Switching 2" lens with a 2.5" will affect autofocus accuracy?

[Dan Sobel]

Hi there,

I'm a new owner of a BOSS LS-1416 with a 70W tube and a standard 2" focal lens. I purchased on Amazon a spare 20mm 2" lens and extra 2.5" lens which I plan to use when cutting thicker material 1/4 and up.
The machine comes with different extra nozzles for specific size lens, one for 2" lens one for 2.5" and one for 4".
The laser use auto-focus which I'm not sure if it is set-up in relation to the focal lens length in use. My question is by switching lens from a 2" to a 2.5" will that affect the auto-focus accuracy?

[Gene Uselman]

I have never used autofocus so I have never experienced this problem- Pete is a Boss guy and may be able to help. I would guess it would no longer work correctly as the machine/software does not know which lens you are using.

Welcome Dan, I forget if this is your first post but we recommend saving your Vendor/User files first to forestall future problems. Gene

[Dan Sobel]

Hi, Gene

Thanks for answering and yes, this is my first post in the forum.
It is my first laser and I'm still in the process of learning how to use it correctly and efficiently, I will mostly use it for light duty jobs like wood engraving and to cut 1/8 acrylic and 1/8 and 1/4 birch and so far I'm very happy with the machine, it's very compact and since it's on a mobile stand, I can freely move it around my garage and then move it back to his place when not in use.
So far with the 70W tube I have no problem cutting trough 1/8 birch and acrylic at 85% and 10mm/s.
But when I was doing some test cuts, I wasn't able to cut trough 1/4 hardboard with those settings. I tried again by increasing the power to 90% buts still I cannot go trough it, maybe I should have tried going slower, that's why I decided to buy a 2.5" lens and see if I can cut trough the hardboard since that focal length seems optimal for cutting and I will have to cut pieces of hardboard once in a while.
So, looking for Pete to chime in

[Gene Uselman]

Not sure if you have a mA guage, but that is the best way to set your max usable power, each combination of tube, power supply, etc will be a different power % so that is not really very helpful. I would think you should be able to cut .25 hardwood at max power and 8-10 mm/s. Russ has been impressed with a GaAs 2.5 inch lens and is doing his usual deep dive into cutting lenses. I buy a lot of 1/8" hardwoods and plywoods from Ocooch hardwoods in Wisc, good people.

[Dan Sobel]

Yes, the laser comes with a mA gauge it barely moving when engraving and when cutting 3mm wood or acrylic at 80% or 85% the gauge needle doesn't seems going further than 10.5 mA and for what I remember it never went above 20 mA.
I'm not sure what those mA reading means but the power supply seems to be a Chinese 60W (ZYE-MYJG60W) and the tube is a 70W.
Btw it is ok having a 70W tube and a 60W power supply? I'm still getting the full power of the 70W tube with the 60W power supply?
There is any method to see how much power I get from my laser at max power?

[Gene Uselman]

Some tubes like Reci and EFR will have a label on the tube itself which is often filled out manually by whoever does the testing on the tube. It will have max power with a mA and what is often called agreed power or the safe max and mA to use in the long term. I just got a SPT tube from LightObject and they check the tubes inhouse before shipping and provide a document with recommended operation instructions. It also have the LO test result with max and usable power and mA readings at those powers. In order for them to warrant the tube I had to provide a signed copy saying how I was going to cool it [to be sure I had a chiller]... pretty though in my opinion. I have attached a .pdf of the SPT doc below.
Your 60w Psupply will 'probably' be OK as your tube is 'probably' not actually 70w either... but unless it was tested we just do not know. Dealing with Chinese suppliers is a close to gambling as I get. I know I am going to lose in Las Vegas- with the Chinese it is harder to tell. I would look on a couple tube manufacturers sites for a chart of their tube sizes and recommended currents. May the Gods smile upon us

My tube is written in as 136W at 28 mA and recommended [and advertised as] 130W at 26 mA.

There are various power meters- I have a Mahoney 0-200w which Phototonic has for $105, Russ his own Lollypop version which I believe is cheaper and works the same way- a temp meter with a probe and an aluminum mass on the end, on mine you shoot power to it for 19 seconds and wait a couple minutes for a max power reading. I bought mine 5 years ago or I would have gone with Russ'- I do not believe they are extremely accurate but good for comparisons.

.

LightObject SPT tube doc.pdf

[Dan Sobel]

The tube is a BOSS branded tube, not idea who their Chinese supplier is and beside the BOSS logo it doesn't have any label with the specs on it. I guess I will send them an email and ask for the operating specs for that model.

[Gene Uselman]

I had forgotten already that it was a Boss laser, they seem to be good and reliable- I would ask about the 60w power supply in a 70w machine too?

[Dan Sobel]

Yes I have asked about the 60W PSU as well, thanks.

[Pete Cyr]

Hi there,

. My question is by switching lens from a 2" to a 2.5" will that affect the auto-focus accuracy?

Yes - you have to reset the focus depth in the setup - the focus depth is unique to each lens. Once adjusted it will position the head for that setting until you change it.

focus.png