Oops, my mistake - that's single sided board. The cost is higher for double sided, but not by a ton, and if you buy it in bulk you'll still get it pretty cheaply. -Adam On 4/16/08, M. Adam Davis wrote: > Continuing on the PCB idea - given that there's no need for plated > through holes, you can buy and etch it yourself. A 48"x36" double > sided copper clad board is about $32, and if you cut it into 8"x9" > sheets you'll get 24 PCBs. ( from > http://www.crownhill.co.uk/product.php?prod=1971 - I imagine you can > get it locally for similar cost) > > Use a screen printer to put etch resist on each side, etch and viola! > Each target costs $1.33 and some amount of time. > > -Adam > > On 4/16/08, M. Adam Davis wrote: > > How much can you pay per target? > > > > Get 64 conductor ribbon cable (3.2" wide) and lay two of them > > vertically next to each other, and 2 of them horizontally next to each > > other behind the paper. > > > > Attach connectors to them, which plug into PCBs nearby. > > > > Use a bunch of multiplexors to scan continuity through all 200 wires, > > and compute exact bullet penetration to within 0.05". > > > > It's a very low cost system with high cost replacables - each target > > would use perhaps 4 feet of cable and 8 connectors that would be > > reusable for a few targets, but in the end each target would still > > cost $12 or more, and it would only cover a 6.4" x 6.4" square. > > > > With relatively intelligent scan interpretaion you can use one array > > for more than one target - even if the bullet goes through the same > > hole, it's unlikely that it'll be exact to within 0.05" and miss all > > four remaining wires bounding the hole. > > > > Low cost start up, high cost consumables, or high cost start up, low > > or no cost consumables? > > > > If it works well, you could probably buy or have someone weave custom > > wire cloth with stripped ends that clamps into a frame of contacts. > > Even if several wires never make contact, or short out, you'll still > > have more than enough information for reasonably good position > > information. This could cost less than a dollar per mesh. You might > > even be able to find such mesh available right now, and can strip the > > ends after trimming chemically, or design the frame to pierce the > > insulation. Window screen comes to mind. > > > > Lastely, in quantity PCBs are very cheap. If you get a very thin PCB > > (not standard FR4) then it won't shatter with a bullet. Buy in > > quantity, have one edge for all the contacts and use an edge > > connector. Should be $5 to $0.50 each depending on quantity and size. > > Double sided, not plated through, no mask, no silkscreen. Very, very > > cheap in huge quantities. Or print the target in white silkscreen on > > top of a black soldermask on one side. Lots of options there. With > > space/trace requirements of cheap PCBs approaching 8/8 mil, you could > > get a resolution of 0.016" or 62 lines per inch. With no testing and > > lower PCB quality control you can lower the cost because you don't > > really care if a few dozen traces are bad or shorted. > > > > Feel free to send my royalty checks when you hit it big. Alternately, > > encourage me to make one as a summer project so I can make it big. > > > > ;-) > > > > -Adam > > > > On 4/16/08, Vic Fraenckel wrote: > > > As the OP I apologize for making this such a complicated question. All I > > > wanted was some ideas as to how to make an 'intelligent' target that will be > > > able to say 'that shot was in the 9 ring at 2 O'clock or that shot was a > > > bullseye' and perhaps report the coordinates of where the bullet passed thru > > > the plane of the target. Of course the intelligent target must have a paper > > > target for the shooter to aim at. But the scoring would be done by the > > > 'Intelligent Target' not an observer. > > > > > > Vic > > > > > > -- > > > ______________________________________________________________ > > > > > > Victor Fraenckel > > > KC2GUI > > > windswaytoo ATSIGN gmail DOT com > > > -- > > > http://www.piclist.com PIC/SX FAQ & list archive > > > View/change your membership options at > > > http://mailman.mit.edu/mailman/listinfo/piclist > > > > > > > > > -- > > - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > > - - - - - - - - - - - - - - - - - - - - - - - - - > > Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ > > > > Interested in electronics? Check out the projects at http://ubasics.com > > > > Building your own house? Check out http://ubasics.com/home/ > > > > > -- > - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > - - - - - - - - - - - - - - - - - - - - - - - - - > Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ > > Interested in electronics? Check out the projects at http://ubasics.com > > Building your own house? Check out http://ubasics.com/home/ > -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ Interested in electronics? Check out the projects at http://ubasics.com Building your own house? Check out http://ubasics.com/home/ -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist