Tip for cutting thin wood project mandalas on large pieces of wood

Community Laser Talk
1

We have been cutting a lot of 3mm plywood Mandalas lately and have been having difficulty keeping the board flat during the cuts. In some instances we have six panels being cut in a 300 x 600 mm sheet and the tension in the board causes it to spring up in places that can’t be secured with magnets or fasteners.
I tried something different on the latest sets that have produced great results, maybe everyone already knows this but it was a revelation to me. On the last few sets I started cutting the outside frame (perimeter) of each mandala face first and it seems to be working quite well. It relieves the tension in the board and the pieces lay much flatter, aren’t getting snagged on the laser head and we are getting better cuts. I create a separate layer for the perimeter of each face, cut them first then cut the inner details. A little backwards from the conventional method but it works

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2

I had similar issues working with 1.5mm 3ply baltic birch. I eventually moved to a vacuum hold down method that alleviated any warp by holding the parts down that way.

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3

Thanks Colin, if you have a link to a device that would secure the whole 21" x 34" cutting surface I’d be interested in looking into to it. Too many times we’d lose a whole sheet when a piece pops up in the middle.

4

I used a honeycomb bed, and sealed the edges of this table to my laser bed with tape, and then masked off the unused portions with paper. Then a blank sheet would fill the remaining space. The 1hp blower fan used for fume exhaust holds the material down. So, no specific model.

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Great Idea, I’ll look into it ! Thanks !

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This is precisely what I intend to do once I build the bench where I will mount the laser machine. The blower I have has much lower power than the one you indicate (1HP) but dedicated to exhaust and as it was free it’s worth trying it out.

7

Hi.

Any vacuum cleaner will also provide enough vacuum…and then some.
So a some sort of a contol- or bypass valve is a must.
The active charcoal filtration unit has to be able to withstand the vacuum as well.
For obvious reasons, when cutting flammable materials that release gasses that can produce an explosive mix with air, do not place the filter after the vacuum cleaner, especially if the motor is a brushed type.

For a vacuum bed, You’ll also going to need knife edges or other kind of support structure under the honeycomb bed, otherwise it will droop/sag.

Regards,
Sam

:finland:

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