YAG Laser Short Term Plans

Although the YAG laser has seen some use since we initially got it working a few months ago, there are still a few critical tasks that need to be performed to improve safety, performance and longevity. I’ve created this post to let everyone know what the plans are as well as current issues we’re facing. There are also a few administrative and automation tasks are in the works, but these aren’t critical to the machine’s operation.

1. Shielding

The laser currently has inadequate shielding. Originally, a wall was going to be built to provide shielding. After discussion with a few people I’ve decided that we will instead go for a shield that sits on the head of the machine that can be adjusted to sit just above the workpiece and block laser emissions. This will provide a similar level of protection but will be far more space efficient and practical. Steel tube and ACP sheets were purchased to build the walls. This will instead be repurposed for other space projects and possibly will be sold to members for personal projects.

2. Extraction

The machine has a built in downdraft system to extract the fumes generated while cutting. I have purchased some 200mm inline extraction fans to connect to the table. To avoid cutting holes in the original wall, I’ve made a replacement panel from sheet steel to replace one of the original panels. I just need to fit it to the building and mount some brackets for the fans. This way we can keep the original panel if we ever need to fit it again.

3. Power Losses

Soon after the laser initially began working, it could cut 3mm mild steel at a speed of 7mm/s. More recently, it has reduced to a speed of 3mm/s for the same material. This means there’s at least a 50% power loss which most likely means there’s some maintenance item we need to perform that’s been missed.

4. Algae Growth in Water Loop

Algae has been growing in the water cooling loop. This is the biggest suspect for power losses. The old owners mentioned replacing the water every two weeks and always used water that had been run through a reverse osmosis filter. When we initially setup the laser regular unfiltered tap water was used and has been in the system for months. We need to implement a procedure for regularly changing the water. We have a filter system to filter tap water, but it is very slow and would take about a day to filter enough water to fill the reservoir. To make this easier we will be getting a large drum that can be left to fill overnight so changing the water will be just emptying the reservoir and filling it with filtered water from the drum.

5. Spare Parts

I will be purchasing a few spare parts for the laser. There’s not much that’s fast wearing, but the machine is getting old and there’s a few parts that are prone to failure at it’s age. Any optics are prone to easily being broken if dropped and it’s much cheaper to buy them from the original manufacturer now than having them custom made if the manufacturer runs out of stock. I’ll put a proposal into general meeting shortly with a list of the parts I’d like to purchase for the machine.

6. Machine Cover

Me and others have cleaned the machine multiple times and it very quickly becomes coated in dust again. This will lead to long term wear issues and just creates more maintenance. As such it would be good to have a cover for the machine. The current plan is to build a steel frame that covers the home position with ACP panels. On top of this, we can put a reel of PVC sheet that can easily be pulled out and retracted to cover the bed. This would be a good use for some of the materials originally purchased for the wall.