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perhaps when I get some free time I will borrow a function generator and a scope to test out the laser time response. I've been busy with another project.



Perhaps now that I have 3D on my CNC mill, I might try Mach3 again on the laser. No, I doubt I will do that. The smooth-stepper really does speed things up though. Perhaps it would run a laser nicely.

Now if I can only find a way to take this deep 3D carving and then put fine details on it using the laser.....

One possible solution for 3D is to make a very lightweight lens carraige that can quickly change the Z height of the lens as the X sweeps across. The lens is light enough that perhaps this could be done as a long throw magnetic voice coil. This would change the focus depth into the wood, thereby allowing it to burn shallow or burn deep. This would indeed require a swap back to the Mach3 or EMC control scheme. Still, without the ability to quickly change power level I'm not going to get the great output. But at least it has got me thinking. Perhaps I've got too much scope creep in this topic. I seem to be discussing non-commercially available items more than commercial.

lasersafe1 wrote:One possible solution for 3D is to make a very lightweight lens carraige that can quickly change the Z height of the lens as the X sweeps across.

A miniature RC servo would probably work for this application. They are very small and light, and probably fast enough. But you would not get a huge range of motion, and they are not very precise.

A mechanical system is never going to be as fast as a electronic system.

Epilog gets very good 3D results off their CO2 lasers. I think some of the better companies know some proprietary tricks to get the co2 tube to react quicker and more consistently like trickle pulses to keep the gas ionized.

I am starting a new forum topic called 3D engraving controller under the Electronics section since this discussion has moved beyond what is presently commercially available.
http://www.buildlog.net/forum/viewtopic.php?f=6&t=237&p=1086#p1085

We can come back to this topic for the stuff that is commercial.

I have posted this video in the 3D laser engraver section, but since it is the LightObject DSP, I think it belongs here as well.

As we manufacturer our own control systems, we are familiar with all the available laser control systems.

The RLasercut controller available from Lightobject.com is actually a topwisdom controller. The original website is here: http://www.topwisdom.com.cn/EN/pro.asp? ... name=Laser Control System

The other popular higher end Chinese system is the Leetro system available here: http://www.leetro.com/english/sale/20.html

Leetro has the majority of market share in the Chinese laser systems.

We are confident to say our USB RetinaEngrave software and controller is superior to both of these systems. We have all 3 control cards side by side running on the same machine with the same graphics file and can do an apples to apples comparison.

Our original 1-bit BMP used to make the Aztec calendar is here: http://www.fullspectrumengineering.com/ ... /aztec.bmp

Please supply your 1-bit BMP of the 3D carving and we will raster it on the two different systems and show you the result on the same machine and same wood.

Okay Henry, put your money where your mouth is. Here is the file from Gantry that I have converted to 1 bit at 900dpi resolution. I'm having trouble understanding how you can make a claim to get better resolution than the LightObject DSP that already has .001 mm accuracy (from the website you sent us to). Can you even see .001mm?

Please post high resolution photos showing us the comparison between the typical controller and your controller.

As they say seeing is believing so here is my output on some 3/16" maple. Image on the left is 100% speed, image on the right is 4x slower.

Where is yours again?

I'd be happy to mail this sample to you and you can raster the image on the back for your own comparison and report back which is better.

Your dithering technique is not really a good preparation method for this 3d engraving type stuff.

The laser beam is more like .003"-.005" depending on your lens focal length. You can't just random dither at 900dpi and expect it to turn out ok as there will be overlap. Most dithering algorithms are done to look good on screen or on paper.

When you print a dot on an inkjet printer, if you print another dot exactly on top of it, it looks the same because it's just 2 black dots on top of each other.

When you hit wood with a laser twice in the same spot, it burns deeper and looks different from 1 spot hit once.

Also the 1st time you hit it, it turns white wood black. When you hit it again, you are hitting burned black wood which surely has differently properties than the 1st time you hit it and the depth is not linear.

Here is a different angle. These images are printed straight from your file with no modifications. Direct print drivers lets me print this out from Windows Paint in under 30 seconds (excluding laser time of course). Again must be seen in person. Monitors are 96dpi. Apple's iphone 4 is 326 dpi and called "RetinaDisplay".

We go to 1000dpi and call it RetinaEngrave