How to remove old analog meter? - Page 1
Forum section: electronics / repair

author: Unknown
author_rank: Unknown
timestamp: October 17, 2018, 08:10:42 pm
content: Here's a dumb question for you all.I picked up an ancient junked power supply to harvest the nice old analog meters from it. One I got out fine, but I can't figure out how to remove the other one.It's got 3 screws that go thru a steel panel, with nuts on the other side of each. But the nuts are so close to the meter itself that there's no room to get a nut driver in there to move them!I'm sure there is some simple way to do this, but I'm just too dumb to figure it out. See photos.

author: MK14
author_rank: Super Contributor
timestamp: October 17, 2018, 08:14:28 pm
content: I'd try and use (fairly small) pliers, to loosen the nuts.

author: maginnovision
author_rank: Super Contributor
timestamp: October 17, 2018, 08:14:47 pm
content: Does it have a removable fascia?Edit: If not, like above, use small plier or adjustable wrench. If you still can't get it dremel through the nuts.

author: Unknown
author_rank: Unknown
timestamp: October 17, 2018, 08:16:00 pm
content: Quote from: MK14 on October 17, 2018, 08:14:28 pmThat's the first thing I tried. It'll work if I'm willing to spend 45 minutes getting it out. The nuts literally scrape against the meter body if I try to turn them.There must be some other way it was meant to go in (/come out).

author: maginnovision
author_rank: Super Contributor
timestamp: October 17, 2018, 08:17:54 pm
content: Quote from: Dave92F1 on October 17, 2018, 08:16:00 pmOnce you get them all loose a bit you'll be able to move it and make it easier.

author: Unknown
author_rank: Unknown
timestamp: October 17, 2018, 08:22:07 pm
content: Quote from: maginnovision on October 17, 2018, 08:14:47 pmExcellent, nay, brilliant suggestion. I should have thought of that.But, no. (See photos.)

author: GeoffreyF
author_rank: Regular Contributor
timestamp: October 17, 2018, 08:23:37 pm
content: What the other guy said but it is also possible that the front part of the meter can be GENTLY popped off. Be careful because the movement may be exposed when that happens. I have worked with meters back in the day which were just like that. You may see a spot where the edge of the front is not entirely flush with the panel. That is where I would explore gentle popping.

author: Unknown
author_rank: Unknown
timestamp: October 17, 2018, 08:26:43 pm
content: Quote from: GeoffreyF on October 17, 2018, 08:23:37 pmI just tried it (see my previous post). I got little tiny shards of brittle plastic (nothing I can't fix), but no access to the screws. (In the 2nd photo above, you can even see the other end of one of the screws - inaccessible).My question - how the heck was it meant to be installed in the first place?

author: duak
author_rank: Super Contributor
timestamp: October 17, 2018, 09:55:12 pm
content: I wonder if they're the original nuts. It looks like they have plating similar to that on the terminals. I've dealt with panel meters where there wasn't very much room for standard hardware so they had smaller nuts and washers sized to fit. Too bad if you lose one.I had to tighten a sensor in place once and needed a thinwall socket to tighten the nut. This is in a machine that was about 4 x 6 x 3 meters and the designers had to fit a sensor right next to a casting. One more mm clearance would have made it easy. Anyway, I pounded a piece of stainless tubing over a nut the right size to make a socket and then ground it down slightly to fit. Like a chom, it voiked!Best o' luck

author: lowimpedance
author_rank: Super Contributor
timestamp: October 17, 2018, 11:13:32 pm
content: It looks like some home brew power supply using old Harrison ? meters and thus most likely non original fastening nuts, still begs the question of how the hell they got them on !.Are there no scrape marks ?

author: Nusa
author_rank: Super Contributor
timestamp: October 18, 2018, 02:42:20 am
content: Pliers may work, but the better tool is the right size open-end wrench. If you don't have any small enough, then you're in the market for an ignition wrench set. Two sets, if you want both standard and metric.

author: TerraHertz
author_rank: Super Contributor
timestamp: October 20, 2018, 05:02:17 am
content: Like Nusa says, open ended spanner. How did it take so long for that to be said?Once loose, finger turn the nuts.I too think the original nuts would have been smaller, if the thing was manufactured in quantity.Before you discard those nuts, check what the screw threads are. With such old gear they might be BA size, and you'll have trouble finding new nuts to fit.

author: ivaylo
author_rank: Frequent Contributor
timestamp: October 20, 2018, 06:39:34 am
content: If nothing else works you can grind/cut the nuts with a Dremel and a small diamond cutter or something. It may slightly damage the bolts, but if you are careful they should be fine. Again, if nothing else works...

author: tkamiya
author_rank: Super Contributor
timestamp: October 20, 2018, 03:41:12 pm
content: I have a set of small wrenches. It comes in handy for things like this.

author: vidarr
author_rank: Frequent Contributor
timestamp: October 20, 2018, 03:54:29 pm
content: Get a piece of rubber tube that fits very snug over the bolt. If you have to, put a little glue on it. Put the tube into a drill and the other end over the nut. Then slowly unscrew it.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 21, 2018, 01:13:59 am
content: I don't think there is an easy way. I have encountered many of these things from an era when labor was cheaper. Markets were smaller too, so it just wasn't as worthwhile to optimize assembly.