I’ve done what I can to tweak the settings for cutting 2.7mm bamboo ply for making earrings but I’m really not happy with the results, can anyone suggest better settings or if it is just bad ply for the purpose?
I’m using an Emblaser 2 with 10W diode, set for 70% @ 300mm/m with 2 passes. At 50% it doesn’t quite cut through. I’m using a z-step of 0.9mm. The bamboo is prepared using a yellow coloured masking tape on both sides to prevent burning of the face where possible. I finished the outside with sandpaper to remove most of the burn marks, but haven’t done anything about the inside. (any tips would be most welcome)
The tops of the earrings broke off where the hole for the findings are meant to go even before any sanding.
I’m pretty new to this, but if that’s 2.7mm ply, your loop holes were only connected by maybe 1.5mm of wood. If you have to go that thin, you may be better served with solid wood or a lamination with all grains running parallel…tho, that may compromise the loop itself…sides may break off or top may split. Maybe consider attaching a metal loop of/with wire or something. Or design the part with more support., either a thicker “neck” or put the hole right in the body of the leaf.
As far as the burning…well, you are burning the wood. I’m not aware of a way to prevent the discoloration. I consider it part of the charm and embrace it. If the contrast is too great, a complimentary top finish (stain) may help.
The amount of discoloration (caramelization) or charring is related to speed/power. I’m still too new to offer much on that front, but I believe bamboo is one the tougher wood fibers to laser well and 2.7mm is asking a lot of a 10W diode. My gut tells me more power and speed with more passes (and air assist).
Bamboo is one of the tough materials to use, as @cggorman points out and people with co2 machines have some difficulty with it. I don’t use as the results are not what I can accept.
Doesn’t mean you can’t, just that even with more power it’s not a laser friendly type of material.
Most videos you find will be for co2 lasers with at least 40W… but I know of this one I stumbled across and it may be useful. I believe there is a video on the site also… I think he actually grew some of it…
With a machine like the Emblaser, where does speed start to affect accuracy of the cut? I’ll certainly try faster with more passes like you suggest, but it would be good to know at what point the quality will noticeably suffer.
From a post where I was exploring a “mode” feature of my machine that alters speeds and accelerations. For smaller items like these earrings, you’re going to limited more by acceleration than max rate.
Set up a material test similar to that pictured below. Cheap material is fine. Bump up the square sizes a bit…8-10mm works for me. Power is relatively inconsequential for this, just need enough range to make the marking clearly visible. Run speeds from where you’re current 300mm/min to maybe 5000. Enough to get useful data. You can narrow or expand from there if needed.
You’re looking for geometric anomalies like overshoot/rebound at the corners or wiggly lines.
If you want to really dig in with tuning, you can tweak your acceleration values at $120 & $121, just save your current values before making any changes and keep notes as you go.
