[QuinnSjoblom]

Ran into an issue with my mill turn. My swap axis switches spindle control between the mill turn and the main vertical spindle. Because of this, both are following the same spindle pulley settings which i need set to 24000 rpm max for the main spindle. This means my step/dir controlled mill turn spindle needs to have it's max velocity set to 24k rpm for the units to work correctly with the spindle pulley settings even though I don't run it above 3k rpm. With a minimum acceleration setting (about 4 seconds to max rpm) this takes my mill turn spindle from 0-3k in a half a second, which is too much and
Usually faults the servo drive, especially on the deceleration.
How can I get around this and set the acceleration lower than the minimum it's allowing? Not sure why there's a limit there in the first place. Should be able to accelerate as slow as you want.

[Jim Dawson]

Can you override the accel setting in the aux servo drive?

[QuinnSjoblom]

Can you override the accel setting in the aux servo drive?

Not with step/direction control. In speed mode you can, but since this is a spindle/4th axis, I need to use step/dir for both

[Jim Dawson]

I dunno, change the accel to 8 seconds maybe? Not sure how to solve this one.

[QuinnSjoblom]

I dunno, change the accel to 8 seconds maybe? Not sure how to solve this one.

Yeah that's the issue, mach3 won't allow me to set it any slower. If entering a lower value, it just comes up to a minimum amount based on the max velocity that happens to be about 4 seconds from zero to max. Right now all I can do is switch it back and forth depending which spindle I'm using, but once I start running parts that do turning and milling in the same program, it's not gonna work other than letting my main spindle run at its minimum rpm of 7200, which it automatically does if the max speed is set less than that

There's a way to do it. I found a post where a guy needed to do the same thing. Something about editing the xml or something like that but couldn't find much on the details. If I keep digging I might be able to figure it out, but thought I would check here and see if there's an easy answer

[mactec54]

Yeah that's the issue, mach3 won't allow me to set it any slower. If entering a lower value, it just comes up to a minimum amount based on the max velocity that happens to be about 4 seconds from zero to max. Right now all I can do is switch it back and forth depending which spindle I'm using, but once I start running parts that do turning and milling in the same program, it's not gonna work other than letting my main spindle run at its minimum rpm of 7200, which it automatically does if the max speed is set less than that

There's a way to do it. I found a post where a guy needed to do the same thing. Something about editing the xml or something like that but couldn't find much on the details. If I keep digging I might be able to figure it out, but thought I would check here and see if there's an easy answer

What do you have the ON Pos Range set at in the Dmm Drive

[QuinnSjoblom]

What do you have the ON Pos Range set at in the Dmm Drive

Default. I believe it was 127. I don't really see it as an issue with the drive settings though. 0 to 3k rpm in half a second with a heavy servo and spindle is a lot to ask. The problem is I can't set a reasonable acceleration in mach3 because of the max velocity I have to set to make the spindle swap work

Ok, I think I see what you mean. If it gets set to a low number, it can send an alarm to mach3 with only a small position error. 127 only sends alarm if the drive faults which is how I have it set, so not my issue. I think it's simply just too high of acceleration. It's a lot of mass to go from zero to 3k in a half second

[mactec54]

Default. I believe it was 127. I don't really see it as an issue with the drive settings though. 0 to 3k rpm in half a second with a heavy servo and spindle is a lot to ask. The problem is I can't set a reasonable acceleration in mach3 because of the max velocity I have to set to make the spindle swap work

Ok, I think I see what you mean. If it gets set to a low number, it can send an alarm to mach3 with only a small position error. 127 only sends alarm if the drive faults which is how I have it set, so not my issue. I think it's simply just too high of acceleration. It's a lot of mass to go from zero to 3k in a half second

Yes the mass and the inertia could be where the problem is

In Mach3 spindle set the Velocity and acceleration to the lowest numbers, that work for you, velocity can be 0 and acceleration can be 1 so you can play with those numbers to get where you want to be

[QuinnSjoblom]

Yes the mass and the inertia could be where the problem is

In Mach3 spindle set the Velocity and acceleration to the lowest numbers, that work for you, velocity can be 0 and acceleration can be 1 so you can play with those numbers to get where you want to be

The problem is, the velocity needs to match the max rpm set in the spindle pulley setup for the steps per unit to work out properly. The max rpm for the pulley needs to be set at 24000rpm to not limit the speed of my main spindle. So my mill turn spindle also needs to be set at a velocity of 24000rpm which is why it's limiting me to such a high minimum acceleration value. The only other work around I can think of is if I can switch pulley selection in my spindle swap macro. Then i could have a different pulley setup for the mill turn and be able to drop that velocity number down which would allow me to drop the acceleration. Can pulleys be switched in macro?

[QuinnSjoblom]

Ok, found some details on the subject. Here's a quote:

"The great team at Artsoft hooked me up, for those who are curious:

If you open your XML File in a word editor(IE: Note Pad or Note Pad++) you can manually change the Acceleration to what you would like. Once the XML is open search(CTRL-F) for ACC0 for the X, ACC1 for the Y, and ACC2 for the Z. Save the file run mach3 and you should be good to go.

by XML, he was referring to the XML for the Mach 3 profile I wanted alter.

Happy Hunting!"


I haven't tried it yet but will when I get home. I'm assuming the axis number for spindle is 6 as it is when doing axis swaps so i should find it by searching for ACC6 in the xml file.
There also another solution that is simpler as you can enter it right in vb editor, but I'm not sure what exactly the code should look like. For setting x accel for example it's:
SetParam "AccelerationX", then value

For spindle accel, I'm assuming use "s"? Not sure though. I'll try this before digging through xml

[mactec54]

Ok, found some details on the subject. Here's a quote:

"The great team at Artsoft hooked me up, for those who are curious:

If you open your XML File in a word editor(IE: Note Pad or Note Pad++) you can manually change the Acceleration to what you would like. Once the XML is open search(CTRL-F) for ACC0 for the X, ACC1 for the Y, and ACC2 for the Z. Save the file run mach3 and you should be good to go.

by XML, he was referring to the XML for the Mach 3 profile I wanted alter.

Happy Hunting!"


I haven't tried it yet but will when I get home. I'm assuming the axis number for spindle is 6 as it is when doing axis swaps so i should find it by searching for ACC6 in the xml file.
There also another solution that is simpler as you can enter it right in vb editor, but I'm not sure what exactly the code should look like. For setting x accel for example it's:
SetParam "AccelerationX", then value

For spindle accel, I'm assuming use "s"? Not sure though. I'll try this before digging through xml

Yes you should be able to swap the pulleys settings as well, then have a different acceleration and velocity profile

Here is a video how to do it https://www.youtube.com/watch?time_c...&v=KkQso5yWj3A

[QuinnSjoblom]

Yes you should be able to swap the pulleys settings as well, then have a different acceleration and velocity profile

Here is a video how to do it https://www.youtube.com/watch?time_c...&v=KkQso5yWj3A

Great, that's good to know and probably the best solution since I can set the mill turn spindle velocity to it's actual max velocity instead of just putting in 24k yo match the main spindle.

Here's another thing that's funny, a few days ago I ordered a braking resistor since I figured it would probably at least help the drive handle quick deceleration. Apparently it does and also helps with acceleration as well. I just wired it up and now I can ramp up and down from 0-3k rpm with a half second ramp no problem lol. Just cycled it up and down like 20 times without a single fault. without the resistor it would fault most of the time on ramp up and all the time on ramp down. Looks like now I can just leave it on crazy ramp speed. I guess why not. As a mill turn spindle, quick ramping will save cycle time since it switches back and forth from turning to indexing. I'm really surprised it handles it now. Half a second is pretty crazy. I guess it might be hard on the belt to leave it this way

[mactec54]

Great, that's good to know and probably the best solution since I can set the mill turn spindle velocity to it's actual max velocity instead of just putting in 24k yo match the main spindle.

Here's another thing that's funny, a few days ago I ordered a braking resistor since I figured it would probably at least help the drive handle quick deceleration. Apparently it does and also helps with acceleration as well. I just wired it up and now I can ramp up and down from 0-3k rpm with a half second ramp no problem lol. Just cycled it up and down like 20 times without a single fault. without the resistor it would fault most of the time on ramp up and all the time on ramp down. Looks like now I can just leave it on crazy ramp speed. I guess why not. As a mill turn spindle, quick ramping will save cycle time since it switches back and forth from turning to indexing. I'm really surprised it handles it now. Half a second is pretty crazy. I guess it might be hard on the belt to leave it this way

Breaking Resistors have a habit of working like that, this is what they are used for, anything that has / needs high deceleration rates needs a braking resistor more so because of the high inertia you have, not so much on the acceleration but may help if it is part of the acceleration circuit, the way the Braking Circuit is designed it is normally only affective on the deceleration side, but for a servo drive like this knowing the designer of these drives he most likely covered all possible situation's

Your Mill spindle will benefit from a braking resistor also if your VFD Drive supports the use of one some of the cheaper VFD Drives don't have all the internal electronics parts needed

[QuinnSjoblom]

Breaking Resistors have a habit of working like that, this is what they are used for, anything that has / needs high deceleration rates needs a braking resistor more so because of the high inertia you have, not so much on the acceleration but may help if it is part of the acceleration circuit, the way the Braking Circuit is designed it is normally only affective on the deceleration side, but for a servo drive like this knowing the designer of these drives he most likely covered all possible situation's

Your Mill spindle will benefit from a braking resistor also if your VFD Drive supports the use of one some of the cheaper VFD Drives don't have all the internal electronics parts needed

I'm pretty sure my vfd allows it. Until now I kind of assumed breaking resistors were more expensive than what they are, so I never really considered using one. Now that I know i can get one for 20 bucks, I'll probably add one to the vfd as well so I can increase the deccel and save some more cycle time. I imagine it's also easier on the vfd

[mactec54]

I'm pretty sure my vfd allows it. Until now I kind of assumed breaking resistors were more expensive than what they are, so I never really considered using one. Now that I know i can get one for 20 bucks, I'll probably add one to the vfd as well so I can increase the deccel and save some more cycle time. I imagine it's also easier on the vfd

What VFD do you have if you have a regular HY then no it will not support a braking resistor, most other VFD Drive manufactures work though,there are some parameters to set to get them to work effectively

[QuinnSjoblom]

What VFD do you have if you have a regular HY then no it will not support a braking resistor, most other VFD Drive manufactures work though,there are some parameters to set to get them to work effectively

Yes it's the HY, So i guess not then. No big deal, it ramps down in about 2 seconds.

[mactec54]

Yes it's the HY, So i guess not then. No big deal, it ramps down in about 2 seconds.

They can be ordered Braking Resistor ready, so you will know for next time if the drive fails 2seconds is good most stick to around 3 seconds for the HY