Re: [CAD_CAM_EDM_DRO] Re: What kind of motor should I use?

The thought of running a motor rated at 3000rev/min at 14,400rev/min is
terrifying:
1. Bearing capability
2. Rotor integrity and possible bursting
3. Out of balance problems
4. Overal efficiency and heating problems

Stick with motors designed for the task and go for longevity of your own
life !!

Regards Peter

----- Original Message -----
From: "bwrfromuk" <bwjarandall@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Tuesday, February 05, 2002 12:03 AM
Subject: [CAD_CAM_EDM_DRO] Re: What kind of motor should I use?


> --- In CAD_CAM_EDM_DRO@y..., JanRwl@A... wrote:
> > In a message dated 03-Feb-02 15:42:15 Central Standard Time,
> > datac@l... (Chris) writes:
>
> Hi, I'm fairly recently over from the UK, while I was there I had a
> hydraulic copy mill that used a small Bridgeport head. It was a PITA
> to change speed, so I ran it from a variable frequency controller.
> This unit, single phase i/p 3 phase o/p, was adjustable from 0 to
> 240Hz, in the UK which uses 50Hz, this meant that the motor could run
> up to almost 5x faster than faceplate RPM. In practice I never
> operated it at the higher speeds, but I did run it up to see how much
> vibration was produced.. not very much.
>
> How practical it is to run say a 3600 RPM motor at 14,400 RPM I don't
> know, and how long the bearings would last is another question.
>
> The UK units were fairly reasonaly priced, a .75kw (1HP) unit was GBP
> 284 (US$300) and a 1.5kw (2HP) was GBP 284 (US$450) 1999 prices.
>
> I'm still finding my way around in the US so I don't know what's
> available over here.
>
> >
> >
> > > You had a LOUD Perske ??<< HORRIBLY-so! (a BIG 'un: 3.5 HP)
> >
> > > The two (note correct use of word [!!!] ) I stood behind were
> very quiet. <<
> > > There are two "groups" of Perske spindle-
> > > motors, one with an external fan (sirens!) and TENV kind. The
> ones YOU
> > stood behind: Fans?
> >
> > As you pointed out, they > get expensive because the Inverter
> costs so
> > > much more than the spindle.
> > > We could use a few newcomers *to the affordable spindle field
> *too! <<
> > > Scho' nuff! Listen-UP, 'Merikun mfgrs!!!
> >
> > > Some of the German stuff does not seem to have any resellers over
> here.<<
> > Yeah, Perske has a reseller in NJ. Been 15 years, so I'd have to
> look in
> > file to see who/where.
> >
> > I wonder what kind of $$$$ they can buy stuff like that for over
> there?<<
> > Even HIGHER, I think, due to the German VAT and Lohnsteuer.
> >>
> > Maybe one of the
> European Group
> > members > could set up someone in the states *to market spindles at
> a lesser
> > > rate.....<< Lossa luck!
> >
> > Did I read somewhere in this group that "regular 3-phase tool-
> motors" can be
> > used at higher frequencies [with care] to produce high-RPM
> spindles? Seems
> > dangerous and dubious. Can an expert "in here" on that comment?
> The ONLY
> > experience I have with HF motors is with a 95 watt "aircraft
> instrument
> > motor" running on 115 VAC 400 Hz. (which I get from a self-
> designed/cobbled
> > stationary inverter that "simulates" sine-wave 400 Hz/115 VAC).
> That is for
> > a PCB drill, and it works just fine (12,000 RPM, not 24,000!!!)
> But, took
> > some fancy machining to install a collet and larger ABEC-7 spindle-
> bearing in
> > place of original "plain shaft", etc.)
> >
> > P.S: The Perske stuff DID seem like well-did hardware, but even
> still, the
> > pricing was what I'd guess would be half- to as-much-again as any
> American
> > mfgr. would want for "same thing". Comments? American HF spindle
> makers?
> >
> > Sincere ignernce, Jan Rowland, old troll
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
>
>
>
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