Speaking lenses, picked up a 72mm for the fiber

I actually ordered a 63mm, but there were none available. Anyway, close enough :)

I know many if not most fibers come with 100-110mm lenses, I wanted a 150 for the extra working area. Then I got my 220, which is closer to 250, the thing will engrave 11" diagonally. Not a lot of vertical space available, but I was able to run 1" high characters across 11" when I checked it...

So I got a new customer via an old customer, gobs of work, small parts by the hundreds, all fiber. But some require deep engraving. The new customer proper has a 20w fiber, and they did a test engraving they were okay with and share the settings. Pretty much the same settings I would've used, but I cut back a bit to account for my 30 watts. They okayed my first article. Best I could muster was 3 minutes 18 seconds...

I ordered this new lens the minute I got the parts, did the proof with the 150 lens.

When the 72 showed up, first thing was to find it's focus distance-- 4.78". Second thing was to find a crate so I could get the parts close enough! ;)

Third was some test engraving. I found out what Tim went thru with his 50 watter :) - I used the same settings I'd normally use, and it literally left melted goo inside the letters, the result of the much smaller focus spot and the resulting increase in power density - in my lens research lately, I found that a 50% decrease in beam spot size will increase power density 200%--!

Seems it's true, as the beam spot is VERY noticeably smaller, so much so vs the 150 that I had to cut my hatch spacing almost in half. And I also had to add .0015" to my project's text and logo outlines to get the same finished cut width as I got with the 150 lens...

But even with doubling the hatch (adds work time) and fattening the work (more added time), I was still able to increase my cutting speed by 5x (actually I NEEDED to), and reduce the passes from 12 to 9. in the end, I'm probably a snick deeper than my first article, and a 9x3 hatch pass run only takes 1:17 ! 77 seconds vs 198 seconds with the 150 lens... THAT is huge, especially when running hundreds of parts!

The caveat of course is the work area is less than 3" square, but none of these parts are that big!

I knew a smaller lens would help, but nearly 3x faster I wasn't expecting!

This is why I'm in need of a 50 watt machine. Not only will I have nearly the same power with a 150 lens, I'll have the wider beam spot which may speed up the engraving even more. Plus I need the extra work area. And with the 220 lens, I get even more work area, and I should have about the same usable power as 30w gives me with the 150 lens. Another reason: right now-Sunday afternoon- I have jobs running on 10 machines, and the fiber has about 4 days worth of work already backed up, with more always coming in...

I'm supposed to (semi-) retire next summer, and I have more work piling up than ever...

anyway, if any of you have fancied getting a small factor lens for your fiber, especially if you're engraving AR lowers, I highly recommend one! Mine was $103 on Ebay...

Quite interesting. I could see my 110 Vs 150 a difference in power, but going the other way is even more interesting. Yeah, 3x3 on lowers or for that matter other handguns that would allow my 20watt to cut deeper, faster would be great. I DO want to get a larger lens as I've got some jobs that I only use 10 percent power on. Size is a bit of a factor with my 150mm lens, but going to a 200 would make me use what? 30 percent or maybe even 50 percent power but would allow me to do most of a 8 1/8x11 sheet with the fiber. (maybe) I'm afraid edges vs center would cut differently and material is not really conducive to excess power.

But with the Fiber vs my CO2, I can get WAY finer definition.

Where are you sourcing your lenses Kev?

Darren, good ol' ebay! Place called Cloudray Laser in particular-- as for regular C02 lenses, theirs seem to resist scratches and darkening much better than others I've gotten (from who knows who)-- My 220 lens I got from them was $100, no complaints. The only issue I found with it was during testing its extremes, the lower right corner area would 'bend' before the other corners, but to be fair, I was over 125mm from center, well beyond usual limits. This small lens works great too, only issue is that since it's so close to the work, it collects cutting dust pretty quick!

This customer supplied plate below is one that's been giving me fits for years. They have some guy do a special hard anodize on them, hitting them with the C02 turns them medium gray with low power, higher power turns them a blue gray. When I got the fiber I figured my troubles were over, but nope- with my 150 lens it takes several passes to clean out the black specs before it's nice & white. I can hit it once with lower power but the settings have to be perfect, and then it only goes C02-white if that. If not perfect, any further passes tear into the anodize further and then it's more passes anyway.

With the small lens, I got this result using 10% power, 30 freq with a .025 hatch, 2 passes.
It'll remove the anodize at zero power, but 10% turned out perfect.
Attachment 395350
note that this plate is 3" square, which is actually to large for this lens to reach edge to edge, the compromise for the extra power (but so far, worth it!)

Cheers Kev, will check out Cloudray...

Cloudray = good ebay seller for me. I went on and ordered a 330mm lens for my fiber.
And a spare cheap 50mm lens for my CO2 machine as I don't have one.

I expected the slow boat, but NO, DHL in 3 days. Wow, shipping was included in price.

YES, it should be very underpowered for my 20watt. Well, I did a 220x220 mm image (max for the new lens)
onto my material I've been using with my 210mm with a 150x150mm max. Same power, and it worked!
Sweet, So I'll be able to get a much larger image onto parts that don't require deep cutting with the fiber. Thanks KEV!

RayFine charged me $50 for my last lens I purchased from them. I went with a 300mm and was not happy compared to my 160mm. Tried it a few times and took it off.

I'm fine with what I'll do with it. If I were to try and engrave metal, it would result in poor outcome. I have to up power a bit vs the smaller lens, but not as much as I anticipated. but I was originally using 7 to 10 percent of 20watts. What's going up to 15 %? nothing.