#### RedCowboy

##### Well-known member

- Joined
- Jul 10, 2015

- Messages
- 8,066

- Points
- 113

40mm is the shortest FL and they are 53.00 each. Hmm

The problem is our beams divergence, are you talking about KE four 6X corrected beams from nubm44's with G2 primaries ? I see you said 2 sets of four......you might as well KE all eight as the bars will grow way past the height of 8 stacked ribbons in short order, by 30 feet eight might look square.

For the nubm44 with a G2 and a 6X pair I get about 6mm wide bar at the exit that tapes down to 5mm at about 7 feet then opens back up to 7mm wide at 15 feet, then by 35 feet its a bar about 15mm wide and by 75 feet it's about 35mm +wide.

What really helps is adding a beam expander to the corrected beam, I was told that using a 2nd concave cyl back to back when setting the 6X pair could tighten it up quite a bit but it's been raining here all week and I have not tested.

The problem is our beams divergence, are you talking about KE four 6X corrected beams from nubm44's with G2 primaries ? I see you said 2 sets of four......you might as well KE all eight as the bars will grow way past the height of 8 stacked ribbons in short order, by 30 feet eight might look square.

For the nubm44 with a G2 and a 6X pair I get about 6mm wide bar at the exit that tapes down to 5mm at about 7 feet then opens back up to 7mm wide at 15 feet, then by 35 feet its a bar about 15mm wide and by 75 feet it's about 35mm +wide.

What really helps is adding a beam expander to the corrected beam, I was told that using a 2nd concave cyl back to back when setting the 6X pair could tighten it up quite a bit but it's been raining here all week and I have not tested.

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