Ok, I've settled my choice on a delta 14". But in their catalog there is a
3/4 & 1 HP model. So here's my 2 questions
1) Would it make a big difference to use a 3/4 HP instead of a 1 HP ? Is a
smaller motor tend to break the blade more often ?
2) Digging a bit further, I saw another brand of bandsaw (King Industrial)
where they don't show the HP but rather the amps : it was a 7.5 amps for the
3/4 HP and 10 amps for the other. So as we know, Watts = Voltage x
Intensity 120Vx7.5A=900W to convert it to HP = Watts x 0,00134. So a 7.5A
gives 1.2 HP and a 10A gives 1.6 HP. I'm sure I missing something here, I
would doubt very much that they gives so much HP for a small bandsaw like
that. Any electrician in the croud ?
Ok, your are right and remembered my electric courses. It's the cos phi
factor which is essentially the true efficacy of an electrical apparel. For
motors, it ranges from 0,5 to 0,9 essentially. What I didn't know is that
cheap motors (chinese) don't show HP but only amps because they are... well
crap motors. Torque is so low and they don't use capacitors so it jams every
so often. That would explain the pain I have to drill a 3/4" hole in oak on
my Mastercraft press drill.
So, as always, don't just look at the mechanics of the tools but also at the
electrical parts also.
It changed my mind on the bandsaw.
> Not an electrician but.... Your math is essentially correct except 120 is
> the nominal voltage household electricity. >
C & S wrote:
> tend to be about 9-10 amps. HP ratings have been known to be stretched by
> the marketing departments of some tool manufacturers. Amps are a much more
> objective yardstick IMHO.
It's not true. My shop vac delivers 6.8 HP because it says so on the
sticker, and because it's printed on a sticker, it MUST be true. I also
have a 5 HP router that runs on batteries.
--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/
http://rosegarden.sourceforge.net/tutorial/
> 1) Would it make a big difference to use a 3/4 HP instead of a 1 HP?
Big, no, but more is better. 3/4 HP would be "tested" by significant
resawing but plenty for sawing wood in the thin direction.
> Is a smaller motor tend to break the blade more often ?
No, but it may bug down or stall it a really thick cut.
> 2) Digging a bit further, I saw another brand of bandsaw (King Industrial)
> where they don't show the HP but rather the amps : it was a 7.5 amps for
the
> 3/4 HP and 10 amps for the other. So as we know, Watts = Voltage x
> Intensity 120Vx7.5A=900W to convert it to HP = Watts x 0,00134. So a 7.5A
> gives 1.2 HP and a 10A gives 1.6 HP. I'm sure I missing something here, I
> would doubt very much that they gives so much HP for a small bandsaw like
> that. Any electrician in the croud ?
Not an electrician but.... Your math is essentially correct except 120 is
the nominal voltage household electricity. 110-115v is more realistic. Your
math does not account for the inefficiencies of the motor. 1HP motors tend
to be about 9-10 amps. HP ratings have been known to be stretched by the
marketing departments of some tool manufacturers. Amps are a much more
objective yardstick IMHO.
Steve
On Fri, 21 Jan 2005 20:17:54 -0500, "Junkyard Engineer"
<[email protected]> wrote:
>Ok, I've settled my choice on a delta 14". But in their catalog there is a
>3/4 & 1 HP model. So here's my 2 questions
>
>1) Would it make a big difference to use a 3/4 HP instead of a 1 HP ? Is a
>smaller motor tend to break the blade more often ?
Why would it break the blade more often? If you're going to be
resawing stock, go for the more powerful motor- if you're just going
to be cutting shapes in 4/4 lumber, then you'll do just fine with the
smaller.
Aut inveniam viam aut faciam
On Fri, 21 Jan 2005 20:17:54 -0500, "Junkyard Engineer"
<[email protected]> wrote:
>Any electrician in the croud ?
Ratings on cheap motors lie. As a measure of usable power, you're as
well off by weighing them.
All other things being equal, I'd pay a small amount extra to get the
bigger motor. But check if it's a standard fitting anyway (most are) -
you might be able to re-motor it quite simply anyway.
Along these lines, the sticker amount is the maximum HP or current at the
millisecond before the motor detonates into colourful red, orange and black
flames..
"Silvan" <[email protected]> wrote in message
news:[email protected]...
> C & S wrote:
>
> > tend to be about 9-10 amps. HP ratings have been known to be stretched
by
> > the marketing departments of some tool manufacturers. Amps are a much
more
> > objective yardstick IMHO.
>
> It's not true. My shop vac delivers 6.8 HP because it says so on the
> sticker, and because it's printed on a sticker, it MUST be true. I also
> have a 5 HP router that runs on batteries.
>
> --
> Michael McIntyre ---- Silvan <[email protected]>
> Linux fanatic, and certified Geek; registered Linux user #243621
> http://www.geocities.com/Paris/Rue/5407/
> http://rosegarden.sourceforge.net/tutorial/