boothg-3

just to be clear my c/a hinges were installed correctly
the fact is they began to fail from the control horn area
and began to move outward one hinge at a time
Dick Pettit of R/C report performed a test on robart hinges
he glued one into balsa blocks and using a fish scale
exceeded 90 pounds of pulling force before tearout
i have never sanded the robarts that would radius the sharp
edges and reduce their holding power
i have had no issues on .60 or smaller aircraft but had them fail on giant scale
heres how to improve an arf that comes pre slotted for c/a hinges
start by installing the c/a hinges and control surfaces with c/a glue
then seperatethem with an exato knife this both fills and bonds the wood that was removed for the c/a hinges
and after trimming the hinge flush
drill new holes and install the robarts
i have used robarts for at least thirty years now and they are by far the
easiest to drill ,align,and install

nonstoprc

My Feedback: (90)

No. By sand the stem I meant the smooth sections. You want to increase the grip, right?

I have experienced one case where Epoxy lost the grip on the Robart hinge. It was a 50CC gas. I lightly sand the stems of Robart hinges since then. If you look at Dubro pinned hinges, you will notice the uneven surfaces.

boothg-3

i was referring to the quill area on the hinge
besides the mess epoxy makes it doesnt bond that well to
plastic , so the holes need to be slightly oversized to allow enough epoxy
to encapsulate the hinge quills while bonding to the wood