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Hashtags are not a requirement. In fact, I'd rather not see a huge number of hashtags suddenly appear for no good reason. However, I can see a use for the hashtags #tonertransfer #CuCl #KiCAD if you feel that what you are posting might be relevant to some future person looking for information on that topic. As such, please be cautious when using the # symbol. If you use it with spaces on either side, all is well. But the moment you have some alphanumeric immediately following, such as for a phone number, 开云体育 turns it into a hashtag automatically. It isn't a huge deal, but the moderators will have to go in and clean those out periodically. And we don't get paid anything. The same goes for spelling of hashtags. If you misspell it, it doesn't appear under that hashtag, but creates a separate hashtag. The moderators can delete the offending hashtag, but cannot add your message or any thread created under it to an existing hashtag. The hashtag only has to appear somewhere in the message or Subject line, everything else gets taken care of automagically. I think I'd prefer they be in the message body, as it takes up limited reading space for the Subject. Or if you are writing a message online, under the Subject line, there is an "Add Tags" box that will show all existing hashtags. If you are reading a message online, you can click on the hashtag in the message to see a list of all messages with that hashtag, regardless of subject threads. Or look to your left, and you'll see "# Hashtags" just under "Messages". Click on this, you'll see a table of all hashtags available. Just click on one to see the list of messages with that hashtag. -- Steven Greenfield AE7HD

How do you clean the needles used to dispense solder paste? I thought I had it figured out as I got a 100ml luer lock syringe and ran 100ml of hot water through my #21 and #22 needles but the next time I try to use them I find them clogged and the last one I could not get it opened up again. I hope the needles are not 1 time use only. Is there a way to actually clean those needles? Thank you. Jim Pruitt

Hi all, I had an unpleasant experience recently but fortunately not a complete disaster. I have been making PCBs for years using the toner transfer method. The software I use is Sprint PCB and I have used a succession of HP laser printers. Recently I had to get a new printer and went for a Brother. It works very nicely and the toner actually seemed to give better coverage than the HP. After I made my first PCB which was a little one with a few passive components and transistors on it everything looked pretty good and I was quite happy. Yesterday I made a bigger board with several DIP packages on it and it still looked good. But when I went to populate it, it became apparent that the new printer was producing images that were slightly too small. Sprint allows a calibration factor to be specified and after some experimentation it turns out that factor of 1.04 gives properly sized images. All it cost me was some time and some PCB material but it was quite frustrating and a waste of a few hours. So be warned - if you change software or a printer make sure you check the sizing before making a board! Regards to all, Morris

Is there an easy way to convert 274-X files into files that a laser can understand? The Laser is 10W and can AFAIK accept G-Code. I would like to try etching isolation layers by painting the copper clad black. Ideas? Sam W3OHM

Sorry for the crosspost ... I have come across a way of producing an isolated mains supply by connecting 2 identical transformers "back-to-back" i.e. the primaries connected together ... It occurred to me that the following could provide me with a 480v supply or thereabouts to test the A/C option on a Fluke 8840A ... There will be little or no current load (a few mA as a maximum). Is this going to work ?? or will I release the magic smoke ??? Regards, Dave

Can anyone tell me how to correctly merge 2 GBR files into one file? I have a project from a web site. The designer sent me the gerbers but the project lacks a top solder mask. Also when the designer made the original boards 15 years ago he split the top layer into 2 separate files. Since the top layer is MOSTLY ground plane (but not completely) I could not figure out why he has a ground.gbr which is the top layer ground plane but also has a compside.gbr for the 3 or 4 runs that do not tie to that top ground plane. He used a pcb program from that time but I had never heard of it. As you might guess, no board house I found would even touch that. JLCPCB finally told me to go back and put that top layer into one file and then resubmit it. I have Kicad 6. The designer did not share his project file or any schematic file. The gerbers consisted of the bottom layer (solder.gbr) and a solder mask for that bottom layer (mask.gbr) and then the 2 top layer files (compside.gbr and ground.gbr). I was hoping I could take a text editor (Notepad++) and merge/combine those 2 top layer gerber files but not sure what I am doing or how to do it. I did some comparison and both files started out with the same 20 or so first items but then some items were different after that. The board is a 2 layer board for through hole components so no smt parts involved. Also how can I make the top layer solder mask be created since none was included? Or is it even possible without having the schematic file and a complete project? Any help would be greatly appreciated. Thank you. Jim Pruitt

I have several questions about smt solder mask templates. A while back I ordered some bare pc boards from/for the Adafruit Si5351 pll modules. The board is small as about an inch by 3/4" or so. When I ordered the boards from JLCPCB I also ordered a stencil (unframed). When they arrived the stencil was on a piece of stainless steel about 11x17 inches. Did I mention that the board it was for is only an inch by 3/4 inch? I wondered if I had ordered the framed stencil if it would have been board size. A few nights ago I was doing some internet searching and ran across an Adafruit series on stencils: https://learn.adafruit.com/smt-manufacturing/laser-cut-stencils https://learn.adafruit.com/smt-manufacturing/solder-paste-syringes https://learn.adafruit.com/smt-manufacturing/stenciling-machines One of those articles recommended this stencil frame which is a glorified screen printing style frame: http://www.madelltech.com/stp350.html Unfortunately that frame is $1000 so that is way out of my hobby budget! Does anyone know of a much cheaper stencil frame than the Madell tech one? The next questions deal with how to cut the stencil. I want to be able to lay the stencil on the board so that the stencil is exactly the size of the pc board and registers correctly. I do not know how to do that. If I lay the stencil on the pc board then I can not cut the stainless steel without moving it which looses registration. So the question is how do I trim the stencil to board size and keep it so it registers correctly? I asked JLCPCB that question but they did not understand the question and told me to put registration guides in the gerbers (that would not help). I had also bought a stencil from ProtoAdvantage for the TSSOP10 Si5351 chip but that was a big mistake. The TSSOP10 footprint is a very thin 2x5 footprint and it was almost impossible to get it registered over the pc lans to apply solder paste because there was nothing else to reference against (in/on the frame) and with the very tiny slits I never was able to get it aligned on the board and apply paste. I ended up just hand soldering the IC but there has to be a better way to do it. Do you have any suggestions? Thank you. Jim Pruitt

I used to buy JetStar transparent sheets for inkjet printers from Mega UK. However Mega is now out of business. Those transparent sheets did have a "sticky" layer on one side. Has anyone found a source of equivalent sheets? I recall trying some sheets earlier, but I didnt gett the needed black saturation that I got with the Mega UK sheets.

Please excuse my ignorance. Can someone tell me what a framed solder mask stencil is? My suspicion is that it is a stencil that fits into some kind of contact frame like screen printing but I have not found an explanation that makes sense to me. If I am correct then where does one find these contact frames and what are they called? I asked because I was looking to order some smt boards from one of the Chinese board houses and for $7 I can get a frameless stencil but for $9.20 or so I can get one for a frame. To me it would be ideal to have a frame since registration would be easier. Also I have not figured out why all the board houses send a 380mm x 280mm even if the board it is for is small like 32mm x 22mm and that confuses me. Why isn't the stencil a few mm larger than the pc board but not gargantuan like it is? Again what are the solder mask stencil frames called and where can I get one? What is a stencil for frames compared to frameless? Why are the board house stencils so huge compared to the actual size of the pc board the stencil is for? Thank you. Jim Pruitt

Hi, I have built a manual pick and place system that gets around my rather unsteady hands (the indignities of age) and have a USB microscope mounted on it to provide a means of aiming, but I need some sort of cross-hair to help. I have found PixMicro which works well but only under Windows. Ideally, I want to use a Raspberry Pi 4 with (ideally) Ubuntu to display the camera output. Can anyone suggest a Linux webcam viewer that has a cross-hair facility ?? Regards, Dave

Hi all, I've been using the regenerated copper chloride method for etching PCBs for years and have had very good results. One problem I do have though is getting adequate supplies of hydrogen peroxide which I use to give the solution a boost while etching a board. The local pharmacies only sell it in 100 ml bottles of 6% and even then they keep it behind the counter and give you the third degree when you ask for it. I thought I could get larger volumes from a hairdressing supply place but it turned out to mixed into a gel. However I was at the swimming pool shop yesterday and was surprised to find 1 litre bottles of "chlorine free pool sanitizer" that contains 35% H2O2 and 0.33 g/L of silver nitrate which is 1.9 millimoles/litre. My question is, can this be used instead of pure H2O2? Should I be concerned that the AgNO3 would interfere with the etch or have a detrimental effect on the stock CuCl2 solution that I have built up over the years especially as it would accumulate? Any advice from someone who knows more chemistry than I can remember from half a century ago would be most welcome. Morris

OVERVIEW: This is a simple procedure for preparing 1 liter of cupric chloride etching solution. The tradeoff for the simplicity is a bit of patience as it may take a while to complete the preparation. The value of this patience is that the resulting solution won't be overburdened with hydrochloric acid and thus won't be as smelly and as corrosive to materials around it as some more quickly prepared solutions may tend to be. It also won't have any residual hydrogen peroxide which will result in a very slightly lower tendency to undercut your PCB traces. That last effect is really quite small, but why not? Also, since we won't be depending on the presence of H2O2 once the etching solution is prepared, we don't have to worry about over diluting our solution by trying to regenerate it with the weak 3% H2O2 commonly available in drugstores. We'll be regenerating with an air bubbler, which can serve double duty to agitate the solution when etching. MATERIALS: One large (at least 2 liter/0.5 gallon) glass container with a plastic lid. A 1/2 gallon "iced tea" jar with a plastic lid (plastic lid liner or no lid liner) and a small pop open spout would be ideal because you can open the spout to insert a fritted glass bubbler for use in rejuvenating the solution after use. If you need more than 1 liter (1 qt) of solution, consider using a larger container and increase the amounts of materials below accordingly. I suggest the container be only about half full when done. Only partially full plus a small opening in the lid keeps any spray resulting from regeneration by air bubbling inside the glass container. One small aquarium pump. The cheap vibrating kind is fine. One fritted glass bubbler, preferably long enough that it can reach the bottom of the large glass container with at least an inch or more of glass tube sticking out - preferably. If you can't find one that long, then your plastic tubing will extend into the container. I don't like that, but that's just me. Plastic tubing to connect the pump to the fritted glass bubbler. I like enough tubing that I can place my pump higher then the top of my jar. Not likely the solution will syphon out if the pump is lower, but it's 100% impossible if it's higher. 200 grams (7 oz) of copper wire, copper pipe or other pure copper. I used solid copper wire, but stranded copper will dissolve quite a bit faster. Pennies (even the old type) and some misc plumbing or electrical hardware aren't pure copper and are unsuitable. Tarnish (discoloration) is OK, but it must be clean otherwise. 200 gms of copper is about 14 feet of #10 copper wire... 22 feet of #12... 36 feet of #14... 56 feet of #16. 32% - 37% Hydrochloric Acid - also called Muriatic Acid - free of detergent or other additives. READ THE LABEL! This really needs to be 32% - 37% HCl and free of additives, so READ THE LABEL! You can get concrete driveway cleaner that meets these requirements at Home Depot, Lowes and assorted hardware stores. Look until you find 32% - 37%, Hydrochloric Acid or Muriatic Acid free of additives. You'll be sorry if you don't. It should be easy to find in the USA... might require some looking elsewhere. 3% Hydrogen Peroxide. This is readily available at Walmart, a grocery store or the drugstore. You only need a few ounces so forget about stronger solutions that are harder to find and more expensive. If you think stronger is better and manage to hunt down 35% H2O2, please don't bother to tell me... especially if you hurt yourself... perhaps seriously. SOLUTION PREPARATION: Pour 1 liter (4-1/4 cups) of water into your container and clearly mark the level on the outside of the container. Pour out the water. This is the level you will want to maintain later after etching and rejuvenating. Add the copper to the empty glass container. Carefully pour 0.6 liters (2.5 cups) of hydrochloric acid into the glass container. Add 0.1 liter (0.5 cup) of hydrogen peroxide. This should be all the hydrogen peroxide you'll ever need. The copper wire will begin dissolving as evidenced by a green color forming in the solution and bub

Steven Greenfield AE7HD <alienrelics@...> added the album Commodore PET CNC Drill by Janwrl: Janwrl wrote a custom program to take drill files on his Commodore PET and drill them using his custom built CNC drilling machine. The following photos have been uploaded to the Commodore PET CNC Drill by Janwrl album of the [email protected] group. Dscn0329.jpg By: Steven Greenfield AE7HD <alienrelics@...>

Anyone tried this? I feel foolish for not thinking of it. The fastest way to make crisp PCBs at home! The fastest way to make crisp PCBs at home! Steve Greenfield AE7HD http://www.linkedin.com/in/stevenjgreenfield -- Steven Greenfield AE7HD

I want to make a PCB with BGA ICs (up to 0.5mm pitch) DIY. Is that even possible ?

Hi all I have got hold of a cnc to use for drilling pcb's that I make with Eagle 6.4 pro but need some help with software and best way to set it up, would also like to be able to cut out the board Hope I can get some help Thanks Howard

Hi all, I picked up a large sheet of surplus single sided copper clad board that is coated with a reddish colored photoresist. I don't know anything about it or whether it's positive or negative. I would like to remove the photoresist and just leave the copper layer so I can use it for toner transfer. The resist is not affected by acetone, turpentine or naphtha. Any advice on where to go from here would be much appreciated. Thanks, Morris

Hi, I need a way to make small cheap SMT stencils at home - I do not have a CNC or have access to one so I would prefer the toner transfer and etching method that seems popular in some quarters. I loved the idea of using the thin aluminium of a drinks can see here but he uses a mixture of Muriatic Acid and Hydrogen Peroxide and I have found Muriatic Acid rather hard to find in the UK. Has anyone used this technique ?? How good is it ?? Are there alternatives to Muriatic Acid?? or where can I get it in the UK ?? What other DIY methods work well ?? Best regards, Dave

Can anyone advise me where I can obtain some ??? Regards Dave

Hello Steve and the group. I am willing to help out if you need it. I own a few groups and also moderate a few other groups. Thank you. Jim Pruitt WA7DUY