do I need a collimator for my 2011 vls 6.60 to use an HPDFO 2.0 lens

[Shelley Parsell]

Just purchased a used mint HPDFO lens for my VLS 6.60 and since it's Saturday I can't contact Universal Laser support so thought I'd try this forum. After reading on here that it can't be used without a collimator. It is a perfect fit and looks identical, so my question is will it work but just not focus properly without the collimator. Also does anyone know cost of this item or why it wouldn't come packaged with the lens if it is indeed needed? Thank you in advance for any help.

[Dave Sheldrake]

Focus is controlled by the final lens Shelly, the collimator should be better known as a profiling beam expander that fits in front of the mirror to expand the beam and reduce the final spot size ergo increasing the power density.They are usually multiple element (lens) systems so a specialist lens unit will be required.Quality beam expanders run from $300 upwards.

All the sales hype aside a bigger input beam to the final lens gives a smaller spot size no matter how that is achieved.

cheers

Dave

[Shelley Parsell]

Thank you Dave

Bottom line,I can't use his without one?

[David Somers]

Shelley,

Ignore me. I am popping in to see if I am interpreting Dave's answer correctly? (a newbie with lots of curiosity and trying to learn from the forum. I have an awful feeling this is like a kid in class raising his hand and going Oooh! Ooooh!!!)

I think Dave was saying you could use it as is, but will not be getting the full benefit of it without the collimater. The collimater will provide a wider beam into whatever lens you have right before your target and that will result in a smaller focal point dot size. It sounds like your HPDFO lens will work as is, but just not as well? Am I interpreting this right Dave?


Dave

[Dave Sheldrake]

Yup spot on both of you, without a collimator it will work the exact same way as the standard lens system with some noticeable difference or benefits.


or why it wouldn't come packaged with the lens if it is indeed needed?

It likely got damaged or destroyed hence it wasn't included (if the collimator gets dirty the incident beam can crack it)

278207

cheers

Dave

[David Somers]

So Dave, Would Shelley be better off getting a collimator to work with this? Or would a shorter focal length lens give her the same result, assuming that limited clearance between the work surface and the lens that would result from a shorter focal length would work for her? I assume the Collimator and HPDFO combination is designed to give you a smaller, tighter, and therefor more intense or powerful dot size while still retaining a more useful working distance between the lens and the working surface?

Dave

PS Hope you had a terrific Christmas!!! You too Shelley!!!

Dave

[Shelley Parsell]

One more pic....is the lense in the front of this a built in collimator?

[Shelley Parsell]

I have been lasering for about 8 years now and want to improve my photo work on stone. Customers are always very happy with the results, I just want better quality. few pics done on marble, granite and slate

[David Somers]

Shelley!

Once again the curious voice of inexperience pipes up!

That photo makes it look like there are multiple elements in that top lens. If I understood Dave correctly that would be a feature of a collimator. I do know that the normal lenses we see on a laser are all single element lenses. So it could be that is the collimator, feeding the broadened beam to the mirror, which then sends it down to the lens?

Don't take my word for it. Just trying to see if I am following Dave correctly.


Dave

[Scott Shepherd]

One more pic....is the lense in the front of this a built in collimator?

No, it's not. Well, technically it might be, but it's not the part you need. I have the part you need on my machine, but don't have the lens system you have. It replaces the lens in the back of the cabinet where the beam comes into the cabinet. The little yellow lens gets replaced with a small tube that has a lens on it. I don't know what it costs, there's not much to it, just the little tube, some adjustment screws, and a small 3/8" or so lens. You unbolt the other one, bolt this one in, align it all up, and you're set.

When it was installed the guy said "You now have 1/2 of the High Density Optics system", so that's all I'm going by. My guess is it's about a $500 part, just from seeing laser part pricing over the years.

[Dave Sheldrake]

The lens in the photo is the expanding component, the lens at the output of the cabinet is likely to be a collimator (it straightens the beam and *possibly* a polariser although I'm not sure on that one)

It will work without a collimator but the results won't be quite as good. It looked like the expander was missing in the original photo but now we know it's in place the system will work just not quite as well as is possible. $500 sounds about right, possibly a little less but based on the overpricing of most optical components 500 wouldn't surprise me.

Using a short focal lens will give the same results as using the HPDFO without the collimator but at a much shorter focal distance.

cheers

Dave

ps: Hectic Christmas Dave, 5 kids,2 grandkids and 19 cats make it fun :)

[Dan Hintz]

why it wouldn't come packaged with the lens if it is indeed needed?

I have two more/different possible reasons than Dave:
1) The original owner didn't know or forgot about the collimator (since it's essentially hidden against the firewall and is never touched after initial installation)
2) The original owner considered it too much of a pain to remove the collimator and replace with the original lens (it's not a 2-minute job).

[matthew knott]

You can't make a collimator with a single lens, minimum is a 2 element (1 positive and 1 negative) the 'lens' at the bulkhead is normally not a lens but simply a window that stops smoke and dust getting back at the laser. On epilog they use a little tube that's has a lens at each end, the distance is adjustable between these lenses (don't ever fiddle with it). Normally you want the collimator as close to the laser as possible.
I don't know what expansion ratio ULS use but without it will not give a smaller spot as with but you will have a better depth of field. I notice on their website they say it's equivalent to a 1" lens or less but this is not practical, not sure why you can't just use a shorter lens on most materials?

[David Somers]

19 kitties? Yeeks! If I ever pop by your neck of the woods to say hey please pardon me if I down about 1 antihistamine a minute as we chat!! Glad you had a terrific Holiday!!!

Dave

[Dan Hintz]

I don't know what expansion ratio ULS use but without it will not give a smaller spot as with but you will have a better depth of field. I notice on their website they say it's equivalent to a 1" lens or less but this is not practical, not sure why you can't just use a shorter lens on most materials?

If memory serves, the first lens on the HPDFO grouping is an expander, followed by the mirror, and then the focal lens. Even without the collimator, you should get a small decrease in focal point size. The downside is a reduction in depth of field. The collimator keeps the beam consistent across the entire table, which is a necessity with the reduced depth.