About to do my first basic clear acrylic scratching.
I set zero with Endmills etc by paper drag method. Does this still apply or would spring tension make a difference?
Also through videos it seems like a 120d is the choice over 90d?
TIA
A bit of paper works fine.
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There’s not a lot of tolerance at the end of the spring, so if your table isn’t trammed, and you zero very lightly on one side, you may find it isn’t touching on another side. A perfectly flat table is best, or you may have to reduce z height by 1mm or so.
I always give a couple of thousanths extra on the zero. Acrylic is not uniform in thickness, regardless of how excellent your tramming is. The spring loaded drag bit doesn’t care if it’s a little compressed.
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Am i doing it wrong then? I think i get desired results.
I zero with the paper method and then run my path with ‘doc’ of about 1 mm.
I dont understand how tramming would impact a drag bit as the tip is so tiny. I have never trammed my nomad, i figured my bit diameters were too tiny to show anything and i dont feel ridges when surfacing a wasteboard.
Agree that the surface of the material needs to have less variance in height vs the ‘doc’ and remaining spring movement in the drag bit.
I also try not to let the bit leave the edge of the stock. If it needs to i reduce the ‘doc’ and test that my job will always make contact with the bit. If the bit leaves and then returns to stock then i fear damaging the tip. Explanation: I sometimes need to over shoot the stock on purpose in order to make sure my design reaches to the edge in case i have a drift in stock squareness set up over length of the job (etching silver over 200 mm long (8mm wide)) in a nomad means i need to place it at 45 degrees on the bed and with it being silver there is no contouring the edge afterwards, too expensive.
As a follow up to my first experience.
Paper method worked fine to zero
I did have one really surprising low in the acrylic. Everything was nice and level, completely flat and the etcher missed a 1" tiny spot. It did well enough that a knife could scratch the rest by hand without knowing.
I was set at 0.381mm and like charles noted i could probably go to a deeper depth by a few 1000’s and the imprefection in the acrylic wouldnt have been any issue.
Either way, super fun, easy and great results. Another talent someone will think i have haha 
Stay safe
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I do have a question about tool selection drop down.
When choosing ‘Endmill’ i see two MC Etchers. Theres no way to tell their difference unless clicking on them. Is this just me?
Could we potentially name them?
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