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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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11th May 2019, 10:13 pm | #1 |
Heptode
Join Date: Mar 2010
Location: Hemel Hempstead, Hertfordshire, UK.
Posts: 847
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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 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 7,662
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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.
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12th May 2019, 9:49 am | #3 |
Dekatron
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,274
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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 |
12th May 2019, 10:14 am | #4 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,107
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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 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,935
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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
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12th May 2019, 3:58 pm | #6 |
Heptode
Join Date: Mar 2010
Location: Hemel Hempstead, Hertfordshire, UK.
Posts: 847
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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.
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13th May 2019, 12:35 pm | #7 |
Octode
Join Date: Dec 2010
Location: St Ives, Cambridgeshire, UK.
Posts: 1,180
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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
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15th May 2019, 8:29 pm | #8 |
Octode
Join Date: Jul 2004
Location: Dundee, UK.
Posts: 1,813
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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 |