Syringes and needles

[The Natural Philosopher]

UK AWG is a couple of gauges apart from SWG, if that's what gauge means.

Google for tables of what corresponds to what.

[Graeme]

In message , "Nightjar "@?.?.invalid> writes

Bingo :-) Yes, lubricating models. A friend in the US swears by Vaseline to lubricate electric motors in old 0 gauge toy trains. Much better than oil, he says, although there are as many recommendations as there are people running these things.

Anyway, I thought I would try Vaseline, assuming I can find a suitable syringe and needle. Thanks to all the contributors here, I now know more about the subject than I would have thought possible. Thank you, all.

Just out of interest, and to put the discussion in context, this is what my friend said about lubricating a 20v Marx motor :

You can make the screech go away if you use a hypodermic syringe, preferably with a 25 gauge needle (like a "B-D 3ml 25G1" from CVS), and put a bit of Vaseline Petroleum Jelly under the gear on the end of the armature shaft opposite the brushes so it gets into the bearing that is hidden under the gear. I do not like oil for Marx trains. As I have written before, oil gets thrown into the reverse unit, drips onto the commutator, runs down onto the track, gets gummy when it gets old, eats up the bonds in the powdered metal gears and does not lubricate very well for very long. Vaseline was recommended by Marx, and is still the best lubricant for Marx trains. If you can't get a hypodermic syringe, put a glob of Vaseline against that gear, and push it down under the gear with a torn-off cardboard tab from a cereal box.

[Jules Richardson]

The 10:20 to Didcot is running late due to the wrong sort of oil on the line...

[Nightjar]

I said supply, not make. Unless they have changed the product range since they bought the business, blunt cannulae are a standard item. As I said originally, it would be a lot less hassle to buy a ready made product than to modify a needle.

Are you being deliberately obtuse? I was pointing out my experiences of what happens when you score and snap needle tube. The only application I can think of where anyone deliberately scored needle tube was for ultrasound marking.

product then.

I would think it more likely that they didn't have the materials to make from scratch.

Same difference.

So, you have heard of them, despite claiming never to have seen one?

Colin Bignell

[Nightjar]

Unless you really need the small size to get into the space, I would suggest something larger than 25 AWG, which is about 26 SWG. That is very small to push Vaseline down. Were I doing it, I would look at using a haemorrhoidal needle. The main shaft is relatively large - 15g or 16g

- with a short tip that is 19g or 20g. That makes it much easier to push a thick fluid down the needle.

I also wonder whether Vaseline is still the best product, even if the manufacturer recommended it when the locomotive was new. Tribology has come a long way in the past 40 years.

Colin Bignell

[Steve Firth]

[snip]

Perhaps you can reference the post where I made the claim that you allege above?

Here's a clue - just because you can make it doesn't mean that it is in any way useful in the real world. And where one does need such a thing they are trivial to knock up oneself. Like glass knives and Pasteur pipettes.

[Owain]

On Mar 7, 1:56=A0pm, "Nightjar

[Skipweasel]

We use syringes at school for Y3's DT bit called Moving Monsters - two syringes connected by a pipe; push one in, the other pops out, make model from junk and animate it.

Splendid fun - but sometimes stiction stops it working as well as it should - a little squire of silicone spray soon fixes it.

[Nightjar]

On 07/03/2011 15:38, Steve Firth wrote: ...

The NHS seem to disagree with you - they bought enough of them.

Which in no way negates my original point that, if that is what the OP needs, it would be a lot simpler to buy a blunt cannula in the first place than to buy a needle and modify it.

Colin Bignell

[Steve Firth]

They also buy bizarre surgical instruments that, when one analyses the purchase, seems to be entirely because the resident consultant designed the awful thing. Often one opens a cupboard to have dozens of bespoke, entirely useless instruments fall on one's head.

It depends what he has to hand, doesn't it? If he already has a needle why should be buy a cannula. Indeed why are you busy collecting molehills and carrying a plan marked "Dolomites"?

[OG]

No idea about what size they correspond to, but inkjet refill kits come with syringes with (blunted) needles.

inner bore about 1mm if that helps

[John Rumm]

[Chris J Dixon]

[Nightjar]

[Tim Watts]

Chris J Dixon ( [e-mail]) wibbled on Tuesday 08 March 2011 07:00:

[OG]

Wouldn't you be better off warming the vaseline and sucking up a few mm^3 into the tip end of the needle rather than filling the cylinder and trying to push the vaseline down the full length of the it?

[Graeme]

More accurate than you realise :-)

[Graeme]

In message , "Nightjar "@?.?.invalid> writes

OK, noted, thank you.

Suggestions welcome :-)

Vaseline was recommended before the war, and this is a subject that rears up on a regular basis, with more recommendations than anyone needs, from good old 3-in-one to thick motor oil, clipper oil, sewing machine oil, specialist lubricants, Vaseline and a whole lot more. The only universally agreed no-no is WD-40.

To be honest, I'm not sure that the actual lubricant makes a great deal of difference for normal day to day use. These are motors designed in the 30s, solid, well made, and I don't doubt that, with care, most will be running long after I've hit the buffers for the last time.