New lens for cutting

Hi folks
Can anybody help
I have a 60w omtech
And im looking for a new lens with nozzle
Suitable for cutting
the lens i have is a 18mm diameter
Which is suitable for engraving
Please keep things simple as im a 65 year old tecno muppet who is newish to lasering:)

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You don’t say what you want to cut or how thick it is. That would help inform a reply. However, a good place to shop lenses is American Photonics [Co2 Laser Lens & Mirror Spare Parts & Upgrades Engraving and Cutting 1 – Tagged "a) Focusing Lens" – American Photonics]

The website is a bit clunky to navigate, but they have good lenses and prices.

Thanks for the reply im just looking to cut 5mm acrylic
I did look at the site you mentioned
But im lost i haven’t a clue what im looking for :frowning:

I can cut 5mm acrylic with my 60w OMTech with a 1.5" lens from APC. But a 2" might be better. If you buy from APC, give them a call, give them the specs of your laser and what you want to cut and they can make a recommendation. Another consideration to research is whether the acrylic is cast or extruded. Each has different properties.

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So an initial question I should have asked: have you tried cutting 5mm acrylic yet?

My initial setting for 5mm acrylic is 10 speed and 65% power. That should just be a starting point for a test for me or you anytime a start with a new batch of acrylic is tried.

Sorry to sound thick but 1.5" 2" ? Is that Focal Length?
From the bottom of the nozzle or bottom of the lens??

Any focal length is from the lens to the material. The nozzle length can be different with certain model lasers, that way the distance between the nozzle tip and the material is always the same when you change the nozzle and lens together. As long as your nozzle length is shorter than the lens focal length you measure from where the lens is. Search for “laser ramp test” on YouTube to see the best/easiest way to find the focal point to use for a lens.

So what does 2" etc stand for ?

Simple terms, a longer lens has a longer area of focus (depth of field) along with a larger focused dot.

You should have no trouble cutting 5mm with a 1.5" or 2" lens… I predominately use a 2", a 4" for cutting thick mdf >6mm.

I have a different head on mine … These are C series lens tubes (20mm) and how you can change them around for different uses. The lens position is dark black, where the beams start in the illustration.

The nozzle is usually smaller for cutting and larger for engraving. The 18mm group is more limited, but similar in the idea…

These are mine…

We learn by asking… please sing out if there is confusion about :upside_down_face:

Good luck


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Thanks for the info I’m still a bit confused

I have a omtech 60w

When I change or clean my lens all I have to do is unscrew the nozzle simple

To put new lens I do I have to remove the whole laser head ???

Thanks again


The lens in within the lens tube, generally with a standard lens it’s in the nozzle.

There is usually a ring that screws down onto the lens to hold it in place…

I’m afraid you will have to remove the down tube/nozzle…

My original was a small piece that screwed in by hand to hold the lens in place…

I’ll hunt around for a photo…


No!@!!! :frowning :frowning:
Will i have to realign anything :frowning:

There should be no alignment needed… just a focus adjustment…


I can do focus … i think lol

You need to be able to align it also… :wink:


Well im going to order the kit so fingers crossed lol

If you have any issues… sing out…

Good luck


YES…American Photonics is where I get all my lenes.

I have got some on the way :slight_smile: watch this space
I may be crying out for help lol

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Just use what came with the machine. Then as you learn or find you want to do something you can’t then upgrade. The 60W should cut that 5mm like butter. Don’t get caught up in the upgrade rabbit hole.