A Cheap Honeycomb Table Replacement for your Laser

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CO2 lasers make use of a honeycomb table which allows you to support parts you are cutting — without cutting into the bed too much. Unfortunately they are a consumable part, so they will eventually wear out, and they aren’t that cheap. [Claptrap] came up with an excellent alternative.

A few months ago, his radiator blew in his station wagon, and it had to be replaced. He was about to throw it out when he realized the similarity of the radiators cooling fins, to that of his honeycomb table… He cut it down to size, pressure washed it (though he notes you should probably wash it first before cutting) and put it in place. It works great!

The only caveat we have is that you should probably flush the radiator with a water pump first — you don’t want to be heating up any residual radiator fluid inside the radiator channels!

No laser, no problem — Check out the open source axCut diy laser! Feeling even more ambitious? What about making your own CO2 laser tube?

34 thoughts on “A Cheap Honeycomb Table Replacement for your Laser

    1. Because the laser will burn up the plate after time. The honeycomb reduces the area of contact and the rest of the structure is out of the focal range of the laser.

      1. Thank you, i was also wondering the same, i didn’t account for the focal point of the laser and then it made no sense.

        Thanks!

      2. Laser engravers (150W & less, without oxygen assist – specifically meant for cutting metal) generally couldn’t burn up a metal plate. Metal plate reflecting the beam back can be an issue though, which is why some laser brands offer a solid metal plate for engraving work, and a table with expanded metal honeycomb for cutting.

        This radiator is a lot tightly spaced than typical engraving honeycomb. Ideally, you want something that’s more spread, though I guess this does the job.

    2. The two main reasons are for better ventilation and less chance of burning your material. Ventilation is simple – you’re cutting through something by setting it very precisely on fire (/ablation depending on how fancy you want to be), which is going to cause smoke and ash. Having an open bottom surface gives more space for the smoke and ash to be drawn out of the laser, keeping it off the lenses, mirrors and linear motion, and out of the beam path. You also want as little surface area touching the material you’re cutting – every place where the laser cuts through the material and hits the bed below, it flashes back and scatters, causing extra burning. If your speed and power settings are well tweaked, this may not do much; but if not, or your material is particularly susceptible to burning, too much flash back can cause anything from slight blemishes to an actual fire.

  1. Also why is there a warning to flush the coolant from the radiator? It is just water and antifreeze (ethylene glycol). The latter being not dangerous unless you’re drinking it.

    1. Ethylene glycol and propylene are flammable. Heat them to their flash point and the vapor will ignite if there’s an ignition source.

      Get a 50/50 mix with water hot enough and it’ll burn. It’s a worse danger in an engine fire than gasoline because it’s all in there with the fire, unlike the fuel which should no longer be getting pumped to the engine.

      1. I dunno, but I’d worry about reflections from that, or refraction or whatever. Too unpredictable to shine a laser on I’d’ve thought. Even if the whole system’s under a cover, I think steam or moisture or condensation would bring too much trouble. There’s not a lot of thermal mass with a laser so I’d guess it shouldn’t get too warm.

  2. I think an A/C condenser would make a better choice, given you have access to the proper recycling equipment, or can find them already pulled from vehicles. They’re likely to be harder to clean to remove the oil, but they are usually thinner than a standard radiator.

    1. True, but usually they are not. Thrown out like garbage throughout most of the country.
      So a little hacky recycling might be a good use under the circumstances you have a laser, need a new bed, you have a local auto repair shop willing to give you their junk, and said repair shop isn’t offered a recycling incentive/legal obligation for them.

      I don’t know how much the tables go for, but usually you can go to a remove it yourself style salvage yard and get some radiators for $10 or less a piece.

      1. True, but here we are not talking a salvaged part, he used the radiator he replaced.
        Compared to the price of having the old radiator fixed this new laser cutter bed costed him quite a bit :)

  3. losing the core value is alot better than a new honeycomb grid because many auto parts stores charge a core charge because the old parts can be rebuilt cheaper than new ones can be made

    and sometimes the core can discourage the improper disposal of parts like batteries by having a core value encourages returning the old battery and prevents it from getting in the land fill

  4. A lot of the newer radiators have a plastic insert that makes them impossible to repair.

    My concern would be from lead vapor when the laser hits the core.

        1. Hey RandyKC
          it used to be that way. My first job 45 years ago was repairing radiators and you are right – I have repaired radiators that are made of straight brass!!!!
          In the “Old Days” most radiators were made from copper with usually brass tanks either end. They could be repaired very easily if you knew what you were doing (not rocket surgery) . These days it seems everything has gone the way of built in obsolescence. I am not just talking radiators, what you buy today wont be fixable in 2 years time cos no one has got parts for it.
          On that note. does any one know where I can get me little scratchers on a 3V3 triode valve? Wouldn’t mind resurrecting a 1 valve super regen HF receiver I made when I was a 12 yo….(sigh) – 48 years ago…….

          Hey – thats one of the great things I find on Hackaday – young dudes bringing old relics back to life with a different twist…..

          keep it up

          Claptrap

          .

  5. I’m not a car buff by any means but I’d imagine radiators are made from Aluminum? If so, I’d be more worried about the aluminum (or aluminum oxide) reacting with any waste from cutting steel (or anything with Iron in it).

    When I worked in metal fabrication we always had to clean a laser after cutting aluminum. Maybe it was an overly cautious cooperate mandate but better safe than sorry? Also we always cut our own slats, but I guess it was easier because the bed was 120″x 60″ (about 4″ spacing) for a 4kW laser.

    A+ for creative use of an otherwise useless object

    1. Also arent the fumes from aluminum burning supposed to be especially toxic? I remember reading something about that in regards to aluminum armor on things like the Bradley Fighting Vehicle.

      1. Aren’t the fumes from pretty much anything burning toxic to some degree?

        Now think of the quantity of aluminum that is actually burning during any given use. Can you actually even see marks left on the bed after a run? If so maybe you are doing something wrong!

        Now think of the percentage of the fumes that aren’t getting sucked away by the exhaust fan (and hoepfully caught in a fitler)

        Now, what percentage of what is left are you actually sucking into your nose?

        Is this really worth worrying about? Do we really need to look for hazards in everything anyone ever does? You know, the plastic that bubble you are living is is made from probably offgasses something carcinogenic!

        1. The fumes from aluminum don’t require any more care than other commonly laser cut materials. However, my concern had nothing to do with fumes. I was more concerned with the possibility for a reaction between oxidized materials setting the aluminum ablaze in the presence of intense heat bathed in (depending on the material you are cutting) oxygen. I would Imagine the person who put this in his machine is aware of the risks involved. I just wanted to point this out for anyone who may not.

          “Can you actually even see marks left on the bed after a run? If so maybe you are doing something wrong!” – Depending on the thickness of the material, the required focal length, pierce method, and a host of other things, you may or may not cut into your slats. It has been my experience most times you do.

  6. I have an Epilog 32EX I use for aircraft manufacturing. When the vector grid “died”, I simply bought an aluminum egg-crate florescent light diffuser. The depth of the grill was exactly the same as the outgoing one, and I got to use the same housing over. The best part was the price: $12.

  7. Honeycomb tables can get unsightly especially after cutting engraving plastics. I’ve used oven cleaner sit for about 20 min then hose off. But doing it periodically will keep in newer longer. If its real bad I just purchased one at http://bosslaser.com as they’re fast and reasonable

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