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-   -   Meter pointer repair? (https://www.vintage-radio.net/forum/showthread.php?t=138860)

ITAM805 9th Aug 2017 9:52 pm

Meter pointer repair?
 
1 Attachment(s)
hi all

I have a pair of meters on a 32ch mixer that have both lost their pointers, I dont how they managed it but someone wrecked both :-) Incredibly they still work, well the bit that's left does ! The meters are little under 3" square

Has anyone suggestions how (if?) they could be repaired seeing as what remains of the pointers are short stubs and rather fragile

Many thanks

The Philpott 9th Aug 2017 10:05 pm

Re: Meter pointer repair?
 
Judging by the condition (and corrosion) doesn't look like you've anything to lose trying. (Although putting feelers out for replacements might come up trumps)

I think cutting donor needle from another meter would be tricky without kinking it (simply because it will likely be made from very springy tough alloy)
If you WERE able to solder a replacement in place the tail balancing would of course need to be redone (but this would be the easy bit- relatively speaking.)

This is not a repair i have done- and i would be interested to know if you're successful!

VT FUSE 9th Aug 2017 10:13 pm

Re: Meter pointer repair?
 
A true "needle in a haystack" problem-once I got away by carefully super gluing a ready trimmed length of very straight, dry & varnished hay from pet bedding to the remaining stub,I was concerned with issues of inertia combined with not wanting to try a solder repair or very risky disassembling and reassembly.
This was on a receiver signal strength meter and was still good 10 years on.

Craig Sawyers 10th Aug 2017 9:31 am

Re: Meter pointer repair?
 
Sort of a needle in a haystack?

Station X 10th Aug 2017 9:47 am

Re: Meter pointer repair?
 
I have successfully soldered on new needles made from copper wire. I held the new needle in place using Blutack prior to soldering it to the stub of the old needle.

Craig Sawyers 10th Aug 2017 11:38 am

Re: Meter pointer repair?
 
Quote:

Originally Posted by Craig Sawyers (Post 966655)
Sort of a needle in a haystack?

I ought to read the post before I come up with a smart ass comment ;D

David G4EBT 10th Aug 2017 1:07 pm

Re: Meter pointer repair?
 
In the past, I've used fine steel wire pulled out of a wire brush, which is stiffer than copper, and used a small blob of epoxy cement to fix it to the stump. Much less tricky than approaching the stump with a soldering iron. I made a support from thin card on which to rest the new 'needle' to line it up with the stump until the joint had set. Worked a treat.

ITAM805 10th Aug 2017 6:18 pm

Re: Meter pointer repair?
 
thanks for the replies chaps.

I hit on the idea of using slim clock second hands trimmed to size, so ordered some from ebay. Using Graham's good idea with the blue tac to hold the repair in place should make gluing a bit easier?!

I'll let you know how it goes ...

emeritus 10th Aug 2017 9:50 pm

Re: Meter pointer repair?
 
1 Attachment(s)
I have used Plastikard styrene strip that you can get from model shops to repair broken dial needles. The stuff I have used was some 0.2" x 0.4" rectangular section that came in a packet of 10" lengths. Styrene strip is rigid and light, and easily attached using traditional Evostik.

GMB 11th Aug 2017 9:42 am

Re: Meter pointer repair?
 
I once used a bristle from a stiff brush as a pointer.

The key thing is that meter pointers are very light, so your repair plus glue is likely to be heavier and you end up having to add a lot of weight to the little balance stub to balance it.

Tim 11th Aug 2017 8:51 pm

Re: Meter pointer repair?
 
They probably drove them over to the stop one too many times. Turn it up to 11!

The Philpott 12th Aug 2017 11:29 pm

Re: Meter pointer repair?
 
I would favour a salvaged needle from a scrap meter over an adapted clock second-hand, but good luck with this project anyhow!

Bazz4CQJ 12th Aug 2017 11:53 pm

Re: Meter pointer repair?
 
Quote:

Originally Posted by The Philpott (Post 967463)
I would favour a salvaged needle from a scrap meter over an adapted clock second-hand,

Totally agree! I've done a repair like this previously using a needle taken from another meter. Joining them is the first problem, but don't forget you then have to balance it all or you'll never get it to adjust to a zero setting. When I started, I was fairly oblivious to to the issue of balancing meters, but I'm sure there are experts on the forum and articles via Google.

B

mole42uk 13th Aug 2017 8:10 am

Re: Meter pointer repair?
 
I would use cyanoacrylate adhesive, there are some slightly thicker ones that would be easier to use. Much lighter than solder so less balancing to do.
Bear in mind this is an audio mixing desk, accuracy of the metering is not too critical!

ITAM805 13th Aug 2017 11:04 am

Re: Meter pointer repair?
 
Thanks guys. As Richard says, meter accuracy isn't critical as the desk also has LED masters, so the analogues are somewhat cosmetic. Regarding using pointers from scrap meters, yes a good idea but I aint got none !

The Philpott 13th Aug 2017 11:48 am

Re: Meter pointer repair?
 
If you can give us an idea of the length and breadth the needle might have been (perhaps more photos?) i will see if i have got anything suitable.

ITAM805 13th Aug 2017 12:40 pm

Re: Meter pointer repair?
 
1 Attachment(s)
Thanks TP, that would be handy ! The length between the 'elbow' of the movement and the scale line is approximately 35mm

The Philpott 14th Aug 2017 8:39 pm

Re: Meter pointer repair?
 
Sorry the only ones i can find are offset so have a massive kink right where you don't want it. I would think as these meters have to accelerate rapidly the new needle would have to be a very light one with a small cross sectional area..


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