Simon's Skywriter Build Blog

[sihinch]

OK, so here we go, creating a dedicated build log for my Skywriter.

My first post I am going to show you the weights that we started discussing int he build class thread.  I'm happy with my rudder at 10g. 

The fin as per the plan, built exactly as it shows, comes in at 26g.     I cant show you much because I've attached the ply side reinforcements.  So you need to take my word for it!

I built a second fin tonight, as per the plan but without the ply sides.  This is shown in the thrid photo and weighs only 8g!   

I will be using the lightweight version! 

[sihinch]

Just finished the horizontal stab and it weighs 14g. But I may add some balsa sheet. Not sure. It feels pretty sturdy.

[sihinch]

I decided to add some 1/32 balsa sheet. I'm new to this building game so who knows if it will make any difference! I'm hoping it will add some rigidity and little weight. We'll see.

[Papa]

The 1/32nd will increase the thickness and make it a 1/32nd thicker than the rudder.

You could use my solution and use 1/64th ply.

Either way it will all work so go with what makes you comfortable.

Looking great with all this building.

jack.

[sihinch]

Bizarrely my rudder is actually wider than the fin at present.

But I was adding the sheet to the horizontal stab.

I may copy Michael and add sheet to the fin, too. But I'm not sure it needs it. It feels solids enough.

[Papa]

The Fin should be 1/4" uncovered which is 8/32". The rudder should be 9/32" (3/32" x 3).

Does that make sense?

Jack.

[sihinch]

Well, it worked. Adding balsa sheet to the horizontal stab definitely made it stiffer. But it more than doubled in weight. Still lighter than Jack's with the ply, though.

The frame was 14g. With 1/32 sheet on both sides it's now 34g.

Was it the right decision?

[imran13]

Jack sheeted his with 1/64th ply, and from what I can remember, it was somewhere around 26g (??). Either way, since I'm new to this I don't know how much difference 20g can make.

[Michael]

20 grams of extra weight in the tail, could require 3 or 4 times that extra in the nose to balance a model, if it is unbalanced.

[sihinch]

Jack's horizontal stab was 53g vs. mine at 34g.

[imran13]

Oops. Ignore what I said 

[sihinch]

Well, I finished step 1.

Elevator is finished and I'm happy with the strength of the joining wire now they are hinged. I've not glued the hinges yet , of course.

Elevator and stab weigh 56g. I used some carbon tow to reinforce the joiner.

I messed up the ply reinforcements and put them on the elevator halves before the balsa leading edge doubler, so I had to sand a groove. Anyway the nice thing is that you can fix these mistakes!

[Michael]

You mentioned (in another thread) that your wing is crooked.

What is the problem?

Post an image with a description if possible.

Your "live online Skywriter help team" (Robert and Michael) are standing by.

[sihinch]

Thank you "Help Team!" I actually do need some reassurance. I'm learning as much about my character as I am about building. I'm miffed that my wing is not perfect, and am eager to complete it, which talks to me about my perfectionism and need for a payoff (seeing the finished article.)

I made a few mistakes building the wing. First, I built the wing square to the LE and main spar, which was different to Frank. I think he used TE and main spar. I only realized by looking back at the photos. Anyway, remember the LE & spar comment.....

Then, one of my LR3 ribs was not glued in level with the bottom of the wing. So I cut it and reinforced the rib on both sides then sanded the top profile to match the other LR3. I'm not too worried about this repair.

I wanted to compete the wing as much as possible - I felt I was on a roll. So I decided to add the additional rib at the wing center. Again, I lined this up with LE and main spar. But I noticed the front section of the rib was not straight (it's a 2 piece rib because of the dihedral brace.) So I cut that out and repositioned it. Again, not worried about that.

What I am miffed about is that one of my LR1 ribs was obviously not cut to the right length (by me) and it's pushed the lower mid-wing spar back and the TE is now not perfectly straight. I think this is only minor again, and will probably be hidden when we add sheeting and the tapered TE section (inboard of the aileron) but I'm annoyed about it.

Please someone tell me all these issues are OK and won't mean I need to build the wing again?!

[Michael]

Robert says it's not a problem.

As long as your wing is not warped, it is not an issue at all.
As you continue building your wing, make sure it remains as flat as possible.