Using a 50w Chinese gantry style laser.
I have been using 10k mm/s2/s2 for quite some time now and decided to play around with vendor x max and engraving x max acceleration. I went up to 25 or 30k and did not seem to shake the machine apart or anything, but I did notice decreased engraving quality at edges of details. Was able to dial back to 15k without any appreciable difference, but wondering if there is some type of setting like scan offset or something else that might help improve this or if it is just the nature of the beast and increased acceleration beyond a certain point just delivers decreased quality. 15k is still a significant time reduction for small images, but would like to milk as much as I can out of the machine.
Any ideas?
What limits acceleration is the mass of what you are trying to move and the available power to do that…
You should be able to increase acceleration until you ‘hear’ it failing. Or you can see it’s losing steps/location.
When the fields move faster than the motor can move, it sounds almost like hitting it a hammer … They claim a small amount of this doesn’t hurt the machine… I think I would know as I’ve done it enough…
Sounds like I have the same animal that you have, a China Blue… it’s been modified a bit… On the left, after replacing the honeycomb… current on the right…
With this head configuration (lightweight), no drag chain, I have my acceleration set somewhere around 65,000mm/s^2. It will run 1650mm/s without issue… fast, but pretty useless at that speed. Except to play with…
If you can push it, it will pay off mostly in scanning operations as the overscan is much smaller… Keep in mind that the limiting factor in head speed is that it’s easy to outrun the lps response time.
I can see no reason it’s quality fails as you increase acceleration. This generally only causes a loss of positional awareness.
I would think it would be a mechanical issue flexing or lose…
What current is your motor drivers set? My motors were very hot, and I found that the motor drivers were set to twice the allowable current… from the factory…
Thanks for your reply!
I do in fact have the same machine and definitely understand the potential benefits of reducing the overscan which is why I started experimenting as most of what I do is scanning operations. Had no noises coming from the machine at the max of 25 or 30k that I tried, but there were definite issues with quality. With the only 50w, most of what I am doing (powder coated items) would not benefit from over 500mm/s as requires 70-80 power at that point. Was hoping to make up my gains with the acceleration. I have no idea what current the motor drivers are set at and had not thought to check motor temp.
500mm/s is pretty fast… what dpi are you trying to achieve?
You stated the image isn’t as good, can you post a photo of what isn’t as good?
If the edges are getting fuzzy, you’d probably have to adjust your scanning offset table, because the change in belt tension with the higher acceleration would likely affect those.
It might be shaking the laser head a little, and if things aren’t super stiff it could even be metal flex.
Thanks. That last sentence is a little scary. 
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