[naspc]

I wonder if it is safe to set base freq to something lower? Has anyone reported damaging a spindle if it was "under powered" ?

[mactec54]

I wonder if it is safe to base freq to something lower? Has anyone reported damaging a spindle if it was "under powered" ?

No it won't run well at all, if you went lower, & you could do damage to the drive, It is not that normal for a manufacture to give a Base frequency that is lower than the Max frequency, normally all 3 setting are set the same at what ever the max frequency of the spindle

I'm wondering if when they mean base frequency, it is the minimum frequency for the slowest speed the spindle can run at, which makes more sense

[naspc]

Mactec54

I guess the only way to find out is test it with the setting on the plate and run it at 300 and see what the rpms are.
I am still a couple of month from putting the machine together. But I will definitely post my findings.

[Al_The_Man]

Normally when using a VFD with a 'standard' 3ph Induction motor, the base speed refers to what it would run on the name plate frequency, normally at 50hz or 60Hz.
And whether 2 or 4 pole etc.
The high RPM water cooled 2 pole 24krpm spindles are not designed or capable of running on 50 or 60hz due to the very low inductance of the motor winding and rotor.
Those that have ignored or overlooked the minimum setting have usually resulted in the burn out of their motor.
Al.

[mactec54]

naspc

Some VFD Drives for you to look at, Hitachi Delta Commander Teco Yaskawa there are other good drives as well, don't buy a cheap one, as it won't last very well with your spindle

[naspc]

Mac tech

Thanks for the VFD recommendation.
I will check them out tonight.
I'm glad this post wasn't to old and abandoned.

[mactec54]

Thanks for the VFD recommendation.

When you started posting I thought you had your VFD, unless you have the same VFD that this post was about, the setting parameter letters & numbers may be different, not all VFD setup/programming are the same

[mactec54]

The VFD in the start of this thread is a Lenze VFD Drive, this is a good VFD Drive

[naspc]

I was thinking of that one also. The guy who I bought the spindle from recommends them.
But I am having a hard time finding specs on it.

[ger21]

Looking at that plate, I wonder if they're telling you you can configure the spindle two different ways? Either as an 18,000 rpm spindle, or a 24,000 rpm spindle?

[naspc]

please don't say that! It took awhile even begin to understand this stuff!

[mactec54]

please don't say that! It took awhile even begin to understand this stuff!

Nothing to worry about 24,000 is the max rpm for this spindle, the minimum speed is 18,000 is the slowest the spindle can be run, just the name plate is a little confusing

[ger21]

Why would the spindle be limited to a minimum of 18,000 rpm?

[naspc]

I wonder if that 18000 for single phase and 24000 at 3 phase?

[Al_The_Man]

The figures that I have come across and from those that have had failures, the minimum RPM, particularly with the air cooled models is 100 to 120Hz, this relates to 6000rpm.
These motors are very low inductance and the inductive reactance below around 120Hz is very low, which makes the motor prone to overheating and burn out.
In spite of the ads that state 0-400Hz.
Al.

[mactec54]

Why would the spindle be limited to a minimum of 18,000 rpm?

Because it is air cooled

It is on there web site they give the RPM range, for all the different spindle's they make

I'm sure it could run slower, but without cooling it would not last very long

[ger21]

Because it is air cooled

It is on there web site they give the RPM range, for all the different spindle's they make

The only rpm range I see on their website is in the catalog. For the model 4147, it states 12,000-18,000 with a single bearing spindle, and 12,000-24,000 for a double bearing spindle.

[mactec54]

naspc

naspc will have to post the series # of what spindle he has, as they have many different models with the same starting series #

The C42/47-SB will run @ 18,000 RPM with a Minimum of 12,000 RPM

The C41/47-DB-2DB will run @24,000 RPM with a minimum of 12,000 RPM

[Al_The_Man]

6000 could be the minimum for the water cooled that I have ran across in ads.
When you look at the diameter, it is not hard to imagine how much inductive material there is for that potential rotor diameter.
Al.

[tahustvedt]

naspc

naspc will have to post the series # of what spindle he has, as they have many different models with the same starting series #

The C42/47-SB will run @ 18,000 RPM with a Minimum of 12,000 RPM

The C41/47-DB-2DB will run @24,000 RPM with a minimum of 12,000 RPM

You seemed so sure before when you said his minimum was 18000. Where did the 18000 minimum speed come from? His photo shows a spindle with a part number that starts with 4147, but I can't find the exact number on the Teknomotor site: http://www.cnczone.com/forums/spindl...ml#post1454878