Optics & Laser Machine Autofocus – lets take a closer look….

August 20, 2020 1:22 pm

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Laser Machine Autofocus

We have already taken a look at the laser machine autofocus and how it can reduce your set up time when changing materials and jobs. We’ve also discussed the importance of focus and the effect that it can have on a job.

In this episode, we are going to take a look in more detail at the laser optics and, more specifically, how to ensure that your autofocus is correctly set up.

We will also take a look at some basic lens handling and maintenance tips.

As mentioned in previous blogs – the autofocus tool is not infallible, if it’s not set up correctly then it’s more likely to be a burden than a blessing. Setting the correct height of the pen sounds simple, but its actually very important.

So, when would we need to look at checking focal distance, especially if the machine is delivered with everything set up?

It’s actually a check you should carry out every time you change lens’. As you disassemble the laser head to do this, its advisable to re-calibrate the autofocus before you start cutting to ensure that the offset is correct from the workpiece and the focal distance is correct.

This might sound like a laborious task, but we have developed a special tool that will help to streamline this process and make it the work of minutes. It’s also a good place to start with troubleshooting if you find your machine is not cutting as it should do.

The Focus Ramp tool is designed to allow you to see quickly where the effective focal length is, i.e the range in the Z axis where the energy density is sufficient to cut your material.

If your autofocus is set incorrectly, then the effective focal length will be too far above or below your material and so you will be out of focus – this is actually part of the PDI process we carry out at Thinklaser, prior to shipping your machine to ensure the autofocus is set up correctly.

I’ll hand you over to the master himself to run you through the program and how to assemble the Focus Ramp tool. The files can be found here

On to basic lens maintenance.

The lens is a critical component, if damaged, dirty or worn out then it will affect the performance of your machine. Thinklaser supply a dedicated lens cleaning kit with the Lightblade to ensure that the optics are kept in the best possible condition – the kits can be found here if you need more supplies or a new kit.

We will go into a full rundown of lens and optics care at a later date, however as an entry point to lens care, this is a good guide.

More often than not, the main reason for poor cutting performance is dirty optics. Imagine driving at night, in the winter, when the roads are covered in muck.

That dirt quickly clogs the headlights and you struggle to see very far up the road – often you find yourself in a layby, scrabbling about for something (tissues, glasses wipes….socks?) to clean the dirt off the headlights so that you can see where you are going.

The same applies to the mirrors and lens’ on your machine, hopefully they’re not covered in the contents of a farmers field, but dirt and dust accumulate on the optics and reduce the amount of laser emission getting to the workpiece. This is especially true when cutting lots of MDF or plywood as the glue from the wood burns off when cutting and sticks to everything.

A good clean can restore the machine to full power in no time, and it’s part of the reason we advocate a good machine cleaning regime. 

So, with that we hand you back to our tame superuser.

If you would like further information on this blog, or any other laser marking application, please request a call back or, talk to one of our laser marking specialists by going to our contact page – link below.

Contact Us for Laser Engraving, Marking & Cutting Advice (thinklaser.com)