Does anyone know how to get the corner brackets off this case? - Page 1
Forum section: electronics / testgear

author: TerraHertz
author_rank: Super Contributor
timestamp: January 27, 2017, 07:27:19 am
content: Refurbishing a bit of equipment, I've struck a problem. Part of the gear uses what appears to be some standard commercial 19" rackmount case. I need to partly dismantle the case. But the front rackmount flanges and rear corner pieces don't seem to have any screws holding them in. Maybe they are pressed into the side extrusions with some kind of spike?Does anyone recognize this case type, and know how to get the rackmount flanges off?Maybe they just hammer out with brute force. But I don't want to try that until I'm sure there is no better way.

author: Vgkid
author_rank: Super Contributor
timestamp: January 27, 2017, 07:33:09 am
content: Have you looked into the flat black trim covers on the side, posdibly unbolt the handles. On my HP power supplies once you remove the exterior sheet metal, you gain access to the internal screws.

author: TheSteve
author_rank: Unknown
timestamp: January 27, 2017, 07:52:59 am
content: Are the black trim covers glued on? As suggested it looks like they are hiding things...

author: 2N3055
author_rank: Super Contributor
timestamp: January 27, 2017, 08:12:25 am
content: You have to remove front or back panels and than black stuff will slide out... The black pieces are thin plates just slid inside profile... Unless they put glue too..

author: TerraHertz
author_rank: Super Contributor
timestamp: January 27, 2017, 08:20:18 am
content: The black trim bits were my first thought too. But they slide into grooves in the side extrusions, and are locked in by... the front brackets and rear corner pieces. Nope, they can't be levered or bowed out of the slots.The black sheets are thin metal, and are a little loose in the side extrusion slots. Can be slid back and forth slightly. But not got out.The front handles are held on by screws at the rear of the brackets, but even those screws are captive unless the brackets can be removed from the frame.Quote from: 2N3055 on January 27, 2017, 08:12:25 amFront and back panels _are_ removed. No, it's the corner pieces (front ones also serve as rack brackets) that have to be removed. But how? That's my question.By the way, the two pairs of diagonal holes in the center (wider) black piece in first photos, were drilled by the people putting the electronics in the case, to mount external slide rails. They have nothing to do with the case mechanics.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 27, 2017, 08:42:05 am
content: More: The black strips are aluminum, with textured black vinyl surface. Looking at the holes drilled through them, they are about 1.5mm thick. So definitely not something that can be bowed out to remove first.Couple more pics.I've tried putting a bit of hardwood against the lip of a rear corner piece, and tapping quite hard with a hammer. Nothing. It doesn't seem to be a simple pressed-in fit.Oh, and a magnet says there _are_ screws through the side extrusions into the horizontal rails. Screws hidden by the slid-in side panels. As expected.But as for steel screws somehow hidden, holding on the corner brackets, it doesn't seem so. A little ambiguous, due to other metalwork nearby.This is frustrating.

author: CJay
author_rank: Super Contributor
timestamp: January 27, 2017, 01:25:11 pm
content: Are *all* the black vinyl bits aluminium or are the narrower ones at the top and bottom of the side possibly self adhesive plastic that can be removed to reveal screws?

author: nctnico
author_rank: Super Contributor
timestamp: January 27, 2017, 01:56:11 pm
content: I'm quite sure you have to remove the narrow trim strips on the side. From the pictures I think they snap into place so you could try some kind of prying tool.

author: edpalmer42
author_rank: Super Contributor
timestamp: January 27, 2017, 03:46:14 pm
content: Isn't this a standard 'build a box' system from someone like Schroff? Can you find the instruction manual for that system?

author: TerraHertz
author_rank: Super Contributor
timestamp: January 28, 2017, 02:37:39 am
content: Quote from: CJay on January 27, 2017, 01:25:11 pmThey are ALL the same aluminum. All of them are slid into slots in the side extrusions. They definitely don't come out any way other than sliding out endways after the end/corner pieces are removed (somehow.)I know these suggestions are trying to be helpful, but please keep in mind that I'm not an idiot, I'm familiar with stuff like HP cases, stick-on strips covering screws, etc. I wouldn't start a thread to ask this if I hadn't already tried everything obvious. And since it'snon-obviousthe question I asked was 'does anyone recognize this case type?'But, the question is now academic. Since I gave up this struggle and just did the repairs needed (sanding and spray painting some rusted areas on the front panel, and hammering a bent rack-flange corner into workable shape) with them all still attached to the case. Didn't want to waste too much time on some stupid commercial box that can't be disassembled without wrecking it. I'm pretty sure the corner pieces are fixed on with some kind of one-way barbed tabs that are forced into slots in the ends of the extruded side pieces. I can see the sides of them in the tiny gap between the brackets and the end pieces. Does not seem to be any way to make them let go, and I suspect tearing them out by force would be a non-reversible option. Really dumb design, if it's actually like that.Thanks for all the suggestions.

author: xrunner
author_rank: Super Contributor
timestamp: January 28, 2017, 02:41:46 am
content: Quote from: TerraHertz on January 28, 2017, 02:37:39 amHe really isn't, I can personally vouch for that.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 28, 2017, 04:03:56 am
content: So, after the non-removable corners frustration, hammering, sanding rust, painting, cleaning rain-splash+dust grunge and replacing rusted screws, pics 1 & 2 are the result. Not too bad. The front panel is steel painted with satin-finish black. The bottom edge was rusty. I only had gloss spray paint, so the repainted bottom strip looks odd.Oh well, I'm only trying to get the system working, not attempting to do an antique restoration. Rust-flaking paint has to go though. And couldn't do the whole panel without losing the texts.This box is just an interface between the PC and actual mass spectrometer sensor head. Not much in it.I consider there's a very low chance of getting schematics from the manufacturer (who still exist), so I won't even bother trying unless I get stumped by some circuit failure later. Also there is a lot of potential for the mass-spec quadrupole sensor to be stuffed, and I doubt I'd be able to afford a replacement.The worst part is that I really have to open the high vacuum bits, to separate them from an unsuitable metal panel to which they are attached. Though there is an alternative - angle grinding the steel panel down to a size that fits my setup, with the mass-spec attached. I'm not keen on that idea. But then I'm even less keep on opening it. Incredibly difficult to achieve adequate cleanliness & avoid contamination for a high vacuum system like this. There are even bake-out heaters (removed) for the conflat joints in that top part. To boil off residual air molecules. One tiny spec of oily dust or fingerprint inside, and it's rooted.Also 3 pics of the vacuum parts.Quote from: xrunner on January 28, 2017, 02:41:46 amhttp://oglaf.com/fountain-of-doubt/

author: CJay
author_rank: Super Contributor
timestamp: January 28, 2017, 08:11:56 am
content: Quote from: TerraHertz on January 28, 2017, 02:37:39 amWasn't asuming you were, I've also been caught out with 'non-obvious' things like that which were, on dissassembly, absolutely obvious in the spotlight glare of hindsight.

author: F64098
author_rank: Regular Contributor
timestamp: January 28, 2017, 02:15:23 pm
content: The black stripes on the side are hold by the spring force of a small silicone tube that sits at the bottom of the inner slot which is much deeper as the outer slot.You have to slide the black stripe in the direction from the edge to the middle stripe. The silicone tube will be compressed and you can remove the stripe by tilting it over the outer edge.I hope you understand my explanation of this simple mechanism...Best regardsFrank

author: Fungus
author_rank: Super Contributor
timestamp: January 28, 2017, 08:20:41 pm
content: Yes, the black panels probably go up/down with some sort of compressed rubber strip on one side of them.Easy to put in, not easy to get out.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 29, 2017, 07:13:39 am
content: BINGO! Thanks F64098 and Fungus. That's exactly it. A small silicone tube on the 'inner' slot of the narrow top and bottom strips. See pic.Even knowing how, it's not so easy since it takes quite a bit of force to compress the tube, and the strip barely moves down enough to get a thin blade underneath to lever it up. I had tried pushing those strips around (with no visible effect), but didn't think to lever them really hard.So, the same screws hold all three pieces at each corner together.Sigh. I suppose the case manufacturer thought they were so clever. Too bad they didn't think to put an explanatory sticker inside.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 30, 2017, 12:05:09 am
content: Bah. It seems to be my week for struggling with tricky side panels.Ironically, the very next thing I want to take apart is this Edwards vacuum gauge. Which has slid-in side panels hiding whatever clips hold the case together. And there's some trick to getting the side pieces out. Presumably by sliding in a thin shim to release a detent. Not tried yet.Model: APGX-M-NW16/ALI Active Pirani gaugeNaturally the user manual doesn't mention anything about opening the gauge case.http://www.pascaltechnologies.com/files/Gauging/Others/Edwards/Edwards%20APGX%20Pirani%20Gauge%20Manual.pdf

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 30, 2017, 12:13:15 am
content: Quote from: TerraHertz on January 28, 2017, 04:03:56 amIf you're concerned about damage from vibration with an angle grinder, plasma cutter or oxyacetylene is always an option...

author: TerraHertz
author_rank: Super Contributor
timestamp: January 30, 2017, 12:03:33 pm
content: Quote from: mikeselectricstuff on January 30, 2017, 12:13:15 amNo, vibration isn't much of a worry. 3mm thick cutting disks go through sheet steel like butter, and the vacuum system has so much mass that vibration in the sheet steel wouldn't do much anyway.It's just the idea of angle grinding, with all that dust and grit, a few inches away from such super high precision cleanliness. Not really a rational concern, since it doesn't matter what gets on the outside of the plumbing. Especially since I'd cover and tape all that nice shiny stuff to protect it. And it was out in the weather for a long time, so worrying about some grit is stupid.Also, I have plenty of time to think about it. Won't be mounting the RGA on the rig for a while yet. Not till after other things are working, and the RGA system is known to work too.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 31, 2017, 01:22:42 am
content: For the information of anyone wanting to open one of these Edwards active vacuum gauges...No, the side trims do not come out with some trick, revealing the case fastenings.This little bugger is one of those things designed to never be opened, and which cannot be opened without pretty much wrecking the case. It uses steel barbs, pressing into plastic posts to secure the two case halves together. Also there are two fat plastic cylinders that mate with each other very tightly. The case was pressed closed, never to be opened.The only way to separate the case halves, is to use brute force. Once it's separated a few mm, the side trims fall out. After levering it a few more mm you can get an engraver bit in to cut holes in the sides of the fat plastic pillars, relieving their grip.I didn't mind messing this one up, because it's a dumpster find and has been exposed to corrosive gasses inside and out. Even the IC legs are greenish. Very likely buggered. I can't even extract the vacuum port filter (stainless steel mesh) because the surrounding aluminum fitting has corroded and 'glued' it in. The steel circlip supposed to be holding the mesh in place snapped on touching it - hydrogen embrittlement. I expect the delicate Pirani sensor inside to be ruined.Still worth a try though.I like the silkscreen warning: "Contains static devices"There was plenty of room for the missing word.