Plastic fitting on steel pipe - just a fraction too tight.

[d000hg]

I bought a computer monitor stand which is essentially a stainless steel pipe mounted vertically (clamped to the desk) with a metal fitting which is mounted on this pipe and slides up and down, on which you attach your monitors. The metal mount doesn't touch the pipe directly, inside is a simple plastic collar which allows you to tighten things up with a screw - the screw pushes the collar up against the pipe.

Anyway, at one end of the pipe the bracket moves very easily, but at the other it is rather tight. I have loosened the screw-tightening thing fully I am guessing the pipe is just a fraction thicker or has minuscule bend at one end, nothing is visible to the naked eye and running my hand along it detects no difference in feel.

Is it feasible to simply sand the pipe? I have no idea how much I need to wear off, if it's something a quick sand would achieve or if that would take hours. Also, is roughening the pipe by sanding going to make things worse?

Perhaps sanding the inside of the plastic fitting would be better, but since the tightness varies along the metal pipe it seems the pipe is to blame to me.

 

[foxhole]

The plastic collar will be a little loose, not tight and twists slightly when you move it causing it to feel tight.A spray with silcon spray or even wd40 should ease it , any sanding will make it rougher and more likely to stick.
You should not need to move it much as once adjusted will not need to move.

 

[d000hg]

No, it's definitely always the same parts of the pipe where it moves easily and becomes very snug.

And I do need it to be adjustable - I will move it between two positions frequently (standing and sitting). Where it gets tightest, it is a struggle to move so I just need a little more freedom.

I could try spray though, the tolerance might be such that this will give me what I need.

 

[footprints]

Might be a bit oval any chance of dismantling and reversing the tube to put the tight bit where it is not used?

 

[d000hg]

I'll take a look, not sure if it's bolted or welded. Good idea.

On the original point though, if I did want to gain a tiny bit more tolerance, is that something I could do with a bit of wet'n'dry or is that a non-starter? Given it will move over the tight bit, I assume the amount I'd have to lose is really very tiny.

 

[footprints]

You could try fine wet and dry used with some 3 in 1 oil as lubricant but the finish will look different to the existing one.

 

[foxhole]

No, it's definitely always the same parts of the pipe where it moves easily and becomes very snug.

And I do need it to be adjustable - I will move it between two positions frequently (standing and sitting). Where it gets tightest, it is a struggle to move so I just need a little more freedom.

I could try spray though, the tolerance might be such that this will give me what I need.

You need a different model for frequent change in hight, but more expensive.

 

[d000hg]

You need a different model for frequent change in hight, but more expensive

Hence the DIY . Such products are rare and typically cost several hundred pounds, rather than £25-50.

If I can make it slide easily on the main pipe, I already have a design to make it easier to raise/lower. But That design simply won't work with too much friction in the system.[/b]

 

[pinenot]

How did you get on with reversing the stand/pipe, as guessed it may be a bit of ovality causing the tightness at one point only, in fact I think that's more than likely. Do you have anything like a set of callipers (manual or digital) to test this out, if so and there are any discrepancies, then it would be easy to take out of a thin walled/soft pipe, with a wood "G" clamp protected with something to prevent any damage and retain the existing surface. As you rightly say "Hence the DIY"...pinenot

 

[d000hg]

Just an update: I didn't have callipers but it definitely did seem the pipe was not totally round. Without proper tools I resorted to using wet'n'dry (240,320,400,600) with 3-in-1 oil and after a bit of elbow grease, got it working well enough for my purposes.