6X 635 correction lens

[polishedball]

Anyone have a set from the last GB they want to sell? paying $75

Thanks

[Solarfire]

Dave just started a GB on some 4x and 6x cylinder sets.

[polishedball]

Dave just started a GB on some 4x and 6x cylinder sets.

Yes but he mentioned only ordering 4x or 6X not both, so it looked like it was gonna be 4x so I posted here.

[dave]

There really isn't a lot if difference between the 2 mag ratios. The 6x can be a little closer to the diode, but that's about it

[planters]

I could sell you a set if you really need it. But, here are a few thoughts. I decided to substitute out the GB neg cylinder from my current two red modules because the -9.6mm lens has to be placed VERY close to the diodes. In a quad this meant almost touching the front surface of a tightly grouped PBS. I am substituting an Edmund -25 mm cylinder placed 65 mm in front of the diode(s). It gives the same beam diameter/far field spot product and is a lot easier to align. Dave is right. The inherent divergence of these diodes is so great that if you have 1/2 meter you do not even need the negative lens for the beam correction. But, let me know.

[tonyaztec]

Hey Planters,

I've just started to also build a quad. I have roughly placed the lenses close to the PBS but not getting very good results, so Its possibly because the first lens it too far from the diodes?

Dave, what distance would you say you can get the first lens from the diodes without effecting the performance.

Thanks Tony

[planters]

If the second ie.positive cylinder is free to be placed at whatever distance collimates the beam then the results should be good. The only problem with a too far spacing of the first cylinder will be a too fat beam; the far field spot will actually be even tighter. The very short FL first cylinder requires very precise alignment and spacing however, and this requirement is inversely proportional to the FL squared. That could be part of the problem.