Re: [Emc-users] What Would You Suggest?

Sigh... A web link or two would be more helpful than just a comment. > From: Robin Szemeti via Emc-users [mailto:emc-users@lists.sourceforge.net] > > Sigh ... > > " Perhaps you can find some and post those that do show flat torque up to a > 'corner speed'?" ... all ... every single one, when

Re: [Emc-users] What Would You Suggest?

The link I posted for stepper motors might give you a better idea. Also there's this data sheet which I've found has a good description on how micro-stepping works. How the current in one phase is set with respect to the other for each micro-step. https://www.ti.com/lit/ds/symlink/lmd18245.

Re: [Emc-users] What Would You Suggest?

> On Feb 5, 2022, at 6:48 PM, John Dammeyer wrote: > > No. The motors are designed to handle N amperes although they get quite warm > that should be a 24/7 rating. Because they get so warm many drivers back the > current off when the motors have been idle for a period of time. Yes, N ampe

Re: [Emc-users] What Would You Suggest?

Sigh ... " Perhaps you can find some and post those that do show flat torque up to a 'corner speed'?" ... all ... every single one, when connected to a current limited driver. On Sun, 6 Feb 2022 at 00:45, John Dammeyer wrote: > No. The motors are designed to handle N amperes although they ge

Re: [Emc-users] What Would You Suggest?

No. The motors are designed to handle N amperes although they get quite warm that should be a 24/7 rating. Because they get so warm many drivers back the current off when the motors have been idle for a period of time. Let's take a step backwards with a long explanation. When I first sized

Re: [Emc-users] Execute MDI command, from hal pin

I've implemented some safe probing routines here . They are examples of subroutines that might be called by external switches -- or in my case from buttons on a pendant. Ken Kenneth Lerman 55 Main Street Newtown, C

Re: [Emc-users] Execute MDI command, from hal pin

The other half of the pins that Sebastian mentioned is that the commands must be defined in the .ini file. This will tell you that you can put things like: - *MDI_COMMAND = G53 G0 X0 Y0 Z0* - An MDI command can b

Re: [Emc-users] Execute MDI command, from hal pin

On 2/5/22 1:13 PM, Nicklas SB Karlsson wrote: Anybody know about a method to execute a MDI command with g-code then on a hal pin flank? I'm not entirely sure what you're asking for, but one of my machines has a hardware button coming in to HAL through a gpio, connected to a halui input which

Re: [Emc-users] Execute MDI command, from hal pin

On Sat, 5 Feb 2022 at 20:24, Nicklas SB Karlsson wrote: > > Anybody know about a method to execute a MDI command with g-code then on > a hal pin flank? What is the MDI_COMMAND? I think that if it is pure G-code then it can be an OCALL and you can use that same format in your G-code. Alternative

Re: [Emc-users] What Would You Suggest?

I believe the flat part of the curve is defined by the motor thermal limits. Is this correct? > On Feb 5, 2022, at 11:44 AM, John Dammeyer wrote: > > All fine and good but doesn't help anyone choose a stepper motor. For > example: > https://www.geckodrive.com/support/step-motor-basics.html >

[Emc-users] Execute MDI command, from hal pin

Anybody know about a method to execute a MDI command with g-code then on a hal pin flank? Nicklas Karlsson ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] What Would You Suggest?

Le sam. 5 févr. 2022 à 18:44, John Dammeyer a écrit : > All fine and good but doesn't help anyone choose a stepper motor. > .. > Perhaps explain how _you_ choose a stepper motor for a given axis? What > process do you go through to do this? Earlier today reading this thread, I thought such

Re: [Emc-users] What Would You Suggest?

All fine and good but doesn't help anyone choose a stepper motor. For example: https://www.geckodrive.com/support/step-motor-basics.html tries to explain corner speed but fakes the curves by showing that the torque of a stepper motor is constant up to a certain speed. I've yet to see any curves

Re: [Emc-users] What Would You Suggest?

On Sat, 5 Feb 2022 at 12:34, Stuart Stevenson wrote: > > Guys, > Causing me to 'think' this early hurts my head but I need to express this > thought. It may be totally crazy but is there a way to 'double wind' a > motor to cancel/use the back emf? Yes, absolutely. Unfortunately this also cancels

Re: [Emc-users] What Would You Suggest?

Guys, Causing me to 'think' this early hurts my head but I need to express this thought. It may be totally crazy but is there a way to 'double wind' a motor to cancel/use the back emf? thanks Stuart On Sat, Feb 5, 2022 at 5:55 AM Robin Szemeti via Emc-users < emc-users@lists.sourceforge.net> wrot

Re: [Emc-users] What Would You Suggest?

"comment about corner frequency with stepper motors _might_ well be valid as long as the maximum current for each step is reached before or at the end of the ste" Yes, that is exactly what the corne frequency is ... the step frequency at which the current no longer reaches the desired value befor

Re: [Emc-users] What Would You Suggest?

John, You are fundamentally incorrect when you state " the torque of the motor to drop off the faster it goes" .. although the back EMF is correct, with a modern current limited drive, the torque is flat until the corner frequency, then drops off ... up to the corner frequency the torque is const

Re: [Emc-users] What Would You Suggest?

Hi Chris, My issue is that a comment about corner frequency with stepper motors _might_ well be valid as long as the maximum current for each step is reached before or at the end of the step. But the motor is turning pretty slowly there compared to how they are used in real life. However the c

Re: [Emc-users] What Would You Suggest?

What motor driven surface grinder with power feed *doesn't have* automatic reversing in X and adjustable auto feed step in Y? Even ones 100 or so years old had features like adjustable X travel stops. I'd bet there were grinders with Y travel stops so an operator could set it and forget it, then

Re: [Emc-users] What Would You Suggest?

John, You described it correctly. But I think what Robin meant by "Corner Frequency" might be the peak of the power vs. RPM graph. Basically, the frequency where power output starts to fall with RPM. But now it can get worse, or really better but more complex. We have these so-called "closed