[dertsap]

Curious as to what rapids you guys are getting out of your torus mills (without smooth stepper) , z in particular .
It's taken some tweaking , a good number of scrap parts , and broken tools to get my mill set to a comfortable point ( for my liking) . I used the xml from the site , and I know that some tweaking was inevitable , so the parts and tools are typical to any sacrifices that I've done with tweaking my other mills .
The z in particular needed to be slowed down to 75ipm , otherwise the motor stalls at the preset 100ipm have had nasty results .
The power save being turned on with the drivers has caused a lot of clunking from the mill and I'm expecting that was causing the x axis to crap out and lose its positioning in a couple of intances . This has since been turned off and the clunkiness has been reduced if not eliminated , though the x axis does resonate . I have spare drivers for my other mills which are an exact match so I will probably swap out the x drive to see if the resonance can be reduced or eliminated .
I asked about this particular drive when I was setting up the mill , it's marked in sharpie as bad . I've been assured that it is a good drive and that someone made a mistake , I'll take it on that value though the next mistake was not scratching that out . It's no biggy if it is a bad drive so I'll give it a try since these drivers are pretty cheap .
All of my programs are quick short coded moves , which means that the mill needs to be set fairly optimal and I think I'm pretty much at a point that I'm comfortable to walk away and let it do its thing
Overall I love the mill and I've made a lot of product on it in a short while , at the rate things are going it'll definitely have itself paid off within a few months .
Anyhow , I'm curious what the typical rapids are on a stock mill

[SCzEngrgGroup]

My machine was first purchased as a stepper machine, and later converted to AC servos. As delivered, rapid speed was limited by jitter in the step pulse timing coming out of the parallel port. Steppers to NOT deal well with jitter! I immediately installed a KFlop motion controller, as I intended to do all along. I was then able to run all three axes with no errors at 350 IPM just doing random moves while "cutting air". I ran the machine for about 9 months with rapids set to 250 IPM, to provide some safety margin, and never had a single instance of position loss, unless I ran into a vise, fixture, etc.

So, if you're using the parallel port, 75 IPM may well be the limit, unless you can figure out some change(s) to the PC (most likely some software settings) to get more consistent step pulse timing. Or, better yet, just install a motion controller, like the SmoothStepper.

Regards,
Ray L.

[dertsap]

Jitter hasn't been an issue for me . I've been holding back on hooking up a uc100 which I have an extra on hand . At this point I'm just curious what others are getting and whether the xml is set a bit unrealistically for a straight parallel port system . I'm thinking that it's more set up as a start point for a mill that is upgraded to the smooth stepper .
Overall I can't and won't complain about the speed that I'm getting out of this mill as it is .Faster is always great but it wasn't an expectation .

[SCzEngrgGroup]

[QUOTE=dertsap;1785692]Jitter hasn't been an issue for me ./QUOTE]

On what do you base that? Have you looked at the Step signal on an oscilloscope when moving fast?

Regards,
Ray L.

[dertsap]

No !
it doesn't react jittery when running my programs , which is something that I have had to deal with while setting up some of my other stepper driven mills .
I hooked up the uc100 and saw no noticeable difference , so thats been thrown aside and I'll stick with the pp for now .

[SCzEngrgGroup]

No !
it doesn't react jittery when running my programs , which is something that I have had to deal with while setting up some of my other stepper driven mills .
I hooked up the uc100 and saw no noticeable difference , so thats been thrown aside and I'll stick with the pp for now .

The jitter I'm talking about would not be noticeable by simply running the machine, other than you would be limited in speed, which you are seeing. Without putting an oscilloscope on the step signal, you have no idea how bad the jitter is, but stepper motors are VERY sensitive to it, and it WILL cause lost steps to occur at MUCH lower speeds than the motor would otherwise be capable of.

Regards,
Ray L.

[dertsap]

At this point I believe that I've set up mach to a point that the mill seems quite reliable . Changes to the z rapids and the accel on all axis has put it to a point that I'm not seeing any lost steps or issues in my parts . I'm just a simple machinist so I don't have equipment like oscilloscopes and such to test such things
Funny thing is that when I first set up the mill the z did run at 100ipm with no problem for a number of parts , then it stopped . If anything - I'm expecting it would be mechanical stiffness etc . Since I've done the tweaking its been good so far

I'm really not looking to diagnose my mill , I'm only looking to compare what my mill is running at in comparison to what others are running the same bare bones mill at .
If there is a big discrepancy then I'll want to diagnose , but until then ... .