how to stiffen up plastic desk lamp joints

[therustyone]

I put a 3W 240 v. LED MES bulb in a desk lamp but, as it's a
tad on the heavy side, the lamp's plastic joints don't hold
the arm up as required and it sags. This is a half size
version of an anglepoise without balance springs and the
arms are held up by tightening wing nuts on the joints.
What sort of friction material could be put in the joints to
stiffen them up while still allowing adjustment. The
plastic material is fairly hard and glossy, a bit like
the keyboard I'm typing on.


rusty

 

[NT]

I put a 3W 240 v. LED MES bulb in a desk lamp but, as it's a
tad on the heavy side, the lamp's plastic joints don't hold
the arm up as required and it sags.  This is a half size
version of an anglepoise without balance springs and the
arms are held up by tightening wing nuts on the joints.
What sort of friction material could be put in the joints to
stiffen them up while still allowing adjustment.  The
plastic material is fairly hard and glossy, a bit like
the keyboard I'm typing on.

rusty

A picture would help


NT

 

[Brian Gaff]

I think more to the point, how big are the surfaces that grip, if they are
quite small I suspect you are not going to get it to work.

One might break the material before you could get anything to grip.

Brian

 

[harry]

I put a 3W 240 v. LED MES bulb in a desk lamp but, as it's a
tad on the heavy side, the lamp's plastic joints don't hold
the arm up as required and it sags.  This is a half size
version of an anglepoise without balance springs and the
arms are held up by tightening wing nuts on the joints.
What sort of friction material could be put in the joints to
stiffen them up while still allowing adjustment.  The
plastic material is fairly hard and glossy, a bit like
the keyboard I'm typing on.

rusty

Make up some"washers" out of emery cloth or sandpaper & put them in
the joints.

 

[Rod Speed]

harry wrote

Make up some"washers" out of emery cloth or sandpaper & put them in the joints.

I'd be more inclined to try something like chamois leather.

Less likely to wear out as quickly.

 

[therustyone]

I think more to the point, how big are the surfaces that grip, if they are
quite small I suspect you are not going to get it to work.

One might break the  material before you could get anything to grip.

Brian

Here's a pic. with a 20p for scale (if it all works). Not enough
space for a sandpaper shim.
http://www.flickr.com/photos/rustyshots/6815252032/

 

[Chris J Dixon]

Here's a pic. with a 20p for scale (if it all works). Not enough
space for a sandpaper shim.
http://www.flickr.com/photos/rustyshots/6815252032/

So, if you've no room for sandpaper, what material thickness can
you accommodate?

Chris

 

[therustyone]

So, if you've no room for sandpaper, what material thickness can
you accommodate?

Chris
--
Chris J Dixon  Nottingham UK
(e-mail address removed)

Have dancing shoes, will ceilidh.

sliding a cigarette paper in would be a struggle. I think I'll try
the fine sandpapering idea and maybe spread some superglue in the
process so that bits of the grit stick on the plastic surfaces.


rusty.

 

[Newshound]

I'd be more inclined to try something like chamois leather.

Less likely to wear out as quickly.

Ordinary leather? Fibre washers?

 

[djornsk]

I put a 3W 240 v. LED MES bulb in a desk lamp but, as it's a
tad on the heavy side, the lamp's plastic joints don't hold
the arm up as required and it sags. This is a half size
version of an anglepoise without balance springs and the
arms are held up by tightening wing nuts on the joints.
What sort of friction material could be put in the joints to
stiffen them up while still allowing adjustment. The
plastic material is fairly hard and glossy, a bit like
the keyboard I'm typing on.


rusty

Two possibilities are firstly a bolt through the frame a couple of cm
above the hinge bolt to pinch the frame slightly and thereby increase
the friction, and another might be to lock the thing in position with a
small screw.

j

 

[Dave Liquorice]

Here's a pic. with a 20p for scale (if it all works). Not enough
space for a sandpaper shim.
http://www.flickr.com/photos/rustyshots/6815252032/

Looking at that unscrew the handle, take off the first flat washer,
use that as a template for a bit if cartridge paper, put this paper
washer between the two bits of plastic and replace the handle. Might
need two of the paper washers.

 

[NT]

Here's a pic. with a 20p for scale (if it all works).   Not enough
space for a sandpaper shim.http://www.flickr.com/photos/rustyshots/6815252032/

Sandpaper is a total fail, it would make things far worse.


NT

 

[Rod Speed]

Newshound wrote

Ordinary leather?

Too thick. Even chamois leather may be.

Fibre washers?

Likely to slip too much.

 

[Gary]

Newshound wrote

Too thick. Even chamois leather may be.

Likely to slip too much.

Try rosin thet they use for violin abd chello bows.

 

[Gary]

Try rosin thet they use for violin abd chello bows.

full sugar coke has magic properties when spilt on moving things by
accident.