Drill Press RPM's

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Date: 01 Nov 2006 14:32:27
From:
Subject: Drill Press RPM's

I received a drill press from a friend of mine. near as i can tell its
a "no-name" import one with 5 speeds. Problem is that it does not have
an RPM chart for adjusting the belt. I dont know which wheels are for
what speed. I was able to find out which is the fastest and which is
the slowest but beyond that I don't know what speeds they are. Is
there any way to find out? I didn't see any make or model info on the
drill itself but found the sticker/plate where it was most likely
attached :)
any ideas?
Thanks

Date: 01 Nov 2006 23:50:47
From: Leuf
Subject: Re: Drill Press RPM's

Date: 02 Nov 2006 06:05:16
From: Prometheus
Subject: Re: Drill Press RPM's

On Wed, 01 Nov 2006 23:50:47 -0500, Leuf <legend65@dontemailme.com >
wrote:

>On 1 Nov 2006 14:32:27 -0800, 1800rob@gmail.com wrote:
>
>>I received a drill press from a friend of mine. near as i can tell its
>>a "no-name" import one with 5 speeds. Problem is that it does not have
>>an RPM chart for adjusting the belt. I dont know which wheels are for
>>what speed. I was able to find out which is the fastest and which is
>>the slowest but beyond that I don't know what speeds they are. Is
>>there any way to find out? I didn't see any make or model info on the
>>drill itself but found the sticker/plate where it was most likely
>>attached :)
>>any ideas?
>
>Put it on the second slowest speed and leave it there. If you're
>doing something exotic there's about a 95% chance your slowest speed
>isn't slow enough anyway.

Second that- though I leave mine on the slowest speed. It gets used
for steel as well, so slowest is best in my case. Even though you
could jack up the speed for smaller bits in wood, I've never seen a
real advantage to that.

Date: 02 Nov 2006 04:35:00
From: Edwin Pawlowski
Subject: Re: Drill Press RPM's

Date: 01 Nov 2006 22:16:43
From:
Subject: Re: Drill Press RPM's

In article <1162420345.790704.224670@m7g2000cwm.googlegroups.com >,
<1800rob@gmail.com > wrote:
>I received a drill press from a friend of mine. near as i can tell its
>a "no-name" import one with 5 speeds. Problem is that it does not have
>an RPM chart for adjusting the belt. I dont know which wheels are for
>what speed. I was able to find out which is the fastest and which is
>the slowest but beyond that I don't know what speeds they are. Is
>there any way to find out? I didn't see any make or model info on the
>drill itself but found the sticker/plate where it was most likely
>attached :)
>any ideas?
>Thanks
>

It wouldn't be too hard to make your own chart. Either measure the
pulleys & calculate from that, or turn motor pulley by hand until
quill pulley has made a full turn. repeat for each pulley step
combination, a little division & multiplication, and there you are.
The motor is almost definitely 1750 RPM ut it should be on the motor
nameplate just to be sure.

If you need more detail post a question or you could find the
explanation on the web somewhere I'm sure.

--
Often wrong, never in doubt.

Larry Wasserman - Baltimore, Maryland - lwasserm@charm.net

Date: 01 Nov 2006 17:26:17
From:
Subject: Re: Drill Press RPM's

On 1 Nov 2006 14:32:27 -0800, 1800rob@gmail.com wrote:

>I received a drill press from a friend of mine. near as i can tell its
>a "no-name" import one with 5 speeds. Problem is that it does not have
>an RPM chart for adjusting the belt. I dont know which wheels are for
>what speed. I was able to find out which is the fastest and which is
>the slowest but beyond that I don't know what speeds they are. Is
>there any way to find out? I didn't see any make or model info on the
>drill itself but found the sticker/plate where it was most likely
>attached :)
>any ideas?
>Thanks

Won't be exact since you're not using pitch diameters of the pulleys
but will be close enough for practical application:

First measure (Dial or vernier outside calipers recommended) the
overall diameter of each step in each pulley. You could use the
diameters at the bottoms of the groove, but the ODs will be closer to
the pitch diameter and, therefore, more accurate, especially for the
smaller pulleys.

For each set of pulley steps, let:
A = Diameter of a step in the Motor Pulley
B = Diameter of the corresponding step in the Quill Pulley
M = Motor Speed - Probably either 1725 or 3450 rpm. Should be
stated on the motor's nameplate along with voltage, etc.
Q = Quill Speed

Then, Q = M * A/B when the belts are running in that particular set of
pulley steps.

With only 5 speeds, it's unlikely that you have two belts and a
stepped idler pulley like that on my Jet. But, if you do, then it's
slightly more complex.

Let everything be defined as before plus:

I = Speed of Idler Pulley
D = Diameter of the Idler pulley step corresponding to the Motor
Pulley A
E = Diameter of the idler pulley step corresponding to the Quill
Pulley B

Then I = M * A/D
And Q = I * E/B

Or, combining the two equations, and eliminating I,

Q = M * (A*E)/(D*B)

Hope this helps.

Date: 01 Nov 2006 22:41:06
From: bigegg
Subject: Re: Drill Press RPM's

1800rob@gmail.com wrote:
> I received a drill press from a friend of mine. near as i can tell its
> a "no-name" import one with 5 speeds. Problem is that it does not have
> an RPM chart for adjusting the belt. I dont know which wheels are for
> what speed. I was able to find out which is the fastest and which is
> the slowest but beyond that I don't know what speeds they are. Is
> there any way to find out? I didn't see any make or model info on the
> drill itself but found the sticker/plate where it was most likely
> attached :)
> any ideas?
> Thanks
>
Can you get in to measure all the wheels?

Is there a speed plate on the motor?

Spindle speed = Motor RPM X Driver Diameter
(divided by) Driven Diameter

Driver=wheel attached to motor
driven= wheel attached to spindle

It doesn't matter what units you measure the diameter of the wheels in,
as long as you measure both in the same units.

Most wheels I have seen are in whole inches.

If the drill uses gears, count the teeth on each gear, and use that
instead of the diameter.

motors are usually 1425 or 2850 rpm unless they are internally geared

--
BigEgg
Hack to size. Hammer to fit. Weld to join. Grind to shape. Paint to cover.
http://www.workshop-projects.com -
Plans and free books - *Now with forum*

Date: 01 Nov 2006 16:35:34
From: Chris Friesen
Subject: Re: Drill Press RPM's

1800rob@gmail.com wrote:
> I received a drill press from a friend of mine. near as i can tell its
> a "no-name" import one with 5 speeds. Problem is that it does not have
> an RPM chart for adjusting the belt. I dont know which wheels are for
> what speed. ... Is there any way to find out?

Measure the pulley diameters, work out the ratios for each combination,
multiply by motor speed.

Chris

Date: 01 Nov 2006 22:34:15
From: The3rd Earl Of Derby
Subject: Re: Drill Press RPM's

1800rob@gmail.com wrote:
> I received a drill press from a friend of mine. near as i can tell
> its a "no-name" import one with 5 speeds. Problem is that it does
> not have an RPM chart for adjusting the belt. I dont know which
> wheels are for what speed. I was able to find out which is the
> fastest and which is the slowest but beyond that I don't know what
> speeds they are. Is there any way to find out? I didn't see any
> make or model info on the drill itself but found the sticker/plate
> where it was most likely attached :)
> any ideas?
> Thanks

Is it not on the inside of the pullys housing lid?

--
Sir Benjamin Middlethwaite

Date: 02 Nov 2006 00:12:31
From: Nova
Subject: Re: Drill Press RPM's

1800rob@gmail.com wrote:

>I received a drill press from a friend of mine. near as i can tell
>its a "no-name" import one with 5 speeds. Problem is that it does
>not have an RPM chart for adjusting the belt. I dont know which
>wheels are for what speed. I was able to find out which is the
>fastest and which is the slowest but beyond that I don't know what
>speeds they are. Is there any way to find out? I didn't see any
>make or model info on the drill itself but found the sticker/plate
>where it was most likely attached :)
>any ideas?
>Thanks

A mechanical tachometer would give you a fairly accurate RPM reading.

--
Jack Novak
Buffalo, NY - USA
novasys@verizon.net

Date: 02 Nov 2006 12:21:04
From: Mike Marlow
Subject: Re: Drill Press RPM's

<1800rob@gmail.com > wrote in message
news:1162420345.790704.224670@m7g2000cwm.googlegroups.com...
> I received a drill press from a friend of mine. near as i can tell its
> a "no-name" import one with 5 speeds. Problem is that it does not have
> an RPM chart for adjusting the belt. I dont know which wheels are for
> what speed. I was able to find out which is the fastest and which is
> the slowest but beyond that I don't know what speeds they are. Is
> there any way to find out? I didn't see any make or model info on the
> drill itself but found the sticker/plate where it was most likely
> attached :)
> any ideas?
> Thanks
>

Well, let's see... I opened Mozilla, typed "drill press speed chart" into
the google search bar and came up with this and many other links.

<http://www.woodmagazine.com/wood/story.jhtml?storyid=/templatedata/wood/sto
ry/data/85.xml >

Hope this helps.

--

-Mike-
mmarlowREMOVE@alltel.net

Date: 02 Nov 2006 12:26:54
From: Mike Marlow
Subject: Re: Drill Press RPM's

"Mike Marlow" <mmarlow@alltel.net > wrote in message
news:91259$454a2918$45289638$26551@ALLTEL.NET...
>
> <1800rob@gmail.com> wrote in message
> news:1162420345.790704.224670@m7g2000cwm.googlegroups.com...
> > I received a drill press from a friend of mine. near as i can tell its
> > a "no-name" import one with 5 speeds. Problem is that it does not have
> > an RPM chart for adjusting the belt. I dont know which wheels are for
> > what speed. I was able to find out which is the fastest and which is
> > the slowest but beyond that I don't know what speeds they are. Is
> > there any way to find out? I didn't see any make or model info on the
> > drill itself but found the sticker/plate where it was most likely
> > attached :)
> > any ideas?
> > Thanks
> >
>
> Well, let's see... I opened Mozilla, typed "drill press speed chart" into
> the google search bar and came up with this and many other links.
>
>
<http://www.woodmagazine.com/wood/story.jhtml?storyid=/templatedata/wood/sto
> ry/data/85.xml>
>
> Hope this helps.
>

ARGH!!!!! Apparently I can't read today. The above is a completely
irrelevant reply.

So - do this. Measure the pulley on your motor. Then measure each of the
other pullies. Do the simple math to determine the ratio, then apply the
ratio to the motor speed.

--

-Mike-
mmarlowREMOVE@alltel.net

Date: 02 Nov 2006 07:39:27
From: John Martin
Subject: Re: Drill Press RPM's

On Nov 2, 9:12 am, spamb...@milmac.com (Doug Miller) wrote:
> In article <1162476016.857738.312...@e3g2000cwe.googlegroups.com>, "John Martin" <jmartin...@aol.com> wrote:
>
>
>
> >On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
>
> >> motors are usually 1425 or 2850 rpm unless they are internally geared
>
> >Well, I guess that depends on where you live. In the U.S., with 60
> >cycle current, they are generally 1725 or 3450 rpm.Can you explain why that is? 60 cycles per second = 3600 cycles per minute. So
> how come motors spin at 95.8% or 47.9% of the frequency of the AC supply,
> instead of 100% or 50%?
>
> --
> Regards,
> Doug Miller (alphageek at milmac dot com)
>

It's called slip. I won't try to explain it, as I'm not an electrical
engineer. If you really want to know about it, I'd suggest an EE
textbook.

John Martin

Date: 02 Nov 2006 06:00:17
From: John Martin
Subject: Re: Drill Press RPM's

On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com > wrote:
>
> motors are usually 1425 or 2850 rpm unless they are internally geared
>
> --
> BigEgg

Well, I guess that depends on where you live. In the U.S., with 60
cycle current, they are generally 1725 or 3450 rpm.

John Martin

Date: 02 Nov 2006 14:12:00
From: Doug Miller
Subject: Re: Drill Press RPM's

In article <1162476016.857738.312450@e3g2000cwe.googlegroups.com >, "John Martin" <jmartin957@aol.com> wrote:
>
>
>On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
>>
>> motors are usually 1425 or 2850 rpm unless they are internally geared
>
>Well, I guess that depends on where you live. In the U.S., with 60
>cycle current, they are generally 1725 or 3450 rpm.

Can you explain why that is? 60 cycles per second = 3600 cycles per minute. So
how come motors spin at 95.8% or 47.9% of the frequency of the AC supply,
instead of 100% or 50%?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Date: 02 Nov 2006 15:02:50
From: George
Subject: Re: Drill Press RPM's

"Doug Miller" <spambait@milmac.com > wrote in message
news:Q0n2h.98$Mw.30@newssvr11.news.prodigy.com...
> In article <1162476016.857738.312450@e3g2000cwe.googlegroups.com>, "John
> Martin" <jmartin957@aol.com> wrote:
>>
>>
>>On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
>>>
>>> motors are usually 1425 or 2850 rpm unless they are internally geared
>>
>>Well, I guess that depends on where you live. In the U.S., with 60
>>cycle current, they are generally 1725 or 3450 rpm.
>
> Can you explain why that is? 60 cycles per second = 3600 cycles per
> minute. So
> how come motors spin at 95.8% or 47.9% of the frequency of the AC supply,
> instead of 100% or 50%?
>

http://www.iprocessmart.com/leeson/leeson_singlephase_article.htm "Slip."

Date: 03 Nov 2006 05:23:51
From:
Subject: Re: Drill Press RPM's

In article <Q0n2h.98$Mw.30@newssvr11.news.prodigy.com >,
Doug Miller <spambait@milmac.com > wrote:
>In article <1162476016.857738.312450@e3g2000cwe.googlegroups.com>, "John
>Martin" <jmartin957@aol.com> wrote:
>>
>>
>>On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
>>>
>>> motors are usually 1425 or 2850 rpm unless they are internally geared
>>
>>Well, I guess that depends on where you live. In the U.S., with 60
>>cycle current, they are generally 1725 or 3450 rpm.
>
>Can you explain why that is? 60 cycles per second = 3600 cycles
per minute. So
>how come motors spin at 95.8% or 47.9% of the frequency of the AC supply,
>instead of 100% or 50%?
>
>--
>Regards,
> Doug Miller (alphageek at milmac dot com)
>
>It's time to throw all their damned tea in the harbor again.

I'm going to oversimplify a bit here but here's the basic idea:

In a conventional induction motor, the stator creates a magnetic
field that "rotates" around the rotor. As the field crosses the rotor,
it induces a current in the rotor, which causes the rotor to develop
its own magnetic field. The rotor field is attracted & repelled by the
rotating stator field and causes the rotor to turn. Here's the part
that you need to wrap your mind around: The stator field rotates or
fluctuates according to line frequency. If the rotor rotates at the
RPM that the line frequency would indicate, then the stator magnetic
field would not cross the rotor windings, because as the stator field
rotated, the rotor would be rotating right along with it. Since there
would then be no induced current or magnetic field in the rotor, the
motor would be operating at 0 (zero) torque.

Of course there is always some load on a motor, even when not
connected to anything there is some drag in the bearings. So the load
tends to slow down the rotor, which means that the stator mag field
starts crossing the rotor more frequently, inducing more current, etc.

The speed listed on a motor data plate is the RPM at full load. A 1.5
hp table saw motor, for instance , might spin at "almost" 3600
RPM when it's just sitting there running. But when you start ripping
some 8/4 maple, it slows down, draws more current and produces more
torque. At it's full design load, it might be spinning at say 3450
RPM.

Now, there is a type of motor called a "synchronous" motor and it does
rotate at synchronous speed. Unlike an induction motor, though, a
synch. motor has DC current supplied to windings in the rotor to
create fixed magnetic fields, relative to the rotor. Theoretically
permanent magnets could be used. These synchronous motors are usually
3 phase, and the stator windings are arranged more or less the same as
in an induction motor, causing a rotating magnetic field. Instead of
depending on this field inducing current and a magnetic field in the
rotor, though, the magnetic fields of the rotor want to chase
the rotating stator field around. No induction is required to generate
the rotor field, so the rotor doesn't "slip" like it does in an
induction motor.

--
Often wrong, never in doubt.

Larry Wasserman - Baltimore, Maryland - lwasserm@charm.net

Date: 02 Nov 2006 19:53:25
From: bigegg
Subject: Re: Drill Press RPM's

John Martin wrote:
>
> On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
>> motors are usually 1425 or 2850 rpm unless they are internally geared

> Well, I guess that depends on where you live. In the U.S., with 60
> cycle current, they are generally 1725 or 3450 rpm.
>
> John Martin
>

oh bum

I fergot that bit

ta!

--
BigEgg
Hack to size. Hammer to fit. Weld to join. Grind to shape. Paint to cover.
http://www.workshop-projects.com -
Plans and free books - *Now with forum*

Date: 02 Nov 2006 16:41:25
From:
Subject: Re: Drill Press RPM's

barry@sme-online.com wrote:
> Doug Miller wrote:
> > In article <1162476016.857738.312450@e3g2000cwe.googlegroups.com>, "John Martin" <jmartin957@aol.com> wrote:
> > >
> > >
> > >On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
> > >>
> > >> motors are usually 1425 or 2850 rpm unless they are internally geared
> > >
> > >Well, I guess that depends on where you live. In the U.S., with 60
> > >cycle current, they are generally 1725 or 3450 rpm.
> >
> > Can you explain why that is? 60 cycles per second = 3600 cycles per minute. So
> > how come motors spin at 95.8% or 47.9% of the frequency of the AC supply,
> > instead of 100% or 50%?

> 'Tis so for induction motors, not synchronous.

To make a synchronous motor, the rotor is a permanent magnet (or
polarized electromagnet).
Permanent magnet has problems: it's weaker than electromagnets, and
iron bits
get caught in the works.
Polarized electromagnet has problems: you have to provide current to
the rotor, and
it's harder to make balanced than a simple lump of iron.

So, you use a lump of iron (with some addons, lamination and conductive
rivets), and
it gets magnetized by the stator. When the motor is asked to do hard
work, the magnetic
field lags the stator field (if it didn't lag, there would be no
torque), and when the motor
is fully loaded (and about to reach thermal or other limits) it's
typically
five percent phase lag, i.e. 95% of the speed of a synchronous motor.
A synchronous motor would also have a phase lag, but it doesn't
re-imprint the
magnetic field of the stator onto the rotor, so the lag doesn't
remagnetize the rotor
and it isn't usually the rotor part of a synchronous motor that burns
up at stall...

Date: 02 Nov 2006 12:56:39
From:
Subject: Re: Drill Press RPM's

Doug Miller wrote:
> In article <1162476016.857738.312450@e3g2000cwe.googlegroups.com>, "John Martin" <jmartin957@aol.com> wrote:
> >
> >
> >On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
> >>
> >> motors are usually 1425 or 2850 rpm unless they are internally geared
> >
> >Well, I guess that depends on where you live. In the U.S., with 60
> >cycle current, they are generally 1725 or 3450 rpm.
>
> Can you explain why that is? 60 cycles per second = 3600 cycles per minute. So
> how come motors spin at 95.8% or 47.9% of the frequency of the AC supply,
> instead of 100% or 50%?
>
> --
> Regards,
> Doug Miller (alphageek at milmac dot com)
>
> It's time to throw all their damned tea in the harbor again.

'Tis so for induction motors, not synchronous. Stator windings induce
magnetic
field in rotor. Field in stator rotates, in effect, and line freq. With
no load, rotor
essentially does same. With increased load, rotor speed droops from
no-load.

In engineering classes, arm-waving was used to explain why.

J

Date: 02 Nov 2006 23:23:29
From: Doug Miller
Subject: Re: Drill Press RPM's

In article <1162500999.730566.34470@e3g2000cwe.googlegroups.com >, barry@sme-online.com wrote:
>
>Doug Miller wrote:
>> In article <1162476016.857738.312450@e3g2000cwe.googlegroups.com>, "John
> Martin" <jmartin957@aol.com> wrote:
>> >
>> >
>> >On Nov 1, 5:41 pm, bigegg <n...@hardboiled.plus.com> wrote:
>> >> motors are usually 1425 or 2850 rpm unless they are internally geared

>> >Well, I guess that depends on where you live. In the U.S., with 60
>> >cycle current, they are generally 1725 or 3450 rpm.
>>
>> Can you explain why that is? 60 cycles per second = 3600 cycles per minute. So
>> how come motors spin at 95.8% or 47.9% of the frequency of the AC supply,
>> instead of 100% or 50%?

>'Tis so for induction motors, not synchronous. Stator windings induce
>magnetic field in rotor. Field in stator rotates, in effect, and line freq. With
>no load, rotor essentially does same. With increased load, rotor speed droops from
>no-load.

OK, thanks -- that helps.
>
>In engineering classes, arm-waving was used to explain why.

Arm-waving is used to explain *lots* of things in engineering classes...

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.