Test005

OK, I have a problem with cutting the slots for mounting CA hinges.
The wood is too hard and I just don't have the patience to carve 32 slots...Either the slot is to tight to fit the hinge, or I carve out a big hole that looks bad
Is there an alternative way of attaching the CA hinges?

I was thinking to glue them ontop of the control surface and maybe hammer a small needle in for extra strengh, would this be strong enough?

pettit

My Feedback: (23)

Beg, borrow, buy or steal a Top Flite hinge slotter. It's like a tiny electric knife that cuts the correct size slots in almost any kind of wing structure.

I would not recommend gluing the hinges to the top of the wing or control surface.

Besides being very ugly and difficult to cover, it only is attached on one side. CA hinges are designed to be inserted in a slot.

What about Robart point hinges? You only need to drill a hole with a small drill bit.

MinnFlyer

My Feedback: (4)

Ditto to everything Dick said.

Gringo Flyer

My Feedback: (18)

What about monokote hinges? Do a search and you will find a ton of info on how to do it.

Scar

My Feedback: (3)

1. There is an alternate method, and
2. Your idea has a glaring flaw.

First, let me endorse the previous suggestion about the hinge slot cutter.
Then, I'll mention that if your parts weren't built, you could split the wood (or use half-thickness strips) and laminate new pieces with the hinges in between (using thin CA.)

However, I suspect your parts are built and ready to be hinged, which would make lamination of new parts difficult. So I will just stick with the hinge slotter suggestion.

The flaw with laying CA hinges on top is that the hinges are a laminate themselves, two layers of tough fiber separated by a plastic sheet. Both fiber layers must be bonded to each of two hinged parts, to make these hinges both strong and flexible. If you lay a CA hinge on top of your joint, the bottom layer will stick to the wood and the top will not be adhered to anything. It will slide off the pin, so will the plastic sheet, and you will have one thin, short segment of fiber atop your joint.

The monokote hinge idea would be a more desirable choice.

Best wishes,
Dave Olson

Test005

Thanks for the ideas and warnings.
I bought a bag of "Steel pin hinge point" by Robart.

I have drilled holes in the 7mm balsa and inserted these, it looks very good and feels solid.

Those CA hinges are not good, these are far better and feel much more pecise.

....Back to building

pettit

My Feedback: (23)

Remember that Robart point hinges are designed to be glued in place with either epoxy or some sort of white or yellow glue, NOT CA!

One false drip and the hinge point gets really tight.

I use Pacer Hinge Glue or yellow construction glue (aka Elmers)

You may do well by putting a drop of oil or some Vaselene petroleum jelly on the pivot point.

Just a little since it may work its way down the point and it'll never stick at all!

Test005

I've now covered the tailplanes and hinged rudder/elevator. I used 5min epoxy and it's rock solid!
A bit tight, but I figure I can loosen it by moving the surfaces 10.000 times

Great stuff!

FLYBOY

My Feedback: (11)

And you thought the larger holes would look bad.

The hinge points are good, but in the future, if you bend them and heat some vasilene and dip just the hinge point in it, you won't get glue in the hinge point and it wont' get tight.

Test005

No worries, I wiggled the surfaces while the epoxy cured and the hinge is smooth now.
These are easy to install, look good and feel rock solid... Definately getting more of these for future projects...

FLYBOY

My Feedback: (11)

Make sure you check them good on preflight. They will eventually vibate and loosen up. I used to use them a lot. They don't always loosen up, but I have never had other hinges do it, and have had many robarts do it. Might rough them up a bit to make the glue stick better.

JoeAirPort

My Feedback: (41)

I just use a toothpick to dab vegetable oil on the hinge joints and move them back and forth until the oil is well inside the hinge. You can tell when the oil penetrates because they get really easy to move.

Also using 5 minute epoxy is not the best choice because the epoxy does not get a chance to absorb into the wood before it cures. That could be one reason why sometimes they loosen up in certain cases. I would go with at least 30 minute epoxy in the future. Also a slower curing glue gives you more time to push the control surface around in case it moves. The last one I did on a DPM Edge 540T 26% I wrapped rubber bands around the entire wing/stab to hold the surface in place. They always wanted to back off and increase the hinge gap if they were not held on during setup.