Scratchie

I'm building my first RC plane (BUSA Smoothie) and am nearly finished. Before I cover it I decided to check out a few things, the first being how the wing mounts to the fuselage. The kit has two nylon bolts going through the TE into a 1/4" hardwood peice. I used thin CA to strengthen the threads, but I'm wondering about using some type of blind nut. Additonally, the head of the bolts dig into the TE a little bit when tightening, should I use a metal washer to prevent this?

Lightfoot

My Feedback: (1)

I have mounted the wings with hardened threads and with flange nuts. I never had a problem either way. I used nylon washers under the heads of the bolts and they helped to reduce the compression but did not eliminate it.

vpresley

My Feedback: (162)

Hi

One of the things I have seen done is, glue a piece of 1/64 ply in the area around the wing hold down bolts. Another is using a pin, punch holes (not all the way through) around the bolt hole area, then coat with thin CA. Either one should reduce the compression of the balsa.


Vince

MinnFlyer

My Feedback: (4)

To answer your question, no, you don't need blind nuts. The tapped holes in the plywood will be plenty strong enough.

planebuilder66

My Feedback: (8)

The trick thing to do is either the ply plate flush with the wing surface, or you can get a 1/2" dowel or 5/8" and bore a hole through the center for the 1/4" wing bolt, now bore the wing mounting holes out to accept the hollow dowels, sand flush after gluing in place. The ply plate is soo much less work though. The CA soaked threads will hold up for almost ever.

Gray Beard

My Feedback: (-1)

I just drill and tap the hard wood mounting block and harden with CA, never really had a problem and if I ever did then there is enough wood left to redrill the holes and install the brass thread inserts.

bipeguy03

I would just drill and tap the mount block also, But if you do choose to use blind nuts use only a nylon bolt! A metal bolt will vibrate loose, I almost lost my CGM Sukhoi becuase I was'nt thinking and used metal bolts!

planebuilder66

My Feedback: (8)

VERY TRUE!!

Scratchie

Thanks for the replies. A couple more questions:

1. Does thin CA "wicked" in hold as tight/tighter as thick CA put between two surfaces before they are put together?

2. In some pictures, it looks like people "pour" CA when making the joints. Is this much CA necessary?

3. I use enough CA to make a bound, but don't really use a lot of glue - do I need to reinforce?

planebuilder66

My Feedback: (8)

I just use thin CA for hardening the threads and retap, as far as regular wood glue joints are concerned, the tight fit is what transfers the load, A fillet is used to give the bond a little more base and support, it's hard to say which joints need a fillet and which ones don't, but in general, every fillet is adding weight to the plane. I see alot of people do fillet beads everywhere, it's a big waste of money to me and just unneccessary weight added. But that's my own personal opinnion. The structure as a whole is what gives it the striength, not the glue sticking it together.

F-16WpnsTech

Would appreciate it if you could post some pics. I'm thinking about building this plane...it's absolutely beautiful!! Did you run into any problems or have to make any modifications? Thanks.

stevenmax50

My Feedback: (1)

How are you going to cover it?  Monokote?   Dope & fabric?  Would you mind telling us what method you choose and why?  I am looking to go away from Monokote and like to hear opinions on all covering methods. 

Gray Beard

My Feedback: (-1)

On RCU that is a never ending question. I gave up MC and went over to Ultracote years ago and avoid Mono if I can. If a plane calls for a fabric type of covering I like the TEX types, Solartex from BUSA or any of them with TEX in the name. Very good stuff. A lot depends on the plane though and sometimes I glass and paint.
There are just too many ways to do the same thing and most all of us have a favorite or use a number of different things.

Flyeboy

Gray Beard; You mentioned that you painted some of your birds. I would like to know what kind of paint you used, and did you have to fuel proof the paint??? thanks Flyeboy

stevenmax50

My Feedback: (1)

Hey Greybeard....I havent tried it yet but from what i understood, fabric is paintable. 
If I chose to dope & fabric I have to sand smooth prior to prime then paint. 
If I cover with 1 of the Tex type fabrics no sanding is required prior to paint. 
And dope & fabric is lighter weight than glass. 
Are these true statments? 
I do not mind sanding at all so I believe my next project will be Dope & fabric....maybe Sig.  Are there specific determing factors in chosing a covering or is personal preferance and experiance the largest factor? 
I am "D" checking a PT60 that has been flown maybe 10 times but not since 2002.  I have removed all the old Monokote.  and am in the process of filling and sanding the nicks throughout.  I know its just a trainer but I figure I may as well train on covering as well.

Thanks for your input.   Stevenmax

Input from anyone is welcome here as well.  "Cept for the guy who always says buyinf an ARF is his solution!!!

jrcaster

Instead of filling and sanding the nicks, heat up the sealing iron. place a drop of water in the nick and lay the hot iron on it. You should be able to raise all of the nicks.

With fabric and dope you still need to sand the framework before you lay the fabric. Then you also need to use fine steel wool, or 300 or finer grit sandpaper between coats of dope. Dope raises the fibers of the fabric. The first coat or two you will notice a very rough texture as you rub your hand across it.

You may want to check out the Vintage/Golden age area.