Larry, I have been getting my presensitized PCB material from the company Circuit Specialists I believe they are located in Arizona, there material is fresh and is delivered in about one week. Their website is .... http://www.circuitspecialists.com/ Usually I get the 4.6" x 6.6" size double sided boards http://www.circuitspecialists.com/gd114.html and then trim them down to 3.3"'4.6" to match the size that eagle software allows. Are you offereing boards like that? I use the UV exposure process and it seems to be working for me alright here is a you tube video of... Making PCB for the FTDI Vinculum 2 Chip http://youtu.be/qK6DKbzm024 If you interested in my youtube videos please subscribe. If you are going to make up a bunch of double sided positive photoresist boards I would give some a try. Let me know. Tom From: Larry Battraw <lbattraw@...> >To: homebrew_pcbs <Homebrew_PCBs@yahoogroups.com> >Sent: Tuesday, October 11, 2011 1:32 AM >Subject: [Homebrew_PCBs] The case for crowd-sourced PCB materials > > > >Hi All, > >I've been lurking on this list for some time and seen a lot of different >takes on making PCBs, whether it's toner-transfer, direct-print via >last/inkjet, or UV-exposed resist (And a few stranger ideas). One thing I >have noticed is that it is sometimes difficult or impossible to obtain the >raw materials for our projects. In some cases (Dry film resists) it either >takes forever (2 weeks to over a 3 months!) to get some from Hong Kong or >the Czech Republic (via eBay), or you have to buy a lot at one time (Think'n >Tinker 100-foot rolls for example, at $150+ w/mandatory express shipping). >There are exceptions, but finding them and having any idea of how "fresh" >the film is (Which is important to get reasonable results) is problematic. >A couple years ago a company called Genesis MT sold a great product by the >name of AQ-3000 water-based photoresist. It worked very well, was very >reasonable for the amount you got for the price, and was available via >eBay. Recently I found they had been acquired by another "professional >services"-type company that requires large, company purchases of anything >(i.e. ask for a quote, and no way to buy electronically). It is now >impossible to get any of this great resist, the only water-based photoresist >around. I don't consider the VOC-based resists as viable for use due to >health concerns. > >What I propose is that we as a group of hobbyists provide our own materials, >where some of us will volunteer to be a source for a particular material, in >this case photo-imaging materials. I know there has been a lot of >experimentation with direct/transfer tech but for repeatable, high-quality >boards you really can't beat photoresist-based boards. I'm sure some people >will differ with me but I've read too much about problems with board >coatings, pre/post-heating, different inks (Sometimes very expensive), and >the challenges modifying inkjet printers to be very interested, especially >after I ruined a perfectly good printer trying it myself :-) > >Naturally I am volunteering for the dry film photoresist, since I have >already placed an order which should be here in a couple days. I'd like to >do the same for the Genesis AQ3000, although I have to find out the minimum >order quantity (Apparently they make up a fresh batch for each order) and >available payment methods. I'd like to think that we can use enough of the >purchased products to have them avoid going bad (Shelf life for AQ3000 is 6 >months, similar for dry-film). I would suggest charging actual cost plus a >small surcharge to cover gas and time spent (Maybe $3.00 per order?). I >want to make it possible for us to use high-quality products without a lot >of delay or uncertainty/experimentation in regards to product quality. The >cost would include cost of postage plus mailing materials (Padded envelope >or plastic bottle+box for AQ3000). If it's popular enough, I could offer >additional things like drill bits, PCB blanks, etc. > >I am certainly not adverse to having someone else take all the "business" >from me, as the whole point of this exercise is to provide the materials at >near-cost, quickly. However, since nobody else has suggested this (That I >can remember) I figured I could at least start the process. I have to add >some disclaimers here: I reserve the right to ship within 2-3 business days >of a prepaid order, and if there are unusual restrictions on shipping items >there (i.e. countries that have export regulations for the USA) I also will >not even try to ship an order. Likewise, if I find out after the order has >been placed it's going to be a lot of hassle to ship to I reserve the right >to refuse/refund orders. Ditto for people who piss me off, sorry, I just >won't work with people who can't be polite. If there are unusual >circumstances like having a package refused and returned I also will charge >a fee based on the time spent plus shipping/materials (Assuming the PCB >materials can be re-used and are not damaged). And finally, I reserve the >right to halt the service at any time, refunding any outstanding orders. > >This whole idea is an experiment in supply and demand and so I apologize for >all the disclaimers. I don't want to be sued or even given a bad reputation >because I had a package returned from Elbonia after being opened and >damaged, and the person is upset. > >I apologize for the length of this email, but I'd like to gauge the interest >levels (And potential orders) from people in the group and elsewhere. >Please email me if you're interested, and what you would like to see >offered. I would probably accept PayPal (Yes, they aren't wonderful but >they're big and fairly reliable) for payment. Materials could either be >ordered direct from me or I could post auctions on eBay, but I'm more >interested in serving the community we have here rather than the entire >world. I have a day job and this is just a way to benefit a group of >like-minded people, so it can't be too much of a hassle or I will need to >either put a stop to it or raise prices. It may be necessary to go the eBay >route just to avoid having materials expire but I'd like to avoid it. Let >me know! > >Kind regards- >Larry Battraw > >[Non-text portions of this message have been removed] > > > > > [Non-text portions of this message have been removed]
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Re: [Homebrew_PCBs] The case for crowd-sourced PCB materials
2011-10-11 by Tom Biery
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