mach3 cv and smooth stepper

[Montabelli]

I have looked through many old posts, but have not found a specific reference to cv mode used in conjunction with a smooth stepper. I am using granite devices to run an old motion master I was planning to use mach3 to drive that, but I need to be able to count faster than Mach3 will. the question is is there a way to get the acceleration curves out except when required for inertial reasons? and will this also work with the smooth stepper?

several years back I had a setup that was able to do this with a double buffered driver, but as yet I haven't approached a fully smooth toolpath . I am switching encoders because I don't think the old fanucs on my machine are quite fast enough, they tend to do funny things at higher speeds.

[Montabelli]

OK so I'll tell you what I found out. since there is no trajectory planner in the smooth stepper, it will not affect the tool path, it will only allow for higher pulse rates with less load on the cpu of the computer.

[Montabelli]

I am having a problem with jerky motion it is only prominent when I am running at about 2.5 to 3m/min or faster. even on long straight linear interpolations and even jogging at 100% speed. the resolution on my machine is .001 mm per step. I am hoping this is an unusual thing, I am suspecting windows interrupts but I would like some general feed back if possible that Mach is capable of moving in smooth straight lines etc. I am running windows pro sp3.

[ger21]

Does it jerk on a single G1 move, or in between moves? Do you have CV distance or CV Angle turned on?

[Montabelli]

it jerks multiple times at seemingly regular intervals as though it was related to counts, in some way. if I get it going fast enough it will do it in jog mode too. I have replaced two of the 3 encoders, and their wiring. the motors seem to work fine, they appear to operate as expected from the driver shell, but they do the same thing with or with out load. the table is pretty heavy, 38" x 60" x 2" solid alu.

I get the impression that mach 3 breaks a long linear move into segments, and that the ca chunks are the interval of the segments. g1 or g0 doesn't seem to matter.

[ger21]

I think you have a Windows process interfering. You might want to go through the optimization list and see if that helps.
http://www.machsupport.com/downloads...timization.txt

[Montabelli]

I got a suggestion from hood on the Artsoft forum to use electronic gearing and reduce the resolution, which I did , and the axis I changed smoothed out. the one I left alone still had some bumping going on. whether it is a feeble parallel port, or windows interrupt I can't say for certain but I am in the process of getting a smooth stepper. that should improve both ends of the thing.

Thanks for your help.

[damae]

How goes the progress? I'm curious if you were able to solve your problem with the smoothstepper.

[Montabelli]

yes. it took a couple weeks to get the smooth stepper in and it arrived as I left town for a trade show, but i got it mounted and running smooth as silk. I ended up having to re install win xp pro. but it cuts air incredibly nicely now. I also have tried the tempest planner ( in development ) and it works very nicely. at this point I need to get my limits homes, 4th axis and lubrication system on it, as well as my spindle. for starters I'll use a 7.5 hp colombo manual, I still have much to learn about mach, I have used a different system for the last 18 years so this will be an interesting adventure.