Stan,
Volkan also built a direct UV laser writing system that immages the pattern directly on the Riston coated PCB. It raster scans the laser over the board using a hacked printer mechanical. Even tested it on some boards I coated with AQ3000 pos photo resist for him. The resolution was just amazing. It takes about 20 to 30 minutes per side to expose an average board so the drum plotter is a better solution if you need to make more that one or two of the same board.
Both of these projects are on my list of things to build once I get my CNC mill finished up.
Craig
--- In Homebrew_PCBs@yahoogroups.com, "stan_katz" <stan_katz@...> wrote:
>
>
>
> Marvelous!
>
> I've been looking for a way to get consistently high quality negatives for fine pitch (surface mount) photoresist hobby work. I use Riston. To get the desired quality, I actually make litho negatives ( I don't mind darkroom work) from inkjet positives to increase density and resolution. This works after a fashion, but I have always wanted to go directly to film negative.
>
> My local print shop has gone away. Anyhow, paying $10.00 - $15.00 to a printshop to imageset one design to film on a diy budget got ridiculous.
>
> Therefore, I looked into purchasing a used print shop imagesetter from Ebay to do what you have accomplished. These beasts weigh a ton, take up too much room, and use proprietary chemistry and film rolls. They are smelly brutes that would pollute one's home. Anyway they are becoming obsolete. Supplies, if still available, are sold in industrial quantities, for a fortune.
>
> Small quantities of letter size litho and RLN4 using standard A&B chemistry are still available from Ultrafine (Stateside). Your plotter's modest appetite for inexpensive films, and it's manageable size make it a winner! If you don't have plans to sell a construction manual, or manufacture the plotter for resale, I do hope you will post the construction details when you have a chance.
>
> BTW Can it be built without access to a machine shop?
>
> --- In Homebrew_PCBs@yahoogroups.com, "Volkan" <v_sahin@> wrote:
> >
> > Hi All,
> >
> > Recently, I worked on a homemade drum plotter to expose negative acting film. I added some photos under Photo Albums > Drum_Plotter_V_Sahin and there is also a video on youtube
> > (http://www.youtube.com/user/vulcanmicronics).
> > Later, I will add more videos.
> >
> > Short performance summary of the plotter
> > Resolution 832x2032 dpi
> > Optimum exposure time on RLN-4 Film=9.5 microseconds with 405nm 150mW laser.
> > Optimum drum speed:~615 rpm
> >
> > Thanks,
> >
> > Volkan
> >
>