I was gifted a basic ("Professional Woodworker" brand) lathe with a
dead 3/4 horse motor. I have an old Dayton 3/4 horse motor (which is
much bigger and heavier than the one in the lathe) which I'd like to
use for the lathe, but the spindle on the "new" replacement motor is
maybe 1/16" too large for the pulley from the dead motor.
How should I go about getting the pulley on the motor? Should I crank
up the motor and just use sandpaper on the spindle until the pulley
fits or what? I'm hesitant to try to drill out the pulley because I
don't want to make the hole off center and ruin a mostly irreplaceable
part.
Also, since the "new" motor is so much larger than the dead one, I
have to relocate the motor to below the lathe's motor enclosure...
would one of those link belts be a good option for connecting the
pulleys or should I just go to an auto parts store and try to find an
appropriate size belt there?
Thanks!
Nathan
On Sep 10, 9:53=A0pm, dpb <[email protected]> wrote:
> N Hurst wrote:
>
> ...
>
> > ... but the spindle on the "new" replacement motor is
> > maybe 1/16" too large for the pulley from the dead motor.
>
> > How should I go about getting the pulley on the motor? ...
>
> Purchase a pulley of the proper diameter and bore.
>
> Did the original motor run at the same rpm as the replacment?
>
> ...
>
> > have to relocate the motor to below the lathe's motor enclosure...
> > would one of those link belts be a good option for connecting the
> > pulleys or should I just go to an auto parts store and try to find an
> > appropriate size belt there?
>
> Either way would work...
>
> --
I hate to double post, but I found someone with a Craigslist ad for
the same lathe I picked up:
http://phoenix.craigslist.org/wvl/tls/803909507.html
On Thu, 11 Sep 2008 18:56:25 -0700 (PDT), N Hurst <[email protected]>
wrote:
>The only 4 step pulleys I can find have minimum sizes ranging from
>1/4" larger than the original at the smallest step to 1/2" larger at
>the largest step. I know that will yield a higher overall rotation
>speed, but does anyone out there think it will be any more dangerous
>than otherwise?
You'll probably be OK. The important thing is the Pitch Diameter for
the belt section you'll be using and that's not obvious from the OD.
It depends on where the belt rides in the groove.
>
>Also, after measuring, I discovered that the original pulley bore is
>1.5cm! I'm glad I came here for help, because I hadn't even thought
>about this thing being metric! The pulley steps on the original are 4,
>5, 6, and 7 cm, and the replacement ones will be 1-3/4", 2-1/4",
>2-3/4", and 3-1/4".
>
>-Nathan
You sure about the 1.5 cm measurement? The closest I see to that in
the IEC frame charts is a 71 frame with a 14 mm shaft.
Tom Veatch
Wichita, KS
USA
"N Hurst" <[email protected]> wrote in message
news:0b4d3828-8ad1-4bdb-b082-43133704a684@j22g2000hsf.googlegroups.com...
>I was gifted a basic ("Professional Woodworker" brand) lathe with a
> dead 3/4 horse motor. I have an old Dayton 3/4 horse motor (which is
> much bigger and heavier than the one in the lathe) which I'd like to
> use for the lathe, but the spindle on the "new" replacement motor is
> maybe 1/16" too large for the pulley from the dead motor.
>
> How should I go about getting the pulley on the motor? Should I crank
> up the motor and just use sandpaper on the spindle until the pulley
> fits or what? I'm hesitant to try to drill out the pulley because I
> don't want to make the hole off center and ruin a mostly irreplaceable
> part.
>
> Also, since the "new" motor is so much larger than the dead one, I
> have to relocate the motor to below the lathe's motor enclosure...
> would one of those link belts be a good option for connecting the
> pulleys or should I just go to an auto parts store and try to find an
> appropriate size belt there?
>
> Thanks!
> Nathan
Have you looked into having the old motor repaired?
On Sep 12, 9:01=A0am, "Leon" <[email protected]> wrote:
> "N Hurst" <[email protected]> wrote in message
>
> news:0b4d3828-8ad1-4bdb-b082-43133704a684@j22g2000hsf.googlegroups.com...
>
>
>
> >I was gifted a basic ("Professional Woodworker" brand) lathe with a
> > dead 3/4 horse motor. =A0I have an old Dayton 3/4 horse motor (which is
> > much bigger and heavier than the one in the lathe) which I'd like to
> > use for the lathe, but the spindle on the "new" replacement motor is
> > maybe 1/16" too large for the pulley from the dead motor.
>
> > How should I go about getting the pulley on the motor? Should I crank
> > up the motor and just use sandpaper on the spindle until the pulley
> > fits or what? I'm hesitant to try to drill out the pulley because I
> > don't want to make the hole off center and ruin a mostly irreplaceable
> > part.
>
> > Also, since the "new" motor is so much larger than the dead one, I
> > have to relocate the motor to below the lathe's motor enclosure...
> > would one of those link belts be a good option for connecting the
> > pulleys or should I just go to an auto parts store and try to find an
> > appropriate size belt there?
>
> > Thanks!
> > Nathan
>
> Have you looked into having the old motor repaired?
No, I haven't. I'm not sure it would be worth it. It's not a very
impressive specimen, and I think it would probably cost me more than
$20 to have repaired, which is what a new belt and pulley would cost
me.
Here's a photo of the old motor and the "new" one, side by side:
http://img169.imageshack.us/my.php?image=3Ddsc00013mediumng9.jpg
Something tells me that the 3/4 hp I'd get from the Dayton brand motor
would be better than the 3/4 hp the unbranded one would give me.
I was under the impression that small motor repair was generally a
comparatively expensive proposition. If I'm going to be out around
$20, wouldn't it be better to have a more robust motor driving things
than repair something that's already broken down once?
And to Tom:
I'm not 100% sure on my measurements. I've been using the "inside the
house" tape measure, which sometimes doubles as a toy for my 2 year
old son, so you're most likely right in that it's 14mm. I would hope
the motor would have that information on it, but I'm learning to not
expect too much from these cheap imports. :-)
-Nathan
On Sep 10, 11:51=A0pm, dpb <[email protected]> wrote:
> N Hurst wrote:
> > On Sep 10, 9:53 pm, dpb <[email protected]> wrote:
> >> Purchase a pulley of the proper diameter and bore.
>
> > Any recommendations on where to go for one?
>
> Local hardware for a start, motor shops and/or auto parts places and
> other industrial distributors.
>
> There's always the online route of McMaster-Carr, Grainger, et al, but
> ordinary items like this shouldn't be any problem locally.
>
> > Rather than a flat side section on the spindle like most motors I've
> > seen, my motor has a notch cut out of the spindle in which a small
> > square metal peg was inserted.
>
> That's typical keyed way -- more than likely 3/16". =A0Key stock or precu=
t
> keys are a dime at the hardware store or may well come w/ the pulley.
>
>
>
> >> Did the original motor run at the same rpm as the replacment?
>
> ...
> > ... The replacement is a 1750rpm, and I'm pretty sure a machine of
> > this level wouldn't spin at the 3000rpm mark.
>
> That's why I asked -- if you had a common 3450 rpm motor, I was betting
> the original was likely 1725.
>
> --
The only 4 step pulleys I can find have minimum sizes ranging from
1/4" larger than the original at the smallest step to 1/2" larger at
the largest step. I know that will yield a higher overall rotation
speed, but does anyone out there think it will be any more dangerous
than otherwise?
Also, after measuring, I discovered that the original pulley bore is
1.5cm! I'm glad I came here for help, because I hadn't even thought
about this thing being metric! The pulley steps on the original are 4,
5, 6, and 7 cm, and the replacement ones will be 1-3/4", 2-1/4",
2-3/4", and 3-1/4".
-Nathan
On Sep 10, 9:53=A0pm, dpb <[email protected]> wrote:
> Purchase a pulley of the proper diameter and bore.
Any recommendations on where to go for one?
Rather than a flat side section on the spindle like most motors I've
seen, my motor has a notch cut out of the spindle in which a small
square metal peg was inserted.
> Did the original motor run at the same rpm as the replacment?
I have no idea. There is no plate of any kind on the original motor,
and aftermarket support of this brand of machine appears to be pretty
slim. The replacement is a 1750rpm, and I'm pretty sure a machine of
this level wouldn't spin at the 3000rpm mark.
N Hurst wrote:
...
> ... but the spindle on the "new" replacement motor is
> maybe 1/16" too large for the pulley from the dead motor.
>
> How should I go about getting the pulley on the motor? ...
Purchase a pulley of the proper diameter and bore.
Did the original motor run at the same rpm as the replacment?
...
> have to relocate the motor to below the lathe's motor enclosure...
> would one of those link belts be a good option for connecting the
> pulleys or should I just go to an auto parts store and try to find an
> appropriate size belt there?
Either way would work...
--
N Hurst wrote:
> On Sep 10, 9:53 pm, dpb <[email protected]> wrote:
>> Purchase a pulley of the proper diameter and bore.
>
> Any recommendations on where to go for one?
Local hardware for a start, motor shops and/or auto parts places and
other industrial distributors.
There's always the online route of McMaster-Carr, Grainger, et al, but
ordinary items like this shouldn't be any problem locally.
> Rather than a flat side section on the spindle like most motors I've
> seen, my motor has a notch cut out of the spindle in which a small
> square metal peg was inserted.
That's typical keyed way -- more than likely 3/16". Key stock or precut
keys are a dime at the hardware store or may well come w/ the pulley.
>> Did the original motor run at the same rpm as the replacment?
>
...
> ... The replacement is a 1750rpm, and I'm pretty sure a machine of
> this level wouldn't spin at the 3000rpm mark.
That's why I asked -- if you had a common 3450 rpm motor, I was betting
the original was likely 1725.
--
N Hurst wrote:
> On Sep 10, 11:51 pm, dpb <[email protected]> wrote:
>> N Hurst wrote:
>>> On Sep 10, 9:53 pm, dpb <[email protected]> wrote:
>>>> Purchase a pulley of the proper diameter and bore.
>>> Any recommendations on where to go for one?
>> Local hardware for a start, motor shops and/or auto parts places and
>> other industrial distributors.
>>
>> There's always the online route of McMaster-Carr, Grainger, et al, but
>> ordinary items like this shouldn't be any problem locally.
>>
>>> Rather than a flat side section on the spindle like most motors I've
>>> seen, my motor has a notch cut out of the spindle in which a small
>>> square metal peg was inserted.
>> That's typical keyed way -- more than likely 3/16". Key stock or precut
>> keys are a dime at the hardware store or may well come w/ the pulley.
>>
>>
>>
>>>> Did the original motor run at the same rpm as the replacment?
>> ...
>>> ... The replacement is a 1750rpm, and I'm pretty sure a machine of
>>> this level wouldn't spin at the 3000rpm mark.
>> That's why I asked -- if you had a common 3450 rpm motor, I was betting
>> the original was likely 1725.
>>
>> --
>
> The only 4 step pulleys I can find have minimum sizes ranging from
> 1/4" larger than the original at the smallest step to 1/2" larger at
> the largest step. I know that will yield a higher overall rotation
> speed, but does anyone out there think it will be any more dangerous
> than otherwise?
>
> Also, after measuring, I discovered that the original pulley bore is
> 1.5cm! I'm glad I came here for help, because I hadn't even thought
> about this thing being metric! The pulley steps on the original are 4,
> 5, 6, and 7 cm, and the replacement ones will be 1-3/4", 2-1/4",
> 2-3/4", and 3-1/4".
The speed difference will be the ratio of the diameters--I didn't do 'em
all, but the first is roughly 11%; I wouldn't worry at that difference.
The other choice still, of course, is to get the existing pulley rebored
at a machine shop--depending on whether you have a local kind-hearted
retiree w/ a shop in his basement you might get it done pretty
inexpensively; commercial shops tend to be pretty pricey.
--
On Wed, 10 Sep 2008 19:16:35 -0700 (PDT), N Hurst <[email protected]>
wrote:
>On Sep 10, 9:53 pm, dpb <[email protected]> wrote:
>> Purchase a pulley of the proper diameter and bore.
>
>Any recommendations on where to go for one?
http://www.mcmaster.com/ (my preferred online "go to")
http://www.grainger.com (my preferred local "go to")
http://www.mscdirect.com
http://www.grizzly.com
etc.
or do a Google search for "sheave" any your city location and it may
bring up some local outlets.
>
>Rather than a flat side section on the spindle like most motors I've
>seen, my motor has a notch cut out of the spindle in which a small
>square metal peg was inserted.
>
A square key fits in the notch and mates with a similar notch in the
sheave to prevent the sheave spinning on the shaft. If you check the
motor dataplate, find the frame size, and compare it to the entries in
a NEMA frame chart, it will give you the diameter of the shaft and the
dimensions of the notch. Or, since the key slots are standardized
based on the shaft diameter, you can just get one that matches from
the same place you get the sheave.
For example a motor with a NEMA 56 frame has a 5/8 dia shaft which
takes a 3/16 square key. See for example:
http://www.electricmotorwarehouse.com/PDF/NEMA.pdf
Any keyed sheave/pulley fitting that shaft would also have a 3/16
keyway. Here's an example
http://www.grainger.com/Grainger/items/3X896
Note the description and specs indicate that the sheave has a keyway.
A 12" length of 3/16 keystock from Grainger is about 95 cents if you
want to cut your own.
Tom Veatch
Wichita, KS
USA