and flying speeds.
They are not over or under designed at all.

Weight can be saved by ensuring perfect joints so you do not build up glue fillets and unnecessary weight, and by going easy on the finish.
I would not change anything else.

Well........
Last Saturday my Miniplane finally got its maiden flight. Allthough I didn't fly it myself the plane looked very nice in the air.

I allready read that this plane had a tendency to climb but the person who flew it was not happy at all. The elevator was trimmed down for approximately 1/4 " and the plane still climbed. During the flight the behaviour was checked with a few maneuvers to find out what might be the cause (CG or angles). Allthough the plane was landed with the fuel tank still quite full to keep the CG as much forward as possible it stalled close to the ground. The good news is that damage is very limited and can easily be repaired.

The bad news:
Today I did some measurements to check the incident angles of the wings and stab (again). Everything was within 0.5 degrees from neutral. I also checked the the CG again wich was in the place as indicated on the plan.

Should I move the CG forward or even give the top wing a negative incident angle?

Is there anyone who made this kind of adjustments to this kit?

Mine climbs if the elevator is at nuetral and as you found needs about 4 to 5 deg down to hold level. Don't try to land this too slow as it (mine) is heavily built so is not a floater. Some have written here about shimming under the rear bolts on the upper wing but I have not tried this. Please don't crash that incredible example again. It deserves some serious air time as you have put so much effort into it.

Chris