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Building Tips and technical articles. => Building techniques => Topic started by: Dennis Saydak on January 27, 2014, 04:50:36 PM
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Can someone explain how to properly install these so they don't bind because of vertical or horizontal misalignment? Assume the model is painted and the hinge points are about to be installed followed by the elevators and flaps.
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Robart makes a tool to align them. I've used them several times. I like them.
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Thanks for the information Randy.
I should have done a Internet search search before I made this post as this subject is covered on the Robart web site as well as in detail here:
http://airfieldmodels.com/information_source/how_to_articles_for_model_builders/construction/hinge_points/05.htm
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Avoid the Robart "Horny Hinge Points" at all costs. They're way too horny for us old geezers. Except for Varley, of course. LL~ LL~ LL~ Steve
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The only people I ever new that didn't like them were those that never used them.
They have an absolute advantage with some scale applications.
Besides, change your mind, you can always use the Heimlich maneuver to pop them out. LL~ LL~ LL~
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The only people I ever new that didn't like them were those that never used them.
They have an absolute advantage with some scale applications.
Besides, change your mind, you can always use the Heimlich maneuver to pop them out. LL~ LL~ LL~
Just so no one is mislead, you can not just "pop them out". They are difficult to pull out even with no glue applied. I've never been able to get one out after the glue sets. I've always had to cut them in half at the hinge joint (with a Dremel disc) and just leave the glued portion in the surface. Grind away the protruding portion and fill with a good putty/epoxy to hide the area. Not fun!!
Paul
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Thanks Dennis for posting that website.
Doug
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Just so no one is mislead, you can not just "pop them out". They are difficult to pull out even with no glue applied. I've never been able to get one out after the glue sets. I've always had to cut them in half at the hinge joint (with a Dremel disc) and just leave the glued portion in the surface. Grind away the protruding portion and fill with a good putty/epoxy to hide the area. Not fun!!
Paul
If they are placed in with epoxy, heat will activate the epoxy and they can be removed with a tad of effort.
We would drill a couple of holes in them.
That "pop out" thing was ment to be a joke.
The only thing that pops out with the hobby, is money out of your wallet. LL~ LL~ LL~
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Charles,
Sorry I missed the joke. Looking back, that's really pretty funny. I didn't mean any offense, just trying to clear up any misunderstanding.
Paul
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I used hinge glue to put them in.
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Can someone explain how to properly install these so they don't bind because of vertical or horizontal misalignment? Assume the model is painted and the hinge points are about to be installed followed by the elevators and flaps.
Well, I will try to explain. I have been using Robart type Hinge Points for years on all of my stunt and scale airplanes. Also, the hinges are not installed until everything is completely painted. First, I install the Hinge Points in the elevators, flaps, (and the rudder for the Rabe rudder operation thing). I use slow setting epoxy (30 minutes or more) for the entire operation. The hinge line is positioned in the desired position relative to the leading edge of the respective elevators, flaps (and rudder). Great care is used to make sure the position of those Hinge Point hinges is perpendicular to the leading edges. This is accomplished by use of the small Robart drilling fixture that almost guarantees a perpendicular hole for the hinge. Also, you can sight down those pivot points to see that they are in line and you can tell they are properly rotated in their holes by deflecting the loose end and see if it is perpendicular to its respective flap, elevator (rudder).
After the epoxy has set, carefully mark where those hinge points are to go in the wing and elevator trailing edges (and rudder post). Those holes can also be drilled using that drilling fixture. (If there is a mismatch in the drilling of these holes, it might be necessary to ream out those hole so that the hinges do not bind when inserted into position If this occurs, just use more epoxy when doing the final installation.) Then carefully apply epoxy to the loose ends of the hinge points by not placing any more than fills the barbed areas. A spot of epoxy in each hole, then insert the flaps, elevator (rudder) hinges. Use some kind of spacers between the flaps, elevators (rudder) and the respective trailing edges along the span of the moving surfaces to maintain the desired and constant distance between those moving and fixed surfaces. (I usually use either small strips of 1/64" ply or 1/32" ply for those spacers.) When the epoxy has set, simply remove the spacers and bingo, your moving surfaces are done, aligned and properly positioned.
Now, there is a little thing to do if there is any concern of getting epoxy in the actual pivot pin during either of the epoxy operations explained above. Apply a small portion (as in a "dab") of Vaseline (TM) over the pivot pin area before adding any epoxy to the Hinge Point. After the epoxy has cured, you can wipe off the excess Vaseline (TM) and any that remains around the pin acts as a decent lubricant. (I recommend the use of any sand free petroleum jelly for this process.)
Keith