Hi, im building a small CNC type machine using steppers and belts to move a dremel in 3 axis, controlled from parallel port. I will use eagle pcb and then create a gcode file for mach3 to route the isolation. for moving a laser diode around you will not need any torque at all, so it would be possible to get away with using a few small stepper motors from printers or using the assembly from flatbed scanners to perform x and y movement. but it will be very slow. if you google up 'orbit picstep' you will find a very nice stepper driver that has step, direction & enable signals. I know of UV sensitive boards, where can i get the red sensitive ones as mentioned before? -Michael --- In Homebrew_PCBs@yahoogroups.com, "roel_cnc" <atmelletje@...> wrote: > > --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <andrewm1973@> > wrote: > > > > >> Roel CNC wrote: > > >> > > >> i like the idea of making me own laserplotter. > > >> tested: a pointerlaser (some cheap thing) > > >> with an extra focus lense, a red sensible > > >> film gave me super fine lines (close to a > > >> single cloth fiber). > > >> > > >> did any of us fouling around with this idea !! > > >> > > >> tips and suggestions always welcome:) > > >> > > > > > Roel also wrote: > > > Hi all, > > > M i started this toppic - got lots of replys > > > on it with ideas :) > > > > > > i gonna use Cunningfellow's pll thing some > > > stepper for the laser and a dma-16 card - > > > high speed dio card up to 250kB/s some code > > > compiled (TPascal)that eats the the 274 (gerber) > > > files and output to the drum > > > > Roel - I have done a bit more work on the PLL > > thing. That one posted so far was just a test of > > concept / prototype. There are a few things > > un-needed and a few other things that are needed. > > > lots of schematics on the net for pll that can be used i think > > > It was built to do some tinkering with a > > commercial DC servo motor I had lying around. > > I finally want to just use a DC brushed motor > > with some optos ripped out of mice (to make it > > easier for others to get parts to build) > > > > Also - I was planning on getting the data out of > > a USB port (via an FT232) instead of some custom > > hardware in the PC (again ease to duplicate). > > > > The FT232 can do 4 Mb (which is same ballpark to > > 250 KB). However if you compress the 1000dpi > > data even with a simple algo like G3 fax you can > > fit the data stream down 100 kilo baud (assuming > > 1000dpi and 10" x 10" board in 10 minutes) > > > > I have sourced some toothed belts and linear > > shafts for moving the laser head. I have also > > found a source of cheapish lasers that can be > > focused down to small enough dot size if I can't > > find a simple repeatable solution for people to > > do the same with a cheap laser pointer. > > i was thinking to use a ldiode from a dvd burner they > can trow up to 70mw and with a good lense a super ultra thin line > > > > Very interested in your thoughts on the carraige > > part. You seem to have a lot more experience > > than I with CNC things (and PVC etch tanks). > > > Do you think at 1000 (or 2000) DPI that there will > > be a sticktion problem? Do you think the tooth > > belt idea is going to be good enough or do you > > think that I might need to use a very fine pitch > > leadscrew? > > a lead screw for this job will be expensive i think > first touhts was to use a beld but after some thinking > a steel wire is super stiff and easy to gear > > > > I have done some software on the PC to read a > > BMP file compress it and send it out to my > > hardware. I was just going to use and external > > gerber to BMP thing. However - I have no > > objections to reading geber directly if you would > > like to work together on the project. > > > > > The only other though I had from the PC side > > was to maybe write a GDI driver. That might be > > a bit out of my league though. > > > > andrewm (or cunningfellow to some) > > > email me if you like Andrew or maybe msn its faster hey' > > gr Roel >
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Re: homebrew laser plotter
2006-06-29 by loco_labs
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