WTB: Old Jap. 'radio buttons' - source or any old PCB with these. - Page 1
Forum section: electronics / general

author: TerraHertz
author_rank: Super Contributor
timestamp: January 18, 2015, 12:59:47 am
content: An old chart recorder I'd like to repair has some push button shafts broken off. See pics of the board with the button assembly.The chart recorder is by Sekonic, model SS-250F.It appears that if I can find any row of these pushbuttons, I can extract the individual switch units and replace the broken ones in this module.Actually only two are broken; the ones nearest the metal bracket. The one at the opposite end is supposed to be clipped short like that.Does anyone have any old circuit board with the same type of buttons?(Edit: The EXACT SAME type, not 'similar'.)Or know of a supplier selling the button components?There's also a broken-off mains push button of a different kind - last pic.I think I can improvise a repair on that, but still, if anyone has an identical button, intact, please let me know.There's a shot of the chart recorder in another thread here:https://www.eevblog.com/forum/buysellwanted/wanted-recording-chart-rolls/msg532871/#msg532871

author: free_electron
author_rank: Super Contributor
timestamp: January 18, 2015, 01:13:43 am
content: ALPS and ITT/CANNON are your best bet. they still make those. digikey and mouser stock em.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 18, 2015, 01:59:45 am
content: Quote from: free_electron on January 18, 2015, 01:13:43 amI was reminded to try hunting for these again by this thread:https://www.eevblog.com/forum/buysellwanted/for-sale-sunday-18th-jan-2015-electronics-surplus-sale-(vic)/then seeing these similar switches (1st pic in thread):http://www.aussieradioforum.com/forum/viewtopic.php?f=48&t=124&sid=6567eb32aa416e8862542a0178f2143cThose are not the same. Are those the type you're thinking of?The only name I know these type of button assemblies by is 'radio buttons'. But I'm not having any luck with that search term. Just waded through 25 pages of Mouser button listings. Nothing.

author: EEVmarty
author_rank: Contributor
timestamp: January 18, 2015, 05:19:11 am
content: Hi there,I run the "Aussieradioforum" as linked below...I have an absolute pile left of those banked-switches (shown in the link) *IF* you feel you can butcher them to get your switches working again.FREE to pickup in Melbourne, or postage at cost interstate.Regards,Marty.Quote from: TerraHertz on January 18, 2015, 01:59:45 am

author: Flump
author_rank: Frequent Contributor
timestamp: January 18, 2015, 06:35:52 pm
content: try searching for " Alps push switch"I couldnt see where you said if they were latching or not.latchinghttp://www.ebay.co.uk/itm/Alps-ASUE98015-Latching-Push-Switch-2PDT-PCB-Mount-4-pcs-/251342436117?ssPageName=ADME:L:OC:GB:3160some morehttp://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR11.TRC1.A0.H0.Xalps+push+switch&_nkw=alps+push+switch&_sacat=0http://www.ebay.co.uk/sch/i.html?_odkw=alps+push+switch&_from=R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xalps+push+switch+2+pole&_nkw=alps+push+switch+2+pole&_sacat=0

author: TerraHertz
author_rank: Super Contributor
timestamp: January 19, 2015, 01:47:57 am
content: Quote from: EEVmarty on January 18, 2015, 05:19:11 amHi Marty,Thanks for the offer, and I'd take you up on it even though the ones you pictured are not compatible with the chart recorder I have, however I already have a box full somewhere, of ones just like yours. (Not that I'm able to find them.)I do wish I could drop in and pick through the stuff you have listed. But I have an urgent need to buy some specific things in the near future that are going to exhaust my cash again. So... just have to pass on nice cheap components.Quote from: Flump on January 18, 2015, 06:35:52 pmI didn't say, because what I'm after is the exact same model of button assemblies, though I don't care about the number of buttons in a line. They're modular - each button can be unclipped from the metal mounting strip. So I can replace individual ones - if I can find *anything* using the same type buttons.They are 'radio buttons', ie pressing any one pops out the others. In groups, determined by where the springy interlock strips are inserted. You can see the springs sticking out the ends of the metal mounting frame.Have to be identical, to suit both the PCB and the button holes in the equipment casing. This PCB is the 'front panel controls' board.I can't replace just one or two with vaguely similar style buttons, as that won't work with the 'select one' functionality.For the mains switch, the constraints are looser. I probably can find something I can hack to be more or less OK. Better if I can find the exact same switch, so the front panel hole lines up.

author: EEVmarty
author_rank: Contributor
timestamp: January 19, 2015, 07:49:17 am
content: Hi TerraHertz,I've been diggin and have found these Alps switches (re-badged under Sony).These are the locking type, not momentary.The number on the blue body appears to be "636Z" if that helps?If the switch isn't a drop-in fix, maybe you're up for some surgery to just replace the inner plunger stem (assuming it matches internally).Yours free if you need them, i have a few....Regards,Marty.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 19, 2015, 09:45:04 am
content: Thanks Marty, that's very kind. But I'll decline. They won't help with this recorder, and I too have boxes of assorted switches already.With the broken ones, I have some of the pieces. Pic below. The shaft that looks intact is actually broken in half, same as the other one. I could glue that one, but there's still the missing spring contacts.See how the shaft has that detent, and the slopey side above it? Those surfaces interact with the spring that runs along the whole group of switches, so depressing one releases any other that was depressed.I just thought I'd ask here if anyone recognized those particular switch sets. Otherwise it looks like I'll be trying to duplicate tiny bits of plastic and fabricate some tiny little spring contacts like that one in the pic.

author: mubes
author_rank: Regular Contributor
timestamp: January 19, 2015, 10:57:05 am
content: They look eminently printable...if you can produce some sort of drawing with the critical dimensions on it then it wouldn't be a big deal to create an openSCAD file which you can probably get produced locally....you're the other side of the planet from me I'm afraid.DAVE

author: TerraHertz
author_rank: Super Contributor
timestamp: January 19, 2015, 11:36:23 am
content: Quote from: mubes on January 19, 2015, 10:57:05 amHmmm. What's the resolution of 3D printers? These are quite small and detailed.Apart from that I currently have no CAD software, and another problem with that idea would be that these are made of GRP, and have a quite thin constriction in the middle. Where they broke off, though I'm guessing that was due to some careless impact/misshandling by the previous owner. In normal use, GRP is rigid enough that they should be OK for purpose. But the thermoplastic of 3D printers, isn't as rigid as GRP, is it?Oh, and also it seems to be a very hard plastic, that resists wear from the edge of the round hole in the thin spring-steel interlock strip, that has to slide smoothly over those slanted surfaces on the moving plastic part.Actually, I thought one of the switch fragments was missing. When I originally opened up the recorder I'd saved all the pieces rattling around inside, and was a piece short. But just now, looking at the photos I took for this thread, I see there's a fragment still inside the switch body. Hadn't noticed it there before - maybe it just then moved down far enough to see.That means all that's missing are some of the contact springs. I can make those, I think.The broken plastic shaft ends fit together well, as usual with hard GRP breaks. Superglue should work.