Elevator Hinged W/Monocoat?

[John Stiles]

How do y'all hinge your elevators? What's the easiest, fastest, most feasible method, on large planes? Do any of you use only monocoat? Why/why not? Thanks for your wisdom on this!

[john e. holliday]

Hi John,  Monokote hinges are easy to do.  Make sure you have your scraps left from the covering job or the color you plan on doing.  I cut strips about an inch wide.  Then lay one strip down with adhesive side up.  Take another strip and over lap the first one a good 1/8 inch or more.   Run the edge of the iron down the overlap.  Use just enough heat to activate the glue.  After they are seled together then start cutting them into 3/4 to 2 inch wide peices.  Iron them onto one surface with the overlap centered on the hinge joint.  You are basically doing the old cloth hinges thing with out the mess.  When one surface is done, line up the other surface and iron the hinges to it.  If you cut enough hinges so you can put them full span you will have a sealed hinge joint and not too much time in it.  I have several planes that I have done the monokote hinges that are still flying.  DOC Holliday

[Brett Buck]

How do y'all hinge your elevators? What's the easiest, fastest, most feasible method, on large planes? Do any of you use only monocoat? Why/why not? Thanks for your wisdom on this!

     It works pretty well in some cases. My infamous Skyray 35/20FP has had monokote hinges all along. The only problem I have had is the same problem I have had with the rest of my monokote jobs - after a while, outgassing and UV light make monokote brittle after a while. After about 5-6 years, they started cracking, and had to be replaced. Actually I just covered over the old hinges. It's not a big problem for hinges, and when you get right down to it, how many airplanes like that actually last 5 years in the first place?   For thin surfaces like the Skyray it's a very good way to go. The only thing that would be better and probably last longer would be sewn hinges.

    Monokote just turns to powder after about 15 years of exposure to California sunlight. It's quite amazing how brittle it is. I put a piece of tape on the elevator of one of my airplanes to hold it in position, and when I pulled it off, the monokote came off completely cleanly right where the tape was. It was actually worse than pulling paint off - at least paint pulls off other paint, the monokote came off like it was cut. In another case, I was just wiping it down, lightly, and the pull wrinkled up a bit of it - and it cracked like a very thin eggshell!

    For more serious models with sufficiently thick control surfaces, I use Klett pinned hinges with the pins removed and replaced with a single long bit of wire. Some sort of hinge with pins and sockets is *absolutely required* for serious work - its the only way to ensure that the controls move freely and smoothly enough. Any flexible material thin enough to be free is not strong enough. The so-called EZ-hinges, or CA hinges which work fine on an R/C plane, are completely unacceptable for CL. They are far too stiff, and you only have line tension to move the controls, not a servo. The Klett hinges may no longer be made (I have several stories on that topic) but almost any of the similar nylon hinges are OK. I don't care for the DuBro, but they will work if you cut and remove the pins, remove all the molding flash, and then reassemble them.

    Brett

     

[Phil Spillman]

Hi All, I too have had good luck with Mono Coat hinges! I've also had some less than good luck with the same! One secret I have learned is to first put a strip of mono coat over the surface to be hinged both edges. That is wrap a one to 2 inch piece around adjoining edges respectively. Then when to apply the hinges they have a plastic side to adhere to. finally after the hinges have been installed cover the wing or stab as usual. The hinges are out of site and out of direct sun exposure, and most importantly sheltered from the fuel exposure. I have a model which I've been flying since 1997, and it was flown prior to that buy its original owner for several years! I have 600+ documented flights on this thing and although I've replaced the entire tail, due to wood failure, the flap hinges are original! That's a lot of wear and tare on Monocoat hinges! I do go the entire length of the surface and thus "seal" the entire surface!

Tally Ho!

Phil Spillman

[johnbyrne]

When you are finished making a Monokote hinge be careful when going back over the hinges with the iron.  On my ARF Nobler I shrunk the hinges to get all wrinkles out and close the gap but ended up going too far.  I shrunk the film to the point that the hinge became like a self centering spring.  I then had to flex it in one direction, heat the appropriate hinges to stretch the film, and let cool.  After doing this on both sides it was better but still not floppy free like it was when I first finished. 

Actually in retrospect I believe what I did was flex the hing and then shrink it.  If you do this one set will be right but the other can shrink too far. 

[Steve Fitton]

John has a good point about not getting carried away and getting the hinges super shrunk and tight.  My 52 Nobler has the "self centering" surfaces due to the hinges.  Then again, they are not absurdly springy and I've never noticed any issues with the plane's handling that I could attribute to the hinges. But best to be aware of that quality of the hinges and not get the surface way "overdone".  They have lasted 6 years (but only 200 or so flights) with zero problem.  Vibration as well as light and time can be an enemy of monokote hinges.  My Gieseke Nobler started breaking hinges at 90 flights, presumably due to the fearsome vibration of the Fox 35 on it.  The 52 Nobler has a newer AAC 40 on it that vibrates much less.

[Paul Taylor]

We just got done doing them on the flaps of Ryan's Tutor II. I have done a few sets of them works good and last a long time. I also have used dental floss. I did the elev on my scratch built Cardinal. Easy fast and strong. Here is a pic of the Cardinal. If you look close you can see the dental floss on the elev.

If you do a search here you will find a few post on monokote hinges.

Paul