Robart Hinge Point Attachment
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Home > Articles & Tips Index > Construction > Robart Hinge Point Attachment

Here are two tips on attaching Robart Hinge Points so that they are locked in, yet free to move (one from Ron Graham, and another by Dan Ross).


[Courtesy of Ron Graham airrds1 "at" efortress.com, June 1999]

I use Robart hinge points, they are very easy to install, with the hinge point drill jig. I have been using them for years and never had a failure. Nor have I ever had one become loose.

That may be because of the way I install them, not sure, but it works for me. I draw the appropriate center lines, mark the hinge locations on each surface, and drill with the guide.

I also use an epoxy glue that is called gun bedding epoxy it is a gel. It takes 24 hours to set, but the hinge holes can be filled to a point just below the top of the opening, in both surfaces. I then coat each hinge at the hinge point with vaseline and install all the hinges in that particular surface. All the hinges in a surface can be done without mixing more epoxy. I then clamp the control surface in three or four different places along it length, to make sure that the control surface is lined up along its length with the flying surface. Most of the planes I have built in the past never take more that one or two clicks of trim to fly straight and level on the initial test flight.

Hope this helps in some way, Oh Yeah, the epoxy is available at most gun stores, It's for accurizing barrels on rifles. I typically use bamboo skewer sticks for filling the hinge holes, they give a nice even coat of epoxy around the I.D. of the hole which when curing flows around the barbed edges on the hinge point.


[Courtesy of Dan Ross danr "at" mich.com, June 1999]

Hi Ron your way of setting your hinge points is a good way to do it .

I do it this same way , except I use 30 min epoxy mixed with micro balloons until it get to the consistence of paste then I load it into a 75 cent glue gun and fill the hole half way or until the epoxy get to the edge of the surface when the hinge point is installed .

The advantage to using this is the weight savings the mixture weigh almost nothing. I have had to remove these they come out real easy with the right tool.

You take a empty rifle shell cut off the primmer end make some teeth on the end, chuck it into a drill motor and the come out as fast as they go in, only thing is you have to plug the whole.

I am hinging a cap 232 35% right now and I think I will try something different I think I will try the poly glue. I just bought a bottle a month ago to do some repair and this stuff is the best glue I have ever used it will stick to anything with a vengeance, and it expands to take up any imperfection in match up in you joints. and sand like balsa.

Dan Ross

 


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