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Control surface hinges

Posted: April 23rd, 2009, 10:09 pm
by paul needham
Does anyone recomend a paticular brand of hinge for planes like the lowley, I've been using robart point hinges but find they seem to go brittle and snap at the first small bump in transportation. Any advice would be most welcome.

Re: Control surface hinges

Posted: April 24th, 2009, 5:51 am
by Bob Thompson1894
never had a problem with the LARGE Robarts- are you using cyano? this could make them go brittle. I always use slow (1 hour) epoxy. Although more difficult to fit, there are many good types of ordinary hinges out there, just ensure they are man enough! On another point, I have never pinned hinges, the epoxy is good enough!

Re: Control surface hinges

Posted: April 24th, 2009, 6:29 am
by paul needham
Thanks for the reply, the hinges are the large ones and glued in with epoxy.

Re: Control surface hinges

Posted: April 24th, 2009, 6:56 am
by John Greenfield
Paul

On all the Greenleys and Lowleys I have built including the SDD Greenley 100cc version I use the great planes CA hinges and have never had a failure. They are easy to install by just making a slot with a knife and sliding them in dry. Push the control surface up against the trailing edge and after making sure you have sufficient control surface movement wick in some fresh thin cyno one drop at a time from the top and bottom. Keep adding one drop at a time until no more is absorbed. Finally pin the hinge with a normal dress makers pin pushed in from the underside and put a drop on thin cyno on the end of the pin to stop it falling out.
Elevators and rudder should have 5 hinges each and the ailerons 6 equally spaced out along the surface. Do make sure that one hinge is at the point where the control horn is.

Regards

John Greenfield
Greenley Designer.

Re: Control surface hinges

Posted: April 24th, 2009, 3:46 pm
by Bob Thompson1894
John is right about Cyano hinges, but I have only ever used them on slope soarers. A good trick is to drill a 1/16 dia hole down the centre of the slit you have made and wick the cyano down this, gets more glue in there!

Re: Control surface hinges

Posted: April 24th, 2009, 5:34 pm
by stuart cotgrove
John Greenfield wrote:Paul

On all the Greenleys and Lowleys I have built including the SDD Greenley 100cc version I use the great planes CA hinges and have never had a failure. They are easy to install by just making a slot with a knife and sliding them in dry. Push the control surface up against the trailing edge and after making sure you have sufficient control surface movement wick in some fresh thin cyno one drop at a time from the top and bottom. Keep adding one drop at a time until no more is absorbed. Finally pin the hinge with a normal dress makers pin pushed in from the underside and put a drop on thin cyno on the end of the pin to stop it falling out.
Elevators and rudder should have 5 hinges each and the ailerons 6 equally spaced out along the surface. Do make sure that one hinge is at the point where the control horn is.

Regards

John Greenfield
Greenley Designer.


Thanks John, do you use CA hinges on your flaps too, not sure if these give enough movement when bottom hinged at the 45 degrees angle required...

Re: Control surface hinges

Posted: April 24th, 2009, 10:32 pm
by paul needham
Thanks everybody, I will try the great planes hinges. John, my lowley is comeing up to 3 years old and still going strong apart from the hinges that is. thanks again, Paul.