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Building a Powered Tool Sharpener by Dave Keele

Carving wood is my favorite hobby

and nothing makes this art more enjoyable, or

easier, than sharp tools. Fortunately, there are

many sharpening systems on the market today

to help do just that. Over the years, I have

tried many of those and have found this style

of sharpener works best for me. I have to

admit that learning to use this style of

sharpener took me longer than I care to admit.

However: once I got through the learning curve, I can get all my tools carving sharp… and most

importantly, I can maintain a sharp edge on the power strop with minimal effort and time,

leaving me more time to carve.

This is not an original design, as similar devices have been around for a long time. The

first time I saw one was in March of 1980 while attending my first carving workshop. This

machine had five or six 2-inch wide wheels, with four pillow-blocks; and the motor was mounted

on a shelf below. The drive belt ran though a slot cut in the bench top. The builder freely gave

out construction diagrams, so I soon after began construction of my own, less bulky, machine.

With a limited budget, I used whatever I had: an old washing-machine motor, used v-belt,

particle board for the wheels, scrap metal for the pillow-block risers, ¾” pipe; and I welded

washers onto stop-collars to make the wheel hubs. The only things I purchased were four

bronze-sleeved pillow-blocks and a 6” pulley. I still use this sharpener today.

I do not recommend this type of sharpener to beginners. I prefer to show them how to

sharpen by hand, using various grits of sandpaper and a strop. Once the concept of shaping steel,

creating a wire burr, honing, etc. is understood, I’ll introduce power sharpening. I also

recommend to carvers who are sharpening by hand, and would like to move on to power, to find

a local carving club and obtain hands-on training on how to safely use a powered device. My

suggestion is to find a system that works for you, learn to use it safely, and make sure the process

makes sense to you.

This machine utilizes an electric motor, with the shaft rotating clockwise when viewing

the end of the shaft. (This means the top of the wheels turn away from the user while in use.) I

use a 1725 RPM motor with a 2” pulley and a 6” pulley on the drive-shaft. This means the

wheels turn at 575 RPM. I have found this to be an ideal speed for my use. I won’t build one

that turns faster. I have, however, built ones that turn slower by installing a pulley smaller than

2” on the motor. (I’ll use a notched V-belt for these smaller radiuses.) I’ve also used two-speed

motors, which offer an 1140 RPM wiring option, to slow the wheels down.

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I should point out that if/when I use materials other than those listed in Appendix A, the

base hole patterns for the riser blocks and motor mount, as shown in Appendix B, may need to be

adjusted. For example: using different pillow-blocks may require adjusting the spacing of the

riser block holes & holes in the base, and may require a different bolt size and length; and/or

using different sized pulleys, belts, or motor frame size, may require adjusting the hole locations

and pattern for mounting the motor to the base.

The wheels are made of MDF: the right wheel is covered with coarse emery cloth; the

center wheel is covered with fine emery cloth; and the left one is covered with leather. The

spacing between the wheels allows knife handles to clear. The cloth buffing wheel is mounted

next to the leather wheel and used to buff the inside of gouges. Since I don’t use it on knives, it

is mounted closer to the leather wheel and smaller in diameter to allow knife handles clearance.

Many wheel options are available and only limited by one’s imagination. I’ve made

MDF honing wheels where the polishing compound was applied directly to the wood (no

leather). Commercially made slotted-cardboard wheels are available where compound is applied

directly to the wheel. One can also make MDF, cardboard, and leather wheels that are shaped to

fit specific profiles. I’ll interchange these specialty wheels (which are mounted on their own

hubs) with the coarse emery wheel (which I use the least) as needed.

I have made many sharpeners over the years, but most requests are for the 3-wheel +

buffer arrangement as described in this article. Some of the other arrangements have been:

2-wheel buffing machine (one leather wheel and one cloth buffer).

2-wheel base (one leather and one fine emery wheel) with a 3rd

coarse emery wheel for

occasional use. This unit had the motor in a wood frame directly under the drive shaft,

which makes this a space-saving, compact sharpener.

2-wheel base (one slotted-cardboard honing wheel and one fine emery) with cloth buffer

and shaped-leather wheels.

3-wheel units with many different wheel arrangements.

4-wheel unit with 2 emery wheels, 2 leather wheels, and a cloth buffer. This was my first

build and the one I still use today.

The photos and associated descriptions show the generic assembly procedure. Specifics of the

items used in each step can be found in the Materials List (Appendix A).

Disclaimer of Liability

This article was written for informational purposes only on how I made the sharpener pictured. Should the reader choose to use this article as a

how-to guide to construct one for personal use, the builder assumes all responsibility for its safe and proper construction and operation. The

builder also acknowledges that:

sharpening tools is inherently a dangerous activity.

using power tools improperly or ignoring standard safety practices can lead to permanent injury or death.

the builder understands these dangers and accept all consequences of their actions.

the builder will not hold the article’s writer liable in any event of injury, loss of property due to accident, mis-use of sharpener, or any

other unfortunate occurrence during the construction and/or use of said sharpener.

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Materials

This is a photo of the items that I

make. Two panels of MDF (one for

the base and the other is used to

make 3 wheels) and two riser blocks

for the pillow-block bearings.

Drive-shaft rod; pillow-block

bearings; wooden riser blocks; bolts,

washers, and nuts

Cloth buffing wheel; motor arbor for

buffer; MDF wheel assemblies;

drive-shaft pulley; aluminum hubs

3-prong electric cord; handy box;

light switch; face-plate; metal strain-

relief; assorted screws, wire nuts,

wire terminals, and grounding wire

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Electric motor; drive pulley; v-belt

Sanding sealer; contact cement;

rubber cement; leather strip; two

grades of emery cloth

Prepping the base

Using the template (see Appendix B)

as a guide, I lay out the hole

locations for the motor and riser-

blocks. I make the holes using a

drill-press.

On the reverse side, I counter-sink

holes using a Forstner bit to

accommodate the washers and bolt

heads. (Photo shows motor-mount

holes.) I then staple 3 strips of scrap

indoor/outdoor carpet to the bottom.

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Making the Riser Blocks

The riser blocks are used to raise the pillow-blocks

above the base to provide clearance for the wheels.

The ones in the photo were made from two, ¾” pieces

of plywood, glued together. The holes were made by

slotting each half on a table saw prior to glue-up. Slots

(holes) are sized to the mounting bolts and spaced to

accommodate the pillow-blocks.

I have also made several blocks from 2”x 4” solid

wood, sawn to size, with holes made on a drill press.

Making the Wheels

Since the tool being sharpened rides on the outer surface of

the wheel, it is most important that the wheels run true; that

is, without side-to-side wobble and not out-of-round.

Equally important, for the placement of the emery cloth, the

surface needs to be flat and perpendicular to the sides.

To do this, I first cut six circles on

my band-saw using a circle jig. I

made my jig with a pointed pivot pin

(see photo). This pin allows me to

rotate the wood through the band-

saw without having to drill a center

hole.

With the circles cut, I glue them together in pairs to make three wheel blanks.

Pin under circle blank

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With the wheel blank mounted on a

lathe, I turn the wheel round using a

home-made jig. The jig allows me to

make the surface flat and

perpendicular to the sides.

While the wheel blank is on the

lathe, I use a tail-stock mounted

chuck to drill a center hole the same

size as the drive-shaft rod.

Removed from the lathe, I give each

wheel two coats of sanding sealer,

with a light sanding between coats.

Using a small section of rod, I center a hub on one of

the wheels. I then mark the wood for the screw holes,

remove the hub and rod, make pilot holes on a drill

press, replace the hub and rod on the wheel in the

same orientation, and attach the hub with screws. I

repeat the process on the second wheel and hub.

The process is basically the same for the

third wheel and large pulley, except I

have to first drill holes in the spokes of

the pulley and I use flat-head screws to

hold it to the wheel.

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Base Assembly

The pillow-blocks are mounted on

the riser blocks as shown in the

photo. I put a coat of glue on the

bottom on the riser blocks prior to

mounting. I then align and square

the blocks with the front of the base,

then tighten the nuts.

The bearings float in the pillow-

block housings and usually require

aligning. Using the drive-shaft rod, I

insert it in one bearing and adjust it

until it aligns with the other. I repeat

this on both bearings until I can

easily push the rod through both

bearings.

After removing a knock-out plug on

the back side of the handy box, I

attach a strain-relief in the hole.

I drill two holes in the side of the

box and attach it to the inner side of

the left riser block with two wood

screws. I space the box over the

front edge of the base to allow the

face-plate to clear the base and the

riser block.

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Leather Application

When applying glue to the wheels,

I’ll temporarily mount them to the

shaft. This allows me to work on the

outer wheels and turn them with the

inner one.

To size the leather to the wheel, I’ll

cut (if necessary) one end and insure

it’s square to the edges. I then dry-

wrap the leather on the wheel and

mark the overlap. I’ll then cut it to

length, square to the edges, and dry-

wrap it again to check the fit.

In a well ventelated area, and

following label instructions, I’ll

apply two coats of contact cement to

the smooth side of the leather strip…

… and two coats of contact cement

to the outer surface of one of the

wheels with a hub mounted on it.

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When the second coat of glue is

tacky to the touch, I’ll apply the

leather to the wheel. The leather in

the photo was a bit wider than the

wheel, so I applied it to lap evenly

over both sides. I use a roller to

press the leather to the wheel.

Large rubber bands hold the leather

in place while the glue dries.

Leather is trimmed on both sides

with a sharp knife once the glue is

dry.

Finished glue joint.

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Emery Cloth Application

Applying emery cloth to the two remaining wheels is very similar to the leather application,

except I want to be able to replace the cloth when it wears out, so the glue needs to be releasable.

I use rubber cement.

The process is the same for both emery wheels, but I want the coarse cloth to be on the right

wheel (wheel with hub mounted on it) and the fine cloth on the center wheel (wheel with the

pulley mounted on it).

Starting with a strip of emery cloth slightly longer than I need, I first cut one end at

approximately 45 degrees. I’m not concerned that it’s exact, but it does need to be a straight cut.

I use an old pair of scissors to make the cut and check the edge for straightness.

With one end cut, I’ll dry wrap the cloth

onto the wheel. With the straight cut on top,

I’ll place a piece of masking tape parallel to

the cut end. I’ll use the tape as a guide to

cut the second end. Note: tape is very close

to, but not toughing, the first cut. I’ll then

remove the cloth, cut the second end, and

dry wrap it once more to check for proper

fit.

With the emery cloth cut to size, I’ll clamp it

to a board (tends to curl) and apply two

coats of rubber cement to the back side and

two coats to the wheel.

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When the second coat of cement is

tacky to the touch, I’ll apply the

cloth to the wheel, aligning the edge

of the cloth to the edge of the wheel.

I use a roller to press the cloth to the

wheel.

Large rubber bands hold the cloth in

place while the cement dries.

Finished seam on the coarse

wheel (wheel with a hub

mounted on it).

Finished seam on the fine

wheel (wheel with the pulley

on it.)

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Electrical Installation

Warning ! !

This article was written for informational purposes only on how I made the sharpener pictured. Should the reader chose to use this article as a

how-to guide to construct one for personal use, the builder assumes all responsibility for its safe and proper construction and operation. I have an

electrical background and am comfortable in working with electrical circuits and devices. I’m a firm believer that anyone who works on

electrical devices needs to have a good understanding of sound electrical practices and of the National Electrical Code. Those not familiar with

both of these should seek the assistance/professional services of a licensed electrician.

I purchase motors that are reversible.

These typically come with wiring

diagrams indicating terminals to use

for desired rotation direction.

Using the appropriate terminal connector

types, I attach the 3-pronge power cord

directly to the motor. With a proper stain

relief in place, and the cover plate installed,

I’ll plug the motor into a switched electrical

outlet to test the motor and check for desired

rotation direction. With the motor operating

as it should, I’ll bolt the motor to the base

and finger-tighten the nuts. I will then route

the power cord along the base and next to

the handy box, where I’ll cut the cord at a location that will leave an adequate length of

cable to run the cord through the strain-relief and still make connections to the switch.

(This is around 5” after it passes through the strain-relief.) Since this uses about 18” of

cord, I like to purchase power cords that are 8 to 9 feet in length. Ten foot extension

cords, with the receptacle-end cut off works well. Be sure to use a 3-wire, 3-pronge cord

with ground plug in place.

Next, I remove about 5” of jacket from the end of the

cord attached to the motor and from the end of the

shortened power cord. Feed both cords through the

strain-relief to a point the end of the jacket is inside

the box. I then tighten the strain-relief.

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I terminate the wiring in the handy-box (see

photo) as follows:

2 black wires (one from line cord, one to

motor) connected to switch.

2 white wires (one from line cord, one to

motor) joined under wire nut on the right.

4 ground wires (one from line cord, one

to motor, one to switch, and one to hand-

box) joined under wire nut on the left.

When all wiring terminations are

complete, I screw the switch to the

handy-box and attach the face-plate.

To help keep the wiring away from

moving parts, I install a strain-relief

to the base. (cable-tie is not secure

in photo for illustration purposes.)

I also secure the cables at the motor

vent-holes, with a cable-tie, for

additional strain-relief.

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Final Assembly (refer to Appendix C)

While facing the front of the base, I insert the drive-shaft rod through the right pillow-block,

from right to left, until it’s halfway between the two blocks. I’ll slide on the wheel with the

pulley attached (pulley side to the left) and then the V-belt. I can now push the rod through the

left pillow-block. Next, I put the wheel with the coarse emery cloth on the right end of the shaft

(hub to the left).

With the end of the shaft flush with the

outside of the wheel, I tighten the set-screw

in the hub. I can now position the shaft in

it’s proper place by aligning the outer wheel

face with the base. I now tighten the set-

screws in both pillow-blocks to lock the

shaft in place. I adjust the center wheel to

have 7” between it and the right wheel, then

tighten the set-screw to lock it in place.

Working from the rear, I slide the small

pulley on the motor shaft and place the V-

belt on both pulleys. Pulling back on the

motor, I tighten the four mounting bolts to

lock the motor in place, while keeping the

belt tight and the motor mount parallel with

the rear of the sharpener base. Using a

straight edge, I align the small pulley with

the large one, and tighten the set-screw.

Next, I mount the leather wheel (hub to the left) on the left end of the drive-shaft rod, adjust it to

have 7” between it and the center wheel, and tighten the set-screw in the hub. Lastly, I mount

the buffing wheel arbor on the left end of the drive-shaft rod, tighten the set screws, mount the

buffing wheel between washers on the arbor,

and tighten the nut.

Having tested the unit that it runs as it should, I

use a coarse and fine sanding pad to smooth the

leather wheel for prep of the honing compound.

(notice dust-collector tube in photo… leather

produces a lot of dust)

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Completed Sharpener

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Appendix A - - Materials List

Qty: Item: Discription: Source:

1 Base 16" x 24" x 3/4" MDF 1

1 Electric motor ¼ HP, Split Ph.,115VAC, 1725 RPM 2, 3

Reversible, thermal protected

4 Bolt (motor mount) 1 ¼” x 5/16", + washers & nuts 1

1 Pulley 2” Dia. ½” bore, Chicago Die Casting 200a 4, 5, 6, 7

1 V-belt 3L-310 1, 4, 5, 7

1 Pulley 6” Dia. 5/8” bore, Chicago Die Casting 600A 4, 5, 7

1 Drive-shaft 21 ½” x 5/8" solid rod, Stanley 179812 1, 4, 7

2 Pillow-block drive-shaft bearing w/ locking screw UCP202-10 3, 5, 6, 7

2 Riser blocks 3 ¼” x 5 3/4” x 1 ½” solid or ply wood 1

4 Bolt (Pillow-blocks) 5" x 3/8", +washers & nuts 1

3 Wheels 8" x 1 ½” MDF 6

2 Die cast hub Chicago Die Casting 2123, 5/8” bore 4, 5, 6, 7

1 Emery cloth 26” x 1 ½”, 100 or 120 grit 1, 5

1 Emery cloth 26” x 1 ½”, 320 grit 1, 5

1 Leather 26" x 1 ½”, vegetable tanned, shaved to uniform 5, 8

thickness

1 Power cord Plug to blunt end, 8’, 3-prong , Woods 550589 1, 4, 5, 7

1 Handy box Single gang, 4x2, w/ strain relief 1

1 Switch SPST, heavy duty, 15 amp, Cooper CS115BK 1

1 Face plate Standard light-switch plate, metal 1

1 Buffing wheel 6" x 1”, 1/2" hole, Enkay 156-H80 5, 6, 7

1 Motor mandrel 5/8" bore, 1/2" shaft, Grizzly G5551 1, 6, 9

Additional Items: Source Codes:

Contact cement 1 Local hardware/lumber yard

Elmer's rubber cement 2 zoro.com

Wood glue 3 surpluscenter.com

Sanding sealer 4 essentialhardware.com

Screws, wood, flush mount, 1 ¼” 5 ebay.com

Screws, wood, flat head, 1 ¼” 6 bigfootcarvingtools.com

Electrical terminals to fit motor and switch 7 amazon.com

Wire nuts 8 springfieldleather.com

Cable ties 9 grizzly.com

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Appendix B - - Base Template

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Appendix C - - Component Layout