Need some help

[cheetahcnc]

Baldor inverter duty motors are rated to 6000 rpm max. A little expensive, but are often available on ebay at reasonable prices. These usually start with the prefix "id"

Jim

[Al_The_Man]

Thats a V/F drive, for better performance I would look at a Vector drive, or even better vector/encoder VFD.
Al.

[Hack]

Yes drive has a dymanic braking circuit as well as DC braking.

I looked at the vector drives on the same site and they appear to be 2-3 times the price. What will I gain in performance by spending that much more? Or even better, does anyone have recommendation from another vendor in a comparable price?

Thanks

Dan

[Al_The_Man]

Check this out, there is a chart on p4 that shows some of the difference.
http://www.scrcontrols.com/docs/BR400_2_05.pdf
Al.

[Hack]

Thanks for the link Al. Saved me a mistake I think. Took a quick search on the net and found this one

This seems to be a better fit and the price is right.

[mike_Kilroy]

there is a typo on the baldor comparison chart: it does not have X in v/hz drive for "speed control" Obviously the inverter drive can control speed so don't let that missing X send you to a vector drive if all you want is variable speed, rated torque starting at 100rpm or so upto base speed of 1800rpm and then constant HP from there upto motor limit of usually 2 times this. If you don't need 0 speed torque, don't need speed accurate to within 1 rpm (it will be within about 50rpm or less), don't need positioning or threading, then paying the extra cost for vector may not make sense for you.

[mike_Kilroy]

Thanks for the link Al. Saved me a mistake I think. Took a quick search on the net and found this one

This seems to be a better fit and the price is right.

Keep in mind this model is no longer made, it is obsolete. not that you should not consider it but the replacement model is WJ200 and info on it is here:

WJ200 Series : Inverters : Hitachi America, Ltd.

[Hack]

Mike,

Thanks for the input and the link. While I may or may not use it, I would like the option of tapping with a tapping head on the machine. Will the inverter drive get me close enough to do that?

If not, looking at the link you gave me and comparing it to the motor I have suggested above, it looks like I would need the WJ200-007SF Model? Any idea what the price on this unit is and where to order from if I decide to go with that one? Looks like that is rated at 1 1/2 hp and would be a good match for the motor. (220 v single phase in 220 3 phase out).

I think I will be ordering the motor this weekend, would like to finalize a drive soon.

[mike_Kilroy]

sounds like you would for sure want a vector drive then for future tapping. I do not know if your control (CNC) would tap without encoder feedback or not - you need to check. There are machine owners & operators on here who can answer this.

I think I have heard people say that sensorless vector drives like these (w/o encoder) can tap if not 'solid tapping' I think solid tapping is when the tap is in the spindle and moves with it, as opposed to non-solid tapping where the tap is in a holder that rotates with the spindle but does not feed with it - it slides in and out so the spindle does not need to be so coordinated with the feed axis.