I’ve been wondering about how to dial in the correct amount of overscanning for any given speed. Is it necessary to use the acceleration to calculate exactly how much space the head needs to reach full speed? So with my machine acceleration being 1,200mm/s^ 2 and trying to engrave at 200mm/s, it would need 16.6mm (8.4%) each side to be scanning at the desired speed across the whole graphic. This of course would increase as I go up in speeds, leading to about 14% at 400mm/s, using the same logic.
What’s made me think more about this is that I’ve been making a board game consisting of quite highly detailed 35x35mm pieces. When trying to dial in the settings engraving a single piece, I settled on 200mm/s at 80% power (24W) for a nice sharp, deep engraving. Then, when I came to engrave a full set of 36 pieces, in a 6x6 grid, the quality was just not as consistently deep or sharp across the whole set. I assume it’s something to do with the fact that when doing my test engraves of single pieces, I’ve never actually been hitting 200mm/s at any point across the 35x35mm piece.
Not getting up to speed, OR
There is a variability in the wood that impacts how much burn you get. If you see variability in the individual squares, blame the wood.
This is based on a 8000mm/s^2 value for acceleration. Most stock machines with NEMA23 are in this area.
You can see from the graph that to reach 1000mm/s takes a long time to slow down, stop and accelerate back up to 1000mm/s. The head spends more time changing directions than it does over the work piece.
Left one at 1000mm/s takes 7:08 to execute and the 500mm/s takes only 3:40 to execute. The fastest job occurs at 500mm/s, not 1000mm/s.
