Re: [Homebrew_PCBs] uv resin for a photoresist substitute
2017-03-01 by Rob
WHAT chemical would wash away the cured UV resin after the board was etched? I thought the idea of hardening the resin was to make it harden. Does hardening
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uv resin for a photoresist substitute
2017-03-01 by jeff.heiss@...
Is it possible to use UV resin as a substitute for photoresist? Copper would be coated with UV resin and an image would be made in the resin with a UV laser.
File - monthly.txt
2017-03-01 by Homebrew_PCBs@yahoogroups.com
Monthly Reminder for Homebrew_PCBs list, please read: Messages and threads: Please do NOT start a new thread by replying to another message. Even if you change
Re: [Homebrew_PCBs] reducing mask image with lens
2017-02-21 by Donald H Locker
From my in-house darkroom experience many years ago, I discovered that the lens system required to image a flat plane to another flat plane (i.e. film to
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-21 by Harvey Altstadter
I am resending this post because I was having trouble with my mail when I sent it originally, and I don t think it was posted. Please forgive me if this turns
Re: [Homebrew_PCBs] reducing mask image with lens [1 Attachment]
2017-02-20 by jeff.heiss@...
This is very interesting info, thanks guys. Testing a current day HP laser printer at 600dpi and 1200dpi did not show appreciable resolution increase between
Re: [Homebrew_PCBs] reducing mask image with lens [1 Attachment]
2017-02-19 by Harvey Altstadter
Jeff, In principle, this should work, but as usual, the devil is in the details. The most obvious to me is that you are limited to small boards with this set
RE: [Homebrew_PCBs] reducing mask image with lens [1 Attachment]
2017-02-19 by Andrew Volk
This sort of thing was done for a long time to make plates for fabricating integrated circuits for quite a while. (ICs use a photosensitive resist spun onto
reducing mask image with lens
2017-02-19 by Jeff Heiss
The conventional method of using photoresist is to install a mask on top the photoresist. I m considering using a two-to-one reducing lens and placing the
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-18 by Jim Pruitt
I still say the best sockets by far for soldering under are wirewrap sockets. Yes they have square pins but the leads are about an inch long and so you can
RE: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-18 by keith printy
Heathkit used those in some kits.i used to have reliability issues with them and had to reseat the chips. Better off to use the sockets with the round tooled
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-17 by Harvey Altstadter
... Subject: Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork? Date: Fri, 17 Feb 2017 13:27:40 -0700 From: Harvey Altstadter
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-17 by Roland Harriston
Jim Pruitt: Yes. In the old days Molex only had one or two products. Now, they cover the field. I had some of those plastic hoods that slipped over the
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-17 by Sven Oleson
Hi I use a lot of Photoshop, and remaking the board wouldn t be all that difficult. The bigger question I have is why would you spend all that time remaking it
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-17 by Jim Pruitt
Hello Roland. Yes, they were/are Molex pins. I still have 2 strips of 100 but don t really like them without the plastic cover. I know that Molex later sold
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-17 by Roland Harriston
Hello Jim Pruitt: Could you be referring to MOLEX PINS ? Years ago I purchased a bag-full of these items from a now defunct electronics mail order supplier. I
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-17 by Jim Pruitt
Wire Wrap sockets will allow you go get about as far above the board as you want and solder the pins on top as well. I am not sure you can find some of the
RE: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-17 by roylowenthal@...
It used to be possible to get IC sockets that were solderable from both sides. The socket pins came up over the side of the socket, making it (relatively) easy
Re: Polyimide Kapton KOPTAN tape
2017-02-16 by me@...
I use regular cheap transparent tape for printing. Also use it for the laminato . Not once have I had a problem with melting.
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-16 by Will Kimber
I don t know if the Bishop Graphic sick-on tapes and pads are still available. If so would it be practical to take your scans put some tracing paper on top
RE: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-16 by Tony Smith
You can get rivets for making vias: https://www.megauk.com/through_hole_rivets.php, but ah, a bit spendy. The other option is you cut short lengths of copper
RE: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-16 by Malcolm Parker-Lisberg
For homemade double sided non-plated through I use fine tinned copper wire, through the board and bent over on the top and soldered to the top pad. Then use
RE: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-16 by Brad
Thanks so much for all this! Yes, I think this will be a very difficult project. But I like challenges, even if I fail. Unfortunately as far as I know there
Re: [Homebrew_PCBs] Good techniques for cleaning up old artwork?
2017-02-16 by Harvey Altstadter
Brad, I looked at your artwork scans. WOW. Has anyone suggested that you might be a glutton for punishment? I noticed that the first two scans are much cleaner
Good techniques for cleaning up old artwork?
2017-02-16 by Brad
My TV Typewriter project is getting close to the finish line so I m working on lining up a new project. What I d like to do next is a replica of the SOL
RE: [Homebrew_PCBs] Polyimide Kapton KOPTAN tape
2017-02-12 by Tony Smith
Kapton is a trademark. Often it’s just called ‘high temperature tape’. As an aside get the brown stuff, the green stuff is rubbish. Tony From:
Polyimide Kapton KOPTAN tape
2017-02-12 by Rob
I got some polyimide tape from ebay and noted that it was tagged KOPTAN on a label on the tape. Noting the 3M name is KAPTON The EBAY tape is $2.59 per
Re: [Homebrew_PCBs] Re: Milling PCBs: Leaving behind "threads" of copper
2017-02-11 by roylowenthal@...
Cratex is a US source of similar products.
Re: [Homebrew_PCBs] Re: Milling PCBs: Leaving behind "threads" of copper
2017-02-10 by Cristian
... Wrong, use another two words: abrasive rubber (eraser with glass powder inserts). Specially produced to clean the PCBs. See Farnell UK #141330 and
Re: Milling PCBs: Leaving behind "threads" of copper
2017-02-10 by hickspj467@...
Copper is notorious for its difficult machining characteristics. It has a tendency to be gummy and catch the cutting tool. Careful selection of tool feed
Re: Milling PCBs: Leaving behind "threads" of copper
2017-02-09 by me@...
Well tried on the remaining bits of the board I was cleaning up and a brush didn t seem to help at all. Of course they were the most stubborn of the threads.
Re: Milling PCBs: Leaving behind "threads" of copper
2017-02-09 by Paul Alciatore
Two words. Brass Brush.
Milling PCBs: Leaving behind "threads" of copper
2017-02-09 by me@...
I am milling PCBs. I am using Flatcam to produce the gcode and autoleveller to level the code. Over all it does a great job. But I am noticing what
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-04 by Steve Wright
Acetoneis not carcinogenic. It is liable to cause respiratory irritation and in higher concentrations will cause nausea, sluggish behavior and possibly
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-04 by Stefan Trethan
OK Norm, I _would_ now hesitate in this or any similar application. ;-) I m sure you had the proper clean stuff too, not some cheap fuel alcohol. ST On Sat,
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-04 by Norm Stewart
On 2/4/2017 6:20 AM, Stefan Trethan stefan_trethan@gmx.at ... Depend on what you use the acrylic for. MANY years ago (1970 or so) at the Lawrence Radiation
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-04 by Stefan Trethan
It may depend on denaturing agents as well as the particular acrylic grade. Personally I wouldn t hesitate to clean acrylic with denatured ethanol, since I
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-04 by sjlane60@...
Stephen Lane wrote: Wow what a long thread - I tend to agree with ST all solvents are not good as to how bad I refer to the MSDS s tho I would point out that
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-03 by Tom Crawford
Usually a good idea to read the MSDS document for any chemical safety information. Search with google for msds acetone , and you will find lots of them. In
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-03 by alan00463@...
I asked my sister about acetone. She uses it everyday at the beauty shop where she works, doing fingernails, pedicures, hairstyling. She said they don t
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-03 by Stefan Trethan
Most solvents are not good for you. The cheap widely used solvents derived from crude oil are pretty bad, paint thinner, brake cleaner, petrol, etc. These
Please trim most of the old quoted stuff out of your replies.
2017-02-03 by indigo_red@...
I just gets longer and longer and is hard to find the new added remarks.
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-03 by Donald H Locker
Quats are also common constituents of anti-bacterial soaps. Nasty stuff. They do kill 99.9% of the germs, but the 0.1% (thousands) left behind are the ones
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-03 by Brad Thompson
On 2/2/2017 3:32 PM, Harvey Altstadter hrconsult@cox.net [Homebrew_PCBs] ... Hello-- nail parlor workers are indeed exposed to a variety of chemical
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-03 by Rob
thank you On 02/02/2017 02:04 PM, Stefan Trethan stefan_trethan@gmx.at
RE: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-02 by keith printy
The main thing with acetone is how volatile it is. There is a UL flammability scale with 1 being most flammable and 10 being the least . Gasoline comes in at 6
RE: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-02 by keith printy
Another chemical used in nail salons is ethylmethacrylate this one smells nasty and only a couple drops will stink up a room pretty good. It is used in the
RE: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-02 by keith printy
Tolulene is bad. Kids used to get high off it sniffing glue. I’ve heard it can cause brain damage. From: Homebrew_PCBs@yahoogroups.com
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-02 by Fernando Cassia
On 2/2/17, Stefan Trethan stefan_trethan@gmx.at [Homebrew_PCBs] ... https://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=1 Cancer Classification: None
Re: [Homebrew_PCBs] Re: Printer Is ACETONE a carcinogen
2017-02-02 by David Martin
wow, what would you mix it with during the cocktail hour !! hi hi David Martin - NA1MH - Mountain Home, Ar.