I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds . Problem is
that I think it might spin too fast , and I may need to slow it down . I can
use smaller rollers on the shafts (2 , parallel and both turned by a chain
drive) to slow it some , but might need to lower the input RPM's . Currently
has a 1/3 hp split phase motor turning at 1725 - is there any way to speed
control that motor short of changing the input frequency ? Other choices may
be a smaller motor sprocket , or maybe an inline (planetary?) gear reduction
unit or v belt and jackshaft arrangement . Could also change out to a
universal or DC motor and appropriate control system , or use a 3 speed fan
motor I have on hand . But speed control of the current motor would be the
easiest and cheapest ...

--
Snag

On Fri, 7 Oct 2016 20:52:54 -0500, "Terry Coombs"
wrote:

I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds . Problem is
that I think it might spin too fast , and I may need to slow it down . I can
use smaller rollers on the shafts (2 , parallel and both turned by a chain
drive) to slow it some , but might need to lower the input RPM's . Currently
has a 1/3 hp split phase motor turning at 1725 - is there any way to speed
control that motor short of changing the input frequency ? Other choices may
be a smaller motor sprocket , or maybe an inline (planetary?) gear reduction
unit or v belt and jackshaft arrangement . Could also change out to a
universal or DC motor and appropriate control system , or use a 3 speed fan
motor I have on hand . But speed control of the current motor would be the
easiest and cheapest ...
VFD.

On 2016-10-08, Terry Coombs wrote:
I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds . Problem is
that I think it might spin too fast , and I may need to slow it down . I can
use smaller rollers on the shafts (2 , parallel and both turned by a chain
drive) to slow it some , but might need to lower the input RPM's . Currently
has a 1/3 hp split phase motor turning at 1725 - is there any way to speed
control that motor short of changing the input frequency ?

Speed control of such a motor by frequency is not likely to work
over much of a range. Yes, a 60 Hz motor on 50 Hz runs slower -- and is
closer to saturation.

And the functionality of the motor depends on matching of the
run capacitor's value to the frequency. If you had a VFD locked to a
specific frequency, you could likely adjust the run capacitor for
reasonable performance -- but don't expect to just reach out and adjust a
pot to change the speed over a wide range.

Note that 1725 is not the slowest induction motor on a 60 Hz
line. The next speed down is about 1150 RPM, then about 875 RPM
depending on the number of poles. 2-pole is somewhere short of 3600
RPM, 4-pole is short of 1800 RPM (your 1725), 6-pole is short of 1200
RPM, and 8-pole is short of 900 RPM (see examples above -- loss of
speed is due to slip).

Other choices may
be a smaller motor sprocket , or maybe an inline (planetary?) gear reduction
unit or v belt and jackshaft arrangement . Could also change out to a
universal or DC motor and appropriate control system , or use a 3 speed fan
motor I have on hand .

3-speed fan motors depend on the load of the fan blades or
squirrel cage fighting the input current modified by the number of turns
in the selected winding. In your application, it would likely run close
to full speed on all three windings.

A universal motor, on a dimmer would likely work fairly well for
your application. And at a slower speed, you likely would not need the
full 1/3 HP. Instead of the dimmer, a Variac or Powerstat (variable
autotransformer) would work better -- but they are significantly more
expensive.

But speed control of the current motor would be the
easiest and cheapest ...

Cheapest, yes -- but unfortunately, not easy.

Are you sure that it is currently too fast to do what you want?
Try it first, to see how it does. That could be the cheapest way to do
this.

Good luck,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Fri, 07 Oct 2016 23:07:43 -0400, wrote:

On Fri, 7 Oct 2016 20:52:54 -0500, "Terry Coombs"
wrote:

I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds . Problem is
that I think it might spin too fast , and I may need to slow it down . I can
use smaller rollers on the shafts (2 , parallel and both turned by a chain
drive) to slow it some , but might need to lower the input RPM's . Currently
has a 1/3 hp split phase motor turning at 1725 - is there any way to speed
control that motor short of changing the input frequency ? Other choices may
be a smaller motor sprocket , or maybe an inline (planetary?) gear reduction
unit or v belt and jackshaft arrangement . Could also change out to a
universal or DC motor and appropriate control system , or use a 3 speed fan
motor I have on hand . But speed control of the current motor would be the
easiest and cheapest ...
VFD.

Not if its a single phase motor, and finding small 3ph motors under
1/2 hp can be problematic.

A DC motor and drive may be his easiest and likely cheapest bet. There
are surplus places that sell both as sets for under $50, last time I
went looking for one for another application.


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

DoN. Nichols wrote:
On 2016-10-08, Terry Coombs wrote:
I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds .
Problem is that I think it might spin too fast , and I may need to
slow it down . I can use smaller rollers on the shafts (2 , parallel
and both turned by a chain drive) to slow it some , but might need
to lower the input RPM's . Currently has a 1/3 hp split phase motor
turning at 1725 - is there any way to speed control that motor short
of changing the input frequency ?

Speed control of such a motor by frequency is not likely to work
over much of a range. Yes, a 60 Hz motor on 50 Hz runs slower -- and
is closer to saturation.

And the functionality of the motor depends on matching of the
run capacitor's value to the frequency. If you had a VFD locked to a
specific frequency, you could likely adjust the run capacitor for
reasonable performance -- but don't expect to just reach out and
adjust a pot to change the speed over a wide range.

Note that 1725 is not the slowest induction motor on a 60 Hz
line. The next speed down is about 1150 RPM, then about 875 RPM
depending on the number of poles. 2-pole is somewhere short of 3600
RPM, 4-pole is short of 1800 RPM (your 1725), 6-pole is short of 1200
RPM, and 8-pole is short of 900 RPM (see examples above -- loss of
speed is due to slip).

Other
choices may be a smaller motor sprocket , or maybe an inline
(planetary?) gear reduction unit or v belt and jackshaft arrangement
. Could also change out to a universal or DC motor and appropriate
control system , or use a 3 speed fan motor I have on hand .

3-speed fan motors depend on the load of the fan blades or
squirrel cage fighting the input current modified by the number of
turns in the selected winding. In your application, it would likely
run close to full speed on all three windings.

A universal motor, on a dimmer would likely work fairly well for
your application. And at a slower speed, you likely would not need
the full 1/3 HP. Instead of the dimmer, a Variac or Powerstat
(variable autotransformer) would work better -- but they are
significantly more expensive.

But speed control of the current motor would
be the easiest and cheapest ...

Cheapest, yes -- but unfortunately, not easy.

Are you sure that it is currently too fast to do what you want?
Try it first, to see how it does. That could be the cheapest way to
do this.

Good luck,
DoN.

I'll need to put the finishing touches on one of my drums and load it
with some lead balls to see , but I suspect it is . The 3 speed fan motor I
have is I think a 1/4 hp , has all the controls attached , and should work
fine . It's OK , this motor will work for a couple of other projects I have
in mind for the future .
--
Snag

"Terry Coombs" fired this volley in
:

I'll need to put the finishing touches on one of my drums and load
it
with some lead balls to see , but I suspect it is . The 3 speed fan
motor I have is I think a 1/4 hp , has all the controls attached , and
should work fine . It's OK , this motor will work for a couple of
other projects I have in mind for the future .

Terry, from my book on ball milling (but also an industry-standard), the
speed of a dry ball mill should be about this:

RPM=0.65 * (265.45/sqrt(jar_id"-ball_od")

That's expressed in inches for the id/od figures.

That speed ensures adequate 'slump angle'to ensure the media falls as far
as possible with as many strikes as possible on the way down, while not
centrifuging the media out to the jar walls. It also presumes that the
jar is 50% full of media, with a material charge equal to 25% of the
empty jar's volume.

LLoyd

Lloyd E. Sponenburgh wrote:
"Terry Coombs" fired this volley in
:

I'll need to put the finishing touches on one of my drums and
load it
with some lead balls to see , but I suspect it is . The 3 speed fan
motor I have is I think a 1/4 hp , has all the controls attached ,
and should work fine . It's OK , this motor will work for a couple of
other projects I have in mind for the future .

Terry, from my book on ball milling (but also an industry-standard),
the speed of a dry ball mill should be about this:

RPM=0.65 * (265.45/sqrt(jar_id"-ball_od")

That's expressed in inches for the id/od figures.

That speed ensures adequate 'slump angle'to ensure the media falls as
far as possible with as many strikes as possible on the way down,
while not centrifuging the media out to the jar walls. It also
presumes that the jar is 50% full of media, with a material charge
equal to 25% of the empty jar's volume.

LLoyd

Thanks Lloyd , by that calculation I need about 143 RPM . I'll have to
check the chain drive ratio and figure the FPM of the roller shafts to see
what I'm getting from it now . It might not be too fast after all .
--
Snag

On Sat, 8 Oct 2016 06:40:59 -0500, "Terry Coombs"
wrote:

DoN. Nichols wrote:
On 2016-10-08, Terry Coombs wrote:
I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds .
Problem is that I think it might spin too fast , and I may need to
slow it down . I can use smaller rollers on the shafts (2 , parallel
and both turned by a chain drive) to slow it some , but might need
to lower the input RPM's . Currently has a 1/3 hp split phase motor
turning at 1725 - is there any way to speed control that motor short
of changing the input frequency ?

Speed control of such a motor by frequency is not likely to work
over much of a range. Yes, a 60 Hz motor on 50 Hz runs slower -- and
is closer to saturation.

And the functionality of the motor depends on matching of the
run capacitor's value to the frequency. If you had a VFD locked to a
specific frequency, you could likely adjust the run capacitor for
reasonable performance -- but don't expect to just reach out and
adjust a pot to change the speed over a wide range.

Note that 1725 is not the slowest induction motor on a 60 Hz
line. The next speed down is about 1150 RPM, then about 875 RPM
depending on the number of poles. 2-pole is somewhere short of 3600
RPM, 4-pole is short of 1800 RPM (your 1725), 6-pole is short of 1200
RPM, and 8-pole is short of 900 RPM (see examples above -- loss of
speed is due to slip).

Other
choices may be a smaller motor sprocket , or maybe an inline
(planetary?) gear reduction unit or v belt and jackshaft arrangement
. Could also change out to a universal or DC motor and appropriate
control system , or use a 3 speed fan motor I have on hand .

3-speed fan motors depend on the load of the fan blades or
squirrel cage fighting the input current modified by the number of
turns in the selected winding. In your application, it would likely
run close to full speed on all three windings.

A universal motor, on a dimmer would likely work fairly well for
your application. And at a slower speed, you likely would not need
the full 1/3 HP. Instead of the dimmer, a Variac or Powerstat
(variable autotransformer) would work better -- but they are
significantly more expensive.

But speed control of the current motor would
be the easiest and cheapest ...

Cheapest, yes -- but unfortunately, not easy.

Are you sure that it is currently too fast to do what you want?
Try it first, to see how it does. That could be the cheapest way to
do this.

Good luck,
DoN.

I'll need to put the finishing touches on one of my drums and load it
with some lead balls to see , but I suspect it is . The 3 speed fan motor I
have is I think a 1/4 hp , has all the controls attached , and should work
fine . It's OK , this motor will work for a couple of other projects I have
in mind for the future .

Larger drum pulley and smaller motor pulley (sprockets?) would be the
cheapest for you. You can make 'em if you don't already have 'em.
Gear it down with stepped pulleys if you need some speed variability.
A plain ol' serpentine belt may work on a small motor pulley and
around the bare drum, too, but you may get perhaps months instead of
years of life out of it that way, depending on usage. I've seen a
makeshift concrete mixer and several rock tumblers done this way over
the years. My old wood lathe has a 1/4hp motor hung on a loose bolt
with its own weight keeping the belt tight, but it has 3-step pulleys.

--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

Larry Jaques wrote:


Larger drum pulley and smaller motor pulley (sprockets?) would be the
cheapest for you. You can make 'em if you don't already have 'em.
Gear it down with stepped pulleys if you need some speed variability.
A plain ol' serpentine belt may work on a small motor pulley and
around the bare drum, too, but you may get perhaps months instead of
years of life out of it that way, depending on usage. I've seen a
makeshift concrete mixer and several rock tumblers done this way over
the years. My old wood lathe has a 1/4hp motor hung on a loose bolt
with its own weight keeping the belt tight, but it has 3-step pulleys.

I guess a description of this power unit is needed ... There is a pair of
rods with rollers , motor below . The rods are driven by a chain and
sprocket arrangement at one end of the unit . In use the drum is cradled on
the rollers and driven by them .
Here's an ebay listing for one that is similar in function - just put a
chain drive under a cover on one end instead of the belts .
http://www.ebay.com/itm/Diamond-Paci...-/262525104831
--
Snag

On 08/10/16 16:13, Larry Jaques wrote:
On Sat, 8 Oct 2016 06:40:59 -0500, "Terry Coombs"
wrote:

DoN. Nichols wrote:
On 2016-10-08, Terry Coombs wrote:
I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds .
Problem is that I think it might spin too fast , and I may need to
slow it down . I can use smaller rollers on the shafts (2 , parallel
and both turned by a chain drive) to slow it some , but might need
to lower the input RPM's . Currently has a 1/3 hp split phase motor
turning at 1725 - is there any way to speed control that motor short
of changing the input frequency ?
Speed control of such a motor by frequency is not likely to work
over much of a range. Yes, a 60 Hz motor on 50 Hz runs slower -- and
is closer to saturation.

And the functionality of the motor depends on matching of the
run capacitor's value to the frequency. If you had a VFD locked to a
specific frequency, you could likely adjust the run capacitor for
reasonable performance -- but don't expect to just reach out and
adjust a pot to change the speed over a wide range.

Note that 1725 is not the slowest induction motor on a 60 Hz
line. The next speed down is about 1150 RPM, then about 875 RPM
depending on the number of poles. 2-pole is somewhere short of 3600
RPM, 4-pole is short of 1800 RPM (your 1725), 6-pole is short of 1200
RPM, and 8-pole is short of 900 RPM (see examples above -- loss of
speed is due to slip).

Other
choices may be a smaller motor sprocket , or maybe an inline
(planetary?) gear reduction unit or v belt and jackshaft arrangement
. Could also change out to a universal or DC motor and appropriate
control system , or use a 3 speed fan motor I have on hand .
3-speed fan motors depend on the load of the fan blades or
squirrel cage fighting the input current modified by the number of
turns in the selected winding. In your application, it would likely
run close to full speed on all three windings.

A universal motor, on a dimmer would likely work fairly well for
your application. And at a slower speed, you likely would not need
the full 1/3 HP. Instead of the dimmer, a Variac or Powerstat
(variable autotransformer) would work better -- but they are
significantly more expensive.

But speed control of the current motor would
be the easiest and cheapest ...
Cheapest, yes -- but unfortunately, not easy.

Are you sure that it is currently too fast to do what you want?
Try it first, to see how it does. That could be the cheapest way to
do this.

Good luck,
DoN.
I'll need to put the finishing touches on one of my drums and load it
with some lead balls to see , but I suspect it is . The 3 speed fan motor I
have is I think a 1/4 hp , has all the controls attached , and should work
fine . It's OK , this motor will work for a couple of other projects I have
in mind for the future .
Larger drum pulley and smaller motor pulley (sprockets?) would be the
cheapest for you. You can make 'em if you don't already have 'em.
Gear it down with stepped pulleys if you need some speed variability.
A plain ol' serpentine belt may work on a small motor pulley and
around the bare drum, too, but you may get perhaps months instead of
years of life out of it that way, depending on usage. I've seen a
makeshift concrete mixer and several rock tumblers done this way over
the years. My old wood lathe has a 1/4hp motor hung on a loose bolt
with its own weight keeping the belt tight, but it has 3-step pulleys.
A poly V belt can be used to drive a bare drum if the drum is IIRC 10x
or more the driving pulley size without a problem. There is a good
Contitech design guide for their poly v belts and it mentions it in
there. They've been doing washing machines that way for decades.


--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

"Terry Coombs" wrote in message
...
Larry Jaques wrote:


Larger drum pulley and smaller motor pulley (sprockets?) would be
the
cheapest for you. You can make 'em if you don't already have 'em.
Gear it down with stepped pulleys if you need some speed
variability.
A plain ol' serpentine belt may work on a small motor pulley and
around the bare drum, too, but you may get perhaps months instead
of
years of life out of it that way, depending on usage. I've seen a
makeshift concrete mixer and several rock tumblers done this way
over
the years. My old wood lathe has a 1/4hp motor hung on a loose
bolt
with its own weight keeping the belt tight, but it has 3-step
pulleys.

I guess a description of this power unit is needed ... There is a
pair of rods with rollers , motor below . The rods are driven by a
chain and sprocket arrangement at one end of the unit . In use the
drum is cradled on the rollers and driven by them .
Here's an ebay listing for one that is similar in function - just
put a chain drive under a cover on one end instead of the belts .
http://www.ebay.com/itm/Diamond-Paci...-/262525104831
--
Snag

Is the motor shaft a common size like 0.500", or can you machine
adapters?

If so, moving the sprocket to a jackshaft driven with hardware-store
pulleys could be the best simple answer. A variable-speed universal
motor may not have acceptable speed regulation.

--jsw

David Billington wrote:
A poly V belt can be used to drive a bare drum if the drum is IIRC 10x
or more the driving pulley size without a problem. There is a good
Contitech design guide for their poly v belts and it mentions it in
there. They've been doing washing machines that way for decades.


--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen


I've been using a poly v "serp" belt in place of the flat belt on my Logan
lathe for years . And did you mean dryers ? Most every dryer I've ever
worked on used a poly v to drive the drum .
--
Snag

Jim Wilkins wrote:
"Terry Coombs" wrote in message
...
Larry Jaques wrote:


Larger drum pulley and smaller motor pulley (sprockets?) would be
the
cheapest for you. You can make 'em if you don't already have 'em.
Gear it down with stepped pulleys if you need some speed
variability.
A plain ol' serpentine belt may work on a small motor pulley and
around the bare drum, too, but you may get perhaps months instead
of
years of life out of it that way, depending on usage. I've seen a
makeshift concrete mixer and several rock tumblers done this way
over
the years. My old wood lathe has a 1/4hp motor hung on a loose
bolt
with its own weight keeping the belt tight, but it has 3-step
pulleys.

I guess a description of this power unit is needed ... There is a
pair of rods with rollers , motor below . The rods are driven by a
chain and sprocket arrangement at one end of the unit . In use the
drum is cradled on the rollers and driven by them .
Here's an ebay listing for one that is similar in function - just
put a chain drive under a cover on one end instead of the belts .
http://www.ebay.com/itm/Diamond-Paci...-/262525104831
--
Snag

Is the motor shaft a common size like 0.500", or can you machine
adapters?

If so, moving the sprocket to a jackshaft driven with hardware-store
pulleys could be the best simple answer. A variable-speed universal
motor may not have acceptable speed regulation.

--jsw

I'm not dure what size shaft the motor has , probably a 1/2" , but adapters
aren't a problem and this solution was on my list . I could even use step
pulleys to give more flexibility , like different size drums .
--
Snag

On 08/10/16 18:02, Terry Coombs wrote:
David Billington wrote:
A poly V belt can be used to drive a bare drum if the drum is IIRC 10x
or more the driving pulley size without a problem. There is a good
Contitech design guide for their poly v belts and it mentions it in
there. They've been doing washing machines that way for decades.

--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

I've been using a poly v "serp" belt in place of the flat belt on my Logan
lathe for years . And did you mean dryers ? Most every dryer I've ever
worked on used a poly v to drive the drum .
Those too and I expect many other similar items out there. I didn't
think dryer as I've never owned one, I just hang my clothes on the line
in the garden or on the radiators in the winter when wet.

"Terry Coombs" fired this volley in news:ntb936$rao$1
@dont-email.me:

I could even use step
pulleys to give more flexibility , like different size drums .
--


Snag, you generally WON'T need to adjust the speed for different-sized
drums (jar, actually, in the parlance) if you plan the speed to about
'center' on the correct speed for a middle-sized jar.

If you run the calcs for different sizes, you'll see that you can make
fairly wide excursions in size, and still maintaining an acceptable
speed.

Lloyd

David Billington wrote:
On 08/10/16 18:02, Terry Coombs wrote:
David Billington wrote:
A poly V belt can be used to drive a bare drum if the drum is IIRC
10x or more the driving pulley size without a problem. There is a
good Contitech design guide for their poly v belts and it mentions
it in there. They've been doing washing machines that way for
decades.
--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

I've been using a poly v "serp" belt in place of the flat belt on
my Logan lathe for years . And did you mean dryers ? Most every
dryer I've ever worked on used a poly v to drive the drum .
Those too and I expect many other similar items out there. I didn't
think dryer as I've never owned one, I just hang my clothes on the
line in the garden or on the radiators in the winter when wet.

We line dry too . but also have a dryer for those times the weather won't
allow hanging out ... just a note - puppies and clotheslines aren't always
a happy mix .
--
Snag

Lloyd E. Sponenburgh wrote:
"Terry Coombs" fired this volley in
news:ntb936$rao$1 @dont-email.me:

I could even use step
pulleys to give more flexibility , like different size drums .
--


Snag, you generally WON'T need to adjust the speed for different-sized
drums (jar, actually, in the parlance) if you plan the speed to about
'center' on the correct speed for a middle-sized jar.

If you run the calcs for different sizes, you'll see that you can make
fairly wide excursions in size, and still maintaining an acceptable
speed.

Lloyd

This just gets better and better . Thanks Lloyd !
The yard sale was a fundraiser for a missionary-type group , I only paid 10
bucks for this tumbler base . Motor's worth more than that and it has saved
me a good bit of fabrication .
--
Snag

On Sat, 8 Oct 2016 13:20:02 -0500
"Terry Coombs" wrote:

snip
The yard sale was a fundraiser for a missionary-type group , I only paid 10
bucks for this tumbler base . Motor's worth more than that and it has saved
me a good bit of fabrication .

Dad helped me make one as a kid. We used an old gallon paint can for
the "jar" (thanks Lloyd, didn't know that term) with a big o-ring over
it at each end for traction. It was just jack shafts. Pillow blocks,
belts and old washing machine motor...

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On Saturday, October 8, 2016 at 9:39:52 AM UTC-4, Terry Coombs wrote:

Thanks Lloyd , by that calculation I need about 143 RPM . I'll have to
check the chain drive ratio and figure the FPM of the roller shafts to see
what I'm getting from it now . It might not be too fast after all .
--
Snag

I would be surprised if it were too fast. 1750/ 143 = 12.2 So it is not that great a reduction. You are getting a lot of reduction from the dia of the driving shafts to the dia of the Jar.

I have a potters wheel that get about that much reduction with a poly vee belt and a pulley of about 1 inch dia on the motor and a pulley of about 12 inch diameter on the shaft the head is mounted on.

Dan

On Saturday, October 8, 2016 at 9:39:52 AM UTC-4, Terry Coombs wrote:

Thanks Lloyd , by that calculation I need about 143 RPM . I'll have to
check the chain drive ratio and figure the FPM of the roller shafts to see
what I'm getting from it now . It might not be too fast after all .
--
Snag

You might be able to use the drive from a 10 speed bike if you actually need some reduction.

Dan

On 8 Oct 2016 04:09:34 GMT, "DoN. Nichols"
wrote:

On 2016-10-08, Terry Coombs wrote:
I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds . Problem is
that I think it might spin too fast , and I may need to slow it down . I can
use smaller rollers on the shafts (2 , parallel and both turned by a chain
drive) to slow it some , but might need to lower the input RPM's . Currently
has a 1/3 hp split phase motor turning at 1725 - is there any way to speed
control that motor short of changing the input frequency ?

Speed control of such a motor by frequency is not likely to work
over much of a range. Yes, a 60 Hz motor on 50 Hz runs slower -- and is
closer to saturation.

And the functionality of the motor depends on matching of the
run capacitor's value to the frequency. If you had a VFD locked to a
specific frequency, you could likely adjust the run capacitor for
reasonable performance -- but don't expect to just reach out and adjust a
pot to change the speed over a wide range.

Note that 1725 is not the slowest induction motor on a 60 Hz
line. The next speed down is about 1150 RPM, then about 875 RPM
depending on the number of poles. 2-pole is somewhere short of 3600
RPM, 4-pole is short of 1800 RPM (your 1725), 6-pole is short of 1200
RPM, and 8-pole is short of 900 RPM (see examples above -- loss of
speed is due to slip).

Other choices may
be a smaller motor sprocket , or maybe an inline (planetary?) gear reduction
unit or v belt and jackshaft arrangement . Could also change out to a
universal or DC motor and appropriate control system , or use a 3 speed fan
motor I have on hand .

3-speed fan motors depend on the load of the fan blades or
squirrel cage fighting the input current modified by the number of turns
in the selected winding. In your application, it would likely run close
to full speed on all three windings.


The multispeed blower motor on my old furnace switched the number of
poles and the speed difference with no load was VERY noticeable. The
torque was almost the same at either speed - resulting in a large
difference in horsepower as well.
A universal motor, on a dimmer would likely work fairly well for
your application. And at a slower speed, you likely would not need the
full 1/3 HP. Instead of the dimmer, a Variac or Powerstat (variable
autotransformer) would work better -- but they are significantly more
expensive.

But speed control of the current motor would be the
easiest and cheapest ...

Cheapest, yes -- but unfortunately, not easy.

Are you sure that it is currently too fast to do what you want?
Try it first, to see how it does. That could be the cheapest way to do
this.

Good luck,
DoN.

On Sat, 08 Oct 2016 03:34:33 -0700, Gunner Asch
wrote:

On Fri, 07 Oct 2016 23:07:43 -0400, wrote:

On Fri, 7 Oct 2016 20:52:54 -0500, "Terry Coombs"
wrote:

I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds . Problem is
that I think it might spin too fast , and I may need to slow it down . I can
use smaller rollers on the shafts (2 , parallel and both turned by a chain
drive) to slow it some , but might need to lower the input RPM's . Currently
has a 1/3 hp split phase motor turning at 1725 - is there any way to speed
control that motor short of changing the input frequency ? Other choices may
be a smaller motor sprocket , or maybe an inline (planetary?) gear reduction
unit or v belt and jackshaft arrangement . Could also change out to a
universal or DC motor and appropriate control system , or use a 3 speed fan
motor I have on hand . But speed control of the current motor would be the
easiest and cheapest ...
VFD.

Not if its a single phase motor, and finding small 3ph motors under
1/2 hp can be problematic.

A DC motor and drive may be his easiest and likely cheapest bet. There
are surplus places that sell both as sets for under $50, last time I
went looking for one for another application.


The old treadmill motors - but the controller needs to be started from
zero RPM and cranked up. They don't restart with the speed set to
non-zero in MOST cases.
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On Sat, 8 Oct 2016 10:29:17 -0500, "Terry Coombs"
wrote:

Larry Jaques wrote:


Larger drum pulley and smaller motor pulley (sprockets?) would be the
cheapest for you. You can make 'em if you don't already have 'em.
Gear it down with stepped pulleys if you need some speed variability.
A plain ol' serpentine belt may work on a small motor pulley and
around the bare drum, too, but you may get perhaps months instead of
years of life out of it that way, depending on usage. I've seen a
makeshift concrete mixer and several rock tumblers done this way over
the years. My old wood lathe has a 1/4hp motor hung on a loose bolt
with its own weight keeping the belt tight, but it has 3-step pulleys.

I guess a description of this power unit is needed ... There is a pair of
rods with rollers , motor below . The rods are driven by a chain and
sprocket arrangement at one end of the unit . In use the drum is cradled on
the rollers and driven by them .

I had envisioned a 45-degree drum, for some reason. No big.

BUT, like most of us here, you're a _maker_. You fab up what you
don't have or don't want to buy.



Here's an ebay listing for one that is similar in function - just put a
chain drive under a cover on one end instead of the belts .
http://www.ebay.com/itm/Diamond-Paci...-/262525104831

That's easily modified. To add a larger top pulley, remount the motor
lower, on a new plate if necessary.

--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

On Sat, 8 Oct 2016 12:02:45 -0500, "Terry Coombs"
wrote:

David Billington wrote:
A poly V belt can be used to drive a bare drum if the drum is IIRC 10x
or more the driving pulley size without a problem. There is a good
Contitech design guide for their poly v belts and it mentions it in
there. They've been doing washing machines that way for decades.

I've been using a poly v "serp" belt in place of the flat belt on my Logan
lathe for years . And did you mean dryers ?

I'm sure he did. Washer belts are so very short, Vs are all I've ever
seen on them.


Most every dryer I've ever worked on used a poly v to drive the drum.

The only one I've had to replace was a pure flat belt, a late '60s
Kenmore. It gave me 10 more years before I left it to move up to
Oregon.

--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

On Sat, 8 Oct 2016 13:08:39 -0500, "Terry Coombs"
wrote:

David Billington wrote:
On 08/10/16 18:02, Terry Coombs wrote:
David Billington wrote:
A poly V belt can be used to drive a bare drum if the drum is IIRC
10x or more the driving pulley size without a problem. There is a
good Contitech design guide for their poly v belts and it mentions
it in there. They've been doing washing machines that way for
decades.
--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

I've been using a poly v "serp" belt in place of the flat belt on
my Logan lathe for years . And did you mean dryers ? Most every
dryer I've ever worked on used a poly v to drive the drum .
Those too and I expect many other similar items out there. I didn't
think dryer as I've never owned one, I just hang my clothes on the
line in the garden or on the radiators in the winter when wet.

We line dry too . but also have a dryer for those times the weather won't
allow hanging out ... just a note - puppies and clotheslines aren't always
a happy mix .

You guys can HAVE your dogs. http://tinyurl.com/zrmbpjy and
http://tinyurl.com/zvyp7ds, just to start.

So curb yer mutt, fence off the drying lines, or hang 'em higher.
Better yet, nix the dog altogether.
/dog lover/hater

--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

On Sat, 08 Oct 2016 15:13:21 -0700, Larry Jaques
wrote:

On Sat, 8 Oct 2016 10:29:17 -0500, "Terry Coombs"
wrote:

Larry Jaques wrote:


Larger drum pulley and smaller motor pulley (sprockets?) would be the
cheapest for you. You can make 'em if you don't already have 'em.
Gear it down with stepped pulleys if you need some speed variability.
A plain ol' serpentine belt may work on a small motor pulley and
around the bare drum, too, but you may get perhaps months instead of
years of life out of it that way, depending on usage. I've seen a
makeshift concrete mixer and several rock tumblers done this way over
the years. My old wood lathe has a 1/4hp motor hung on a loose bolt
with its own weight keeping the belt tight, but it has 3-step pulleys.

I guess a description of this power unit is needed ... There is a pair of
rods with rollers , motor below . The rods are driven by a chain and
sprocket arrangement at one end of the unit . In use the drum is cradled on
the rollers and driven by them .

I had envisioned a 45-degree drum, for some reason. No big.

BUT, like most of us here, you're a _maker_. You fab up what you
don't have or don't want to buy.



Here's an ebay listing for one that is similar in function - just put a
chain drive under a cover on one end instead of the belts .
http://www.ebay.com/itm/Diamond-Paci...-/262525104831

That's easily modified. To add a larger top pulley, remount the motor
lower, on a new plate if necessary.


Depending on how big he needs..I often find these for a few hundred
dollars

http://www.ebay.com/itm/BRAND-NEW-MR...-/201081233835

http://www.ebay.com/itm/24-bowl-vibr...-/281809058500

http://www.ebay.com/itm/Vibra-Hone-F...-/251137793130


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On 08/10/16 19:08, Terry Coombs wrote:
David Billington wrote:
On 08/10/16 18:02, Terry Coombs wrote:
David Billington wrote:
A poly V belt can be used to drive a bare drum if the drum is IIRC
10x or more the driving pulley size without a problem. There is a
good Contitech design guide for their poly v belts and it mentions
it in there. They've been doing washing machines that way for
decades.
--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen
I've been using a poly v "serp" belt in place of the flat belt on
my Logan lathe for years . And did you mean dryers ? Most every
dryer I've ever worked on used a poly v to drive the drum .
Those too and I expect many other similar items out there. I didn't
think dryer as I've never owned one, I just hang my clothes on the
line in the garden or on the radiators in the winter when wet.
We line dry too . but also have a dryer for those times the weather won't
allow hanging out ... just a note - puppies and clotheslines aren't always
a happy mix .
Someone I used to know mentioned that puppies and coat racks didn't go
well together either as when they had a bunch of friends over the puppy
did a good job of chewing the bottoms of the coats hanging on a coat
rack in the entrance hall.

On Sat, 08 Oct 2016 15:27:57 -0700, Larry Jaques
wrote:


We line dry too . but also have a dryer for those times the weather won't
allow hanging out ... just a note - puppies and clotheslines aren't always
a happy mix .

You guys can HAVE your dogs. http://tinyurl.com/zrmbpjy and
http://tinyurl.com/zvyp7ds, just to start.

So curb yer mutt, fence off the drying lines, or hang 'em higher.
Better yet, nix the dog altogether.
/dog lover/hater

--


We had something like this happen (1) time. They all felt pain..they
all got buried in the rubble, they all got slung back into the rubble
when they tried to run out of it...they had a very..very memorable
experience. Bery painful, very intense, very negative.

Since then..Ive had pups grab a hot pad or a pillow..and have the
adult dogs go after them and force them to drop it. One dog will find
said hotpad on the floor, and bring it to me or the wife. They of
course get rewarded for good behavior and they have taken over the
task of training the young ones NOT to do this.
Been passed down for about 10 generations so far. Same with house
breaking. And for the same reasons.




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On Sat, 08 Oct 2016 17:18:20 -0400, wrote:

On Sat, 08 Oct 2016 03:34:33 -0700, Gunner Asch
wrote:

On Fri, 07 Oct 2016 23:07:43 -0400, wrote:

On Fri, 7 Oct 2016 20:52:54 -0500, "Terry Coombs"
wrote:

I picked up a rock tumbler power unit today at a yard sale with the
thought of using it to spin a ball mill for other compounds . Problem is
that I think it might spin too fast , and I may need to slow it down . I can
use smaller rollers on the shafts (2 , parallel and both turned by a chain
drive) to slow it some , but might need to lower the input RPM's . Currently
has a 1/3 hp split phase motor turning at 1725 - is there any way to speed
control that motor short of changing the input frequency ? Other choices may
be a smaller motor sprocket , or maybe an inline (planetary?) gear reduction
unit or v belt and jackshaft arrangement . Could also change out to a
universal or DC motor and appropriate control system , or use a 3 speed fan
motor I have on hand . But speed control of the current motor would be the
easiest and cheapest ...
VFD.

Not if its a single phase motor, and finding small 3ph motors under
1/2 hp can be problematic.

A DC motor and drive may be his easiest and likely cheapest bet. There
are surplus places that sell both as sets for under $50, last time I
went looking for one for another application.


The old treadmill motors - but the controller needs to be started from
zero RPM and cranked up. They don't restart with the speed set to
non-zero in MOST cases.

Ayup. So you start em from zero and take em to where you want to go,
with a simply twist of the wrist.


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Larry Jaques wrote:
On Sat, 8 Oct 2016 13:08:39 -0500, "Terry Coombs"
wrote:

David Billington wrote:
On 08/10/16 18:02, Terry Coombs wrote:
David Billington wrote:
A poly V belt can be used to drive a bare drum if the drum is IIRC
10x or more the driving pulley size without a problem. There is a
good Contitech design guide for their poly v belts and it mentions
it in there. They've been doing washing machines that way for
decades.
--
All of us want to do well. But if we do not do
good, too, then doing well will never be enough.
-- Anna Quindlen

I've been using a poly v "serp" belt in place of the flat belt
on my Logan lathe for years . And did you mean dryers ? Most every
dryer I've ever worked on used a poly v to drive the drum .
Those too and I expect many other similar items out there. I didn't
think dryer as I've never owned one, I just hang my clothes on the
line in the garden or on the radiators in the winter when wet.

We line dry too . but also have a dryer for those times the weather
won't allow hanging out ... just a note - puppies and clotheslines
aren't always a happy mix .

You guys can HAVE your dogs. http://tinyurl.com/zrmbpjy and
http://tinyurl.com/zvyp7ds, just to start.

So curb yer mutt, fence off the drying lines, or hang 'em higher.
Better yet, nix the dog altogether.
/dog lover/hater

I'm so sorry you feel that way . Any dog that chews and destroys his
master's stuff needs a new master . Max (11 week old Mountain Cur mix) has a
bunch of stuff beatin' around on the floor to chew on . His attention span
is short , and variety is important to keeping him engaged .
--
Snag

Gunner Asch fired this volley in
:

Depending on how big he needs..I often find these for a few hundred
dollars

http://www.ebay.com/itm/BRAND-NEW-MR...RY-TUMBLER-FIN
ISHING-/201081233835


Not the same animal, Gunner. He's talking about a ball mill (like used
in paint manufacturing), used to grind powders and/or slurries finer.

Vibratory polishers are intended to polish parts.

Lloyd

Gunner Asch fired this volley in
:

Ayup. So you start em from zero and take em to where you want to go,
with a simply twist of the wrist.


That's fine if you're grinding salt. If your grinding gunpowder, being
there with your hand on the knob when it starts isn't quite as safe.

Lloyd

On Sat, 08 Oct 2016 19:44:29 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:

Ayup. So you start em from zero and take em to where you want to go,
with a simply twist of the wrist.


That's fine if you're grinding salt. If your grinding gunpowder, being
there with your hand on the knob when it starts isn't quite as safe.

Lloyd
In other words you want a LONG extention cord?

fired this volley in
news
In other words you want a LONG extention cord?

Yeah, but PWM speed controllers don't get along nicely with motors over
long extension cords...

Lloyd

On Sat, 08 Oct 2016 20:52:02 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

fired this volley in
news
In other words you want a LONG extention cord?

Yeah, but PWM speed controllers don't get along nicely with motors over
long extension cords...

Lloyd
I meant with ANY motor, with or without a controller. The
jar" could become a big firecracker.

wrote:
On Sat, 08 Oct 2016 20:52:02 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

fired this volley in
news
In other words you want a LONG extention cord?

Yeah, but PWM speed controllers don't get along nicely with motors
over long extension cords...

Lloyd
I meant with ANY motor, with or without a controller. The
jar" could become a big firecracker.

Lloyd , didn't you recently post an article on rec.pyro about jar
explosions ? This machine is planned to be enclosed with sandbags on 3 sides
and a piece of ply or ribbed roofing as a top cover . About 50 feet out into
the woods ...
--
Snag

On 2016-10-08, wrote:
On 8 Oct 2016 04:09:34 GMT, "DoN. Nichols"
wrote:

3-speed fan motors depend on the load of the fan blades or
squirrel cage fighting the input current modified by the number of turns
in the selected winding. In your application, it would likely run close
to full speed on all three windings.

The multispeed blower motor on my old furnace switched the number of
poles and the speed difference with no load was VERY noticeable. The
torque was almost the same at either speed - resulting in a large
difference in horsepower as well.

O.K. Quite different from mine, which has a squirrel-cage blower
and a motor with two windings -- a cap shifted one for starting and run
torque, and a multi-tap one for various speeds connected directly to the
power line. Change the tap, you change the speed when the squirrel-cage
is present, but for an unloaded motor, the speed does not noticeably
change (and is *much* faster than any of the speeds with the cage
present.)

Perhaps the vintage of the furnace involved. Mine is a Carrier
from about the mid 1990s when the house was expanded.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2016-10-08, wrote:
On Sat, 08 Oct 2016 03:34:33 -0700, Gunner Asch
wrote:

[ ... ]

A DC motor and drive may be his easiest and likely cheapest bet. There
are surplus places that sell both as sets for under $50, last time I
went looking for one for another application.


The old treadmill motors - but the controller needs to be started from
zero RPM and cranked up. They don't restart with the speed set to
non-zero in MOST cases.

That is likely a safer setup, given what might happen when power
drops, and re-starts when power comes back -- depending on what kind of
machine it is attached to. And is particularly important for safety on
a treadmill. :-)

Someone who used to be a regular here a long time ago (Wayne
Cook) traced the circuit out and found a simple change on the board to
disable the (must go to zero) situation.

On my drill press, I have a three-phase motor, and a small VFD
which is set up with three pushbuttons. Two in recessed guards for
forward and reverse, and one with a big red mushroom on the button for
stop. It will re-start at the previous speed (as set by the pot) when I
hit the FWD or REV button, no matter what caused it to stop, but it
won't re-start (as configured) when power returns, and I would not want
it to do so. If I needed both hands, plus the vise, I would wire in a
foot switch to start and stop it, but this has not been the case so far.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
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--- Black Holes are where God is dividing by zero ---

On Sat, 08 Oct 2016 19:43:06 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:

Depending on how big he needs..I often find these for a few hundred
dollars

http://www.ebay.com/itm/BRAND-NEW-MR...RY-TUMBLER-FIN
ISHING-/201081233835


Not the same animal, Gunner. He's talking about a ball mill (like used
in paint manufacturing), used to grind powders and/or slurries finer.

Vibratory polishers are intended to polish parts.

Lloyd

And when you dump in ball bearings along with your slurries and turn
it on..what happens?


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On Sat, 08 Oct 2016 19:44:29 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:

Ayup. So you start em from zero and take em to where you want to go,
with a simply twist of the wrist.


That's fine if you're grinding salt. If your grinding gunpowder, being
there with your hand on the knob when it starts isn't quite as safe.

Lloyd


How long is the (2) wires between your pot and your controller? You
do know you can make em longer...right?


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