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01-15-2012 | 05:35 PM

#13

Zor

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From: Ontario, ON, CANADA

RE: Hinge question

Red inserts by Zor

Quote:

ORIGINAL: MinnFlyer

Quote:

ORIGINAL: Zor

I wish to read the advantages of using CA hinges over pinned hinges.

Ok, They are easier.

I think you mean easier to install.
For me the pinned hinges are easier to install because I have the Dubro tool to cut accurate slots. 

You don't have to cut the same slot, you have a much easier slot to cut because they are not so thick.

The Dubro tool cuts the slot just the proper size for the thickness of the hinges.
The 0.610 inch wide hinges are 0.032 to 0.035 thick.
The 0.428 inch wide are 0.025 thick.

For a $10.00 tool, who would want to cut 44 slots with a #11 Xacto knife on a biplane.
24 slots for 4 ailerons.
8 slots for rudder
12 slots for elevators.

Of course the tool is there for future models.

Also the gap is small enough to be negligable, yet for flat, nylon hinges you have to cut room in the TE of the Stab and LE of the Elevator to make room for the knuckle - otherwise you get a HUGE gap.

The CA hinges that I have are 0.017-0.018 inch thick.
I would not want that thickness to force apart the grain of the wood.
How to cut 44 slotsto bejust about that thick? I do not know of any tools to do that.
If you did mean "easier to install" then it appears labor intensive and time consuming.
A slot using the Dubro tool can be cut in about one minute or less.

Next is the fact that you need to use epoxy or some other slow-setting glue which must be applied, hinge inserted, glue applied to the other side, control surface added and then all that messy excess glue has to be removed.

That is not the way I do it. I have previously described in this forum how I do it. I will not repeat here now what I already posted. The epoxy is applied only once on both faces of the slots and the hinges and I have no mess and no epoxy coming out to the hinges themselves. There is always a solution to any problem like you are mentioning. 

So basically, once you have test-fit pinned hinges, you have several more messy and laborious steps.

I wonder what messy and laborious steps you are experiencing. After final insertion of the pinned hinges, there is no mess to clean up. Just let the epoxy harden up in less than an hour using 30 min epoxy. 

With CA hinges, after the test-fit, add a few drops of CA and continue on to the next step. No waiting necessary.

Ya ___the next step is to relax with a nice cup of coffee or your favorite beverage _

_

.

I wish to thank you for your response. I see your outlook and I hope you see mine.
It is for all builders to use the method they are more comfortable with and find a way to avoid any messes.

Another viewpoint I differ is that you seem to be more concerned with the work of installing the hinges.
That is all i read . . . comments pertaining to the installation.

I am more concerned with the results after the installation.
I cannot see that CA hinges being 0.017 inch thick can give me a gap between the control surfaces and their support in the order of 0.003 to 0.005 inch gap. I would not consider a 0.020 inch gap as negligeable. If a surface is to rotate up to 45 or 60 degrees then the gap created by the bending CA hinge has to be greater than that.

With the pinned hinges a few strokes of sanding with two made tools (80 grit and 240 grit) quickly recess the wood for the center of rotation axis to be dead on the 0.003" (or so) gap or as some have posted use a Dremel with a small grinding disk (cylinder) to recess the wood.

Have a great day,

Zor

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