pigcop2

Good Morning,

I'm working on an Electricub by GP. It calls for ca hinges for elevator, rudder, and ailerons. I have read good and bad things about CA hinges. I was thinking of using a different kind.

My question is, can I use robart pin hinges? Or should I use a dubro flat pin hinge? The reason I ask is the wood I'm working with is only 3/16in thick. I was thinking of the 3/32 robart, but not sure if there is enough wood left over to hold the hinge in place without breaking out. I'm most likely not going to be doing a ton of acrobatics with this. Mostly scale flying.

Thanks
John

jester_s1

For the hinge point type hinges you absolutely must have enough wood there to completely envelop the hinge and have a bottom in the hole. Otherwise the hinge will push the glue out and the bottom and not be bonded right. The flat hinges would probably work, but do pin them to be sure. That said, the CA hinges are perfect for this application. If you install them properly, they will be stronger than the surrounding wood and will never come loose. The secret to it is to get the CA soaked in to the surrounding wood before any of it starts to cure. When it does that, it actually creates polymer chains that run from within the wood and into the hinge. The negatives you've heard likely come from not getting the CA all the way into the hinge pocket (drill a little hole in the middle of the slot so that it can flow all the way down) or not putting enough CA in the first time and then trying to reglue them later. With CA hinges, you only get one chance to get it right because the CA seals the wood so that no more can soak in. Another slightly less common problem is getting the middle of the hinge saturated with CA and having it get brittle. To avoid that, tilt the wood so that the glue runs into the hinge pocket instead of sitting on the hinge at the middle.

frets24

My Feedback: (15)

A trick I learned on these forums was to draw a heavy line across the middle, top and bottom, of your CA hinge with a crayon or wax builders pencil...keeps the CA off the flex point and marks the hinge for equal penetration at both halves. Combined with the small hole drilled in the hinge slot, as above, makes for a strong hinge attachment that should last for years. Still occasionally flying an Eagle II built @ 1992 and it's still using the original CA hinges.

KitBuilder

also.. apply the ca to the hinges with it installed in both sides, elevator and horiz stab. Do not do the elevator hinges then stick them in the horiz stab and do those next.

The LHS and elsewhere sell the very fine flexi-tips that go on the tip of your CA bottle that allow you to ge CA down in side the hing slot. Indespensible for this taks.

pigcop2

Thanks for the input. I think I will go ahead with the CA hinges. Let you know how it turned out.

Thank
John

tacx

My Feedback: (1)

I built the same plane last winter. CA hinges are fine for that plane. It's a light weight plane which will not get allot of stess on the hinges.

I did go with a different brand of CA hinge, because I didn't like the ones that came with the kit. They were a plastic material with a plastic mesh on both sides. I test fit them and found them diffecult to shove into a tight slot, because the mesh would pull away from the plastic inner material. I think I used DuBro hinge material.

mscic-RCU

My Feedback: (6)

Another tip is to push a couple of t-pins through the center line of the hinge. This will keep the hinge from pushing too far and allow for equal amount of hinging material on both sides of the center line.

Gray Beard

My Feedback: (-1)

CA hinges are just fine if done correctly and I see a lot of good advise here. I think if you go into getting air born, the site RC Ken has it shows you how to install them? I drill a hole in the center of the slot in the wood on both sides and I use the small glue tips on my CA bottle so I can get the glue inside the wood and hinge.
I don't go to the hinge pins or flat hinges until I'm building a bigger plane too. When I build the plane I add wood in the hinge area, on ARFs I use the hinges they recommend. They usually don't have enough wood behind the hinge area to install them correctly so the CA hinges work very well.