So I did a second run with the new bolting method for the GHPad, and things didn't look good. The main problems were:
1. Engraving was not consistent as far as depth is concerned.
2. Engraving was not clean enough.
3. Some acrylic sheets have plastic protective cover instead of paper, this causes problem during laser cutting/engraving because the plastic gets in the crevice of the acrylic sheet and prevents clean cuts (Learnt this the hard way by botching up some red acrylic for my Pokemon case), this means one has to remove the plastic protective cover, then the residual powder from engraving gets embedded on the surface of the sheet where acrylic is engraved due to heat. This looks very bad.
4. General inconsistency in engraving.
The solution and what looks best IMO is to have a larger hole cutout, about 5mm or M3 bolts with head diameter 6mm on the top and bottom most layers, I got to test this thanks to SpamRay and his special request. So this the technique I would recommend for the cleanest look.
Also I had hexagon cutouts for the stand off in all the layers besides the top and bottom. In the next revision, I'm going to keep this only for three layers after the top, as these larger cutouts require the user to align the layers themselves, thus making it harder to get a clean look.
Other than this, the other things i have learned and which should help other people is:
- For 3mm, make sure cutting sped is less than 25 for transparent and 10 for opaque.
- Make sure acrylic doesn't warp, this is one of the reasons why the engraving for the bolts misaligned.