Lubrication of old meter needle - UK Vintage Radio Repair and Restoration Discussion Forum

IanNVJ35 · 11th May 2019, 10:13 pm

I have a WW2 test meter with a BEC movement. It is very accurate and useful, but the pointer sticks near the end and beginning of the scale if the meter is upright. It works perfectly if it is upside down.

I have opened it up and nothing obviously wrong, just sticking.

Is it worth adding a tiny puff of spray lubricant or will this just cause more problems? Were meter movement systems ever lubricated?

It would be nice to get it going again and use it for battery testing etc.

Thanks for any help.

Diabolical Artificer · 12th May 2019, 7:41 am

I've recently had a meter needle sticking in the end some Servisol sprayed on the fulcrums improved the situation.

Andy.

peter_scott · 12th May 2019, 9:49 am

Check that there aren't any small metal particles lodged on the pole faces. If there are then try pushing them out with a small piece of paper.

Peter

The Philpott · 12th May 2019, 10:14 am

(blu-tak grabs ferrous flakes well)

I was going to suggest the needle end-stops had acquired a sticky coating of something- but then noticed you said the needle stuck NEAR beginning and end of the scale..

Dave

Bazz4CQJ · 12th May 2019, 3:45 pm

I think I'd do everything possible to try and clean it as well as possible before going to a lubricant. If you do decide to lube it, I wouldn't spray it directly; spray some lube in to a small container then dip a small jeweller's screwdriver in it and apply the tiny droplet on the end on to the meter. You get better control of the quantity and location of where the lube goes.

B

IanNVJ35 · 12th May 2019, 3:58 pm

Thank you for the input. I'll work through them carefully and report back. I don't know the history of the unit but it has always been a bit sticky but now it's worse. After 75 years things do need a bit of help.

Andrewausfa · 13th May 2019, 12:35 pm

The tacky strip on the back of Post It notes is also quite useful for getting dirt out of the gap.

Andrew

pmmunro · 15th May 2019, 8:29 pm

Are the bearings brass or jewels?

Although oil, of the right type, is used to lubricate the jewels in clocks and watches, the jewelled bearings in instruments such as meters are left clean and dry.

PMM

11th May 2019, 10:13 pm	#1
IanNVJ35 Heptode Join Date: Mar 2010 Location: Hemel Hempstead, Hertfordshire, UK. Posts: 843	Lubrication of old meter needle I have a WW2 test meter with a BEC movement. It is very accurate and useful, but the pointer sticks near the end and beginning of the scale if the meter is upright. It works perfectly if it is upside down. I have opened it up and nothing obviously wrong, just sticking. Is it worth adding a tiny puff of spray lubricant or will this just cause more problems? Were meter movement systems ever lubricated? It would be nice to get it going again and use it for battery testing etc. Thanks for any help.

12th May 2019, 7:41 am	#2
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,658	Re: Lubrication of old meter needle I've recently had a meter needle sticking in the end some Servisol sprayed on the fulcrums improved the situation. Andy. __________________ Curiosity hasn't killed this cat...so far.

12th May 2019, 9:49 am	#3
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,274	Re: Lubrication of old meter needle Check that there aren't any small metal particles lodged on the pole faces. If there are then try pushing them out with a small piece of paper. Peter __________________ http://www.nostalgiatech.co.uk https://www.youtube.com/c/PeterScott/videos

12th May 2019, 10:14 am	#4
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,106	Re: Lubrication of old meter needle (blu-tak grabs ferrous flakes well) I was going to suggest the needle end-stops had acquired a sticky coating of something- but then noticed you said the needle stuck NEAR beginning and end of the scale.. Dave

12th May 2019, 3:45 pm	#5
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Re: Lubrication of old meter needle I think I'd do everything possible to try and clean it as well as possible before going to a lubricant. If you do decide to lube it, I wouldn't spray it directly; spray some lube in to a small container then dip a small jeweller's screwdriver in it and apply the tiny droplet on the end on to the meter. You get better control of the quantity and location of where the lube goes. B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.

12th May 2019, 3:58 pm	#6
IanNVJ35 Heptode Join Date: Mar 2010 Location: Hemel Hempstead, Hertfordshire, UK. Posts: 843	Re: Lubrication of old meter needle Thank you for the input. I'll work through them carefully and report back. I don't know the history of the unit but it has always been a bit sticky but now it's worse. After 75 years things do need a bit of help.

13th May 2019, 12:35 pm	#7
Andrewausfa Octode Join Date: Dec 2010 Location: St Ives, Cambridgeshire, UK. Posts: 1,180	Re: Lubrication of old meter needle The tacky strip on the back of Post It notes is also quite useful for getting dirt out of the gap. Andrew __________________ Invisible airwaves crackle with life. Or they should do. BVWS Member

15th May 2019, 8:29 pm	#8
pmmunro Octode Join Date: Jul 2004 Location: Dundee, UK. Posts: 1,813	Re: Lubrication of old meter needle Are the bearings brass or jewels? Although oil, of the right type, is used to lubricate the jewels in clocks and watches, the jewelled bearings in instruments such as meters are left clean and dry. PMM