15 replies to this topic

[nick217]

Hi all i have recentley picked up a smiths battery condition gauge that needs re calibrating and restored.

Anybody know of the best place or person to send it too?

Also i might need a amp meter checking too.

Cheers

[jayare]

Speedy Cables but it may work out cheaper to get a new one!

JR

[L400RAS]

Hi all i have recentley picked up a smiths battery condition gauge that needs re calibrating and restored.
Anybody know of the best place or person to send it too?
Also i might need a amp meter checking too.
Cheers

Hi Nick,
Why do you think the volt gauge requires calibrating? Does it read low/ high? My experience of these is they work or they don't. Regarding the amp gauge; it is not advisable to fit these to modern alternator cars, due to the large amount of current output going through the cables that would be running through the bulkhead to the gauge. A volt meter monitors the electrics, with the benefit of low current drawn.

Regarding the restoration of the volt gauge, what is actually required? If the black face of the gauge is in good condition, a strip down, clean and polish bring these up a treat. I re-con gauges and sell them on ebay, if you wanted me to do it i would charge around £10+P&P. This would involve a complete strip. grind out all rust on the case & repaint, and a clean and polish of glass and bezel. A picture of the gauge would indicate how much work is required. PM me if you want.

Ryan.

This is a vacuum gauge i did recently:

Attached Files

•  1.jpg   22.3K   52 downloads
•  2.jpg   22.03K   25 downloads

Edited by L400RAS, 26 August 2010 - 02:33 PM.

[nick217]

Hi all i have recentley picked up a smiths battery condition gauge that needs re calibrating and restored.
Anybody know of the best place or person to send it too?
Also i might need a amp meter checking too.
Cheers

Hi Nick,
Why do you think the volt gauge requires calibrating? Does it read low/ high? My experience of these is they work or they don't. Regarding the amp gauge; it is not advisable to fit these to modern alternator cars, due to the large amount of current output going through the cables that would be running through the bulkhead to the gauge. A volt meter monitors the electrics, with the benefit of low current drawn.

Regarding the restoration of the volt gauge, what is actually required? If the black face of the gauge is in good condition, a strip down, clean and polish bring these up a treat. I re-con gauges and sell them on ebay, if you wanted me to do it i would charge around £10+P&P. This would involve a complete strip. grind out all rust on the case & repaint, and a clean and polish of glass and bezel. A picture of the gauge would indicate how much work is required. PM me if you want.

Ryan.

This is a vacuum gauge i did recently:

You sound like the guy i need!
I have fitted the Amp meter into the lighting circuit so it shows me if i have the sidelights on during the day

The volt meter is reading too high and needs a through clean and the rust removing and polish the bezel is in good condition on both of them.
Also i need a light bulb holder for this one too not the screw in one but the bayonet type.
Woll take a photo of them now for you

Edited by nick217, 26 August 2010 - 02:48 PM.

[nick217]

Also is it normal for the needle to be slugish and slow to react when you switch them on?
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 DSCF0060.JPG   1.08MB   12 downloads

[dklawson]

Nick, yes it is normal for the gauge to respond slowly. They work by internal heating of a bimetallic strip which in turn deflects the needle. The electric fuel and temperature gauges are the same.
EDIT: by the way, before you assume the gauge is out of calibration, use a couple of additional multi-meters to confirm that the panel meter on your power supply is accurate.

L400RAS, that is a really nice looking vacuum gauge. Nice work.

[liirge]

Ahhhh, I'm glad this has come up!

I have an issue, I dropped my Vaccum gauge the other day, and it has broken...
The needle has moved to around a quarter of the way round, and just sits there it never moves. I was wondering what is most likely to have broken, and if it possible to repair it?

Alastair

[nick217]

I can conform that the power supply is correct voltage.

[dklawson]

Liirge, I have not opened a Smiths vacuum gauge. However, most of the better ones have inside a bourdon tube connected to a small curved gear sector and pinion. It's not uncommon for severe shocks to bound the bourdon tube and gear sector so they "skip a tooth" or so on the pinion. It's probably possible to repair/recalibrate this if you are willing to take the works out of the gauge case and have the ability to hook your gauge up to a fixed, steady vacuum source like a MityVac or similar. It should just be a question of carefully re-positioning the pinion gear relative to the gear sector.

Nick, if you are comfortable that the power supply is correct, you may want to attempt calibrating this yourself. On the back of the gauge you will find either two little cork disks covering holes with "screwdriver slots" in them... or if the cork is gone you will just find the holes with screwdriver slots. I believe one of the slots is used to adjust the zero reading of the gauge while the other adjusts the span. If you paint mark the back of the gauge before you start tweaking the adjustments you will have reference settings to return to if your attempts at adjustment are unsuccessful.
See this link for a bit more information and an advance look at what is inside:
http://www.mgb-stuff.org.uk/fuel.htm
The link is for a fuel gauge link but the insides and calibration method will be the same.

[L400RAS]

Ahhhh, I'm glad this has come up!
I have an issue, I dropped my Vaccum gauge the other day, and it has broken...
The needle has moved to around a quarter of the way round, and just sits there it never moves. I was wondering what is most likely to have broken, and if it possible to repair it?
Alastair

As the needle is no longer moving, either it has lost its "grip" on the spindle - a dab of superglue... or more fatal, the internal pressure thingy has got a leak, and i don't know how to repair this. I take it hte needle does not move when you suck on the union? - face a mirror to test if you are on your own

I can conform that the power supply is correct voltage.

DKLawson beat me to it !

Edited by L400RAS, 26 August 2010 - 06:17 PM.

[nick217]

The trouble is that i carnt trust that the gauge is working fully hence i asked for some one in the know to test it fully and re calibrate then i know i can trust that its reading correctly so one less thing off my mind.

[dklawson]

Since you have a power supply and you know that the power supply's panel meter is accurate, you have the tools you need to calibrate the volt meter yourself.

To set your mind at ease, adjust the power supply in 1 volt steps between 11V and 15V. At each setting, allow the volt gauge to stabilize and record what it says. You will end up with 5 known input voltages and 5 displayed gauge readings. Armed with that you can tweak the zero and span slots on the back of the gauge until you get "accurate" readings between 11V and 15V. That way you will know that the gauge is operating properly and is in calibration.

[nick217]

I will give it a try

[nick217]

Just spent 10 mins on doing it adjusting it ect and still cant get it calibrated i don't think the internals look in good condition either. So i think the internals need's attention which is out of my hands unfortunately. I am awaiting reply from the guage shop on ebay and another to see if they could fix it for me.
Cheer's for your help guys.

[liirge]

Ahhhh, I'm glad this has come up!
I have an issue, I dropped my Vaccum gauge the other day, and it has broken...
The needle has moved to around a quarter of the way round, and just sits there it never moves. I was wondering what is most likely to have broken, and if it possible to repair it?
Alastair

As the needle is no longer moving, either it has lost its "grip" on the spindle - a dab of superglue... or more fatal, the internal pressure thingy has got a leak, and i don't know how to repair this. I take it hte needle does not move when you suck on the union? - face a mirror to test if you are on your own

I can conform that the power supply is correct voltage.

DKLawson beat me to it !

Nope no movement!!
greeaaaattt! I will source a new one, and put the other one on the bay its face is perfect as is the chrome and bezel!