By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

How do I fix aileron hinges?

All Topics | Latest Posts

Search for:  in Thread Title in  

Articles

Hinging up!

Hinging up!

Andy Green looks at methods for hinging control surfaces - 27/3/12

Mogs09/02/2011 12:53:18
avatar
149 forum posts
1 articles

Background

I’m trying to retro fit ailerons into the wing of my 30 year old Cotswold Square One. The wing is fully laminated with an expanded polystyrene core, balsa leading and trailing edges.

So far I’ve cut out a recess in the underside of each wing to fit a servo and “excavated” a tunnel through the core to emerge out of the wing direct into the radio equipment bay for a Y-lead. The edges of these holes I have reinforced with 3mm ply.

I’ve cut out the control surface approx 35mm wide by 450mm long, starting about 80mm from the fuselage (root?), with about 100mm to go to the tip. Obviously this exposed the core. The cut edges (wing and aileron) I have reinforced with 3mm balsa so that the laminate is top and bottom, incorporating a 45 degree angle on the aileron to allow the surface to drop. Into the reinforcing strip I have rebated slots (3) to allow 20mm hinges to fit flush against the underside of the upper surface laminate.

My little book states glue and fix with cocktail sticks.

Question
“How do I fix aileron hinges?” or more precisely…

How do I mark and drill the holes for the cocktails sticks?

How do I ensure the hinges are in a straight line?

Do I fix the ailerons before the covering or after? and finally

Is there anything else I may have missed?
 
Thanks
Danny Fenton09/02/2011 13:03:44
avatar
9283 forum posts
4113 photos
There are several different methods that people use, and hopefully you will get other oppinions. Personally I like to cut slots in the trailing edge of the wing and leading edge of the control surface BEFORE covereing. Though you will have to clear the film once they are covered to find the slots again.
 
As for cutting them accurately...... well that is by being very careful I am afraid. If your wood is soft enough you may get away with laying a steel straight edge along the aileron parallel to the surface and use a fresh blade in the scalpel. It is a little easier if you use a Mylar hinge as this accepts slight innacuracies in allignment. Another thing you can do is angle the cuts so that the hinges are pre bent by a few degrees, this means the "meat of the hinge is below the outer skin.
 
As for the cocktail sticks you simply guess the centre of the area buried in the wing/aileron and drill through from upper to lower surface, this stops the hinge from pulling out. Push the cocktail stick through and trim to length. You will probably need a small patch of film to hide the stick.
 
Perhaps a drawing is in order if I haven't made myself very clear?
 
Cheers
Danny
Tim Mackey09/02/2011 13:13:09
avatar
20919 forum posts
304 photos
15 articles
Clear as a clear thing - and exactly as I do it as well.
Cotswold square one eh...ah my very first RC model
Richard Wood09/02/2011 22:18:06
avatar
1094 forum posts
164 photos
As Danny says this job needs a bit of care for good alignment.
I've made a pig's ear of it once or twice by rushing it!
 
If you want you could try drilling the wing & aileron hinge areas
for the sticks from the bottom surface with a spacer or mark on
your drill so that it goes through the mylar hinge but doesn't come
out to the top surface.
It just means there are no holes showing on the top but the cocktail
stick is still securing the hinge.
 
It can be a tad difficult to accurately drill these holes all the way through
so that they're not a bit squint on the bottom side - IYKWIM.
The thicker the wing/aileron the easier this is to do.
 
Good luck with your Square One - is that a fibreglass fuselage
high winger?
A bit like the Waterhouse & Ely Superfly if I remember right - mine flew
really well.
 
Cheers
 

Edited By Richard Wood on 09/02/2011 22:19:38

Gary Binnie09/02/2011 22:37:32
avatar
515 forum posts
34 photos
Tape?!!
 
 
Page 9 of the PDF shows the diagrams and page 15 explains how to do it very clearly in English.
 
I've got three large gliders including this one, all the control surfaces (except the rudders) are hinged this way, the flaps are just hinged on the bottom instead of the top.
 
There is a variation of the method using film instead of tape and you cover over the upper tape with the main covering to hide it.
 
No cocktail sticks!! I'm forever getting epoxy on the hinges of surfaces that can't be hinged this way, pre-wiped with Vaseline and keep the surface moving until it sets!!

Edited By Gary Binnie on 09/02/2011 22:40:18

Mogs10/02/2011 13:34:08
avatar
149 forum posts
1 articles
Posted by Richard Wood on 09/02/2011 22:18:06:
 
Good luck with your Square One - is that a fibreglass fuselage
high winger?
 
Yes.
 
 
I'm going with leaf hinges, a bit like the ones used to hang doors. They have six holes per leaf in two rows of three.
 
I think the accuracy needed to find the holes is beyond me. My plan at the mo is to place them in the slots in the wing - no glue, and align them. Masking tape and bulldog the other leaf to a temporary aileron. Remove, grease up the pivot area then glue in place. When dry drill right throught the lot to fix two sticks missing the existing holes completely.
 
Thanks of the hints.
 
Richard Wood10/02/2011 13:56:21
avatar
1094 forum posts
164 photos
Leaf hinges tend to need a 'slot' cutting out rather than just the 'slit'
needed for mylar hinges.
There's a tool available for doing this:
 
Sticks not always necessary with leaf hinges as the epoxy can form
a 'peg' through the holes.
 
Plenty of dry runs to check before committing the epoxy
 
Danny Fenton10/02/2011 14:11:20
avatar
9283 forum posts
4113 photos
Mogs, I would seriously think about whether to use leaf hinges or mylar, leafs are very free but are more noticeable on the surface and much harder to get straight. And as Richard says need more of a slot than a slit lol. But again as Richard has said the holes key them to the surrounding wood so do not tend to need pegging.
 
Leaf hinges are great in the right place but for this i would go with mylar.
 
Danny
Mogs10/02/2011 14:51:49
avatar
149 forum posts
1 articles
Richard
 
The slot cutter looks good and scary, but not needed yet. I was able to chisel the slot easy in the balsa edge prior to me sandwiching between the laminate top and bottom. Sort of rebating job than a mortice.
 
Danny
 
I understand where your coming from, but my SQ1 resurrection project is for me to learn some new techniques, make mistakes, on a plane that I have not invested much cash into. Of course it would be nice if it flies, but I'm thinking that would be a bonus.
Danny Fenton10/02/2011 14:54:48
avatar
9283 forum posts
4113 photos
I can understand that, I often take a more difficult route cos I haven't done it that way before, nothing wrong with that
 
Danny
Mogs17/02/2011 14:23:28
avatar
149 forum posts
1 articles
I'm still working on the wings, I've decided to paint in preference over shrink wrap because I have paint and proofer but would have to buy coverings.

My question(s) this time is "How do I deal with the exhaust?"

It currently stops about 3 inches in front of and slightly to the left of the servo I've fitted into the right wing. It's obviously going to get covered in greasy gunk.

Will this be a problem over and above cleaning?

If so can I extend the pipe to just behind the servo, or will this choke the engine?

and if I can extend, what with?

Alan Cantwell17/02/2011 18:52:27
3039 forum posts
you have paint and proofer, but do you have tissue, dope and sanding sealer? or are you going to paint onto the wood?
 
re the engine, get a rubber exhaust deflector,
 
re the hinges, you are using eaf and pin, good show!!! now then, the hinges are full of holes, whats them for? well, they are glue fill holes, here is what i do,
 
i get an old hacksaw blade, as wide as possible, at least as wide as the hinge, i use it as a slot cutter, few taps, one slot,
 
cut the top of the slot, bth sides, at 45 degrees, this is to allow the hinge point to rebate into the trailing edge? control surface, dri fit EVERY hinge together brefore mixing the 30 MINUTE epoxy
 
lubricate the hinge point, being carefull not to handle the leaf, also, smear a small amount of said lube round the hinge point, this is to allow exess glue to be removed with a wipe, coat ONE HALF of the hinge, insert, and wipe away the exess, do this on all three hinges (you are using three, arnt you?) glue the other side, slide the control surface onto the assemble, wipe away the exess glue, leave to set, but give a waddle now and again,
 
i use baby wipes fort the exess glue thing, dont know how we managed without them!and i would cover seperatly,
 
in ALL the years i have used Kavan type hinges, i have never had one pull out, and have NEVER pegged one, thats what the holes are for,
kc17/02/2011 19:17:46
6076 forum posts
169 photos
A Dubro hinge slotter is almost essential in my opinion! You will not regret the purchase. If you want to economise then the centre marking gadget alone is worthwhile and Alex Whittaker showed how to make one in RCME only a month or two ago. Dead simple to make.
I always pin with cocktail sticks dipped in PVA or use a drip of thin cyano after they are inserted. Leave them over length and clip off the excess once the glue is dry....use nailclippers or end cutting nippers ( electricians ) This way the model can be covered first and they hardly show.
Alan Cantwell17/02/2011 19:36:27
3039 forum posts
you know, i forgot the old faithfull dubro hinge slotter, another vote for this superb bit of kit, i now use the great planes electric hinge slotter, another great piece of kit
 
but sill dont, and wont pin the things,
Mogs21/02/2011 09:17:58
avatar
149 forum posts
1 articles
Alan, is tissue, dope and sanding sealer essential?
 
So far I have given it a 3 of coats of Japlac paint and 2 of proofer.
 
I used three hinges, the gap along the hinges has turned out bigger than I had hoped 1/16th"
Alan Cantwell21/02/2011 18:01:52
3039 forum posts
if your happy with the finish, and its not to heavy, then no, but i have yet to see wood sealed without sadning sealer etc,
 
e the gap, did you sink the leaf and pin hinges, as i mentioned? cut the top of the slot at 45 degrees each side of the hinge slot?
Mogs22/02/2011 08:44:32
avatar
149 forum posts
1 articles
Thanks Alan
 
I think I have taken the learning experience of fitting ailerons as far as I can with these wings now. The paint and the proofer have made what looks like a very nice finish. I did the rebating to accept the hinge pin and it looked ok on the dry run. Something went wrong at the next stage, possibly with the drilling and pinning with cocktail sticks.
 
Next is fitting the servos, linkages and the Y-lead.
Alan Cantwell22/02/2011 20:44:54
3039 forum posts
another tip with leaf and pin hinges, is to snip off the corner of the hinge, this gives it a lead into the slot, you cocktsiled stuck them eh? tell you what, get a leaf and pin hinge, get some scrap wood, glue the hinge in exaclty as i said, let the glue set, then try to pull it out, feel free to fasten one ned in a vice, and use pliars on the other end
 
the holes in the hinge are glue retainers, done properly, it will never need pinning
Anthony Pratt 104/02/2014 15:01:36
4 forum posts

Any advice in using covering film to top hing ailerons would be useful

Anthony P

Cuban805/02/2014 16:34:16
2809 forum posts
13 photos

Robart pin hinges........simples!

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Slec
Cambridge Gliding Club
Pepe Aircraft
Wings & Wheels 2019
CML
Gliders Distribution
electricwingman 2017
Sarik
Advertise With Us
Latest "For Sale" Ads
Do you use a throttle kill switch?
Q: This refers to electric-powered models but do you use a throttle kill switch?

 Yes
 No
 Sometimes
 Rarely

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us