mxaexm

I think this post will become an ultimate build thread...I'm getting ready to start building my first RC kit Sig Mid Star 40.

Any modifications that I should know?

What do you think of building up an elevator, etc?

Any info and pictures will be appreciated

Gray Beard

My Feedback: (-1)

That was one of my students first kit a few years ago, his second plane, he is still flying the plane today, three weeks ago I was flying it too. I see no reason for any mods at all on this plane, it fly's very well and is a very good little stunt plane as designed. I find this with most the SIG kits, perfect as designed. If you add more elevator you will just be dialing it down, it doesn't need more. If you make up a bigger rudder it will be over kill and be a roller. I can take his stocker and do a very good knife edge forever. Just enjoy the build and have fun with the plane. If you like that one take a look at the rest of the SIG line, all very fun builds!!

Alex7403

mxaexm,
The Midstar is my favorite airplane, built two of them, the second one is still flying today.
Thought to retire it several times but it proves to be the best airplane I have, there in no reason to retire it its flying.

http://www.rcuniverse.com/forum/m_65...2Cagain/tm.htm

Very sturdy airplane, takes a lot of beating very easy to repair.
I have two four stars 40 and 60 and I think the midstar is better.

Don’t change the elevator its good as it is, mine is doing loops on a dime.

The midstar likes to be a tail dragger, it balances better this way.
With 46 AX I placed the battery behind the servos, and no extra weight needed.

As for mods I would recommend to make the wing mounting screws into ¼-20 T-nuts and not as suggested in the manual tapping into wood, yes so they will hold better and it will fly more.

Also consider composite push rods instead of the supplied nyrods, the composites are not expanding from heat if you keep the airplane in the car….

Beside that I don’t see any need for mods.

Alex

mxaexm

Based on what you are saying...I will build it stock. How about carbon fiber pushrods?

Alex7403

carbon fiber pushrods should be fine.
when the manual say sig bond i used epoxy, most of my second midstar was built with aliphatic glue not ca.
building with aliphatic glue is not that slower then if building with ca that is my conclusion.
you will need lots of clamps and dont rush it, this kit parts fall into place like a puzzle.
the manual is written for a beginner builder.

Best of luck
Alex

MinnFlyer

My Feedback: (4)

I would say, don't make any changes. Being that this is your first kit, you will have enough things to think about.

Just follow the instructions, learn as you go and enjoy the build.

XTOL

The Midstar is a terrific plane. It was my first kit and the first
plane I soloed. I put many hundreds of flights on it and passed
it on down to a younger flyer in our club and its still flying.

Like the others have said...build it stock. The only thing
I ended up changing on mine over the years was replacing
the tail wheel bracket. The Sig supplied tail wheel wire will
eventually break. I replaced it with a Sullivan unit.

Mike Hammer

0417

Take care when sanding the sheeting on the wing. If your not careful you will be through it before you know it. Guess how I know. This was my first build also.

Fred

rcdude7

My Feedback: (264)

I built one of these kits. I used spruce for my main wing spar as I remember mine just came with hard balsa spars. I really enjoyed the flight performance of the mid-star, it is very aerobatic.
i will have to build another someday. Too bad there is not a 120 size kit, I'd be all over that in a minute.

Gray Beard

My Feedback: (-1)

Well Dude, {just couldn't help myself} ask the OP to trace out the parts for you and send them to you, now you have the templates for all the parts. Go to Kinko's and have the plans and templates made up to any size you like, SHAZAM!!!!!! Big Mid Star, you just have to make your own kit, very easy!! Get your wood from Lone Star Balsa and get to building. A very good way to get the plane of your dreams in the size you always wanted!!

mxaexm

Does any of you have plans that you don't need anymore. I bought this kit "pre-owned" and the plans are missing .

Thanks a lot.

Mike

Nergall

SIG does:

SIGIB256 SIG INSTR. BOOK-MID STAR 40 EACH $3.90
SIGKP256 SIG KIT PLAN RC-56 MID STAR 40 EACH $5.75

twn

I built one of these. Yes it takes a beating. If u build it stock a 46ax is not enough. 55ax would be ok I think or a st g75. I had a 46ax on mine and grew tired of it after about 10 flights. She builds heavy since most of the fusalage is plywood. If you are a seasoned flyer lighten this plane up. Dremel out the fusalage and get the weight down. foam wheels... get it closer to 5 lbs if u can at 5 lbs a 46ax would be ok. Mine was 6 lbs and the vertical sucked. 300 feet at best. Once I put a st 60 and a pump on it it was great but still not enough vertical but MUCH better than the 46ax.

A 4 cycle would be great too. Better than the 2 cycle. Some will probably argue this. I myself like 4 cycles. A cheap magnum 91 4-cycle would pull this plane great and even at 6 lbs the 91 would still be great. The plans call for a 50 size 4 cycle but that would be too small. I always put a 80-90 4 cycle into a 40 size plane and 120-150 into a 60 size plane... There are a few exceptions like I have a GP Extra 300s that I put a saito 100 into and I run 30% heli fuel in it and she is a rocket but at the cost of 30% nitro... A saito 125 on 15% would be very similar. My reason the saito 100 is substantially lighter than a 125...

The Midstar plane flies great slow but it is also very good fast. The wing is surprisingly strong. I have hammered some very hard snaps and hard quick banks and she is still together.

Oh and tail tragger. definately...

MinnFlyer

My Feedback: (4)

I strongly disagree. A 90-size 4-stroke is WAY overpowering this plane.

A 46 - 55 two stroke or 52 to 70 4-stroke is all you will ever need.

XTOL

I have to agree with MinnFlyer...Mine had a Thunder Tiger 46 Pro
on it and it was all the power it needed. I put hundreds of flights
on that plane/engine combo.

Ive passed my old Midstar down to a younger flyer and he is
flying it with an old Magnum XL40. It still flies very well.
Last fall I was showing him how to do basic aerobatics with
that plane.

Mike Hammer

bigal126

My Feedback: (18)

My midstar was maidened last week by an experienced flyer at our field. It has a 46AX, and it came out a little heavy - 6 lbs 2 oz. Now I don't know much about RC flying yet. I was just sittin back and watchin my new plane fly. It has a 11 x 5 master airscrew prop, and when the pilot pointed it straight up, it seemed to just keep on going until he throttled back. The pilot's comment was "she's got all the power you'll ever need.

Alex7403

I have 46 Ax and 11x5 , 11x6 props on my midstar and its flying very well, its doing wild loops on a dime and go vertical until i stop due to my sight.
i always feel its more then enough power for the mid star.
i'll tell you more, the midstar flies on its wing not on its motor.

twn

I'm sure a 70 would do fine...

For myself I now like to over power and manage the throttle. Then when I’m ready to move on I have an engine with a wider range of future use. This is a learned experience. I have too many engines that I don’t use anymore because I opted for the lesser one to begin with… I found that the difference between a 70 and a 90 4-c is marginal. Besides you can run lower nitro and prop it down until yer comfy with it.


But it really boils down to what you can afford!

twn

BTW XTOL, Nice job on the scratch Ultra Sport 60!

XTOL

EXACTLY!

XTOL

Thanks...its a terrific flyer. 126 flights on it and counting.
The old 61 SF got an overhaul over the winter with a
new Frank Bowman ring. Still breaking in but its got
some of that old zip back...


This thread kind of makes me miss my old Midstar...

Mike Hammer

frenchie79

The only thing I would do is make the Ailerons larger by a 1/4 or so inch. This will make it roll faster, it is very slow even compared to the 4* 40 which has bigger ailerons.
4 stoke 52 with a 12x6 APC is ideal-will fly forever on a 10oz tank.

twn

I too used a MA 11x5 & 11x6 (I found the 11x5 best) and 15% nitro with my 46ax and it was ok. It pulled it all over the sky. It is great that you are content with your 46ax. I see a number of people saying ""a 46 it is all the plane needs" All that I am saying is that for "me" it wasn't enough. I really enjoyed it with the pumped Supertigre 60 & MA 12x5 tho. I put more than 400 flights on it last spring before going to my sse/saito 82 and made a number of mods that included larger ailerons and dual aileron servos and a Sullivan tail wheel. It is a fantastic aerobatic trainer with lots of potential for mods.

I included some pics. Yes the covering is dog ugly but I could see it everywhere.

BTW: The larger ailerons were made from 2" aileron stock tapered. 2" on inside and 1.5" at the tips. The roll rate before was about 1.5 per sec with the 60. With the larger ailerons and 1.5" of throw on high rate I got a bout 4 rolls per second and with the ST 60 I could maintain about 1 roll per second on the upline wide open without slowing down.

twn

mxaexm, most mods if not all can be done even after constructing the plane. I did all of my mods in a progression. Primarily I built the plane as per instructions. I'd fly it think about it, mod it, fly it, mod it, fly it more etc... Hence the reason for the ugly covering with many changes I became lazy at the covering and just wanted to fly it. First I moved from the 46 to the 60. Then I added the pump because I had too many dead sticks from intense vertical climbs. Gravity would pull the fuel away from the engine… Then I put on the tail wheel and then I went to the larger ailerons and dual aileron servos. But really the only mod the plane can use is the tail wheel and aileron size. But if u mod the ailerons it can become quite unstable mainly on landings and take off so don't do it right away if you are inexperienced in flying or if you do enlarge the ailerons keep the rates low, as low as sig suggests until you are ready. The larger ailerons become touchy at low speeds, like during take off and landing. I solved it for me by dialing in some expo and never taking off or landing on high rates. With my 60 the landings were a bit fast and hard to flair cause she would float easy. I just let the front wheels touch, kill the power and keep the tail down.

The fuselage in my opinion is built for noobies. Built to take a beating so if you lighten be aware of that you will take strength out.

With my GP Extra 300s I lightened the tail/fuselage EVERYWHERE so that I could tail mount my digital mini servos for the split elevator in the tail even with a light saito 100 up front. I managed to get the weight down on that to 7.1 lbs. Most build up to 8-8.5lbs... But my landings are mostly soft. If you lighten the fuselage it may not stand up to a hard landing. But lighter flies better…

Something else the midstar wing has no sheeting on the front of it so it is easy to get a covering induced warp. I did and it baffled me for a few flights because it was so minor and hard to see.

You will love this plane.

Alex7403

twn, your covering is not bad, its bad when it confuses you about where the airplane is flying, it can be beautiful but if it gives you the wrong information it doesnt serve its purpose.
so its better to have ugly simple to see covering scheme then guessing in which direction the plane is flying....
guess how i know that...