Pomona 2259 plug to banana enclosure - Are there alternatives? - Page 1
Forum section: electronics / projects

author: AndersJ
author_rank: Frequent Contributor
timestamp: February 25, 2022, 10:32:45 am
content: The 2259Phenolic Box Component Mounting Double Plug To Binding Postsis no longer manufacturered.Does anyone know if there are similar products that still are in production?Anders J

author: jonpaul
author_rank: Super Contributor
timestamp: February 25, 2022, 12:41:09 pm
content: we have many similar modified to add fuses, contact me PM if you are interested, perhaps a swap?Am in USA now, your location?Jon

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 25, 2022, 02:05:29 pm
content: Just 3D print an enclosure to fit off the shelf plugs and sockets?

author: jpanhalt
author_rank: Super Contributor
timestamp: February 25, 2022, 03:13:47 pm
content: Finding a phenolic box today for any reasonable price may be difficult. If ABS or other plastic is OK, check out Polycase:https://www.polycase.com/product-sizes?height=0.65-12&length=1.75-32.68&width=1.44-24.8My list of enclosure providers is:BudHammondOKWPacTecPolycaseSerpacI have not updated that list in several years. Some may have been acquired or there may be new ones.

author: TimFox
author_rank: Super Contributor
timestamp: February 25, 2022, 04:16:15 pm
content: One problem with undrilled plastic boxes is that many of them are molded and have sloping sides, while the discontinued Pomona box is a rectangular prism with perpendicular sides.(This is also true of die-cast aluminum boxes, since the sloping sides are required to get the box free of the casting mold.)

author: tooki
author_rank: Super Contributor
timestamp: February 26, 2022, 11:23:41 am
content: Maybe a tiny extruded aluminum case? Something likehttps://www.hammfg.com/files/parts/pdf/1455D601.pdfYou can always cut them in half and buy extra end panels to make shorter versions.

author: coppercone2
author_rank: Super Contributor
timestamp: February 27, 2022, 01:03:52 am
content: Quote from: TimFox on February 25, 2022, 04:16:15 pmthis is a problem, the way to deal with it is to unfortunately print the template out (from a CAD program) and stick it on the box and work with jig saw etc, rather then trying to mark out the box with calipers and stuff.. I did the template and got it right the first time and tried to do it with hand layout tools and I ended up having to do a fair bit of filing. Square switches on sloped box = problem. Be careful because its easy to compress the switch in the hole in such a way that it does not turn off because its under pressure! Not saying you can't do it with a caliper, but its easy to think 'easy street' because you think you will have right angles on every face.. I thought I had a broken mains switch but then I realized it was being compressed by the slightly off dimensions of the hole, which caused it to turn on and not turn off! Don't stuff square switches in stuff until you know for sure.If you need to do it by hand you can try to use adjustable squares to draw lines, but caliper is not great at it. Printer is king.

author: TimFox
author_rank: Super Contributor
timestamp: February 27, 2022, 04:16:19 am
content: If you can tolerate the sloping sides for the application, it is easy to mark them accurately using a height gauge, a right-angle fixture, and a flat surface.You can set the box down on an edge, against the right angle, and scribe it with the height gauge. Dial height gauges with scribers are available for < $100 USD new.Years ago, I bought small "B-grade" granite plate. Later, I went to a university party and was introduced to a geologist. I told him that I knew little about geology, but I had a nice piece of granite. He asked me if it were gneiss, or were it granite? My wife and I were the only others there who got the joke.

author: coppercone2
author_rank: Super Contributor
timestamp: February 27, 2022, 08:40:28 am
content: Oh yeah now I have a surface plate to do this on (or really a table saw is probobly good enough if its cast iron). If you use iron stone the surface gently and lubricate a little before you slide a height gauge around. For some reason though.. I never thought to use the height gauge on those boxes lol. And keep in mind thats only horizontal lines, vertical lines are not essential but nice, especially if you need to file after cutting wrong. Easy enough to vertical lines, but you might want a miniature square to be sure about them, but I think a folding lockable steel t-bevel would be great here so you can scribe along the edge after you mark your horizontal lines.

author: tooki
author_rank: Super Contributor
timestamp: February 27, 2022, 09:19:21 am
content: Quote from: TimFox on February 25, 2022, 04:16:15 pmHow does Lego do it? I know I’ve read that it’s one of the technically challenging parts of their manufacturing, but they do manage to do it on a colossal scale, with a high level of precision. Tapered sides make part ejection much easier, but are decidedly notrequired.

author: TimFox
author_rank: Super Contributor
timestamp: February 27, 2022, 03:11:26 pm
content: Quote from: coppercone2 on February 27, 2022, 08:40:28 amBesides a granite plate or good saw table, another possibility for a flat surface (good enough for this kind of work) are cutouts of kitchen counter material (such as the rounded rectangle cutout for a sink) from a kitchen contractor.A good right angle plate (machined iron 6x6 inch ones are readily available at reasonable prices) allows scribing the vertical lines (when you rotate the box appropriately).With the tapered sides, always place one or more edges of the "maximal" rectangle on the flat plate, and the open face against the right angle plate.An example of a suitable moderately-priced right-angle plate (4 by 4 inch):https://www.mscdirect.com/product/details/00140046There are smaller units at lower prices, and precision ground units are far more expensive.

author: Bassman59
author_rank: Super Contributor
timestamp: February 28, 2022, 03:06:45 pm
content: Quote from: NiHaoMike on February 25, 2022, 02:05:29 pmThis is the way.

author: thm_w
author_rank: Super Contributor
timestamp: March 01, 2022, 12:05:29 am
content: I don't know what Pomona used, but you can get threaded male banana plugs:https://www.aliexpress.com/item/32948366707.htmlWith a CNC, assuming the tapered edge was thick enough, you could flatten it out and drill precise holes all in one operation.Surprised coppercone you don't have a CNC machine at this point?

author: coppercone2
author_rank: Super Contributor
timestamp: March 01, 2022, 08:37:50 am
content: being able to take worthwhile measurements and electromagnetic behavior understanding are (still) the bottle necks right now, and I am trying to explore the 'casting' route for what I want vs the auto machining route.I also kind of know what a CNC machine will get me, but casting is a interesting mystery. And maybe I can get a foredom tool and some sculpting supplies to have some fun with..at this point I kinda want connectors, cables, test equipment to appear rather then end mills.I would do a MF70 CNC conversion, if the CNC conversion let me keep my knobs. I have not seen 'easy' plans/kits on how to do this, only very good suggestions that require engineering. But on the positive side, I have started to use my micro-mill to do things that I would normally do with a file or dremel, to try to benefit from owning it... it does actually make life easier if you think the problems through (and it helped to make a actual kit for it that makes it pleasant to work with, cutouts for wrenches, caliper , etc.. finally feels like a kind of useful tool. I am more interested right now to see how it does on 'hard' jobs with water cooling. Haha, I just kinda started to force myself to learn to read the manual ruler indicators to do actual 'machining'.Since the machine saves me that kind of work (and it needs to be around and ready to be useful and fast), converting it to CNC without retaining control of the knobs would actually hurt my workshop.Tempting to though, scroll down on this page for something real interesting with the micro mill, they actually turned it into a 'MICRO' mill.https://www.mdpi.com/2072-666X/11/2/135/htmhttps://www.mdpi.com/micromachines/micromachines-11-00135/article_deploy/html/images/micromachines-11-00135-g004.png

author: tooki
author_rank: Super Contributor
timestamp: March 01, 2022, 10:31:00 am
content: Quote from: thm_w on March 01, 2022, 12:05:29 amPomona makes threaded banana plugs, why would you recommend aliexpress junk?

author: thm_w
author_rank: Super Contributor
timestamp: March 02, 2022, 01:40:06 am
content: Quote from: tooki on March 01, 2022, 10:31:00 amI didn't "recommend" anything, simply pointed out that they exist, while asking what pomona used as its not clear from the photo.It looks like Pomona charges $14-30:https://www.mouser.com/ProductDetail/Pomona-Electronics/72918?qs=fxxZwZgTYwCxYe10prEVlw%3D%3Dhttps://www.mouser.com/ProductDetail/Pomona-Electronics/3264?qs=M3Z5UvI%252BDu3Det1o3ACarA%3D%3DA bit excessive.