I was on Tarkin for a couple of hours this afternoon working on cutting some 1/2" birch ply. I had read here on discorse that somebody else had luck cutting 1/2" birch at 15mm/s and 100 power.
Originally on some test cuts, I was getting decent results on 10mm/s and 100 power, but when actually cutting my project, those settings didn’t cut all the way through. I did a second pass on the pieces that didn’t cut at 10mm/s and 50 power, and when THAT didn’t cut all the way, I did a third pass at 10mm/s and 70 power.
That also did not cut all the way through and I ended up having to scrap my project for the day.
Question I’m leaving with is: is Tarkin running at reduced power? I know it was red tagged earlier today, but that was removed before I went in.
The issues I was seeing were very similar to this thread from last month, including the mysterious circular light artifact.
Anybody have any thoughts? I’d love to go back on Tuesday and cut this project, but I don’t want to trash another piece of ply. Three passes on Tarkin at 100, 50, and 70 power should definitely cut through 1/2" ply, right?
I’m not so sure it’s back to full power. I attempted to make a quick cut with some 1/2" ply last night to make a sign for the space and I took it all the way down to 8 speed 100% power, still did not quite cut all the way through and started getting really disintegratey charry on the deeper layers. I bumped the speed up a little to 15 still 100% power and did 3 passes still not quite fully cutting through. I cut out the laser desks which are 3/4" ply in a single pass on Tarkin, so this is definitely not the same power I’ve seen in the past. I will say the 1/2" ply I was working with seemed like pretty good quality dense ply so maaaaaaaybe that material was just exceptionally tough?
Regardless of whether there are posts on the forum or not, I always highly recommend doing some small test cuts on your material at the start of every laser session to be sure you’re getting the expected results. Really sucks to lose material because it didn’t perform as expected, I’ve definitely experienced that before too.
The thing that I’m a bit confused by is that it was working just fine on some of my cuts, including the test cuts, but not on everything for my actual project.
I’m cutting a bunch of mortise and tenon style tabs in this 1/2" ply, so I’ve got 10 rectangles that are all 3.5" x 0.5", and only 2 of them cut through on the first pass, 2-3 more on the second or third pass, and the rest didn’t cut all the way through after all three passes. Same exact cut, same exact material.
If it was cutting or not cutting consistently, that would make sense to me, but it seemed to cut some lines and not some others, despite them being the same shape.
I will say that it seemed to be cutting better towards the back and right of the bed for me than the front and left. Not sure if that rings a bell for anyone else using it recently or not.
Plywood is never gonna be consistent since it’s an amalgamation of mysteries
I did try to cut 3/4” BB a month or two ago and even at 1mm/s with full power I still couldn’t punch through, all I did was start a flaming cave on a board of wood
Couldn’t get through 1” white oak either, which I realize it’s a very dense wood and also a thick piece, but I had a little higher expectations out of hardwood
Even though it is less power, I find Dorian more reliable in just about every way
@jdschu I wonder if there are bed leveling issues. I was testing front left area of the bed last night. @dannym usually checks that sort of thing out pretty thoroughly, but it’s probably worth focusing the laser on your material in one spot, then moving the head to several other spots to verify it’s the same. Of course there’s also flex in material/hold down considerations to think of which can cause variance in outcomes, but I’m sure you’re already thinking of that.
@DirtHurt very true on plywood! I would have hopped on Dorian if it was available at the time. Love that we have a remote controller for it now too!
one thing im finding is that (if you have a choice) its better to have smaller pieces of stock to cut at a time, as opposed to a full sheet of something. its harder to keep things flat in the middle of a big panel than it is keeping a 12" square flat.
a lot of times the middle will sort of float above the bed in the middle like a bubble, i always push down all around the panel to see if theres any play in it, since thats gonna throw off your focus
Yeah, now that I’ve got the specs pretty much dialed in, I should have more space available on the board to run tests in each corner and then do most of the cutting in the middle. For me, the middle was all flat on the bed. No bowing up in the middle.
Unfortunately, I’ve got multiple pieces that are 24" long, so I can’t really cut down the workpieces that much. Just going to have to give it a shot again and see if it works.
Historically Tarkin’s been very reliable and very consistent across the bed and across time. Consistency is king in laser cutting.
I did have to realign the bed and swap some components recently but had limited time to do testing.
I did notice a hardware error signal that would result in an amp shutdown in operation that would put it at half power. It didn’t reoccur while I was testing it. I’ll recheck this and see if I need to replace something. If it’s coming up again I can shut that amp down for now and it will be at half power, roughly equal to Dorian. But consistent.
I’ve got a new system management board in the works that will do more advanced self diagnostics and logging as well as clean up the wiring in back. I’d ultimately like to be able to check the status online so there’s an ESP module on it.
Awesome. Thanks, Danny. I’ve got time booked this evening to get back in there, so I’ll give it another go on my backup piece of wood and see how she goes.
Awesome! Thanks for updating and showing your project! I’ll have to try my material again and see if it just has some thin steel layers in it I wasn’t noticing
Bringing this thread back up because today I noticed Tarkin getting very smoky when cutting on the right side of the bed, especially near the front. I don’t think if I’ve cut in that area before, so I can’t tell if that’s expected. I was cutting 5mm plywood from Lowes at (I think) 50 mm/s and 100% power. Maybe that’s just how exhaust works on that side?
It still worked as expected it just seemingly developed a smoking habit I wasn’t expecting.
