The use of my Sculpfun 10W Diode laser is mainly for cutting out balsa wood used on model aircraft construction.
Mainly I’ve been cutting wood from 1.5 mm to 8mm with great success however, I recently attempted cutting of a 12.5 mm thick sheet, which although eventually succeeding ‘somewhat’ I did waste one sheet of balsa and set off the smoke detector.
The difficulty with the thick balsa is striking a happy medium between cutting power, cutting speed, air assist & how many cuts - too much power & too slow burns, so the best so far is 85% power, 8mm per sec. & air assist, but due to the expensive nature of balsa wood, I am wondering if anyone out in “Lightburn Land” has experienced this and what setting you found the best?
Thanks indeed.
That’s simply not the best idea. Balsa is prone to getting lit up and the thicker the material, the more likely it will start to burn.
You can lower the focus to reduce the number of passes required.
But 8mm is already a good value for 10W laser, I’d not using thicker material.
I think it’s also exacerbated by the spot size of the diode.
My 2" only has a depth of focus (dof) < 3mm, the 4" has a dof of just under 11mm.
Most of these led lasers seem to have a short focal length resulting in less dof.
If I do 10mm acrylic, I use the 4" lens and focus 1/2 way into the material.
Thanks for your comments, I did manage to produce a ‘reasonable’ cut following a couple of exciting moments, the air assist probably didn’t assist the fire front and any future experimental thick balsa cutting won’t add any oxygen to the flame !!
Regards.
Thanks Jack, being a ‘newbee’ to laser cutting you have lost me a tad in the technical description given however, I’m sure some investigation into your technical jargon will probably enlighten me further with my dilemma & in short, ensure my balsa cutting future will certainly be restricted to thinner sheeting, with which I have no issues - thanks again.
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If you were to cut the 1/2" plank with an exacto knife, what would you do?
Many light cuts, or a few heavy pressure cuts?
More passes and less power.
Break the job up into sub layers of there is more than one shape… That way it will take 5 passes on one shape and move to the next shape for 5 passes, then move on for the next shape. It spreads out the heat load that you put into the media
Your laser has a magnifying glass type focus. As you get farther away the laser spot looses the concentrated focus, making cutting less efficient and heat transfer more likely.
Focus your laser spot approximately 1/2 through the plank depth. A little out of focused on each end is much better than way out of focus at the bottom of your cut.
Really, a 1/2" plank is a pretty big ask for a 10w laser. Be aware that balsa smolders very easily.
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Hi Jim. cheers for the reply. Used the Exacto for many years, the problem is when cutting across the grain, tight corners or small narrow cuts, your chances of a good cut are reduced - enter laser cutting, what a break through. I hadn’t thought about ‘laser focus’ as I’m not familiar with the technical terms and possible variations available, which seems to be many and a new learning curve, which I’m yet to master.
Thanks again for you considerations, regards.
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I’m still a rookie so this response is more of a question for our seniors… Would the amount of air makes a difference? I have my 50 gallon air compressor connected with an inline brass valve that I can dial in or out. I’m able to get triple digit PSI; however only run single digit with laser.
If he ran max air, more layers, and refocused half way through, do you think he would get better resolution?
That’s not easy to answer. In general, more air will improve cutting, because it moves the dirt particles out of the way faster. But there will be a limit when more air won’t give better results. At some point the air pressure will start to push the objects from the workspace, wich is usually not desired.
It’s also difficult to give absolute numbers, because every nozzle and pump system is different. I’d recommend testing what’s working best for you personally.
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