Difficulty cutting 3/8" Bocote Hardwood

wood
cutting
#1

I’m having a difficult time cutting through 3/8" Bocote hardwood, and maybe it’s just not a material that i’ll be able to cut through at 3/8". I wanted to ask all you lovely people in the forums, before I gave up, if it’s actually possible to do.

I’ve used several settings, most of them using Full Power and various speeds of 110-200. I have the focus on 0.375 for the cuts.

Thank you in advance for any help or guidance!

#2

Have you tried multiple passes and moved the focal point deeper into the wood as you did?

#3

The last attempt was 5 passes at the .375 fp. So you suggest doing maybe 2 passes at .375 and then another 2 at maybe .5?

#4

Looks like about 2,000 on the hardness scale and pretty dense.

First thing I would do is set the focus below the surface, say .340” and set it to do a couple of passes at power around 130.

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#5

You don’t want to go up. You want to go down, into the wood. And the beam, with the 50mm lens is considered in focus for approximately .1”. But, wood can also reflect the beam, helping it to keep tighter for longer distances.

This is my opinion, but you need to move fast enough that the wood isn’t charring when it cuts.

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#6

I think I had a similar problem with some 3/8" thick zebra wood.

The laser only cut about half-way down.
My solution: Build a harness to position the wood (I use a ton of magnets to make a stable framework). Cut it half-way, then flip the wood over WITHOUT changing the UI – so it cuts in the exact same place, but on the back side. Then cut the other half.

With any luck, the two half cuts will meet in the middle.

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#7

Dense indeed! We were almost there but it didnt cut through. i see a couple dots, so we’re close.

#8

Are you seeing a lot of charring on the edge?

#9

That is definitely a solution. I have a ticket in to the staffers for alignment issues. I’m sure i’ll need to get that fixed first. I’ll get some magnets though and try out the frame idea. Right now im using the honeycomb pins, but of course, id lose the location if I removed those to flip the wood. So, is it true you really cant trust the UI positioning? What my screen says is never where the actual design cuts. **That is a topic for another post, I know lol

#10

@dr.krawetz yes I am seeing charring on the edge. I managed to cut through some 1/4" purple heart and I ended up having charring on those edges too.

#11

Bocote is a nightmare to cut, one of the hardest ones I’ve come across, and I was only trying to get through 1/8".

I did get through 0.5" of Ipe by doing 9 passes at like 200 speed and full power (pro). The way I pulled off 9 passes was to lay three same-color paths on top of each other, and set them to be 3 passes in the UI.

If I were going to do it again with changing focal depth, I’d use 3 (or more, depending on how many passes you want to do) colors so you can set the depth of each set of passes to a new depth.

Good luck.

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#12

I’ve used the honeycomb pins for positioning, and it works great.

Don’t have them actually hanging over your material. Line up several on the top and sides, then give them a little twist to create tension against your material.

After cutting the front of your material, open the Glowforge front panel, slide the material out, flip it and slide it back in. The tension from the pins will act like a featherboard on a table saw and keep the piece perfectly aligned.

#13

I think i am going to try the magnet frame this weekend. but…UPDATE: I managed to (pretty much) cut through the bocote! By “pretty much” I mean that outline made it through to the other side. I just gently tapped with a hammer and it came out.

It took 9 passes at Full Power and a speed of 200. Thanks for all the help. I am going to go to a 1/4" next time, just to make it easier on myself.

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#14

Quick tip: it’s doesn’t look like it, but the passes box will accepted input, not just the drop down selection.(Unless they’ve changed it in recent iterations.)

#15

Doesn’t seem to work (if it ever did. I have never tested it for all the times I’ve seen it mentioned). I change it to 9, it resets to 1. (Chrome, windows.)

#16

I was able to type in 9 for # of passes. It only works if you click that mouse in the right place after :wink:

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#17

Ah there you go. I was able to replicate it by clicking in the depth field after. Simply clicking out to the main UI didn’t work.

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#18

I was having a very tough time cutting through 3/8" baltic birch. I had to finally go to 100 speed at full power, 2 passes. It cut but lots of charring.

#19

… and used a .5 fp

#20

Why?

3/8" is .375". You were telling it to focus above the surface.

If you make any FP adjustment you should adjust for below the surface for a cut. The rule of thumb amongst laserers who focus in the material is to set it for the midpoint of the material or in this case .188". That puts the narrowest part of the beam in the center of the thickness.

Setting it at .5" for 3/8" material puts the narrowest part of the beam and eigth inch above the surface and a spread beam on the surface.

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