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Polishing Motor


#1

My 20 year old Baldor polishing lathe is growling a lot. I know that
I can have it rebuilt and will as there is a service shop about 7
miles away. My problem is that I need more room between the motor
and the polishing wheel and have been looking at 3/4 hp motors built
by Baldor, Arbe and others that have a 5/8" shaft and a tapered
spindle. The spindle is pulled onto the shaft by threads on the shaft
and inside the spindle. This all appears to allow for a longer shaft,
more room between the wheel and motor and a larger diameter wheel.
This would allow me to not only solve the problem of needing more
room between the wheel and motor, but also use a proper hood.

My current hood is a plywood box that I built 40 years ago. I have
always applied suction in different ways to collect the dust, try to
keep things clean (including me and my lungs) and recover any metal
included in the dust. I currently use a big shop vac and a dust
cyclone for suction and filtration. I still have a lot of dust
escaping the hood and hope that one of the tapered open metal hoods
with a 3" suction hole will reduce the amount of dust that escapes
into the shop. I have also found a near by source of 1" wide tightly
spiral sewn 6" cotton wheels that improve my polishing and don’t
produce as much duff compared to the looser wheels that I have been
using. This may also help the dust problem. I know that this is a
ramble, but I have looked into the archives and can’t find a lot
about this topic, so I am looking for pros and cons about the motor,
spindle and hood that that I describe. Keep in mind that I make
large silver cuffs bracelets. My polishing is fairly aggressive, so I
need a heavy duty motor and a lot of room around the wheel. I do a
lot of cut down with tripoli or Luxi Blue which creates the dust
problem. Any thoughts are appreciated.

Thanks. Rob


#2

Hi Rob,

Any of us here that make bigger things need the right tools to do so
and the same applies to polishing. Can I suggest you think along the
following lines?

You see a stand alone motor off some other machine opens the door to
doing what you want in a much better way than the Baldor solution.

Get a stand alone motor say 1.5hp to 3hp,. mount that under the
bench. put on that say 3 wheel pulley 2in 3in and 4in dia. To run an
A section belt.

Then have a seperate shaft on 2 bearings likewise with the same size
3 wheel pulley on it on you bench. To this you can mount the taper
threaded wheel holders what ever distance you want from the bearing.
Would 8in be enough? if you have say 18in between the bearings this
would provide the support for your heavy polishing loads. obviously
youll need a l handed threaded one on the left and a rt handed on on
the right. Also you will need to have the shaft and bearings at least
8in above the bench.

then build a suitable plywood shroud around the mop areas. To that
mount a 3in min vac hose connected to a Harbour freight vac unit
that pulls 600 cft a min air. Here in the UK there sold under the
Machine mart brand. Exhaust that directly into your own made vac bag.
I made mine from a single bed sheet sewn lengthwise(singer) and hung
length wise behind the polishing bench.

Now I made mine up to this spec and the mop/wheel height when
standing is level with my elbows. Easiest position when polishing a
big as in 18in dia bronze or silver dish.

Also youll need as in industrial polishing shops bolt the whole
apparatus to the floor. Why? cos when you push hard on the work
youll need to make sure you dont push the machine over.

Ive several built like this, from as small as in 1/2 hp with a 1/2
in shaft for mops up to 3in dia up to 3 hp with 1in shaft for wheels
up to 12in dia.!!

With this setup you then can have shaft/mop speeds from 750 rpm up
to 3500 rpm by just changing the belt over. For sanding with scotch
brite wheel 3M products at slow speed, to swansdown mops for final
finishing of silver at the higher speeds.

On the subject of tools for finishing, I also use sanding belt
machines. with belts usually 36in long by 1/2in wide, so much faster
than filing, these are mounted vertically. I buy these also by 3m
usually 4in wide, then simply tear then down, except where the joint
is! to whatever width I need. Likewise at elbow height. all used
standing up. Then up to 9ft long by 3in wide. Thats mainly for
wood!!.

The only work I do sitting down is soldering.

What do you think?
Ted.


#3

I am following this thread with great interest as I will likely be
replacing my polisher in the near future. The motor I am using is
the polisher that Dad used for twenty years prior to my using it
twenty years ago.

Rob and I produce some similar jewelry and much that is strictly out
own designs but Rob has the benefit of space where I do not. My
entire shop minus the polishing is 5’ X 7’ and the polisher is in 4’
x4’ space.

I need a work horse polisher for the large cuff bracelets we produce
but it needs to be more of a Pit Pony than a Clydesdale. Any
suggestions in that regard?

Don Meixner


#4

Ted, always reed your post with interest, looks like you have some
very interesting equipment in your workshop, do you have any
pictures or website we could admire ?

Peter
Spain


#5

I use a 1/2 horse red wing for larger items like this.

Russ


#6

I have bought a 3/4 hp tool grinder, like from Harbor Freight. Cut
the threaded ends off. It has been running for years.


#7

I use the same thing, bought from Home Depot. I have a medium cratex
wheel on one side, and for the other I bought a tapered spindle from
Rio for my buffs and radial bristle discs. Works great.

Janet Kofoed


#8

Hi Don,

There isn’t anything wrong with buying a complete setup from Rio or
one of the other suppliers.

However, I have opted to go the DIY route. I have a 1/2 HP grinder
to which I have attached LH and RH tapered spindles. Then make
whatever box you want for a filter and vacuum line.

I have bought two grinders at flea markets for $20 to $30 each, but
you can get the 8 inch Harbor Freight grinder for about $40 with a
20% off coupon and build from there. The Baldor is probably a better
motor, but you can burn out and replace five to ten of the Chinese
motors before you reach the price of the Baldor. You need a shop vac
or a vacuum motor for dust collection, easy to come by.

You can control your rpm to some extent with smaller and larger
diameter wheels. If this is not enough for you, go with a jack shaft
and pulleys as Frater suggested.

There should be a lot of other threads on building the box and blower
for it, as this is a perennial question. I would go with whatever was
simplest for me, as that will allow you to get back to making
jewelry instead of a deluxe polisher.


#9

Hello Don,

I bought a polishing motor (Baldor) mounted in a lighted cabinet
with high volume exhaust through a filter. It’s been very
satisfactory for over 20 years. The filter size is available at my
local hardware and is easy to remove for recycling. The footprint is
modest and the top of the cabinet is perfect for my pantograph. The
cost back then was about $200 total and has been well worth the ease
of use and effectiveness.

Nowadays, I prefer to use my time making things, gardening and
reading rather than cobbling together a large piece of equipment.
That’s just me - in my advanced age!! :-).

Judy in Kansas, who is going to experiment with hay bale gardening
next. The new terrace is being planted with some lovely perennials
and annuals for color.


#10

I have wondered if it’s possible DIY a polishing motor. I’m short of
cash and really need a better option than my flex shaft. What is
necessary for the modifications? Is it as simple as just attaching
the spindle?

Monica Yichoy


#11

Hi Monica,

I am just learning a little silversmithing & it’s a pretty big
investment for a retirement hobby. I save where I can. Here is my
polisher. It’s a 1/2 hp used motor from a friend, $20., a Brass
Tapered Spindle for 1/2" arbor Item #: 333042 from Rio, $6.05, and a
plexiglass splash guard made from materials I had at home, $3. I
wired it to a standard off/on light switch in a galvanized box. Wire,
switch, cover plate, & box from Home Depot for less than $5.
Advertise on Kijiji or Craigslist for the motor.


Hope this helps.
Noella


#12

A used motor can be found in yard sales. Add a tapered spindle,
power cord, switch and make sure tht it turns the right way and you
have a polishing motor. You can research this in various catalogs and
online articles. Be sure that the tapered spindle is correct for the
motor shaft in diameter and the shape of the bore of the spindle. It
will likely be a 1720 RPM motor and true polishing motors are usually
3450 RPM, but it is a start.

You will also need to buy buffs and polishing compounds. Very
important is how you handle the debris that comes off the wheel. It
needs to be collected in some way to avoid breathing it and it also
will mess up your shop. You can build some kind of hood to contain
the debris and attach a vacuum cleaner to it to filter and collect
the debris. I am currently in a redo of my polishing area. It is
still a work in process, but the most important piece is done. I have
added a 650 CFM blower to power my hood and filters with the exhaust
going to the outside thru a 6" vent pipe. I need to redesign my hood
a bit and add more suction to it to keep debris from escaping the
hood. This is in part due to the speed of the 6" spiral sewn wheels
that I use. I will be experimenting with 4" wheels to see if I get
the polish that I want with less debris escaping the hood. Remember
that it is the surface feet/minute where the wheel comes into contact
with the piece you are polishing that impacts your polishing speed
and quality. This is controlled by the size of the wheel and the
speed of the motor. Pictures when I am done. Good luck, I would hate
to have to polish my work with a flexshaft. Thanks. Rob


#13
Is it as simple as just attaching the spindle? 

Yup. Pretty much. My first polishing station consisted of a bench
built out of two by fours and a scrap piece of formica countertop,
with a used 1/2 hp furnace blower motor on top. The motor needed to
be raised as it didn’t have any kind of a base, so I added a couple
of pieces of two by four under the mount. I used a standard wall
mounted light switch mounted to the bench as the on-off switch. The
shaft on the motor was 5/8" with a keyway (a square groove for a key
drive) so I found a tapered spindle from Gesswein that was made to
fit a 5/8’ shaft that used a couple of set screws. I bought a used
hood and attached it to a shop vac for dust collection. Noisy as all
get out, but it worked just fine for years.

Necessity can be a mother.

Dave Phelps


#14

Hi Monica,

I will DIY just about anything. My situation is one of " No Space "
so DIY is my best, affordable, solution.

My work could never be done on a flex shaft so I need a hefty motor
and wheel. To give you smh idea of what you are getting into Google
DIY polishing motor and see what YouTube has to show you.

Don Meixner


#15

Many people have done very well with less. Looks good and it will
get the job done for now.

Don Meixner