looking for a pcb switch footprint - Page 1
Forum section: electronics / beginners

author: p.larner
author_rank: Frequent Contributor
timestamp: December 31, 2023, 10:43:06 pm
content: hope its ok to ask here,I am putting together a homebrew atu,i an using a couple of ceramic wafer switches for hi/loz and meter range switching etc,they are 112 pole i think,see pic,i am wanting to etch a pcb that can work as a sort of breakout board,i need something printable for toner transfer,its dia is 31mm and distance between mounting holes is about 26mm,its from an old collins tradio part amplifier,has anyone any idea if its a standard switch and where i can find a footprint to etch onto a pcb?.Sorry about the poor pic but you should get the ideaits double sided, i want to solder the switch to so its terminals marry up with copper pads that i can then incorperate into a pcb to connect everything with,i dont want a rats nest and wires putting stress on the wafer switch terminals,i dont know what it would be called too do a search on kikad fooitprints etc,hence my question.

author: Gyro
author_rank: Super Contributor
timestamp: December 31, 2023, 10:54:42 pm
content: Double post!https://www.eevblog.com/forum/projects/looking-for-a-footprint-for-a-pcb/msg5252655/#msg5252655

author: p.larner
author_rank: Frequent Contributor
timestamp: December 31, 2023, 11:11:42 pm
content: i thought this was a better place for the post!.is it against the rules?.

author: Gyro
author_rank: Super Contributor
timestamp: December 31, 2023, 11:13:56 pm
content: Yes, it eventually gets you banned (because people get P***ed off duplicating each others' answers).

author: tggzzz
author_rank: Super Contributor
timestamp: December 31, 2023, 11:44:52 pm
content: Quote from: Gyro on December 31, 2023, 11:13:56 pmPrecisely.

author: p.larner
author_rank: Frequent Contributor
timestamp: January 01, 2024, 12:34:15 am
content: Sorry,i didnt realise,i just tried to remove the post from here but its not letting me.

author: Yuu
author_rank: Regular Contributor
timestamp: January 01, 2024, 12:54:00 am
content: If you have an idea of what you want, you could always take measurements and make your own footprint in kicad. It's pretty easy.Also, your picture is out of focus.

author: WillTurner
author_rank: Regular Contributor
timestamp: January 01, 2024, 03:29:07 am
content: Yes, you would do this kind of thing in 2024 with a computer package like KiCAD, and then through the magic of the internet, send your design to a PCB fab plant, most likely in China. Huge learning curve, so unless you have the time and energy, you might find another way. The last board I produced optically and etched was in 1982. But I'm sure others are keen on the process. Try your local Amateur Radio club.

author: Kim Christensen
author_rank: Super Contributor
timestamp: January 01, 2024, 04:09:25 am
content: For PCB mounting, I'd use a different switch entirely. That one (Looking at your blurry image) was never meant to be PCB mounted, but rather chassis mounted with point to point wiring. I highly doubt you'd find a premade PCB footprint for that.

author: jpanhalt
author_rank: Super Contributor
timestamp: January 01, 2024, 07:18:03 am
content: I have had a little experience with old avionics and those wafer switches (Narco, King, and Collins for general aviation). Finding an old switch is probably easier than finding a footprint in a piece of modern software. You will probably need to draw your own. Since it's DIY, you could use any 2D program for that.ELMA still makes them:https://www.elma.com/en/products/rotary-switches/selector-switches?Electrical+Connection=Pins+for+PCB&q&sortBy=relevance&sortOrder=asc&page=1The largest I found in a quick search is 25 mm diameter. The attached footprint from EAGLE (Switches>ELMA-01-1X12) on a 2-mm grid is only about 18 mm, but it may give you an idea of what to do. The second image is a schematic symbol. For a DIY BOB, you probably don't need that.There are also sites like SnapEDA (https://www.snapeda.com/) and Ultralibrarian (https://www.ultralibrarian.com/) that may have footprints, but I didn't check them.

author: p.larner
author_rank: Frequent Contributor
timestamp: January 01, 2024, 10:29:49 am
content: well,ive done it old school,layed the switch on copper clad,drew the pads in pencil,then painted the pads and tracks with car paint and an artists brush,its a one off,just etching it now using hydrochloric acid+hydrogen peroxide mix,just thought tonner transfer would of been better but for this its good enough,1 wafer is for switching the variable cap too the atu input or output for hi or low z antennas,the other wafer is for switching power+swr meter ranges ie 10w 100w 1kw etc,i will mount screw terminals on the pcb's,it will make the connections neater than having wires soldered directly on the wafers,basicaly the pcb is for strain relef.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: January 01, 2024, 11:54:59 am
content: I use Sprint Layout 6, but other PCB design packages also have faculties to create your own footprints.In addition to being able to create footprints for obscure parts, it also allows you to edit footprints for easier home soldering. For example, the footprints supplied by SMD IC manufacturers often do not include an extra 0.5 to 1mm extra pad width for easier hand soldering with a soldering iron. TO92 transistor pad spacing is often a little tight, not a problem if you increase the spacing and save the new footprint.I used to use laser toner transfer paper and etch my own boards, but the Chinese board makers are much better and ridiculously cheap. I use JLCPCB and small boards are as little as 5 GBP for 5 boards delivered, inc postage and tax. Delivery is typically 2 weeks.SJ

author: p.larner
author_rank: Frequent Contributor
timestamp: January 01, 2024, 12:54:47 pm
content: Using a chineese pcb company is an option,if it was a day postage i would do that but i want to geton with building not waiting for postage+i have 150 6inchx4 inch copper clad boards i got in a job lot.73

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: January 01, 2024, 01:33:24 pm
content: Quote from: p.larner on January 01, 2024, 12:54:47 pmI used to be exactly the same, over many years (since around 1976), I have etched a lot of boards. Only recently I migrated to JLCPCB and in the past year have had around 6 or 7 sets of boards made. Most were for SMD parts and double sided, while I could have just about managed to home etch them, using tightly spaced 0603 size parts, through hole spacing, stitching top and bottom layers, and small ICs like the LTC4368 (3mm square body, 5 legs each side, each 0.3mm wide), is pushing home etching a bit far.SJ