Proper variables to increase dc steppers

Hi folks,

I have a running machine (been using it for years now), it has always been a slow mover, I never concerned myself with the speed as it did what I needed just fine.
Times have changed, the speed issue is stifling creativity and killing profitability.

I am running Anaheim Automation's NEMA 34 DC stepper motors with matching drive.
I'm getting around 36 inches a minute at best.
I see these guy's running at what must be around 200 and all I can do is sigh.
As I read through the docs I can see you have some options for messing with "Step Rates" in a couple areas.
I am reluctant to just start throwing different values at the ini with no idea how it will affect everything.
Are there some kind of minimums and maximums a person should work with?
Is there more detailed information somewhere?

I imagine the first thing that will be asked of me is "what do you have now", so I'll just include that to help with that.

BASE_PERIOD =100000
MAX_VELOCITY =0.250
SCALE = 2000.0 (I assume that's "INPUT SCALE")
STEPGEN_MAXACCEL =50.0 (I don't have a "STEPGEN_MAXVEL")
MAX_LINEAR-VELOCITY = 0.700 (Not sure this applies)

Any direction or help that can be provided will be most appreciated.

Thanks in advance

I have a couple of routers running Anaheim Automation unipolar drives with NEAMA34 steppers. They have a steps scale of about 1000 and can do rapid feeds over 400ipm. If you're hardware is up to it I see no reason you shouldn't be able to do 200ipm.

Start by increasing the max velocity settings in your ini file to 33.34. (oops, decimal point in the wrong place should be 3.334)

I've set up a couple of machines so I'm not a wizard but those settings look a bit odd. Unless it's something related to an old version of EMC I don't think that MAX_LINEAR-VELOCITY is necessary. Prior to 28, under "AXIS" there should be a TYPE = LINEAR. Everything under that axis should correspond to linear units. As long as type is linear you should only need MAX_VELOCITY. the ini is in units per second, so 0.700 is 42inches per minute or 15ipm if it's using MAX_VELOCITY over MAX_LINEAR VELOCITY

SCALE I believe is the same thing as STEP_SCALE where this is how many steps your hardware requires to move 1 machine unit or 1 inch. This is determined by the screw or belt pitch, stepper degree per step, driver microstep etc. INPUT_SCALE should be an encoder scale setting for a servo or maybe a closed loop stepper. Basically if your machine is accurate down to a thou or 2 then SCALE is already correct, it's not an arbitrary number.

If your shooting for 200ipm I would set it like this
TYPE = LINEAR
MAX_ACCELERATION = 30
MAX_VELOCITY = 3.33 (33.34 above is 2000 inches per minute?)
STEPGEN_MAXACCEL = 40
STEPGEN_MAXVELOCITY =4
STEP_SCALE = 2000

Edit: Sorry, MAX_LINEAR-VELOCITY looks like it's a variable for your GUI to set the maximum speed it will allow you to jog.

Thank you for the data, this gives me a place to start.

I'll do a little fiddling today and see what comes of it.

Todd, what drive is on those machines you have with the Anaheim motors?
(Just curious).

What ever the last version AA made of their black box, 4 axis, AC mains plug in, unipolar drives, DPK70004XDTI or something like that. I'm not sure they even make them anymore and if they do, they charge a ridiculous price for them to discourage their purchase. The world has moved on, and the bipolar drives and motors are cheaper and better.

Before I start messing with this I have an observation.

In my ini, under all my axises (3 linear 1 rotary) there is no "STEPGEN_MAXVELOSITY" to speak of.
Is this something that needs to be there and should I add it?

It has been so long ago when I set this up I simply don't recall any of this.
I did get help from someone who sent me my configuration file, I had done one myself but I must of had some kind of issue with it leading to my original being dumped in favor of the one I have.
This was maybe ten years ago now.

Thanks again

Not necessarily, I don't have one in my configs either and they work fine.

My GOODNESS I had no idea these motors would make this kind of speed.

The only issue at the moment is Homing, it flies past the sensor and takes a fair amount of dumping to get back to the trigger.
I almost changed HOME_SEARCH_VELOCITY but thought maybe it isn't that easy.
Mine is set at -1.700 now.
Is there more top it?

I see the value in that feild is for after the switch is tripped, if you over shot ai think all you can do is move your switch so it will not crash the axis at end of travel.

Have I got that right?

No worries, I got it.
Homing is one part of the manual I do have some recall on.

Thanks for all your help.

If I have any other questions I'll jump back on.

Again, thanks so very much, Allen