I am building my first ARF kit- a SIG 4*60 and need some help on the CA hinges. I read some posts related to this, but wanted to make sure I'm doing it right.

The hinges measure .7" (W) x 1.0" (L) with a slit running lengthwise and centered widthwise. Does the slit go parallel or perpendicular to the hinge line? The instructions show two T-pins sticking through the center line on each of the hinges. Am I supposed to stick the pins through the slots, or stick the pins through the hinge elsewhere?

It appears the pins are used to both center the hinges between the aileron and wing (in this example) and also set the gap between the aileron and wing. My T-pins are .043" in diameter. Is that gap dimension OK? I heard that if the gap is too big between the wing and aileron, it can cause problems in flight.

I also read a previous post that said the slot should go perpendicular to the hinge line. Is that right? Also, does anyone have any special tips on installing CA hinges? Thanks very much for your help.

The 1" length goes into the wing so you will have a 1/2" into each surface minus the pin if you use it for a spacer and the .7 dim. goes sideways to the wing or what ever your doing.
Also for best results you should drill a 3/32 hole in the center of each hinge slot and that will help the glue get into the hinge better.
JIM

Wing Ding, the slit would go perpendicular to the hinge line. (this would, theoretically, give you .5" in both the trailing edge of the wing and the leading edge of the aileron.) I'm not aware of any relevance for the slit.

Before you CA the hinges, drill a small hole into the center of the hinge slot approximately .5" deep into both the wing and the aileron. This will allow the CA to wick more efficiently into the balsa to further saturate the hinge, producing a tighter bond. My experience has been at least 5 or 6 drops of CA in each side of the hinge.

The T pin is supposed to allow you enough clearance between surfaces for bind-free movement. After the hinges are installed, I usually will seal the gap between the wing and the aileron with iron-on covering. This does two things: It strengthens the hinge point and also helps eliminate the possibility of air getting into the groove between the wing and aileron which would create "flutter". (A rather disastrous occurrence.)

I'm, by far, no expert but I think what I've written is pretty sound advice. I'm sure, someone will correct me if it's not.

Best of luck to you.

Drilling a hole in the center of the hinge slot is NOT necessary with this type of hinge. That slit in the hinge is expressly for helping the CA wick into the slot. (Which is the intended purpose of drilling the hole.)

The advice about orientation is correct. The slit goes into the wing/aileron.

Place the Tpins at the center of the hinge so that half the hinge is in the wing, the other half in the aileron. I usually then remove the pins. Next, simply place a couple of drops on the center of each hinge, turn the wing over and place a couple more drops on each. (Two on each is plenty, you don't want to soak everything with the glue.)

As soon as the last of the CA is placed, flex the joint a number of times to keep the hinge pliable.
Dennis-

Throw away those CA hinges and buy some real hinges Du-Bros and epoxy them in.

YES FINALY SOME ONE WHO DOESENT STICK UP FOR THE CA HINGES!!!!!!!!!!!

get the pin kind that you drill a hole for, there easier than the slot hinges (since you still have to make sure that the slots line up)

jdoyle,
I too am building a 4* 60. As far as the hinges are concerned, CA hinges provided are plenty good enough.

The straight pins in the hinges, as shown, is to ensure that there is enough space between the wing, horiz stab, or vert stab and the control surface so that they don't bind after everything is glued together.

Drill a 3/32" hole 1/4 to 1/2" deep in the center of each slot on the wing, stabs, and also in the center of the slot in the control surface you are gluing to it. The CA will wick into the slot and the hinges much better that way, ensuring a good bond.

You can go ahead and cover the space left after the hinges are glued into place but, I don't think you will have a problem with flutter as the aircraft really isn't that fast. You can do it if you want, I'm not going to do mine.

I am also building a Great Planes Shoestring. It will be powered by an OS91FX and will fliy fast enough for flutter to be a concern. I intend to use high torque servos as a preventative measure.

Good luck with it. Keep us posted on your progress.

doubledee

So let's see. With the pin type, you have to line them up both horizontally as well as vertically. This is EASIER???

I use both types of hinges, and CA hinges are easier to use BY FAR.

And they work great if they are installed properly.

Here's a simple "How To" on installing them:

http://www.rcuniverse.com/magazine/a...?article_id=55

Thanks to all for your very helpful information. MinnFlyer: I read your procedure for installing CA hinges and had a couple of questions. Since the hinges that came with my ARF kit have slots in them, do I still need to drill holes? Seems like the slots would facilitate the wicking of the CA.

I've read other posts that discourage sticking pins through the hinges because the pinholes left behind might cause the hinges to tear. One suggestion was to first glue the hinges into the control surface and later glue the other half of the hinges into the airplane. That way, no alignment pins are needed. Having said that, I noticed my ARF instructions say to stick TWO pins through each hinge. It must not be a problem. What are your thoughts?

Thanks again to everyone.

NO! If you glue half the hinge into one surface, the CA will wick into the other half of the hinge. You can't stop it. And once the hinge has absorbed CA it won't absorb more later.

As I mentioned earlier, you do not have to drill holes when using this type of hinge (with the slot). I've used many types of CA hinges, plastic hinges without pins, that have to be epoxied in, the "Robart type" hinge points that I believe Istool and Balsa Master were referring too, as well as about any other hinge out there.

CA hinges are great for most sport type aircraft in the 40 to 60 range, and even slow flying planes like Cubs in larger sizes. CA hinges allow for easy installation and tight (no gap) control surfaces. There is nothing wrong with them if installed correctly. (And installation is simple.)

I prefer hinge points for larger and/or faster aircraft. I don't like most flat plastic hinges though.

You'll be fine with the CA hinges. If installed as in Minn's article they'll work great and last longer than your plane.

You are correct. With the slotted hinges, you don't really need to drill the hole.

And if your're concerned about putting a pinhole where the hinge flexes, a way around that is to insert the hinge into one side(Let's say the wing), and pin through the wing and into the hinge. The whole point of using the pin is to make sure that the hinge stays somewhat centered. If, for instance, you have a solid aileron, and only cut the slot as deep as half of the hinge, you can fit the hinges into the aileron first (WithOUT glue) and then insert them into the wing. They can't slide deeper into the aileron because they are bottoming out in their slots.

And A BIG DITTO to what DB said. DO NOT glue them to one side first! (For the same reason he mentioned.)

Wing-Ding,

Excellent advice from DBCherry and MinnFlyer. Follow it and those hinges will outlast the plane.

So let's see. With the pin type, you have to line them up both horizontally as well as vertically. This is EASIER???


im compairing to the previouslyu stated flat hinges (not ca) they bind easier than the pin hinges do and are relitivly idiot prof...

Im new,
But when I built my plane and installed the hinges, the guy at our local model shop gave me a TINY 1/16" piece of tubing about 6" long just for that little hole you drill. I inserted it into the thin CA bottle then inserted the other end of the little tube into the hole that we are talking about drilled in the center of the slot after the hinge was slipped in. This is supposed to allow the CA to wick in more deeply on the hinge surface and not just get right under the surface of the monokote or whatever. It worked great for me. My hinges are really strong, just an observation.

That's not a bad idea.

Just thinking about it theoretically, I would think the flat plastic hinges (which I think are robart?) would be easier than the round ones. The round ones, I would be nervous about the fact that they can turn radially, and if they are off by even 1 degree, you're screwed. Personally, I have not found a hinge I am confortable with. I used the CA hinges and had a failure. So now, when I install them I put them in, drill a hole 3/4 through it (from the bottom), fill it with thin CA then put a T-Pin all the way through it and clip it off flush.

One other thing, and maybe if I ask here I can avoid posting a whole new question, is that I am building a Venture 60. From past experience with my Great Planes Hinge Slotter, I am very nervous about cutting these slots with the cutter. How do you cut the slots with the cutter such that the blade stays completely straight and not wander at an angle? I feel as though I am not explaining this right..

Nova, There's a guide you can buy to hold the allignment. Tower has it for $3.99

http://www2.towerhobbies.com/cgi-bin...?&I=LXPU13&P=0

Have it, tried it. But it doesn't solve the problem of the cutter not going straight into the wood, wait.. I just though of something. If the blades are thing enough that they will not deflect off into a different path, but will only cut in a straight line, that may work. Is this how it is set up?

Am I overthinking this or what!!!

That works great, I did the same thing and it worked great not just for CA Hinges but for all CA uses if you are experiencing any problems with CA bottles cloging. From my post in Tips.

Here is a solution, Teflon tubing.

The one on the right is thin CA, which was cloged so I cut the tip and inserted 1/8" of teflon tubing and attached it to the bottle with masking tape also used the same on medium and thick CA works great. For the thin one I had 1/16" teflon tubing attach to the 1/8" which also worked great in controling the flow of thin CA much more better than the original tip since it has 1/32" ID.

Now since I am graduate Chem. Eng. student working in lab I don't have problem accessing teflon tubing and tested this, it worked great. You can obtain Teflon tubing from McMaster.

http://www.mcmaster.com

go to page 94 of their online catlog and you will see that 1/8th is $0.58/ft but the min size is 10ft roll. If you use 3 inch per CA bottle you can have 40 CA bottle tips for $5.80 +s/h.

Get your buddies because with 40 CA bottles you can build lots of planes.

No CA will stick to Teflon plus you will have access to hard to reach areas and will have a great control of the CA you hold it down and if you don't sequese it won't flow.

Use masking tape to seal the tip after use. highly recommend 1/16th for thin CA.

If you see anything sticking to the tip you can cut it, I have been using it for 3 months and I did not need to cut any yet.

I finally glued my CA hinges on my ARF. Everything appeared to go smoothly. I used to race 1/8 scale buggies before I got into model airplanes (much more fun) and I used PVA dispensing needles to apply CA when gluing the tires to the wheels. I used the PV-22-1X needle to apply the CA on my ARF. It really allowed me to get the CA right into the interface between the hinge and the slot. Here is a link to their website:

[link]http://www.pva.net/Needles.pdf[/link]

These also work very well:

[link]http://www.howardelectronics.com/kahnetics/needles.html[/link]

Thanks for the info, those needles look good.