Cocktail stick through mylar hinge

[DavidKP]

I have read that when you use the mylar hinges it is recommended to drill a hole through and push in a cocktail stick, trim it off and add a drop of cyano. This makes sense when the hinge is going into nice big flat sheets of balsa. But the plan I am using has a rudder 18cm high, the top two hinges are going into the sheet tailfin, no problem, but the bottom hinge is going into the fuselage below the tailplaneand elevator. At that point it is only going into a 5mm thick cross sheet between the fuselage sides. So do you recommend that I still drill across the 25mm wide fuselage a few millimetres behind the cross sheet and push the cocktail stick stick through the gap? Or do you just rely on the glue?

[TIM Shaw]

I'd ALWAYS pin Mylar hinges, doesn't have to be a cocktail stick, some people use dress makers pins and I normally use panel pins, but you want something through it to stop the hinge pulling out - and when a hinge does pull out it is usually fatal for the model.

In the situation you describe I would probably have added a scrap balsa infill to form the bottom of the rudder post, but I guess its a bit late for that now....

JMTC

Tim

[Engine Doctor]

Better still don't use mylar for hinges , it was ok when nothing else was available but things move on . Buy some furry hinges they won't need pinning . Make a slot in the wood slide in and apply Zap thin cyano , job done . dont try to glue them with DIY cyano as its not thin enough.The 5mm balsa between the fus sides should be ok but if worried then fit some soft balsa behind the 5mm to give added support.

[DavidKP]

Yes ...... it is too late now, the area in question now has the tailplane glued on top and piece of 5mm ply and tail skid underneath.

I have read about these 'furry' hinges but have not seen them for sale in the shop, so I just followed the plan, it's only 3 years old so still up-to-date in my eyes. I will definately put in something as a pinning solution, losing the rudder in mid-air doesnt sound like fun.

[Former Member]

[This posting has been removed]

[Robert Parker]

Hi David,

I always use cocktail sticks when I use my mylar hinges or any other flat hinge.

In your situation I'd be tempted to put the cocktail stick tight behind the 5mm so it prevents the mylar hinge pulling out.

When I fit mylar hinges I drill a 3mm hole into the edge of the rudder and fin as in your case, where the slot is, before fitting the hinge I rub both sides slightly with sandpaper to rough it up a little to give the glue a key. Insert hinge and allow a few drops of cyano into the hole and slot. The hole allows the glue to penetrate the full depth of the hinge.Then the cocktail pin.

Sorry if I'm teaching my grandmother to suck eggs but better to be safe than sorry.

Regards

Robert

[Mike T]

You need to be careful with fuzzy hinges - I've had the fuzzy bit come detached from the core. Check before installing to see if the fuzzy layer can be pulled away. If so - don't use!! I prefer ordinary mylar strip, aggressively roughened (as opposed to 'lightly abraded'.

I've also seen mylar hinges shear on the hingeline - so perfectly you swear they'd been cut with a scalpel.

Mylar hinges: user discretion advised...  (Cue raft of 'I've never had a problem' posts... )

Edit: to answer the original question , put your anchor through the hinge behind the 5mm fin post, so that it bears up against it, as already advised.

Edited By Mike T on 26/03/2017 19:35:56

[Shaunie]

I've also had problems fluffy hinges delaminating. I had some Mylar hinges come loose... on a model I built around 1992, then flew the pants off it, hung it on a ceiling for 16 years and then started flying it again around 2011. Spotted a problem on a workshop preflight and reglued them. As the plane was about 18 years old I wasn't too worried. I never normally pin my hinges but I do aggressively sand the shine off.

Shaunie

 

Edited By Shaunie on 26/03/2017 20:49:25

[John Emms 1]

Sorting out today, I threw away some moulded mylar hinges (or perhaps nylon?) that were still hanging around. I have experienced fluffy hinges with the fluff that peels away, but that would be over 20 years ago. The Kavan and Pelikan hinges that I use have all been good.

[ChrisB]

I use Kavan split pin hinges on all my IC models. I epoxy them in and then use a dress makers pin it pin the hinges.I push the pin in from the underside until it just goes through the hinge. Then I snip it and push it home.

I always use 3 hinges per surface which allows for one to fail and still enables the surface to function.

[john stones 1 - Moderator]

I never pin hinges and never had one fail, i like the fluffy ones and any of quality hinge ones, glue it right it'll be o.k

John

[Andy Blackburn]

I've only ever pinned mylar hinges once, back in about 1984, and that was the only time. I've used mylar hinges almost exclusively until a few years ago, then went to Great Planes fluffy hinges. I've never had a hinge fail or pull out.

[Andy Green]

Don't spoil your model with cocktale sticks, use pins. insert until you can feel the mylar, snip off with 1mm proud, and push in. almost invisible.

This article shows you how.

Andy

[Peter Garsden]

I have certainly experienced unpinned and glued mylar hinges pull out on a Chris Foss Phase 6 Aileron. Fortunately it happened in a crash and not mid air, so this was perhaps understandable. I remember trying to retrieve the model from a thorn ridden thick tree - the only one on the slope, which you always hit. In fact it hit so many trees that I made a special sticker using the Foss Font - can't remember the name, "This model likes trees" After the crash I pinned the hinges with cocktail sticks as advised in the plan.

I have also had fluffy unpinned hinges pull out, but thanks for the tip about just pushing then snipping pins before pushing fully home, because protruding pins have been a problem, so agree re the need for pins - they wouldn't have holes for the pins if you didn't need them.

The best hinges I have used are sealant full length ones which seal the gap perfectly. There are articles on this and they featured in my Jart blog

[gangster]

Cut a small triangular hole in the Mylar hinge on each end with your scalpel. Epoxy the hinge in The glue will make its own pin.

[Former Member]

[This posting has been removed]

[Mike T]

Posted by Tom Sharp 2 on 27/03/2017 00:50:32:

Using metal pins is not on. If they come out and end up in a cows stomach, farmer will not be pleased.

Taking all things in to consideration, the likelihood of that happening (much less having any adverse effects) is vanishingly small!

[MaL]

Ask three modellers the best way of doing something and this is the result.......

cross drill all hinges out to 3mm and fit a High tensile bolt and two locknuts.....job done

[John F]

As others have said furry (or flocked) mylar is unbeatable and does not need pinning. A drop of superglue and it will never come loose!

**LINK**

Here's a vid of how good flocked hinges are:

[J D 8]

Posted by Tom Sharp 2 on 27/03/2017 00:50:32:

Using metal pins is not on. If they come out and end up in a cows stomach, farmer will not be pleased.

 

 

As a stock farmer it is amazing what some cows may attempt to eat and do not think a little pin would have any effect.

However eating the whole aeroplane [ not joking ] would be another matter.

Edited By J D 8 on 01/04/2017 10:53:18

[Mike T]

Posted by MaL on 31/03/2017 22:44:46:

Ask three modellers the best way of doing something and this is the result.......

cross drill all hinges out to 3mm and fit a High tensile bolt and two locknuts.....job done

If possible I always use a full-length piano hinge on ailerons (but remember to get permission from the piano-owner first...). On rudder, I usually use those hinges from restaurant kitchen doors - swing both ways (ooh, err, missus) and are self centreing.