I need to reinstall the ailerons on a 40-sized trainer. What are the best kinds of hinges to use, flat nylon with steel pins, CA, the round post type? Which are easier?

I always use the Dubro nylon pinned hinges. Easy to work with and very strong.

Robart hingepoints I believe are for larger planes.

Edit: Be sure to use hinge glue. http://www2.towerhobbies.com/cgi-bin...&I=LXCX67&P=ML

For a trainer, CA hinges are better. The Dubro nylon hinges are a bit loose.

As long as you have room to do it, CA hinges are by far the easiest, BUT you cannot put the new hinge where the old hinge was, you'll have to cut a new slot next to the old one.

For more on installing CA Hinges, read this:

[link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=55]Installing CA Hinges[/link]

For my last two builds, I used the Dubro nylon pinned hinges, and I like them a lot. When installed correctly, they have less resistance than CA hinges, and are much easier to install. They take a little extra care to ensure they are properly aligned, but the final result is worth it. I install them with Gorilla Glue, which expands in the slot. If you want extra security, drill down through the hinge after its cured, and glue in a toothpick. That sucker is never coming out.

Brad

I would go with the nylon hinges with the steel pin and use the hinge glue as suggested. I also go back and pin the hinges using round tooth picks and wood glue. Then go back and dremel the tooth picks flush with the surface and then seal the ends with a drop of CA. I have never had a failure doing this. There are a few rules to installing CA hinges properly and if not followed, the result is either you don't get the proper movement of the hinge or, it will crack and then break on you. [8D]

I prefer steel pinned nylon hinges on smaller planes but if the plane is big enough I use Robart hinge pins. Hinge glue is the preferred adhesive. The hinge slot machine with the thick blades does a nice job for the flat hinges, the thin blades for CA hinges and a simple drill for the Robarts. Using the appropriate alignment jigs is a good idea to keep all properly aligned.

I don't have a particular type as a favorite I use em all, but robart makes pretty much all sizes of hinges from 1/2A to giant scale,the big gripe on CA hinges is that they crack and break as long as you don't over soak them with glue they work great I have not had any one of them break on me,I have heard that they can, the trick is getting enough glue to hold the hinge in place without over gluing

The "Trick" to CA hinges is to drill a small hole (about 1/16" - 3/32" ) in the middle of the hinge opening so the CA can get in there and penetrate the hinge and wood. If you are overly concerned about the center part of the hinge being stiff, mark a line on it with a crayon on both sides - the CA will stay out of that area.

When using the flat pinned hinges or the Robart hinges do not forget to inlet BOTH surfaces for the hinge area. Failure to inlet both surfaces will result in large gaps.

I have blown-off the following airplane parts in flight due to failure of CA hinges:

1) Left aileron - SIG Mayhem

2) Rudder - SIG Mayhem

3) Elevator - H-9 Super Stick.40

4) Right Elelvator half - H-9 Showtime 4D .90

5) Left Elevator half - H-9 Showtime 4D .90

So, what do you think my opinion of CA hinges is? .....they suck, aren't worth a darn and frankly should be banned for safety reasons alone. (Mind you they work fine for trainers and planes with minimal amounts of throw. I just learned the hard-way that they are not intended for high stress applications).

If you insist on using CA hinges, get the Radio South CA hinges. They are used in Giant sacle planes to 100CC. I like pinned hinges for GS and Robart hinge points for glow planes. If the surface is too small for a good installation of either of those, get the Radio South CA hinges...they are the best CA hinges made.

Wow. I am nothing less than conflicted about all these opinions! So I think here's my plan: I'm going to try again with nylon hinges, using hinge glue which I bought tonight from my hobby store, and seal the gaps with Ultracote per KenRC's method. It's just a trainer and I'm a newbie, no aerobatics planned for this summer. If and/or when I have an aileron disconnect due to hinges, I guess I'll form an opinion after CSI-ing the wreckage. LOL.

Meanwhile I think I'll worry more about learning gentle turns and landing my tame trainer with the help of an instructor. Thanks for everyone's opinions!

Not trying to start a wizzing contest here so please don't take it as offensive. CA type hinges When Properly Installed are second to none. I've used them on everything from a 20mph trainer to a 200+ mph jet and even my 1/4 scale gasser (has some hellashious deflection) with excellent results. i did have some breakage in the early days when i thought you had to soak them with the thin till they refused to hold anymore, but when i changed my installation method I've not had a single breakage or failure of one in well over 10 yrs. the drilling of the 1/16" hole in the center of the surfaces to be hinged is a necessity on large scale planes and fast planes and is an added safety feature on even trainers. the trick is to center the hinge, and put 3-4 drops of thin on both sides (this is for a 1"x3/4" hinge) and that's it, don't put any more on it. when done right (not crocked sideways in the slots) you let the glue dry for about 5-10 min and then flex it a few times and then the weight of the control surface will deflect the hinge they are so free to move.

kc

CA hinges are good, but if youre like me and are trying to not use CA at all, then id go for the robart hinge points. to me they are alot more trouble free on the instalation, b/c you only need a drill to install them. no need for fancy slotting machines or messing around with an xacto knife.

mbilar1, You made the right choice and you won't have to worry about hinge breakage!! I had a Shoestring that was given to me from another pilot. The plane was made from plans and was at least 3 years old. All the control surfaces were mounted using the CA hinges. After a few flights the rudder would suddenly vear hard to the right on a take off run. It took a while to find the problem but it turns out that the bottom hinge on the rudder had broke in the middle. At larger throws the rudder would slip by the broken hinge and twist to the right. When the rudder was straighted out, everything looked ok. I made new slots and managed to replace the hinge with a nylon type with the steel pin. [8D]

Here we go again,

Flying in windy conditions on an elevated runway with a roller, I tapped the rudder on the runway on approach. There is barely a dent in the bottom tip of the rudder. BUT, the rudder came completely off the plane and was held by only the pull-pull cables and the TW springs when all 4 hinges failed. (They failed in the same manner as all of the others failed, by ripping in half).

I went around with the rudder flapping behind the plane and banked and yanked it home with no damage and a surprisingly smooth landing.

What type of hinges failed as a result of such an inocuous rudder tap? mmmm.... uh...CA HINGES! I assume they were installed correctly as I have over 12 gallons of glow fuel through this plane.

From now-on I will donate all CA hinges to a home for the mentally disabled or a tent for stubborn circle flyers. I am done with CA hinges for good.....again.

For those of you who wish to defend the use of inferior hinges because it hasn't happened to you yet...go ahead and use them. It's your plane, just keep your homeowner's insurance paid so you can fix the damage you cause to the rest of us.

I'm sick of replacing failed CA hinges, although I am getting better at it these days.

OK, I'm done venting. I still think CA hinges are adequate for small scale and sport planes, but if you intend to fly 3D or fly any plane for more than 10 gallons of glow fuel, get real hinges.

In most circles of high performance aircraft, Robart pin hinges are the standard but for sport flying CA hinges work just fine. There are failures of course just like anything else. If they are properly installed and you actually inspect you airplane before flying it as you should, you have little or no worry.

I have been using dubro or klett pinned nylon hinges since 1970 glued in place with hobbypoxy,after 37 years no pinned hinge hailure and none have ever pulled out,They have been used in everything from trainers,sport,ducted fan,pylon racersmulti-engines,and sailplanes.I have several planes that are flown every weekend that are over 20 years old including my original trainer built in 1970 .pinned hinges when properly installed leave no gap that requires sealing

i just recently stripped down and gave away my 8 yrs old Ultra Sport 40 that had Many, Many x10 gallon of fuel through it and never so much as a single hinge breaking, it had a Jett 90LX for power so I'm quiet sure they were stressed to the point they would of failed if (and this is the important part) they had been improperly installed.

breakage of the hinge at the centerline (flex point) is from over gluing on CA hinges. as mentioned above they require technique to install correctly and there are people who just can't stop adding the glue after 3-4 drops so they have failure. anything installed with improper techniques is more susceptible to failure and CA hinges are less forgiving when under those conditions. i appreciate everyones decision who has chosen to not use the CA hinges but they are hard to beat when installed correctly and will last forever.

kc

I forgot to add:

don't go taking it as a personal attack, it's not. i had CA hinge failure too when i didn't know the proper technique to installing them and as you i said many times 'I won't use those again" and my breakages were always the bottom rudder where it got the blunt force of tail dragger 3 point landings. when i got out of the mind set to keep gluing the hinges past the 3-4 drops, i stopped getting failures.

kc

Well,

I am still working on replacing the hinges with Robarts, I am delayed by my baby girls who are more important right now. (They say 'Hi' everyone').

I agree, and use that very technique. I think it's a matter of size and force. I have 8611's and 45-50 degrees of throw. The plane is a Showtime 4D .90 with a Saito 1.25 for power...and I abuse it. I am hard on my planes. I fly them every day and rarely maintain them beyond field repairs and...um....more field repairs.

I just think something as critical as hinges should be more substancial than a fibrous scrap of chineese paper, that's all. I appologize for the frustration in my previous posts. I only have one glow plane, and I can't take my gassers to work with me, so .....until I fix it, I am limited to foam during the week.

I regret doing it, but I fear I must exhume this thread in order to avoid doing something that might be considered productive.

I finished re-hinging the rudder and flew on Thursday. Flew great, but I noticed a bit of extra movement in the left aileron...DANG IT!! 2 of the 5 CA hinges had broken in the same manner as the others on the tail.

I re-hinged last night and flew again today without incident. I did notice that the glass engine mount has quite a bit of flex in it these days, however.

As of now, there is only one surface (the other aileron) with the original CA hinges and I will replace those as soon as I make time.

Mind you, this plane has 3D throws, no low-rates, I fly it every day, and I am very hard on it. The original CA hinges lasted, on average, about 8 gallons of glow fuel. That's a lot of flying, and if you couple that with the fact that I rarely clean my planes unless repairs are needed, it stands to reason. ( I have also had to glue the stabs and tube in place, re-blind-nut the canopy bolts, re-plumb the fuel system and replace worn-out wheels, one of which left the airframe on take-off last Saturday.)

I think the combination of excessive throw, constant oil soaking and daily use has caused these repetitive failures.

Because of the way I fly, the frequency with which I fly and the way I (don't) maintain my planes; CA hinges are not for me....and I don't intend to change. BUT...many people have enjoyed great success with CA hinges for many years. I choose pinned hinges when I have a choice, and Robart points for re-hinging because they are very easy to install.