Ok, so I have ordered this kit from ebay [www.ebay.co.uk] I've also ordered some small laser modules for testing.
I've been looking around the web and found a few interesting things. The DIY laser show scheme is quite active, here is an Arduino shield [www.fab-favreau.com] specs are:
A standalone control with ARM CPU called LaserShark : [macpod.net] Notable features
I think either of those would be good platforms for initial development, just need some to port over a RepRap firmware which I think should be straightforward.
Also I found some SLA projects. [www.instructables.com] features a cartesian bot with a top mounted laser. There is an active Indiegogo project for a similar style but with bottom mounted laser called mUVe [www.indiegogo.com]. mUVe may have been posted elsewhere on RepRap already, I have had hardly been able to access RepRap for past few days. I am tempted to pledge to mUVe to help it along.
What I haven't seen, is a DIY SLA with a galvo scanner, so that could be a first? Though I usually find in RepRap someone already did it years ago...:) I am quite convinced the galvo idea is completely doable, and all the components are already available, it is just a question of integration and a bit of software. I think I can adapt my "old" Darwin printer to provide the mechanics.
Of course, there are some devilish details to sort out... do we absolutely need f-theta lens, if so, what type and how much $$? 12 bit DACS provide up to 4096 point resolution, will that be enough for our print area? (I am assuming 100mm x 100mm, initially)
I guess that galvo system designed for laser show will not be as accurate as we would like for SLA.
If we had higher resolution - 16 bit DACs or more, could we do the scanner correction in software, and avoid the need for f-theta lens?
I've been looking around the web and found a few interesting things. The DIY laser show scheme is quite active, here is an Arduino shield [www.fab-favreau.com] specs are:
Quote
Scan Rates: 1 kpps to 30 kpps
XY Resolution: 12 Bits
Color Resolution: 5 bits (for a total of 32,768 colors)
Colors: Red, Green, Blue outputs
TTL Shutter Output
A standalone control with ARM CPU called LaserShark : [macpod.net] Notable features
Quote
ILDA-standard differential +/-10V 12-bit X and Y output. Adjustable to get as close to the spec as possible.
2 0-5V single-ended 12-bit analog/ttl laser channels (Channel A and B)
1 5V single-ended ttl laser channel. (Channel C)*
Interlock connector (INTL)*
Without transfer optimizations the unit is able to drive all channels at full resolution up to 64Kpps. This rate could be increased by general optimizations to the transfer protocol or by reducing the number of output channels/resolution for custom applications.
LPC1343 Microcontroller running at 72Mhz.
I think either of those would be good platforms for initial development, just need some to port over a RepRap firmware which I think should be straightforward.
Also I found some SLA projects. [www.instructables.com] features a cartesian bot with a top mounted laser. There is an active Indiegogo project for a similar style but with bottom mounted laser called mUVe [www.indiegogo.com]. mUVe may have been posted elsewhere on RepRap already, I have had hardly been able to access RepRap for past few days. I am tempted to pledge to mUVe to help it along.
What I haven't seen, is a DIY SLA with a galvo scanner, so that could be a first? Though I usually find in RepRap someone already did it years ago...:) I am quite convinced the galvo idea is completely doable, and all the components are already available, it is just a question of integration and a bit of software. I think I can adapt my "old" Darwin printer to provide the mechanics.
Of course, there are some devilish details to sort out... do we absolutely need f-theta lens, if so, what type and how much $$? 12 bit DACS provide up to 4096 point resolution, will that be enough for our print area? (I am assuming 100mm x 100mm, initially)
I guess that galvo system designed for laser show will not be as accurate as we would like for SLA.
If we had higher resolution - 16 bit DACs or more, could we do the scanner correction in software, and avoid the need for f-theta lens?