52.1mm Borofloat Thickness Poll

I need your help. I'm ordering some glass stock to make some 52.1mm Borofloat lenses for Mag C&D's and I'm not sure what thickness I should go with.

Stock lens thickness is about .077 and leaves a gap between the bezel and head of the light of about .019 or so.

Borofloat thickness A is 1.75mm thick, which translates into an actual thickness on the sheets available of about .065. This would reduce the gap to about .007 - virtually eliminating it.

Borofloat thickness B is 2.00mm, which translates into an actual thickness of .083 these days. This would leave a gap of about .025. This would also ensure that the lens makes a good seal with the o-ring and doesn't leave to chance the possibility that the bezel would bottom out beforehand.

So, here it is.......

Mmm. Can you compared the thickness to the UCL-HS? I think the cap on that if a little bit too much.

Call it the Surefire influence, but I like my thick flat slabs of Pyrex... /ubbthreads/images/graemlins/smile.gif

I think you need some of the "hot wire" guys to chime in.

So let me see if I understand this correctly. BoroA is slightly thinner than the stock Mag lens but BoroB is slightly thicker? I measure the following lenses as:

Stock C/D plastic lens: 0.075" at the slightly raised lip at the edge
UCL: 0.0745"
MagCharger mineral glass lens: 0.915"

Is the gap you're referring to the gap between the face cap and the head itself? The space where the threads come together? If so, I have the following comments.

1. If the lens is too thin to allow sealing against the front O-ring and the lens moves around, that would be bad.

2. If the lens is too thick and results in a largish gap, then one might be temped to screw down too hard to try and close the gap potentially resulting in a cracked lens. That would be bad.

3. The thinner glass seems to be a bit too thin. Sometimes O-ring tolerance is not so good and a shortage of 12-thousandths might be too much.

4. The thicker glass is only slightly thicker at +6 thousandths so I think this would not be too bad.

Thus, my recommendation is to go with BoroB. Especially since I can make the superthick MagCharger lens work just fine in the MagD stealth head for the Aurora.

Wilkey