Which nozzle should I use?

[bionicback321 (Paul)]

So I’m taking a break from watching LBX on YouTube and thought I’d get some stuff done. I have an 18mm ZnSe 38.1mm Meniscus lens that I bought as a combo (with the NO3 nozzle) from Cloudray.

They don’t really tell you how to hold it in place but Russ cleared that up by saying to put the locking collar in backwards and snugging it up against that. If I use this combination of lens and nozzle, I have about 5mm between the workpiece and nozzle. My other option is the NO4 UCE nozzle,

which puts me at 28mm above the workpiece. I’ll beg forgiveness for not really understanding the best use for this lens (I bought it as another lens to experiment with), knowing that would probably drive me in one direction or another. Any suggestions?

PS. I already have the two lens UCE set and it is a real game changer when I’m engraving Acacia cutting boards.

[jkwilborn (Jack Wilborn)]

This is from Russ, I believe… This is how mine are installed.

[bionicback321 (Paul)]

Thanks Jack, that’s how I have my UCE lens set up. I also have the lens/nozzle combo Model A that Cloudray sells. It’s the NO3 nozzle and the D18 FL 38.1mm Meniscus lens (the first picture). I just wasn’t too thrilled about the way you need to hold it in place. The NO4 nozzle is better at that but 28mm is a lot of distance between the nozzle and workpiece. Just wondering if anyone has used the NO3 Model A combo set from Cloudray and how they held the lens in place.

[jkwilborn (Jack Wilborn)]

With that lens and nozzle, 10.4mm is fairly close to the material. Not to mention it’s depth of field is pretty shallow.

I use it, but focus is super critical if you want to make use of the smaller dot it produces… the only reason for having one.

I use the 2" with the pointed nozzle to get to ~5mm off the material. Of course, I’m still using the 2"…

These are pretty low cost… I actually engrave my tubes and have a different lens in each…

[bionicback321 (Paul)]

Good info, Thanks. I’ve got six “C” series lens tubes (Amazon was selling them for $9 and free shipping) and five different lens combinations. Once I get the focal point dialed in I’m going to engrave mine (you shared your files with me). I got an idea from Russ where he was using hot wax application sticks, he said he got them at the spa when he was getting a Brazilian (tmi?). He pulsed the sticks from below to above the correct focal length and picked the one with the smallest entry and exit holes. I labeled each of the sticks with the lens type, focal length and then five points below and above what I expected the correct distance to be. It worked out great and I put each stick in with the corresponding lens tube.