I’m using some cheap chipboard as my test medium, because I figure it should be simple to cut through as well as engrave and I can learn on it without a bunch of extra cost for fancier stuff until I’m more comfortable with the software and the mechanics.
So far, I’ve been able to engrave on it with no problem, but cutting has actually proven trickier than I expected because to get any kind of depth per pass, I need to be moving pretty slow and running the laser at a fairly high power, which just scorches the chipboard.
Should I really need multiple passes on thin (1.45mm), unfinished cardboard?
My K40 is the digital panel version so this coming week I’ll be installing an ammeter and spending some quality time dialing in the alignment just in case that’s my issue, but I’ve measured to ensure the chipboard is already at the correct height, and I am getting a nice, clean and small dot when I test fire on it, so I’m not sure how much more I’ll improve it via alignment testing.
At least with the ammeter I’ll be able to see what my power really looks like.
@Phillip_Conroy thanks for the tip on the mdf and ply. When you say cardboard is hard to cut, do you mean it’s difficult to find the right blend of settings, or that the K40 struggles to cut it?
@Phillip_Conroy I use this chipboard all the time for my test runs before doing a project with acrylic or Baltic Birch. It’s the same stuff that is used to back a pad of paper.
@Bob_Buechler have you been able to cut other materials? How is your alignment? Sure your lens is in correctly? Can you cut MDF or acrylic or Baltic Birch?
@Jim_Hatch I haven’t wanted to graduate to anything else until I figured this out. Just to avoid any confusion, but more data is better than less, so I’ll give it a try.
Question: what speed and power do you use when testing your cut jobs on this stuff?
@HalfNormal Learned this the hard way. My ventilation fan is strong and I swapped the bed out for a simple sheet of expanded steel, both of which seem to have reduced flare ups to almost none.
I bought the LO air assist head but didn’t realize it needed an 18mm lens so that arrives Tuesday. Trouble there is that it changes the height of the lens slightly compared to the stock head, so I’m reluctant to introduce it til I figure out why I can’t easily cut chipboard.
@HalfNormal Oh definitely. For me it was half that and half not being able to justify to myself the cost of a glowforge as an entry point to the hobby. At least this way, when I’ve become baseline functional, I’ll have a pretty decent understanding of the systems involved.
Make sure the bed is 50.8mm from the lens - if you’re using the stock lens that’ll be the bottom of the lens housing. If you’re using the LO air assist head the lens is up where the knurled ring is not the bottom of the head assembly.
@Jim_Hatch I saw a trick where someone measured and cut a Q-Tip to 50.8 (2"), and used that to measure from the bottom of the lens downward. My bed is aligned using this method to half the depth of the chipboard.
I believe it is. Even on the stock head, the lens sits back into the housing a bit. So to avoid any misinterpretation, measured from the lens itself to the bed, 50.8mm.
Is the lens right side up (bump up)? You should be able to cut chipboard at 18ma and 15mm/s. There’s some variation on the tubes (mine is really outputting 38W but I’ve seen some at 30 or 32W) so you may have to slow down to 10 or even 5mm/s but it will cut in one pass. If you don’t have air assist take 2 passes at a faster speed to reduce the chance of it flaming.
I cut a spacer that fits between my nozzle and the bed for common sized materials and another that is 50.8mm that I can measure from the ring. Makes it easy to get the right height. I’m building the Scorch spring loaded bed which will make it even easier to get the height right.
@Jim_Hatch I don’t have any metalworking tools, or I’d make a Scorch bed too :/. Great design though. Good idea on the spacers. Can you maybe post a pic or two of your spacers in use? I’d like to make my own, and want to make sure I am measuring from the right spots (still not convinced I’m doing it right).
I’ll give those speeds / power a try. Though my digital panel is measured only in percentage. The soon-to-be-installed ammeter is measured in mA, but I don’t know how to determine what the true wattage of my tube is.
@Jim_Hatch welp, there is definitely something off. Ran a bunch of test jobs between 300 and 900mm/min, between 60 and 80% power and between 1 and 3 passes. No combinations cut through the chipboard. First thing I’ll check is that the mirror isn’t backwards (should be curved side up), and that the mirrors are aligned. I’m pretty sure the height is right.