Hi Guys,
OK in my quest to get a decent laser cutter, I decided I had to try a new tube so I took the plunge and got a EFR F6 from an ebay seller. The tube packing was excellent (crate/tight foam/box/tight foam/box/laser with diecut foam) and the tube seemed and still seems perfectly intact. I hooked it up and once I sealed the wiring - it was cutting nicely and the beam looked perfect. So then I aligned it and left it for a few days (max Thursday -Monday). On Tuesday, I turned it on and got beam in (some of) the attached pictures. So basically beam on the ends and very little to no beam visible in the middle. The beam also dips down at the end to the metal as is clear in the photos. Some does leave the tube but not much.
Wanting to rule things out, changed the power supply to a unit from our other working machine and got the remaining pictures (date stamp is in name).
Altering the power level does little. The cutting may be off as I jiggled things in between but when I hit the laser button, I do get action at the table, but a test program basically does not cut.
Last week I basically did not cut - I just set up, aligned, test cut, and checked power levels (analog ma gauge) and never showed above about 24-25ma and even that was only to see how power level effected cutting but it was cutting worse so I dialed it back down. I am using a reci 150w power supply for my original z8 tube with this F6 (replacement was the same).
So I don't think I cooked it as I was careful to increase power slowly. For now I am just focused on the tube. Cutting may be affected by alignment currently - but I know what the beam should look like and its nowhere near that.
Other relevant facts:
I once got a shock (laser off - presumably from power in capacitors) near HV end of tube after this started. No arc's from that connection when running last week or this week (though I did have arc's at the splices that I had to deal with). My finger was basically at the edge of the white on the back end of the tube (epoxy I assume?).
On the first start this week, I forgot that it was warm and did not let the water chiller cool down much so I got an alarm. But the water was flowing - it was about 25c water. I shut off immediately after about 8 seconds maybe.
Tube was stamped May 27th 2015 (and I received about June 3) - so its brand spanking new - but it leads me to wonder if a CO2 leak could have been occurring and just not finished yet. The beam does seem weaker today than Tuesday but I can't be certain all the levels are the same with a new power supply.
IMG_20150609_171143.jpg IMG_20150609_171201.jpg IMG_20150609_171241.jpg IMG_20150611_090405.jpg IMG_20150611_090431.jpg
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