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FrozenGate by Avery

7 Watt NUBM44 MX900 Build






Where did you purchase this laser diode?
Actually, if you would be able to provide an exact parts list that would be incredible!

I am looking to upgrade my DIY Laser CNC and this seems like the perfect laser with which to do so :D
 
The diode can be purchased here: http://tinyurl.com/DTR-Diodes

Due to the extra wide fast axis output the NUBM44 multimode diode has, without correction, it might not be suited for use in a CNC setup. Maybe if you are close enough to what you want to burn the output can be such a small spot it could do what you want, but at just a very few feet the output is a bar. Has anyone tried using this diode in a CNC setup yet? If so, I'd be interested in knowing how well it performs and whether you had to use a cylinder lens pair to match up the highly unequal axis outputs.

FYI: Glutton is about to close out a group buy for some 6X cylinder lens pairs to tame this diodes output to be more rounded, but I believe he will be putting his order in for them tonight, unless you pay for a pair right now, I'm not sure he will have any extras.

This diode has a terrible amount of divergence, but I put a 2 inch diameter PCX lens in front of mine to collimate the beam and was able to put a spot on a cloud base 4,000 feet high this morning. Letting the fast axis expand to 50mm/2" diameter before being collimated reduces the divergence to be more in line with that of a DPSS laser for use as a high power pointer, but without correction the beam is a rectangle instead of rounded. When using a pointer with a beam expander on it that isn't a real problem, a few feet from the beam and you can't really see the difference anyway, but more power could be delivered in a smaller spot at distance if both of the axis' were close to the same size before being collimated.
 
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Im still learning about optics and Depth of Field, however I figure that since my current setup is a laser from a dvd-burner and it doesnt burn much of what I want it to at a rate that isnt rediculously slow this looked like it might work much better.
Not sure if I should start a new thread for this or not but I am basically looking for the most powerful laser diode I can buy regardless of price. I have seen 1000W laser diodes for sale from china and that seems too good to be true so here I am admiring this beauty :D
 
China vendors lie A LOT.... there are no single or multimode diodes which can put out anywhere near 1000 watts, for multimode diodes you can get a few watts, but nothing close to a thousand watts unless fiber combining the outputs of a large number of diode arrays or perhaps extremely short pulses in the nanosecond, nothing near that kind of power can be reached with a single diode yet, but power density per square centimeter, that is a different story. For example, if using a single lens and a much lower output single mode BDR 405nm diode you can punch more power into a tiny little spot than a multimode diode can which is many times the power. Although nothing to do with CNC's, using the same lens diameter, a 750mw single mode BDR 405nm laser diode with its tiny emitter can conservatively put more power into a smaller spot at distances greater than 10 miles by a factor of over 15 times the power density above what a 7 watt output NUBM44 445nm multimode laser diode can produce. Counter intuitive, but true.

If you don't need high accuracy fine cutting then maybe the 7 watt output diode is a good one, but I have doubts you can cut at a fine resolution with its much wider spot, more likely to see your flammable materials burst into fire instead of cutting it. Also, even if you could optically solve the problems with the NUBM44 diode, which may indeed be possible by correcting the beam with a cylinder pair and telescoping it down to a fine point, I'd never push it to 7 watts output for CNC use, the duty cycle would be so high it wouldn't be good for it's longevity. For pointer use as a toy fine, push its limits because they aren't used so hard for so long you can risk a failure more, but for a work machine which can have relatively high duty cycles or longer run time, you want it to last by setting the power output on the conservative side or it will fail.
 
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