4. Laser beam adjustments
Posted: Sat Mar 27, 2021
Laser beam adjustment
4. Combining lenses and red LED adjustments- LObject brkt and combining lens between the tube and #1 mirror. this is a real help with beam alignment IMHO. This pict is the combining mount and lens and also a new 'Peep' hole mentioned in 4.1.1
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4.1 Mirrors/lens adjust problems- the larger the bed... the larger the problems. I switched to MO type mirror which are better able to handle the higher power tubes and more robust. I am still struggling with the alignment- I just noticed Russ' video Tan tiger #17- 'fourth corner problem' which may be what I am going around and around trying to cure.
4.1.1 Camera to see Mirror 2 at rear of travel- this does work but a lot of trouble. I used a large [3-4"] hole saw and cut a view hole in the bulkhead [which will be covered in normal operation]. I am working on getting the beam from mirror #1 to #2 perfectly level and shimming the #2 upward and adj in and out [provided in the bracket] to get the best alignment front to rear that I can manage. The hole I cut is large enough to reach thru and change targets on #2 mirror which really facilitates this adjustment. Much better than the camera setup... this is how we learn.
4.2 Targets for Mirrors 1 and 2 and target for Mirror 3 [replaces the mirror in the cutting head.
These are pictures of the targets- they are different sizes to fit the mirror blocks on my machine- the ovals are the actual sight pictures of the mirrors to correct scale- engraved and cut from .020 cardstock and covered with a double layer of 1" application tape- you can still see the target ovals. I also cut a bunch of 25mm circles to replace the mirror in the head and had the 'tunnel' into the mirror bored out when I was trying [fruitlessly] to align the original Reci W6 tube with the bad beam pattern. I glued a screwdriver bit into the mirror plug for easy access. I had only a mm or so excess mirror as the beam was so large. The grid type target is what I am using to attempt to resolve the 'Fourth Corner Problem' that Russ touched on- turns out that the larger the bed... the worse it gets.
.
4. Combining lenses and red LED adjustments- LObject brkt and combining lens between the tube and #1 mirror. this is a real help with beam alignment IMHO. This pict is the combining mount and lens and also a new 'Peep' hole mentioned in 4.1.1
.
4.1 Mirrors/lens adjust problems- the larger the bed... the larger the problems. I switched to MO type mirror which are better able to handle the higher power tubes and more robust. I am still struggling with the alignment- I just noticed Russ' video Tan tiger #17- 'fourth corner problem' which may be what I am going around and around trying to cure.
4.1.1 Camera to see Mirror 2 at rear of travel- this does work but a lot of trouble. I used a large [3-4"] hole saw and cut a view hole in the bulkhead [which will be covered in normal operation]. I am working on getting the beam from mirror #1 to #2 perfectly level and shimming the #2 upward and adj in and out [provided in the bracket] to get the best alignment front to rear that I can manage. The hole I cut is large enough to reach thru and change targets on #2 mirror which really facilitates this adjustment. Much better than the camera setup... this is how we learn.
4.2 Targets for Mirrors 1 and 2 and target for Mirror 3 [replaces the mirror in the cutting head.
These are pictures of the targets- they are different sizes to fit the mirror blocks on my machine- the ovals are the actual sight pictures of the mirrors to correct scale- engraved and cut from .020 cardstock and covered with a double layer of 1" application tape- you can still see the target ovals. I also cut a bunch of 25mm circles to replace the mirror in the head and had the 'tunnel' into the mirror bored out when I was trying [fruitlessly] to align the original Reci W6 tube with the bad beam pattern. I glued a screwdriver bit into the mirror plug for easy access. I had only a mm or so excess mirror as the beam was so large. The grid type target is what I am using to attempt to resolve the 'Fourth Corner Problem' that Russ touched on- turns out that the larger the bed... the worse it gets.
.