[jlind54]

Just had a quick question with regards to minimum spindle speed when using an external control signal. I'm using this VFD along with a 400hz high speed spindle and I've noticed several recommendations to not run these spindles under a frequency of 120HZ. However, with the min speed set to 120 when I'm using the external signal when the signal is reduced to 0V the spindle still runs at 7200 RPM until I hit the stop button. Is it possible change the parameter to 0hz with the understanding that my program would not call a speed under 7200RPM so spindle can stop when the spindle signal is at 0V without needing to press the stop button.

Is there an operational difference in the signal going to 0V vs the stop button being pressed to make the spindle stop?

[mactec54]

Just had a quick question with regards to minimum spindle speed when using an external control signal. I'm using this VFD along with a 400hz high speed spindle and I've noticed several recommendations to not run these spindles under a frequency of 120HZ. However, with the min speed set to 120 when I'm using the external signal when the signal is reduced to 0V the spindle still runs at 7200 RPM until I hit the stop button. Is it possible change the parameter to 0hz with the understanding that my program would not call a speed under 7200RPM so spindle can stop when the spindle signal is at 0V without needing to press the stop button.

Is there an operational difference in the signal going to 0V vs the stop button being pressed to make the spindle stop?

Sounds like you don't have something wired or programed correct 100Hz is the minimum speed for most of the water-cooled spindles 120Hz is a safer speed to use for the minimum speed, if you have everything setup correct there, there should be no problem with the minimum speed setting.

How are you turning the spindle On/Off???

[jlind54]

My grbl based controller is supplying 0-5v. The vfd is set to use 0-5v reference for the speed. Turning it on and off I’m using the run/stop button on the vfd.

With min. speed set to 120 when I send M3S12000 I get an rpm around 15,600. With min. speed set to 0. M3S12000 yields an rpm of 12,200.

When the min. speed is set to 120 once I send any M3SXXXXX then follow up with an M5 the spindle will slow to 7200 rpm until I press the stop button.

Min. speed set to 0 when I send M5 the spindle slows to a stop.

[mactec54]

My grbl based controller is supplying 0-5v. The vfd is set to use 0-5v reference for the speed. Turning it on and off I’m using the run/stop button on the vfd.

With min. speed set to 120 when I send M3S12000 I get an rpm around 15,600. With min. speed set to 0. M3S12000 yields an rpm of 12,200.

When the min. speed is set to 120 once I send any M3SXXXXX then follow up with an M5 the spindle will slow to 7200 rpm until I press the stop button.

Min. speed set to 0 when I send M5 the spindle slows to a stop.

When using remote control, 0-5v you need a Relay to turn it On / Off

The Keypad does not function correctly when using remote control

So, you need a Relay that turns On / Off with your control the Relay output is connected to the VFD Drive FOR and DCM, trying to bypass this is not safe to use.

[jlind54]

Noted, I’m working on getting a relay connected up for use with the external control.

Can you provide details on how exactly pd145-pd147 effect operational performance?

[mactec54]

Noted, I’m working on getting a relay connected up for use with the external control.

Can you provide details on how exactly pd145-pd147 effect operational performance?

Neither will have much effect on your spindle you have. auto Torque may be increased a small amount, too much and you will smoke these spindles

Slip compensation you don't need to worry about, unless you can calculate it, you will need all the needed motor specs, which are not available for these spindles

Messing with Parameters and setting them incorrectly will end in a damaged spindle or VFD Drive

[jlind54]

Which portion of the VF Curve does the auto torque apply to? Should I expect to see the voltage from the inverter increase "x" percentage based on this setting when a load is presented to the spindle? What other parameters are tied in with PD145? I only ask because changing it slightly up and down I saw no change in the voltage reported by the vfd with and without load. Does the spindle need loaded for some predetermined amount of time before this setting comes into play?

[mactec54]

Which portion of the VF Curve does the auto torque apply to? Should I expect to see the voltage from the inverter increase "x" percentage based on this setting when a load is presented to the spindle? What other parameters are tied in with PD145? I only ask because changing it slightly up and down I saw no change in the voltage reported by the vfd with and without load. Does the spindle need loaded for some predetermined amount of time before this setting comes into play?

Unless you have a meter that can be used for the VFD output, a normal meter can't read the output from a VFD Drive, you would not see any change unless you are going above the normal Motor torque, which is not likely to happen for the normal user

That is why you should not be messing with these parameters; the torque of your spindle is not very much, trying to get more Torque than your spindle can handle, will damage the motor

The default of 2% is a good safe number

This meter is one that can be used to read the VFD Drive output, a normal Dmm can't be used.

[jlind54]

I was simply going by the voltage reported by the vfd itself. I’ll pull out the DMM and see what it’s actually doing. I figured the built in voltage display parameter would show it increasing as the spindle approached stall.

[jlind54]

It almost seems like this thing doesn’t actually track rotation or bump the voltage to increase torque when a load is presented to the spindle. Perhaps it’s just not part of its feature set?

[mactec54]

It almost seems like this thing doesn’t actually track rotation or bump the voltage to increase torque when a load is presented to the spindle. Perhaps it’s just not part of its feature set?

You are dealing with a 400Hz spindle, these VFD Drives are designed to be run with 50 / 60Hz motors so there are a lot of things that don't work correctly for these High frequency spindles even on the most expensive VFD Drives the same thing happens, as I said if it did work, and you set it too high you would burn these spindles to a crisp, because of the extra current that the torque boost could deliver these spindles can't take, much above there max rating

[jlind54]

I took several voltage/amperage measurements at various loads and speeds with the suggested v/f curve parameters then adjusted curve to better suit my needs across the desired rpm range. Seems to be working fine currently. Drilled around 825 holes @ 7200rpm without stalling / getting hot or drawing excessive current. They are pretty shallow holes in aluminum so not overly impressive. A spindle stall will be problematic and likely end with magic smoke. I need to experiment with some of the stall detection settings and see how they may or may not work with this spindle.

[mactec54]

I took several voltage/amperage measurements at various loads and speeds with the suggested v/f curve parameters then adjusted curve to better suit my needs across the desired rpm range. Seems to be working fine currently. Drilled around 825 holes @ 7200rpm without stalling / getting hot or drawing excessive current. They are pretty shallow holes in aluminum so not overly impressive. A spindle stall will be problematic and likely end with magic smoke. I need to experiment with some of the stall detection settings and see how they may or may not work with this spindle.

Stall Parameter can only be set at around 110 % there should be no problem in drilling holes in Aluminum many do this all the time and at 120Hz which is a good working speed for this, the current reading you see on the VFD screen you x that by 3 that will give you the total amp draw

[jlind54]

How does that figure correlate to the output amperage rating on the vfd? Say it’s rated at 13A I’m nearly cooking the thing when the current reported on the VFD is 4A? Also, the motor shows an 8amp rating, by the 3x method described it would be cooking the spindle right? Just trying to understand the limits before I let the magic smoke out.

[mactec54]

How does that figure correlate to the output amperage rating on the vfd? Say it’s rated at 13A I’m nearly cooking the thing when the current reported on the VFD is 4A? Also, the motor shows an 8amp rating, by the 3x method described it would be cooking the spindle right? Just trying to understand the limits before I let the magic smoke out.

You obvious have not set the VFD Drive Parameters correct, if the drive can output more than the spindle rating, a 2.2Kw is normally rated from 8.5A to 10A depending on the manufacture

Yes, if you are hitting 4A then over time it will fail. You are cutting too deep or too fast for this to be happening

100% would be up to the max rated Amps that you have set in the VFD Drive 110% is a good safe conservative setting for these spindles this does not mean that it can run at 110% all the time if you are running at this all the time then the spindle will fail, this is only for a short burst to help prevent a stall

[jlind54]

Motor current is set to 8A on setting PD142. The 4A was figure was a peak while loaded heavily to see if the spindle would stall or not. Typically I’m seeing 1.3A-2.1A range while making moderate cuts.

Just wanted to get a feel for what the vfd shows for current and how it relates to the spindles capacity. My plan is to have a viewable display connected to the analog output of the vfd that represents a percentage of the spindle utilization. Make it easy to keep tabs on how hard it’s being run.

If pd054 is set to 1 I should have an analog value 0-10v but it would not correlate to the spindle right only the vfd’s capacity?

[mactec54]

Motor current is set to 8A on setting PD142. The 4A was figure was a peak while loaded heavily to see if the spindle would stall or not. Typically I’m seeing 1.3A-2.1A range while making moderate cuts.

Just wanted to get a feel for what the vfd shows for current and how it relates to the spindles capacity. My plan is to have a viewable display connected to the analog output of the vfd that represents a percentage of the spindle utilization. Make it easy to keep tabs on how hard it’s being run.

If pd054 is set to 1 I should have an analog value 0-10v but it would not correlate to the spindle right only the vfd’s capacity?

Correct you are not measuring the Spindle, only what the VFD Drive current is that is running the spindle

Check you don't have PD119 set at default=150% this is why it would have been able to get up to 12A set to no more than 110%