Making a piano hinge bind and get stiffer

Hi there,

Does anyone have any ideas on how to make a piano hinge stiffer to operate. I have some polycarbonate sheets acting as chip guards on my mill which are hinged like doors on uprights using piano hinges. They swing wildly with the slightest breeze and vibration. I'd like to get it so I move the door into position and it stays reasonably where it is.

Ive tried pinching the hinge with pliers in two places but that seems to have had little effect.

Any genius ideas for me to try.

Thanks

Graham

Hi Graham,
Without removing the pivot pin from the hinges squeezing them will not distort the tube part of the hinges. If you can knock the pin out squeezing the tube part in a vice would give more control than pliers. Remember to squeeze at least one segment of EACH side of the hinge. A way that might work without removing the pin would be to very slightly bend one or more segments of each side of the hinge. Clamp the hinge in the vice with half the length of a segment sticking out and tap it with a hammer to produce a very slight bend in it. If you have any bits of the hinge left over try the above on them first.

Les.

Edited By Les Jones 1 on 03/03/2013 15:16:17

I assume they look like double doors, though maybe not meeting in the middle. Could you fit a peg to the top of each door at the far end from the hinge, open the doors to the required angle, and then slip a Meccano-type strip over the pegs so as to connect the doors together?

Then, viewed from the top, you would have a rigid-ish trapezium, though if the door opening approached 90° it would get more like a rectangle, liable to collapse into a parallelogram in the breeze. To prevent that, put extra pegs at the hinge ends of the door tops, and use two Meccano strips in an X shape (but not fastened together) . Then you would have two triangles, which would be more rigid and permit one door to be open more than the other.

Andy

Slipping some packing between the hinge plate and the support upright to induce a local distortion in the hinge pin might work - my usual problem is the opposite - getting doors to swing freely!

Keith

Try moving "middle" fastners out of line...bow the hinge pin sort off...like the above maybe packing to the same effect.

...drill and tap for grub screw...replacing part of hinge pin...allows for "adjustable" friction..

Try using Loctite, not the very strong stuff but the type that you put on nuts and bolts that allows you to undo them at a later date. In my last house there were several doors that opened or closed themselves due to the frames being out of true. An application of Loctite taught them some manners and lasted for several months before further applications were required.

Brian

Take the pin out and replace it with a similar size length of piano wire but introduce a gentle zig zag shape every half inch or so into the wire with a pair of pliers.

Ive given the loctite suggestion a go first as that involves pretty much no effort. If that doesnt do the trick, then I'll look into packing out the middle screws on the hinges to create distortion, then last resort, remove the pin from the hinge and do some selective pinching.

Les..... "Remember to squeeze at least one segment of EACH side of the hinge." <- on inspection of my attempt number one, i had indeed fallen at the first hurdle!!!

Cheers guys.

Graham

Be very careful with loctite near acrylic or other plastics, some kinds can cause the plastic to break up after a few months. Learnt the lesson the hard way some years ago, we had to replace hundreds of switch assemblies that had been given a drop of locking compound " to stop them coming apart" !

Billy

Hit it wiv an ammer!

Mark P.

Don't you mean a Brumigam spanner ???

Work a little polyeurethane varnish into the hinge and let dry. Make sure it gets in around the pin.

Similar to Falco above, but I've used kitchen sealer or similar, polyurathane type not acrylic. Also good for locking threads etc.