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View Full Version : What's the better hinge type?


Norman_I
03-08-2003, 01:32 PM
I'm building an ARF which came with the popular CA type hinge material. I've been wondering if the plastic hinges with the metal hinge pin are better. I considered factors like longevity and freedom of movement. Installation of the CA hinges is very simple, but if the plastic hinges are better than the CA type, the extra care required to install them seems justified. I have the tools required to install either type, so that's not an issue.
Any opinions?

Thanks.

AJCoholic
03-08-2003, 07:06 PM
I like the CA hinges, have used them on many, many planes without any failure (allthough I have seen some brake, my opinion is that the fellow used too much CA and the hinge couldnt flex enough) and I will trust them.

I used to use sig brand X pinned hinges, they were good and still are, but had to be pinned in place with toothpicks and not as easy to install or line up.

I actually prefer to use robart hinge points when I can, but the CA hinges are used in all my models .40 and under size. I just bought some larger ones from Jim Moss at the WHitby swap, and I will try them in my next large gas plane to test...

rcav8tor
03-08-2003, 07:27 PM
Hinges are a personal preverance type thing....
I doubt if any of the hinges on the market are no good if installed and use in the manner they were intended.
My personal favorite.......... and only hinge I use now...... The Robarts Hinge Points.
Easy to install, and take a good kickin'..... also look good when done corectly

planecrazy
03-09-2003, 09:06 AM
I concur with the guys, I use the Robart hingepoints. usually I'll take the hinges out of a kit and chuck 'em and use the Robarts.

Chris

AJCoholic
03-09-2003, 09:16 AM
When I re read my post I realised I wasnt clear - I use CA hinges on smaller size models (usually 40 and under) since many have this sheet tail surfaces and I have a hard time getting a robart hinge point into 1/8 or 3/16 balsa. So I like the CA type, especially with the slot machine. fast and easy!

But the hinge points are sweet, easy to install and work great.

I was concerned with the larger CA hinges to use them on a larger plane but I think I will still try it some day, but I will use more of them and keep a watchfull eye on them each flight.

As for the rest of my planes (like my profile fun fly's, 40/50 size) that have the CA hinges, they are excellent and stand up well.

Norman_I
03-09-2003, 05:11 PM
Thank you all for your input.

I had been using CA type hinges until I saw the Great Planes plastic hinges which could be glued either with CA or epoxy. The store owner's opinion was that CA type hinges crack where they bend after a period of use so I thought I'd give the plastic hinges a try.
I already owned the slot machine and alignment jig, so I got the thicker cutting blades for the slot machine and a package of hinges.
When I told a friend what I had done, his opinion was that CA hinges were tougher than plastic hinges, and that the plastic hinges broke where the pin was.

Andrew,
I did understand your first reply; it was quite clear. I can understand the logic that planes that will apply more force to the control surface will need a stronger hinge. I wanted to try the plastic hinges because I had poor results with the CA hinges on my Hangar9 UltraStick40. The surfaces resist movement and do not move until the beveled edges meet. Maybe I just put them on too close (with the TE and LE touching). Had I put a pin through the CA hinge to leave a gap between the TE and LE as shown in the instructions, I might be getting full deflection from the surfaces.

My conclusion is that there isn't a big enough difference in the reliability and performance of each hinge type to favor one over the other, but the size of the airplane could dictate the hinge type. Since I mostly fly 40 size airplanes I guess the CA hinges will do a fine job.

Thanks again and
Happy landings,
Norm

can773
03-09-2003, 05:34 PM
I use Radio South CA hinges (available at Central hobbies) in all of my 2 meter pattern models. I can easily get 45 degrees deflection out of them and they do not require a lot of force to move. The flight loads on the rudders are pretty high during manuvers like knife edge loops and rolling loops, as well as snaps and I have never had a surface come loose.

I did lose an aileron one time but that was because the linkage failed and I got flutter. Looking back I am glad the hinges let go because there probably would have been a lot of damage if they did not. As it was I was back in air for the next round :)

On my Seduction FreeStyle I got 70 degrees of deflection out of the rudder using the Radio South hinges.

The trick to using CA hinges is to only put CA onto them one time. Once you have CA'd them into place and it has wicked into the wood, putting on more CA will only make things worse.

Nuker
03-09-2003, 05:45 PM
I use MOSS CA hinges :D

I read in one of the mags to use a wax crayon in the center of the hinge, then add the CA. It's worked great for me though I also monocote over the hinge line as a habit.

Bob

Kevin McGrath
03-09-2003, 07:17 PM
Another vote for Robarts......

monocoupe
03-09-2003, 09:15 PM
Naturally, I use different types of hinges depending on the application, but my favorite is the DuBro 1/4 scale hinges that are supplied with a cotter pin as a hinge pin. I throw away the cotter pins, and install the hinges using a length of .040 piano wire as a hinge pin, for the full length of the hinge line. I make the pin removable, so I can easily remove the control surface if I should need to, and the second bonus is that the full length pin acts as a gap seal.

Cheers, Nigel :P

thepope
03-13-2003, 03:24 PM
Nigel
How do you keep the piano wire from falling out :?:
Bill

monocoupe
03-13-2003, 05:13 PM
Bill,

For the ailerons: If the hinge is toward the upper surface of the wing, which it generally is, and the aileron does not go all the way to the tip, so it is "captured", I just feed it in from above and one end, and it stays in place by it's self, as it too is captured within the aileron cutout.

Elevators, or ailerons that go all the way to the tip: Bend the outboard end of the hinge pin to 90 deg. and fit bent end into a small notch in the stab tip. Put a drop of ca on it, and a tiny patch of Monokote or other covering and touch up paint. It's still easy to get out later if you need to. Another way is to anneal the end of the hinge pin and with small round nose pliers, bend a ring into the end of the wire, solder it, then put the 90 deg. bend in it. Now you can use a very tiny countersunk screw to hold it in place in the stab tip...this can also be recessed into the tip.

Rudder: Can be done as above or as I like to do it: Capture the 90 deg. hinge wire end under the tailwheel assembly. To remove the rudder, just remove one of the tailwheel screws, and loosen the other, and swing the tailwheel assy out of the way to pull out the hinge pin.

I hope this helps....

Cheers, Nigel :)

thepope
03-13-2003, 05:56 PM
Thanks Nigel
I'm going to try it on my next project.
Bill :idea:

monocoupe
03-13-2003, 09:00 PM
Here's another trick, that makes installing these kind of hinges (and the long hinge pins) a breeze:
Normally, you have to cut hinge slots which is a pain. For top hinged ailerons, I made up a sanding board of the same width as the hinge, and the correct depth to suit the hinge thickness, and I just sand into the false and aileron spars while they are together, at each hinge location prior to installing the top cap strips. It' fast and the hinges fit perfectly.
For all other control surfaces, I build up the spars from three laminations with 1/32" balsa as the center lamination, with spaces for the hinges at the appropriate intervals. It's way easier than cutting slots and far more accurate. When you later install the full length hinge pin, it justs glides right through all of the hinges without getting out of line.
I thought I'd mention the above, as it really does make using the full length pins easier...not to mention the dead straight hinges allowing very free movement of the control surface.

Hope this helps too! :)

Cheers, Nigel

thepope
03-13-2003, 09:35 PM
I was wondering how to keep the hinges lined up so the pin would go through easily.
Thanks, Bill