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- Sep 20, 2013
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I'll be looking forward to seeing the new photos when you finish your mods. I'd rep you, but it won't let me right now.
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Im working part time now, well very very part time, mostly health related, but ive been a screw machinist for over 20 years. My machines of choice are Brown & Sharpes single spindle with a 6 or 8 position indexing turret, nothing fancy mostly cam driven. These screw machines are best made for 1000 to 10000 piece runs as itts a single spindle. I guess the point im getting at is I go in as needed to work for a man who I set up and run round knurled brass inserts with an inside thread that go into custom transformors for mounts that are filled with epoxy. The electrical engineering company I make them for is actually owned by my brother in law started by his father. "Its a weird set up I know" but it works and I know first hand what is the best way as I once worked at my in laws company. The owner charges .86 cents a piece for these and we get these brass rods at 12ft. I get about 250 pieces from each bar. I havent been in the material ordering part for well over 10 years and the man im working for is the cheapest man ive ever worked for or even possibly known. I keep mum an to myself and dont take any extra stock home or even use his equipment on my own time. I just do my job an get out as it helps family. As I grind basicly my own form tools and the tooling for this job isnt all that much as brass machines like butter. The long long boring story im getting to is if you do the math and what the owner makes on each bar of stock, Ehgemus is a man truly in the gift of love of his labor.I just cant express it better. Red Cowboy I was looking at that sight and for a 12inch long 1 1/4 bar of round AL at $11.00 thats only maby 7 to 8 heatsinks.......You would think having access to an electrical eng firm I would be way further along on these lasers but its not their specialtyYes, he orders from an established company through the mail, or via ebay. I know that much, but he may have other local sources too. The hosts he offers on the forum are always the best deals, often in the range of 40-120 dollars but I'll be damned if I can catch some of them in time. I'm checking the BST section twice a day every day to look and see if he has put something up.
He added an adapter to allow a JetLasers beam expander to attach by simply sliding it into the end and tightening down a set screw. If I have another one made I will do it differently though, it really needs two set screws to secure the beam expander, one at 90 degrees and one at 180 degrees, otherwise the expander has a little slop and can wiggle around, you can tighten it all you want with one set screw, but at 90 degrees from it the whole expander can move around as if on a pivot point for one axis.
Another thing I learned is that these JL beam expanders probably cannot be used with multimode diodes without cutting a portion of the beam off, I tried it with a NDG7475T 1 watt+ 520nm laser diode and it cuts over 1/3 of the beam off, too much. From this result, it is my belief the only thing a JL beam expander can be used with and have a large enough output aperture to keep from masking or cutting off a portion of the beam is either a DPSS laser which has a very small beam width, or a single mode laser diode which also has a small beam, multimodes just have too wide an output beam. I guess I should have figured this out with the math, I'm estimating the beam width of my NDG7475T is about 3.5mm, maybe more, if you expand that ten times larger, a lens with about 25mm of clear aperture won't be big enough to let all of the expanded beam through. Because of this I installed a single mode PL520 green laser diode which better matches the output lens of the expander and puts out close to 100mw prior to the expander, but even some of it is getting cut off, not too much of a problem, I'm estimating 95 percent or more gets through.
One interesting thing about that particular diode is I've been running them without drivers and so far, no failures. The voltage of two 18650 batteries in series is just right to push this diode hard, but not so much that it kills the diode, at least, not mine. DTR did some tests with this particular diode and found the same result, if you over current it a bit too far, it gets dim, but comes back when the current is reduced to normal again.
I was adjusting it to try to get the bar to become narrower, so it wouldn't cut off some of the beam, but I couldn't adjust it enough to do so as I was trying for as close to infinity focus as I could get. I will try again to see if maybe I can get it to come in for me.
Edit, I just understood what you are saying, adjust the G2 lens, in my case, so the beam is focused closer into a narrower beam, then adjust the expander to focus to infinity, aha...
That's a beauty.
Yes edge clipping is a problem, I still have not used my beam shaping optics other than playing with them, the concave makes a line like our Linos convex lenses we bought from Sam.
In time we will get it worked out, just about the time the next round of diodes are out, lol.
p.s. I hope media units evolve single mode high power light source diodes in the near future, heck I would be thrilled with a 2.5 watt 405
Here's another thread on one of his hosts: http://laserpointerforums.com/f40/pltb-450nm-ehgemus-host-96171.html#post1399282