Holding wings on?

[Jolly Roger]

Anybody used tie-wraps to hold wings onto a fuselage, in models where the wings slide onto a joiner that runs through the fuselage? Sturdy cup hook in each wing root, one tie-wrap clicked tight. Snip it at end of flight.

Experience? Problems?

Thanks.

[RobbieB]

Afternoon Rog.

I've used that method in the past on sport models to which it was ideally suited. I had no problems at all with the added bonus that if you choose the size of the tie carefully they would break on a heavy arrival. Just get another out of the box and away you go.

[Trevor]

Interesting idea. I must admit that I've generally used heavy rubber bands in that situation, which work well. However, on my AV36 build, which has a 3-piece wing, I'm still wondering what to do. The default option would seem to be a strip of tape over the joint. Other possibilities involving magnets and/or self tap screws bearing in the joiner blades are possible, but a bit of a drag. Of course, the brave option is nothing at all, just rely on the friction of the joiners.

Any other candidates?

[terry white]

I like all the ideas,most I have done before all with good results, but mainly on smaller models.

However for my 1/4 scale models and over, I have changed the incidence pegs front and rear for 1/4 inch threaded bar that protrudes into the fus. onto this I slide a reasonable strong cylinder spring and compress it with a wing nut. Tighten it so that it well holds the wing in place but also allows good give on those landings in the rough. Ter.

[Ian Davis]

Yep I use this method on my 1/4 scale Schweizer 2-22. I used to use rubber bands around cup hooks in the wing roots that protruded into the very narrow centre section. While struggling with the last turn of the band in a very confined space, that well known pundit of all things wonderful (BC) offered a tie wrap. Worked a treat.

Ian

[Barry_Cole]

Interesting idea. I must admit that I've generally used heavy rubber bands in that situation, which work well. However, on my AV36 build, which has a 3-piece wing, I'm still wondering what to do. The default option would seem to be a strip of tape over the joint. Other possibilities involving magnets and/or self tap screws bearing in the joiner blades are possible, but a bit of a drag. Of course, the brave option is nothing at all, just rely on the friction of the joiners.

Any other candidates?

Multiplex wing locks.....



BC

[Jolly Roger]

Really useful replies - all of them.

I was about to use Terry's threaded bolt approach, but the model is a Piper Cub and a rough landing could rip the upper cabin structure apart. With the tie-wrap approach, the wings are just pulled together by the tie-wrap and the fuselage should have less stress.

I suspect the required tension will be small on this model for all positive G flight as the wings are naturally held against the fuselage by the wing struts.

I'll let you know how I get on.

Thanks again you lovely people.

[FrankS]

I use rubber bands and Multiplex wing locks (not on the same model ), but another option which was used on the Glenns Maule power plane was to have plastic bolts protrude from the wing secured to the fuselage by a captive nut screwed on with the flat face first (i.e. no fiddly screws and nuts to lose), this worked well and in a hard landing the plastic bolt would shear.

[Trevor]

Thanks guys, I'd never come across the Multiplex wing locks. I'll probably do the maiden flight with just tape then, if all goes well, look at retrofitting the wing locks.

[eric friend]

Hi Trevor,

Just a short tale regarding my use of Multiplex wing locks.

I have an ex-John Elliot 4 metre Multiplex ASH25 which is fitted with said wing locks. I was offered a launch by a long standing flyer who trotted with the model, stopped and then gently thrust it skywards with the inevitable descent towards terra firma. Luckily it landed quite level so I said to the launcher to launch it again as all controls were working OK and they continued to do so throughout the next ten minutes in the air. However, when I was on the final phase of landing, it was apparent that the starboard wing lock had become unlocked as when I banked onto finals the starboard wing must have slid out fractionally, losing the electrical contact between the electrics in the fuselage and the three servos in the wing. This resulted there being no roll response ending in a heavy landing but with luckily minor damage. So now I always tape the wing/fuselage joint to be on the safe side.
I learnt a bit more about model flying from that - I'm never too old to learn!

PS - Reading the text associated with taking the BMFA Slope A and B certificates, it does state that the model should be inspected after every landing and be given an even more detailed one if it is a heavy arrival . . . and I failed to do that. Slapped wrist time.