Alex7403

Congrats for the kit Bob.

Mark about that issue with the rudder, I was thinking to cut a slot with a dremel in the fuse and put a plastic hinge.

I wonder if it will work with no hinge on the bottom part avoiding the whole fuss.

The stock tail wheel is a sad joke, I’ll be using the Sullivan tail wheel bracket.

Pushrods I’ll be using dubro pushrods, I heard the stock ones are heat sensitive.

Alex

UPF-7

Hi Alex,
A plastic hinge epoxied in place should be fine, just don't be tempted to omit this hinge point. This hinge absorbs much of the rudder servo load due to the close proximity to the rudder control horn. Mark

N1EDM

My Feedback: (2)

Oh yeah, right....

I knew that.

Alex7403

This stage is not a must and is not indicated in the manual.

So a perfect fuse gonna have a cut in it.

Added a piece of balsa to the tail which will hold the CA hinge.
Behind it there is another piece of aileron to back up everything.
When the glue will harden I’ll sand it and prepare for hinge slot machine.

MasterAlex

Interesting mod there Alex ...

Did you base this on knowledge that the Rudder hinge point was weak, or are you just taking a precaution? I'll be honest with you, I didn't even consider this when I built mine; I'm wondering now if I should have [:@]

Also, I don't recall, are you adding an aftermarket tailwheel? Probably not a huge concern, but you might want to keep weight & balance at the back of your mind - especially when adding weight to the tail.

N1EDM

My Feedback: (2)

Oh yeah, maybe I didn't do a "Duh" after all, Mark...

If that wing fits both the Mid-Star and the Four-Star, AND (he said, after giving it some thought ) I use separate aileron servos as I had intended to do in the first place, then my original idea will work out anyway![8D].

I'll just have to watch the covering scheme to make it work...

Hah! Thought you had me, huh?

Bob

iron eagel

Good idea Alex, I have seen that area of the tail fail from less than perfect landings, and it will give you a good hard point for the rudder hinge.

Alex7403

Bob, Paul and M Alex about the mod:

Well that mod was not 100% necessary, it’s the way I thought CA hinge can be fitted under the control horn.

Now I’m gluing the pushrod tubes to the tail section.

iron eagel

Alex,
I think that in the long run you will be glad that you did this mod. to the tail. As designed there is very little bonding surface for the lowest rudder hinge to the fuselage. And as Mark pointed out you have the stress of the rudder control rod on the rudder at this point. I have had failures of the hinge in this area on a airplane of similar design (20 size sportster), where I have had the lower hinge let go . I had to repair the vertical fin, rudder and tail wheel link as a result of the damage. That butt joint is not all that strong and is a week spot ready to fail as far as I am concerned.

N1EDM

My Feedback: (2)

I agree with Paul. I think you did the right thing with that mod, and thanks for giving me the idea.

That's a good one to know. Iron Eagel, I agree with you. Found a nice light tailwheel in my junk box. I'll use it if I can get the weight distribution right.

Alex, have you mounted your engine yet? If not, hold off a bit. Make that the very last thing that you do. A friend once showed me a trick... position your engine on your mounting rails with a rubber band. Then, when you do the final balancing, you can move the engine back and forth a bit to help with final balance (within limits). It might not be that easy with the needle or the muffler in the way, but you could always raise the engine off the engine bearers temporarily with some scrap balsa.

Bob

Alex7403

Yes that was correct Mark.

Well now that I’m thinking its good that I created a place for the bottom hinge.
The load from the tail wheel will not go directly to the fuse, I’ll put a ply wood plate between the fuse and the bracket.

I’ll come back to that wheel later.

O.K. which tool should I use to cut off the red pushrod?

N1EDM

My Feedback: (2)

Hi Alex,
You could use a fine X-Acto saw on its side to cut that rod, then sand it flush with a sanding block. After that, carefully trim the burr out of the ID of that rod.

Instead of putting a plate on the outside for the LG, you could glue in some 1/8" lite ply braces from the inside. Then you would not have a 'bump' on the outside of the fuse to cover over.

If you are going to use T-nuts to mount your tailwheel, make sure you leave enough room for the flanges on the inside bottom sheeting.

Bob

Alex7403

Back to building

I had a gap on the horizontal tray so I placed a stick to close the gap.
Then glued it to the wall of the fuse better.
Glued the pushrod tubes to the formers.

I left bigger gap between the tubes and the former near the servos tray in order to compensate for the movement of the tubes to side duo to servo movement.

And drilled the holes for the fuel lines, first marked it from the inside then drill a small diameter hole from the inside, checked for match then bigger 7/64 from the motor side for perfect match.
This was done because of the close gap between the tank and the fire wall.

Alex7403

Hi everybody,
back to build again.
first picture is the bracket that gonna hold the tail wheel assembly.

Last two pictures I need your opinion how bad it is:
Look please at the difference between the horizontal stabilizer and the wing, the stab is looking left.
How bad it is in terms of flying, I don’t want to take the tail apart.
the balsa sheet is not straight 100% eiter, I was thinking to make it wet and try to bent it up,
Only if I have to.

Because of this sort of thing I hate to leave the airplane build, I don’t remember what I need to correct.

iron eagel

Alex,

It looks like the back of the fuselage is twisted to the left, if you look close you will see that the vertical fin is also off to the left. It does not look as bad but it is still there. It might also be that the right side is of the fuselage is a bit higher than the left, it does not take much of an error to translate to a big change in the horizontal stab.
I think that the gap that you mentioned earlier might have been an earlier indicator of a problem,perhaps you can use a diagonal shim forward of the tail to take some of the twist out.

Alex7403

Hi Paul,
Maybe there is a twist its not so bad, the picture is not straight either…
“Diagonal shim” what do you mean???

iron eagel

something along this idea...

MasterAlex

Alex ... yeah, I'm with Iron Eagle - I would go ahead and try and fix this. I don't remember having fillets under the horizontal stab, was that something you added? I added them to support the fin on top, but not underneath. Could those fillets be the culprit? How did you ensure the Hor. Stab was square to the Fuse when you glued it down? Maybe it shifted after you had it square?

I guess I'd like to see us figure out why this happened so it doesn't occur on your next build ... maybe that's just me. [&:]

Anyway, I think you'll be happier fixing this now than dealing will an ill flying airframe the rest of its life. Chalk it up to experience.

-MA

Alex7403

OK

With water from the faucet directly on the fuse on the section behind the wing.
While its wet held it and twisted it, lock it like this for 2 hours.
Its not perfect but its pretty good, its good enough.
Need to see if it wont twist back over time.

I hope I didn’t do and damage to the medium CA glue joints…

N1EDM

My Feedback: (2)

Y'know, Alex gave me an idea.

One of the greatest sources of drag on a plane is where the flying surfaces meet the fuse. I think that the triangle stock under the fuse would eliminate some drag/turbulence. I might try that on my own Mid-Star (when I get around to building it) but I might try a thinner stock underneath, say, 1/4". I'll keep the 3/8" stock on the top to help support the fin and to eliminate drag. Alex, was that included in the kit, or was that added by you?

Bob

Alex7403

Hey Bob,
If the tri stock will eliminate drag so be it.
The reason I placed this triangular stock is to have better and wider attachment between the fuse and the stab.
It wasn’t included in the kit.
From previous experience the mid star becoming nose heavy with OS 46 AX, so I prefer to add some reinforcement to the tail instead just adding led.
If it will be tail heavy I’ll be glad to move the battery pack in front of the servos, now as I plan it its sitting behind the servo tray.

Alex

Alex7403

I just glued the elevator, straight and even.

farr301

Hey all, i am building the mid star as my second plane!! i just finished the second wing half, but i probably won't join them together until tomorrow or monday. I won't be keeping up with the others building this plane because i have school so i don't have much time to work on it. Hope mine turns out as great as yalls will!!!!


Farr301

Alex7403

o.k. canopy

I’m doing the canopy right now.
canopy is the most tedious part in this whole plane.
in my opinion canopy is the hardest part of this airplane to build for several reasons:

1)Its got to stay clean and without scratches.
2) canopy glue need to be used, not recommended using CA or epoxy glues, CA fumes will make the canopy dirty from inside and epoxy I doubt how it will glue the plastic, I tried it on scarps didn’t glue.
3) its got to be perfect fit to the fuse and wing so there wont be any gaps.
It got to be beautiful because the canopy attracts attention.
4) for this glue it takes 3 hours work time and 24 hours curing time…..

I choose to glue the canopy in two parts:
1) back plate till about ¾ base
2) the rest of the cockpit
its easier to clamp it this way and avoiding holes and gaps.

Now im waiting 24 hours without opening the plane.

Alex7403

The canopy adds a lot of beauty and uniqueness to this plane but its also its weak point since it cannot fly without it…
its not an easy thing to build, I kinda got into this loop and being too fussy about it.

Canopy continuation

After 15 hours since canopy glue was applied its still fluid at some points and still white.
Other points it became completely transparent it’s the desired state.
I’m talking about gluing the back plate of the cockpit unit, I could do it all at once but I don’t have enough clamping and its difficult because of the angle and the glued wood, so I decided to make it in two sections.

15 hours passed and 12 more hours at least in this setup.