honey-comb bed
IMHO…
I assumed honeycomb to be the greatest things since slice bread, or at least that’s what I though … however if you look at how the airflow within the machine is working, you come to a very fast conclusion that it is actually the most effective way to disrupt the airflow.
This video is ~3 minutes using acrylic and a honeycomb bed. This video is ~15 minutes and shows it from a different viewpoint.
For now, we’ll ignore the fact, it’s one of the major causes of fire along with other idiosyncrasies that are created by these beds.
I had mine less than a day when I realized it wasn’t ventilating the debris from the material like I imagined. Most of the air went around the material and down the holes in the honeycomb, pretty much avoiding the materials surface. Across the surface is where I needed and wanted it to flow.
Even with air assist, your air is going through a hole or slot that is only ~0.20mm, not much gets through the actual kerf sized cut.
I have a China Blue, the outlet has a relatively cheap fan in the vent, centered, behind and lower than my work bed. There is no designed intake. So I ended up disabling the lid safety and putting one inch spacers in to hold the lid up for intake air.
The honeycomb was replaced with rolled sheet steel, it was also magnetic, and allowed for holes to locate jigs. Went to the steel vendor, it cost me $12 total and included that cost of cutting it accurately enough to fit in the hole left by the honeycomb.
This is a jig for porcelain tile…
This is mine cutting 5mm subflooring, with the lid completely open. When cutting, it’s sitting 5mm above the steel plate and ventilation is working well, even with the junk factory fan and the lid completely open. Engraving, material flat on the steel bed works well with good airflow over the material.
This is 1 foot square mirror tile in a jig…
It’s also set it up so the clean or intake air flows over what has been engraved, so as not to spread debris over an area that was newly engraved.
Multiple fans seem like a good idea … but I’d caution you to look at how it’s handled by propeller aircraft, either a multi engine or rotary wing (helicopter)… Multi engine aircraft feather the props on a failed engine because of tremendous drag of the propeller. Helicopters have a rotary wing, without the rotation, it drops like a rock…
If you have a 100cfm fan going in and a 300cfm fan going out, it’s likely you have a little more than 100cfm of air flow. Once the airflow exceeds the 100cfm, the fan becomes drag and a hindrance to the airflow instead of an asset.
Whatever works for you… this is what I’ve experienced and how my machine is setup.
Have fun