I have been building a 40w co2 laser cutter for a while now and i have run into a issue.
The material i want to cut is quite big, 1220x625mm and finding a proper honeycomb bed is very expensive for that size (400 euro ex. tax) so for now i have made a 6mm poplar bed;
Honeycomb seems like the perfect item for cutting… I’ve found it to be terrible… mainly because you lose control over the air flow. Even when it’s working correctly the debris doesn’t get blown out of the honeycomb spaces…
I replaced mine with a sheet of rolled steel. I have alignment holes for jigs and prop the material I’m cutting on 5mm magnets. Air flows over and under the material during a cut…
IMO that will be the most economical solution in the long run.
OTOH, I really can’t see a way a proper 1220x625 honeycomb bed could be bought for 400€+tax.
Got a link?
Making a fully functioning honeycomb -or nail- bed that works as intended and is cheaper than a store bought is really hard.
And requires skills and equipment most of us do not posess.
There are however ways You can improve Your current design, especially if the eye size You currently have is adequate.
Easiest and cheapest would be to sharpen the spokes with a router or a table saw.
That would reduce charring but wouldn’t eliminate it completely.
A thin (max. 1mm) dead straight steel strip that portrudes ~5 mm+, imbedded on the top of the spoke would probably eliminate most of the charring You’re experiencing now.
The easiest and the cheapest source for the steel strip would probably be the steel band material used to securely wrap stacks of lumber etc. for transport.
Using poplar / any wood as a honeycomb bed is one of the best ways to set your laser on fire. And it will be broken soon. You should always use a material that is not affected by the laser.
Many people just use metal plates with screws or nuts scattered over it to raise the workpiece. Seems to work quite well.
Interesting videos, i would think that if you use air assist (i do) that it would blow the fumes through the bed. In the video it looked like he had air assist but i don’t know if he used it or not.
It is a dutch company but they have them here (1300x900mm)
I also know a guy who can cut 1mm sheet steel so i will remake the bed i have now with the steel and hopefully that should fix all my problems.
Yes he’s using air assist. Keep in mind that any air must go through a hole the size of the lasers kerf or about 0.20mm for most of us.
This means almost no air gets through as you can see in the videos… From the underside you can see how little air actually gets through … but the honeycomb isn’t any help it just traps it there where it condenses.
If you’re going to use a flat steel bed, the best standoffs I have found to suit are made out of 20mm countersunk donut magnets and short decorative spikes they fix to leather dog collars.
Those look suspiciously similar to the 600*600 ones that xTool sells for their machines .
Those work IMLE very well for the price.
Even thought they’re very rigid, when the span gets larger, it probably wouldn’t hurt to have a couple of knife edges underneath though.
I’m rather surprised that they’re galvanized, I assumed aluminium coating because zinc vapors are very bad for ones health.
The cost difference isn’t that great, but “quarter saved is a dollar more profit” and all that I guess.
I don’t have XRF analyzer to positively check the coating on mine, but a friend of mine does.
I have to test it the next time I visit him.
In the meantime, I’ll flame-check it at some point.
You’re welcome.
It does up to a point, but it’s essential to have exhaust -or even better, crossflow- underneath the honeycomb.
Or under nail-bed, punk-spikes, etc. for that matter.
Without the airflow, there will always be some fume staining at least, explosive gasses at worst under the workpiece.
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