On 30/03/17 12:00, Mark Van den Borre wrote:
Hi Tor, hi list,
2017-03-30 23:04 GMT+02:00 Tor, the Marqueteur <Marqueteur@fineartmarquetry.com mailto:Marqueteur@fineartmarquetry.com>:
I haven't put my dial caliper on enough pieces of similar plywood to make a statement about normal variation due to manufacturing tolerances.I have. The 3mm birch plywood we use usually stays within +-0.1mm. Only rarely up to +-0.15mm.
Some extra stabilisation can also be designed into the z dimension by doing things like inserting (laser cut) plywood "grip beaks" along the z axis.
Another laser cutting technique that may come in handy is the "accordeon curve" or "kerf bend".
This could be used in conjunction with a dado in the top and bottom pieces and rabbeting the sides. This would keep the unmarked top and bottom (with optional venting laser fretwork logos, etc.), and still allow the sides to be held. This would require flipping the sides to laser the kerfs for the bends, and alignment of PCB mounting dadoes (on the second laser operation) might be tricky at best.
The other option would be to dado the top/bottom for the full thickness of the sides and let the top/bottom extend past the sides.
If a pair of internal pieces are used for mounting the PCB/card, then you're up to eight pieces, but still less than the 11 I recall being mentioned, and probably at better material efficiency.
Tor
Kind regards,
Mark
http://lusis.eu full service b2b laser cutting