helical interpolation

[Montabelli]

Is there a way to generate, or modify with a c hook, or filter 3d linear interpolations into 3d helical interpolation? I am running v9.1. I have mcu and can filter into arcs, but helical other than entries, no.

I have a mill I am trying to run with mach3 and I am trying to get low jerk 3d motion since a 3d helix should generate moves which are more tangential, I thought it might smooth out the motion.

[foxsquirrel]

Originally Posted by Montabelli Is there a way to generate, or modify with a c hook, or filter 3d linear interpolations into 3d helical interpolation? I am running v9.1. I have mcu and can filter into arcs, but helical other than entries, no. I have a mill I am trying to run with mach3 and I am trying to get low jerk 3d motion since a 3d helix should generate moves which are more tangential, I thought it might smooth out the motion.

I believe what you are trying to do is futile, your hardware is the major constraint, not to slam you but the stepper motor thing is not very robust. You will not get very good 3D contours unless you are running a machine with digital servo drives and look ahead processing.

[Montabelli]

my hardware is not the issue. I am running fanuc ac servos through granite devices vsd xe 160 volt servo drives on an old motion master I got. As an experiment , I squashed a file I have been running and ran it ( flowline ) as linear interpolations on the flattened file, also filtered it to arcs and and ran it and compared the feed rates achieved with the 3d file. with the feed rate set at 4000 mm/min the mach 3 line was showing a rate of travel at about 4000 mm/ min on the arc file. the flat file, it was running a little under 2000mm/min and the 3d file was running at about 300 mm/min. I was using the tempest planner in mac3 with its jerk limitation capability.

my conclusion was if I could filter the file to helical interpolation, I could probably use mach 3, if not I would have to find a new front end for the motion master.

as yet there appears not to be a c hook or other ad on which will do it, which puts me back to using a new front end. since granite devices drives work with step and direction as well as analog and a couple other types of controllers, It won't be too expensive.