WTB: Tiny leaf springs from HP front panel buttons

[SeanB]

Ceramic tile back and waterpaper............. Or for a coarse initial work use 2 cheap chinese whetstones with the stock between them, well lubricated with oil.

[aghp]

One DIY wink

Last time I have repaired (to condition what is like new) these HP front panels I made some springs my self:

I just buy this (look image) and use one strip (not  remember exactly thickness)  and cut exatly right size piece with normal (really good) scissors (it need some exercise to make exatly specially this lenght of spring what is very important (also there may need do some compensation in dimensions if there is some wear in plastic parts) .
(this tool was not expensive and I need only some springs so I use this for material source)

Result: as new original. (it depends of course this metal sheet quality, so do not buy crap)

Also these keyboards cleaning (inside switch) is fun work.
 

[mamalala]

Another bit of lost technology I'm hunting, is a technique for making something like those beautiful photo-anodized aluminum instrument facias that Tektronix used for the 7000 series scopes.

Search for "Alucorex". It's made by Bungard, a German company:

http://www.bungard.de/index.php?option=com_content&view=article&id=26%3Aalucorex&catid=3%3Abungard-produkte&Itemid=77&lang=english

It's rather simple to use, very similar to presensitized photopositive PCB material.

Greetings,

Chris

[TerraHertz]

Update: OK, so the stainless steel shim I purchased first didn't work. It bends to a 'S' shape, ie too ductile.

Then McMaster-Carr (USA) refused to ship a small roll of what looks like the right stuff (1095 Spring Steel - Full Hard Temper, polished) to Australia, quoting 'export rules.'

Next I found an Australian supplier (smallparts.com.au) with full hard, cold rolled, low carbon steel shim, 0.002".
That arrived a while ago, coming in a box that shows it's originally from http://www.precisionbrand.com (in USA.)
I got around to cutting a sample spring yesterday.
It doesn't work. Immediately bends to an 'S' shape, even worse than the stainless.
The HP springs obviously are the 1095 spring steel material, or something similar.

It turns out that  http://www.precisionbrand.com also has the right stuff:
High carbon 1095 hardened spring steel, Blue Tempered Shim Stock Rolls
http://www.precisionbrand.com/ProductsCatalog/PBPCategoryDetails.aspx#l1=14&l2=79&l3=112&lcd=112&l4=0
including:
23110  .002"  .051mm  3" 23C2    0.18

But smallparts.com.au doesn't stock any.
A USA distributor does: http://www.applied.com/apps/commerce/catalog/catalog.do?e=10&s=5534686

I'm about to try them. Will be interesting to see if they have the same attitude about shipping to Australia as McMaster-Carr. It won't surprise me at all if they refuse.

Edit: Thanks Chris, that's an interesting option. But, I'm seeking a way to incorporate multiple colours during anodizing of already machined panels. Some of which I already have, just waiting for surface finish.
Hah... it's taking longer than expected to get around to trying the idea I have for that. What a surprise. 

[mamalala]

Edit: Thanks Chris, that's an interesting option. But, I'm seeking a way to incorporate multiple colours during anodizing of already machined panels. Some of which I already have, just waiting for surface finish.
Hah... it's taking longer than expected to get around to trying the idea I have for that. What a surprise. 

I guess you could laminate the panels with Tenting resist, expose & develop, then anodize. Strip it off, and repeat for the next color.

Greetings,

Chris

[robrenz]

AFIK Anodizing is a 3 step process. First is the actual anodic process that grows a pourous aluminum oxide layer on the surface of the aluminum. Second is the color infusion into the porous aluminum oxide skin. Third is sealing of the pores locking in the color. You could get your parts commercially anodized but tell them not to seal the the anodizing but leave it open pore because you are going to print on it.  HERE is one example of how it is done.  Google "printing on anodized aluminum" and you will get lots of examples.

[TerraHertz]

AFIK Anodizing is a 3 step process. First is the actual anodic process that grows a pourous aluminum oxide layer on the surface of the aluminum. Second is the color infusion into the porous aluminum oxide skin. Third is sealing of the pores locking in the color. You could get your parts commercially anodized but tell them not to seal the the anodizing but leave it open pore because you are going to print on it.  HERE is one example of how it is done.  Google "printing on anodized aluminum" and you will get lots of examples.

Yeah, I've been looking into this for a while, discussed on an anodizing forum, bought a book on it, and also most of the gear and chemicals needed for a hobby anodizing setup. And funnily enough, the method you linked to is almost exactly what I'm going to try. It has to be something I can do at home, with bonus points for posting the complete recipee on the anodizing forum so others can do it too. I'm pretty good at coming up with methods that work, but I've not done anodizing before. Currently it's on hold till I finish a side-track project.

The problem with the DuraJet system is it requires a specialized inkjet printer. What I'm planning on trying is using a standard printer, onto high quality photo (glossy) paper, then contact-transfering the dyes to the unsealed aluminium surface. Various potential means for doing that, we'll see which works best.
Fingers crossed that standard inkjet dyes will work, ie survive the sealing process.
The objective is to produce instrument fascias for my projects, that are as pretty, hi-res and durable as the old Tektronix 7000 series fascias. The primary project this is for needs a lot of different panels with system block diagrams mixed with the controls and indicators. There's a reason why 'looking impressive and professional' is highly advantageous to the whole exercise. And no I don't want to go virtual and have it all on monitor screens. Reasons for that too, to do with needing guaranteed control system function.

Using the paper-transfer method means it's easy to solve the problem of aligning the text to the machining of the panels. Not so easy with direct printing, even if I had a printer that could feed thick aluminium sheets.
The image reversal required is of course just a photoshop step.

[SeanB]

Best inks to use are the photo archival inks from a printer that can handle photo paper. If you have a printer that can do a CD/DVD in a carrier then you can make panels that size and print direct. Otherwise I would try a PCB transfer film that dissolves to act as an ink carrier, with a damp aluminium panel supplying the moisture to mobilise the ink and a roller to provide pressure and keep the ink from diffusing too far. If you are going to do a lot it might pay to take a printer and modify it to have an open back and arrange the paper feed to pick up the anodised sheet to print direct.

[TerraHertz]

I'm planning to try a vacuum system to achieve even contact pressure of the paper on the aluminium. Then add heat and/or solvent vapor and/or electric diffusion to encourage dye migration.

I want something that's fine for one-offs up to medium volume, needs no special printer, and can be copied by anyone.

[SeanB]

Then probably best is photo paper and archival quality ink cartridges.  Vacuum holdown to a damp aluminium panel with open pores will do the transfer if left in contact for a few hours.

[robrenz]

The vacuum may cause bleeding and migration in the carrier sheet and the porous anodize layer.  Just thinking out loud

[yangshen]

so many stuff wanted

[TerraHertz]

The vacuum may cause bleeding and migration in the carrier sheet and the porous anodize layer.  Just thinking out loud

By 'vacuum', I mean pressing the paper against the aluminium by having another sheet of plastic behind the paper (around the entire al-paper sandwich) and evacuating that enough for air pressure to press the paper to the aluminium. But yeah, I know what you mean. The air molecules between the paper and metal have to get out by traveling sideways. Doing so, they may force the ink to blur too. It's going to be a series of experiments, I expect.
The 'porous layer' of anodizing is actually an array of vertical hole structures if done right, so there's little horizontal travel of the dyes possible inside the aluminium.

Anyway, you're just making me feel bad about being too tied up with other stuff atm to proceed with the anodizing experiments. Happy new year to you!

[robrenz]

Sorry, just trying to be helpfull   have a great new year also.

contains how I do graphics for instruments. it works very well and the cover film is very durable. I know you have a lot invested in the anodize process but this can do what you want now up to 11 x 17 "

[SeanB]

Digging this back from the grave..........

Here is a suggestion from a good source about a material for the springs.

http://www.ko4bb.com/dokuwiki/doku.php?do=show&id=test_equipment%3Areplacing_leaf_springs_on_hp_equipment

If you are looking for the tags mentioned contact your local Meto agent or a store using the labels, they might have a roll of them they will give you.

[free_electron]

Oh no... This completely slipped my mind. I have those things ready to be sent. Monday first work...

[robrenz]

Get a quote from these guys for a whole sheet of them, you could sell the extras.  They are in Australia, a photechemical machining job shop they would supply the material.  The quote won't cost anything.

[SeanB]

The tags are available worldwide. If you want free ones go buy a Transcend flash drive, they have them built into the package for loss control use in retail.

[TerraHertz]

Hey thanks, those are some really good ideas!  I definitely will pursue the photochemical machining suggestion. Scrounging shop tags one by one - not so great.

I want to publicly thank Jay_Diddy_B for sending me a bunch of the springs over Christmas. That's taken care of the HP 3497A that was my immediate problem. Free_electron - I'd assumed you decided not to send those, since I PM'd you a couple of times asking for your mail address for the exchange, but got no reply. No urgent need now, so thanks for the thought but save yourself the trouble.

I've been sidetracked by new-year-ism, camping trips,  and some recent acquisitions that are hogging all my bench space. Will be getting back to the 'bulk source of those springs' hunt soon.

[SeanB]

Shop tags are easy, just ask one of the shelf stackers for a roll. Or use the local yellow pages and look for retail security solutions.

[scopeman]

Ahh. The Bill West switch.

Here is the patent. Very interesting.

http://www.google.com/patents/US4017700.pdf

[TerraHertz]

Ahh. The Bill West switch.

Here is the patent. Very interesting.

http://www.google.com/patents/US4017700.pdf

Hey, thanks for that.
I like this: "... a leaf spring ... may be made of a high carbon steel for optimum spring qualities..."
Ha ha... 'may be.' As if anything else works.

These switches really do work nicely. Except for one flaw - if the plunger is depressed very rapidly, like by flicking it with your finger from thumb-tension, the spring end that is buckling upwards has enough momentum to pull its end free of the tiny bottom-stop lip. So then it's a case of SPROIIING, it's gone!

Ah. And reading back a bit I realize that the 'mystery gift' of 30 springs I got in the mail a while ago was probably from free_electron. Sorry I didn't get back to you, I didn't think you'd sent them. The packet had no information from who it was from (eevblog tag-wise.)
But I kept the return address, will find some Australiana for you.