Pin Bed
Last Updated: 9th June 2009
My laser cutter came with a honeycombed panel which can be used to support sheet materials for cutting. However, the mesh area is only 170x190mm and the nature of the honeycomb means that the beam frequently hits the edges of the mesh (which can lead to scorch marks on the underside of the material being cut). The honeycomb cells also tend to trap vapours and small bits of material that fall out of the work piece.
Removing the top and bottom edges of the frame improved things as a) it allows longer sheets to be placed on it and b) the slight gap this creates under the top edge allows vapours to be sucked out from below by the extractor fan.
However my intention is to make a pin-bed which is, as the name suggests, a bed of pins.
With the work piece supported on a matrix of points, rather than a mesh, there will be far fewer occasions when the laser beam hits anything other than the work piece.
Project Status
I've bought a 1/4" sheet of aluminium and a couple of packs of dressmaking pins but I haven't done anything more for two reasons:
Firstly because I'm not sure how big to make it. I've been mulling over some ideas for increasing the working area of the machine.
Secondly, I want to do some research about the best arrangement of the pins.
It occurs to me that if the pins are arranged in a square pattern that runs in the same direction as the XY axes, and a pin is hit by the laser beam, chances at that other pins in the same row or column will be hit too. Especially as most of the shapes I cut are rectangular. Turn that pattern though some weird angle, say 17° and the pins no longer line up with the horizontal or vertical lines of my work piece.
Of course this increases the changes of ONE pin being hit (whereas the aligned pattern is more likely to result in none or many being hit).
Then again, maybe another pattern would be better? Something based on the Fibonacci series perhaps?