rcflier_gi

My Feedback: (2)

I think the crayon technique does have merit .

Only the outer fiber layer of a CA hinge will absorb and flow the the CA glue, the center of the hinge is solid and no CA will flow through it. Marking the center with a crayon fills those fibers with wax. The CA will not bond to and is slightly repelled by the wax, the same reason why we use wax paper over our plans when building. That leaves the center of the hinge CA free and therfore less likely to become brittle and crack from the CA.

archer

Black "greese" pencil is even better then crayon. The biggest thing that the mark does is prevent buildup of excess glue at the hing line that could make it more brittle.
I think the gap seal with monocote is probably the best preventative for breakage though. Avoids any hint of flutter and if you see any pull away you can tell where areas of stress are.

leroifort

crayon

sorry, but my english is not very good
in my mind "crayon" is a fat stuff like "pastel", drawing a line at hinge gap with that stuff should in fact protect the hinges from the CIA to go inside
Am I correct?

StarskiPZ

Your english is fine,

Crayon is that coloured wax used frequently by children, you know, when you were a kid - did you not deliberately leave them on the radiators to watch them melt down - messy.

guilty!!

leroifort

in fact, thanks I see exactly what u mean now

brittain

I haven't noticed anyone talking about air speed and flutter. This type of aircraft is not designed for full throttle flight. The only time you should ever think about full throttle is when you are heading straight up! I had mentioned my DP Extra 330L in an earlier post. It has a Taurus 2.6 and hovers at around 1/3 throttle. I've been doing waterfalls, walls, blenders, and the like all season and the Radio South CA hinges are in fine shape. The only time I've seen folks at our field blow CA hinges has been flutter related, and flutter is related to air speed, slop in linkages, and open gaps on hinge lines.

BTW there is a pix of my Extra at http://home.attbi.com/~wbrittain1/

Pugsley-RCU

My Feedback: (15)

Extra. That is a real pretty plane. How she fly?

OBTW - I used Radiosouth hinges in my UCD as well. No issues. Not even after the plane tore through some trees....

Pug

StarskiPZ

hi folks!

Yep I got this problem once in a too long a dive....

One thing I noticed with some of these 3-D & Funfly models is that some of the trailing edges are quite 'square' in profile ie-don't taper to a fine aerofoil shape.
This must be a significant factor for flutter?

Extra300s7

My Feedback: (36)

I would have to agree on the flutter issue. The only time I had CA hinges fail was in my Sig Extra300XS, high speed full throttle split S down wind (oops ), flutter on the aileron ripped it right out of the wing! I did love the screaming sound though

Also, what type of CA hinge? Is it just their standard CA hinge? For the bigger planes I use Radio South 1/4 scale CA hinges as well, never had a problem!

I thing I might have to get me one of them just to try it out


Justin

Dave McDonald

My Feedback: (19)

The CA hinge failures on my UCD had nothing at all to do with flutter. Vibration?......maybe. Extreme control throws?.....maybe. But flutter?......no way.

rajul

My Feedback: (58)

A great many people have used ca hinges with complete success. You have an issue with many planes in your fleet which points to something you're doing differently. are you using thin ca ? sometimes improperly stored thin ca becomes thicker and unuseable for ca hinges. it's gotta be real thin. as someone pointed out earlier, or you'll get a brittle hinge line. why not you detail your method of hinging and perhaps someone can spot the difference.

Dave McDonald

My Feedback: (19)

Already did that. Go back to the first page of this thread.