Laser Focus electronic device?

Hi all,
Does anyone know of a focusing device for laser diode focussing?
A friend mentioned it about 12 months ago but I have never followed it up till now.
I’ve had a quick Amazon search but can’t find one.
I’ve found an adjustable red filter to assist in focussing but not a stand alone device.

Diode lasers are focused by rotating the lens assembly, which is threaded. Doing so changes the distance from the diode to the lens, creating a focus change. Your fingers would be the device, yes?

I have seen DIY postings elsewhere, many moons ago, which provided a spanner of sorts to match the knurling on the lens ring. Some were laser cut in acrylic, others were 3D printed. One version was a large diameter ring, another had a small handle similar to conventional wrenches.

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Thanks, fred_dot_u,
I’ve already been looking into 3D printed ones, just a matter of the correct size now. But they are for the adjustment of the laser beam.
What I’m really after was described to me as a sort of card with some electronics attached and a meter. Something about the meter went centred when it was perfectly focussed. But then needed to be adjusted by 1.5mm for the test card used.
I’ve scanned Amazon, Ali,Wish but seen nothing.
My eyes are not that good anymore so need the help of something like that.

I tend to keep my (remaining) eye out for laser related tools and accessories of that sort. I’ve not seen what you describe, but I can see that it would be convenient to have something so simple. I’m interested in the physics/science behind such a device.

I’m still going to be searching around for whatever they call it, I’ll certainly leave details if I find it. I’m not going to spend vast amounts of money on it though.
Probably turn out to be some high tech widget in the $k range ha ha.

My eyes are like yours and i solved that using a digital usb microscope

What a good idea, thanks.
Then I did it and found that my digital microscope crashes my new (8 months ago) motherboard.
I think I have had the worst ever 14 months with technology I’ve ever had.
Sometimes think I’m just too old to keep trying to keep up with it.
But having said that I have managed to sort out some problems for other people so it’s just the pendulum swinging back ‘my way’ or is that ‘away’? Have to make the most of it. Lockdown rules, got to do something eh!
Oh I do have another microscope, if I can find it. Off to look for it.

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Hi Killrob,
Couple of questions if you have time to answer please.

  1. What sort of surface did you use to focus on?
  2. What sort of magnification does your microscope use?


i use a black anodized aluminum credit card size (naturally wearing goggles), and my mag is 1000x

Hi, killrob,
Can you tell me how you are setting up the microscope? I seem to be getting flare or nothing.

Well I’ve found the problem in not being able to use the microscope. There is NO focus working.
Wheel turns but nothing changes, no wonder I bouth another one. (But that hangs my computer) I must bee doomed not to get a working microscope.
Anyone (UK side) have any suggestions as to a reasonably usable one?
So it’s back to trying with my not so good eyes.

I bougth mine on Amazon at 20€ and can be connected to pc or smartphone and works as intended

Thanks, Killrob, (Roberto)
I’ve borrowed one from a friend. Still having problems. I have all the drivers in, it works only from on the surface to raising it by 2.2 mm. No other focussing available.
I have just done the same height tests with my microscope and I’m getting exactly the same almost (2.1mm).
All have had a silver rotating rotator within the body of the microscope…
Perhaps I need something with a much lesser focal distance. or should I say 300 times rather than 1000x
I have no instructions on how they are supposed to work.
More play later I think.

Ok this is the one i bought from, i found the same item on
as you can see there is a big silver wheel also on this that allow you to use from 40X to 1000X

Maybe that an endoscope will do the same job even if has no mag but is easier to manage, take a look

I assume on the other side is the ZOOM button. Never seen anything happen when pressing that button. Does it do something?
Just spent about two hours testing both scopes again. If I set it up with the lens assembly on the flat surface I can still only move some 2mm + a bit upwards. Once past that point, I can’t find a single point to focus on.
I set it up in a solid vice so there was no shake and set up various colour pictures at different distances. Nothing unless the picture is between the touching lens assembly and about 2mm away.
I do have a proper endoscope which is android, currently on loan and has just been down my sons drains. Great. Get it back soon. Hopefully clean ha ha
OK will try that when it gets back.

no, that micro uses the wheel, right or left, to focus and you have to move it up and down depending on how much focus you use… sorry if i can’t explain better, you kown, english is not my mother tongue.

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For my adjustable focus laser I did something like this:

But using this:

And for my fixed focus laser I use one of this:

Hi Tribo,
I have a variable focus CNC 3018 device. I hope to make an add-on focus wheel when Santa has been with my new 3D printer.

To: killrob
Looks like I’m not have the best of times with this microscope. Two in the bin now as they seem to fail miserably and I have wasted enough time trying to make them work. I’ve ordered a new microscope which should arrive tomorrow.

To All:
As it’s the season it is, I’ve no idea how much time I will have to spend ‘playing’ for the next 4 or 5 days.
Over run with family (four generations worth)
Well I’d like to thank you and the other happy helpers for all the support given here to sort me out.

Best wishes and seasons greetings to all


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Hi all
Well, a new microscope/endoscope arrived an hour or so ago. It’s been installed and is fully functional.
I have found it a little difficult to work with but have managed to set the laser focus which is the tightest point I think I’ve seen on my CNC 3018.
It’s the usual black cylinder with a silver focus knob but mounted on a flexible arm and a flat plastic base. The base has squares and ruler markings. I will hopefully find a more stable design to use, The flexible arm is a little annoying as when using the focusing knob the slightest jolt or movement changes the focus of the camera. Wondering if anyone has 3D plans for this type of stand. If so can you let me know a link?
Below are two snaps, but out scope is slightly out of focus

Story for the dead one… The cat thinks it’s a mouse! So the cat has had an early gift haha
Kevin (reasonably happy the laser can be focussed, whoopee)


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