20 lines of lookahead mostly. Yes, even for 3D work. But I mill steel and aluminum on a box way mill mostly. So now your question has me wanting to ask questions.
What are you wanting out of the lookahead? A smoothed profile that doesn't hold tight to the path? Or do you want something that holds as tightly to the path as it can?
Either way, the lookahead will not have anything to do with your jogging issue. That sounds like a buffer depth issue to me. And when I say buffer depth, I mean the amount of time that is buffered in the motion controller. If you have a large motion buffer, changes in the feed rate will be delayed. And the start of the profile may be delayed as well, depending on how the motion controller implements the buffer.
ESS ships with very conservative settings. I can't remember what exactly off hand, but I think it is something like 122 or the like? The cycle time for the ESS is 1 millisecond. So that is over a tenth of a second in the motion buffer!
But for Mach 4 on a decent computer, you can get by with extremely small motion buffers. Say like 30 milliseconds worth. Say the motion loop is fired ever 10 milliseconds. I like to stay "three mistakes high" (an old RC model airplane saying) so 3 x10 = 30 milliseconds. With a small buffer like that, feed hold appears instantaneous. Jogs start appear to start instantly. The whole system seem to respond to human input "instantly", even though it really isn't. Any buffer depth less than 100ms is hard for use humans to detect. Personally, I like to stay below 60ms. So 122ms of motion delay is going to be noticeable. However, it will run on even the crappiest of PCs.
So if you left the default setting for the motion buffer, I bet that is you jog issue. Maybe it will solve you other issues as well.
I have milling machines and lasers. No routers. I just like milling metals and catching things on fire.
So unfortunately, I can't run a part for you. But I know there are plenty of people that do run 3D reliefs with Mach 4/ESS.
I saw your Rosetta machine video. ESS and Mach 4 can certainly do that on that hardware. No problem at all. I need to find a video of us running trochoidal tool paths on a machine at IMTS one year. We kept up with the Hurcos! It was amazing to watch. But I have seen ESS do that plenty of times. Now, will your pantograph machine move like that Rosetta? I would like to see a video of that G code running on the pantograph machine. It may shed a lot of light on the issues at hand.
But check you buffer setting first! it may be the answer.
Steve
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