![sheetcam very slow sheetcam very slow](https://www.cncplasmacutters.com.au/wp-content/uploads/2020/09/SR1.png)
I will try to explain a bit better, and I will put it in inches rather than metric. Sorry, perhaps my description of what I saw and thought is a problem was poor. Jitter is what tends to cause motor stalls in steppers at a lower RPM than a smooth waveform. Its true that the parallel port has "jitter" and its worse at lower kernel speeds. If its a parallel port system, all it has to do is be able to generate the pulses fast enough to go the speeds (max velocity). The speeds of the computer is not a factor in this. If you use the CV settings to have to switchįrom CV to exact stop ti will then adhere to the toolpath but does not do lines with multiple nodes well. The longer the acceleration curve the more it deviates.
![sheetcam very slow sheetcam very slow](https://i.ytimg.com/vi/2IQoaix4t6A/maxresdefault.jpg)
CV tries to hold as close to the commanded speed as it can and it will "fudge" turns and either round them off or cut across at an angle. Of course that makes it so you HAVE to use rules on corners and sharp turns because MACH's trajectory planner favors speed over tracking (toolpath). You may find that if you want to use rules you need to retune the motors to more gently make the transition. It DOES have to decelerate and accelerate when switching speeds. Its up to the acceleration curve of your setup. I would really appreciate your knowledge.
![sheetcam very slow sheetcam very slow](https://www.cartoq.com/wp-content/uploads/2012/09/SLOWDRIVING.jpg)
Lastly at what metal thickness’s would you start to use these type of rules, thin metal or thick metal and what settings. Is it the normal thing for it to do this? So have I missed something that is causing these apparent pauses? Now I know the computer is not the fastest but it does seem to deal OK, I have CV switched and on looking ahead 50 lines, I have also tried with Plasma Mode on and off, I have made sure that within Mach3 general config the setting for 'stop CV for angles > is switched off, as the idea I would assume is to use the rules instead. Now I am only cutting thin metal 1.5 mm so probably need very little, but some the cutting rule will slow down the feed rate to 80% going into a sharp corner and speed up going out etc, but what I am seeing when cutting is what looks like a pause as mach3 changes feed-rates during the cut, almost like it decelerates and then speeds up again when changing feed-rate. I have put a few cutting rules in Sheetcam just to see the effects it has when cutting. I am learning as I go trying to pick up things the best I can. I have a complete home made system, done very cost effective, but is a small machine.
#Sheetcam very slow mod#
As I am not sure where this should go for the time being I will leave in the general section and a mod could move it to the correct section if it goes one way or the other.