Carl’s 4x7x2 Sharpening Jigs

Photo: 4x7x2 Sharpening Jigs System - Set It & Forget It (4x7x2_jigs_page0_blue)

Click here for a PRINTABLE version of the above blueprints.

Students come to my studio and fall in love with my quick and easy grinding jigs. Over the years I have struggled with how can students make there own version of my grinding jigs. This is my solution to the problem.

  1. Draw up a set of 4x7x2 Sharpening Jigs blueprints. Where angles are expressed as X and Y lengths in inches that are easy to measure. Rather tiny little degrees on a protractor that are hard to see and measure.
  2. Recommend that students use Easy Grind Vari-Grind or Oneway Vari-Grind jigs as raw materials. Make (remake) 3 custom arms for the off the self vari-grind jigs to create my 3 custom grinding jigs. All the info they need is covered by my 4x7x2 blueprints.
Note: I use what I recommend. I now use 3 custom vari-grind based jigs in my studio. I no longer use the Ellsworth style ones that I made from scratch long ago. For more info see History section at the end of this blog entry.

The 4x7x2 System – Set It & Forget It

Photo: The 4x7x2 System - Set It & Forget It (4x7x2_jigs_page1)

The "Set It & Forget It" system. The idea behind my 4x7x2 System is you set up the jigs once and then forget about them.

When you want to sharpen something. It is 3 easy steps.

  1. Walk over to the grinder.
  2. Pick up one of the 3 color coded vari-grind jigs.
  3. Grind the tool.
No jig setup and adjustment, no hassle, thus no screw up. Fast and easy!

I call it the 4x7x2 system. Because:

  1. The Pivot Point is 4" below CENTER of Wheel. (See drawing above.)
  2. The Pivot Point is 7" from FACE of Wheel.
  3. The Gouge TIP is 2" from FACE of Jig.

The 4", 7" and 2" lengths NEVER change! Set it and forget it!

Photo: Three Vari-Grind Jigs! (4x7x2_sharpening_jigs_01) Three Vari-Grind Jigs!

My 4x7x2 system uses 3 different vari-grind jigs that allow the 4", 7" and 2" lengths to NEVER change!

My 3 jigs are:

Photo: Red Jig - 60° (4x7x2_sharpening_jigs_28) Red Jig – 60°

Used to sharpen:

   • 5/8" Ellsworth Bowl Gouge
   • 5/8" Jordan Bowl Gouge

Use on any gouge that requires a 60° bevel angle.

I color code my gouges to my jigs with electrical tape. The red tape on the gouge just above the handle (red arrow in photo) matches the red tape on sharpening jig.

My Red Jig is the same as Ellsworth Jig. HOWEVER, my jig works on any 5/8" diameter gouge. Ellsworth Jig does not work on Jordan V-Cut Gouge (Thompson) or Robust "Turners Edge" Gouge. There is a tiny pin INSIDE of the round Ellsworth Jig that registers against the top of the flutes on a Ellsworth Signature Gouge. This pin is to low for most other 5/8" diameter gouges.

Photo: Green Jig - 70° (4x7x2_sharpening_jigs_29) Green Jig – 70°

Used to sharpen:

   • 1/2" Stirt Bowl Gouge
   • 1/2" Stirt Detail Gouge

Use on any gouge that requires a 70° bevel angle.

Photo: Blue Jig - 45° (4x7x2_sharpening_jigs_30) Blue Jig – 45°

Used to sharpen:

   • 1/2" Hosaluk Detail
   • 1/2" Oneway Spindle

Use on any gouge that requires a 45° bevel angle.

Photo: Why Three Jigs? That costs to much! (4x7x2_sharpening_jigs_01) Why Three Jigs? That costs to much!

The jig arm length and angle are different on each of my 3 jigs. Changing the arm length is a necessary evil. If you want the 4x7x2 lengths to be fixed. Then the arm length has to change!

3 different arm lengths means you need 3 different CUSTOM vari-grind jigs!

Purchasing 3 vari-grind jigs, rather than using just one, obviously costs more! BUT, it makes life a lot easier! It makes turning more enjoyable! It is a small price to pay. In the long run you may save money when you grind your gouges less due to small jig variations and screw ups.

People purchase more than one EXPENSIVE 4-jaw chuck because they don't want to change chuck jaws! 3 vari-grind jigs is a drop in the bucket!

When I say "vari-grind jig" you can use any jig that floats your boat (Vari-Grind, Easy Grind, Vevor, Ellsworth, DIY). The "4x7x2 Vari-Grind Setup Jigs" on Page 3 of my blueprints allows you to use any jig you want. Just set the arm length and angle using my setup jigs and you are ready to go.

In the photos in this blog entry I am using Vevor (brand) vari-grind jig as a raw material. I suggest you avoid the Vevor brand. Go with Easy Grind or Oneway vari-grind jigs. See my "Vevor vs Easy Grind vs Oneway Vari-Grind Jig" blog entry.

Photo: 4x7x2 is NOT my Idea (ellsworth_4x7x2_1994) 4x7x2 is NOT my Idea

Long ago, David Ellsworth came up with 4x7x2 for his "Ellsworth Grinding Jig". I fell in love with this system and extended it to work on Hosaluk, and Stirt gouges by creating two more custom Ellsworth like jigs. The jig arm length and angle are different on each of my 3 jigs. Thus all 3 can be used with out changing 4x7x2.


1. 4x7x2 makes a lot of sense. 4" is half of 8" diameter wheel. 4" below center of a 8" wheel is the BOTTOM of a 8" diameter wheel. 2" is just a nice easy number. 7" is another nice easy number that works! 7" is not to close and not to far way. 7" gives you enough room to easily swing a gouge while sharpening.

2. There is a well known trick. If gouge tip is extended 2-1/8" from the FACE of the Ellsworth Sharpening Jig (rather than 2") then you can use a Wolverine V-Arm with OUT a block in the V-Arm. Adjust the length of the V-Arm to match the angle on your Ellsworth Signature Gouge.

3. The old SQUARE Ellsworth jig is NOT the same as the current ROUND Ellsworth Jig. The current ROUND jig is 60 ° bevel angle. The old SQUARE jig is 55 ° bevel angle. My Red Jig is the same as the current ROUND Ellsworth jig.

The 4x7x2 Vari-Grind Setup Jigs

Photo: The 4x7x2 Vari-Grind Setup Jigs (4x7x2_jigs_page2)

Telling people how to precisely set the angle on any grinding jig is something I have struggled with for a long time! Ellsworth style grinding jigs are just a metal rod in thin air. Nothing for reference. Vari-grind jigs do not have a precise angle gauge built in. The notches on the Oneway Wolverine Vari-Grind jig are way to big and wide. Completely useless.

X Y AngleI solved the problem when, I remembered that any angle can be broken down into its "X" and "Y" axis lengths. If the X and Y lengths are around 4 inches or more then specifying this length is a lot more accurate than trying to use tiny degree marks on a protractor or what ever. My "4x7x2" Vari-Grind Setup Jigs" are based on this principle.

Making a jig to set a jig may seem like a complete and total waste of time. But, it is not. Because, IT WORKS! You can get it right the FIRST TIME, every time!

Note: If you known the X and Y axis length then you don't even need to know the angle. You can figure it out using arctan, sin, cos and all that math crap.

Photo: You Need 3 Setup Jigs (4x7x2_sharpening_jigs_07a) You Need 3 Setup Jigs

I have 3 sharpening jigs. Red, Green and Blue. The leg angle and length are different on each of the 3 jogs. Thus you need 3 setup jigs.

Make them as per Page 2 in my blueprints . See the "Cut List" on the blueprint. Photo: Carl’s 4x7x2 Sharpening Jigs 1

I cut my 2" x 2" stock out of scrap 2x4s. I cut them on a table saw. They don't need to be 2×2. You could just use raw 2x4s or cut them on a band saw. If cut on a bandsaw then use the straight factory cuts on the inside of the jig where it counts.

Precision counts when making the jigs! Make everything SQUARE!

Photo: How To Use Setup Jigs (4x7x2_sharpening_jigs_10a) How To Use Setup Jigs

Follow the directions on the blueprint. They are:

  1. Remove arm from Vari-Grind.
  2. Install 1/2" or 5/8" rod in Vari-Grind head.
  3. Install Vari-Grind head with rod in setup jig.
  4. Clamp arm to head with bottom of arm touching 4×7 pivot point.
  5. Drill 2 holes and install 1/4" bolts with nuts.

Note the dark brown plywood under the vari-grind head in the photo. It is a scrap of 1/2" thick plywood that makes enough room under the jig to slip the C-clamp in place.

BEWARE! The use of a short scrap of 1/2" or 5/8" steel or aluminum rod is VERY IMPORTANT! The flutes on a turning gouge often reduce the diameter of gouge to be less than 1/2" or 5/8". This will screw things up when the gouge does not fit SNUGLY in 1/2" or 5/8" slot in my setup jigs!

Thus, I STRONGLY recommend using a 5" long scrap of 1/2" or 5/8" diameter steel or aluminum rod. Like shown in my photos. You can purchase 1/2" or 5/8" rod from Home Depot, etc. It does NOT need to be a fancy piece of tool steel. Any crappy piece of steel or aluminum will do the job.

Photo: Drilling the First Hole (4x7x2_sharpening_jigs_11) Drilling the First Hole

Drill the first 1/4" hole AFTER you clamp the arm in correct location in 4x7x2 setup jig. The setup jig sets the arm length and angle.

I drill the first 1/4"hole thru the EXISTING top hole in the arm. See photo. This hole may or MAY NOT line up with hole in the vari-grind head.

Photo: Drilling the Second Hole (4x7x2_sharpening_jigs_12) Drilling the Second Hole

Drill the second hole AFTER going back to the 4x7x2 setup jig and DOUBLE check things!

The second 1/4" hole will NOT line up with anything in the vari-grind head. I select the location by eye. The second hole should go thru SOLID steel in the vari-grind head. If you hit part of an existing hole it will pull the drill off in the wrong direction.

The red and green jig second holes are easy. The blue jig is more problematic. I drill the second hole on the blue arm THRU the slot in vari-grind head. Then, I use a 1/4" washer under the 1/4" bolt head to span the slot. See photo below.

Photo: Assemble Arm (4x7x2_sharpening_jigs_13) Assemble Arm

Assemble with 1/4" nuts and bolts from local hardware store.

In the photo I am using stop nuts. Stop nuts have a nylon washer built into the nut.

Photo: Double Check (4x7x2_sharpening_jigs_08) Double Check

After drilling and assembling things go back to the 4x7x2 setup jig and DOUBLE check things!

This photo also shows the location of the second hole in blue jig with a 1/4" washer spanning the slot.

2″ Gouge Tip Jig

Photo: 2

The 2" Gouge Tip Jig is used to implement "The Gouge TIP is 2" from FACE of Jig" in 4x7x2 system.

Gouge Tip UsageMake as per Page 3 in my blueprints .

There are lots of commercially available and DIY solutions on the web. I like my solution because it is based on the idea that cutting a PRECISELY 2" wide block on a table saw is a lot easier than drilling a hole that is PRECISELY 2" deep with a Nickel coin in the bottom of the hole.

You can use anything here that floats your boat. I like my jig because the holes don't leave a lot of room for error. It is hard to get a 1/2" diameter gouge sideways in a 9/16" diameter hole. See "This" and "Not This" on page 3 of my blueprints .

4x7x2 Custom Arm for Wolverine

Photo: 4x7x2 Custom Arm for Wolverine (4x7x2_jigs_page4)

My custom arm is used in a Wolverine Base. Make as per Page 4 in my blueprints .

You can use anything here that floats your boat. There are lots of DIY solutions on the web. You can use the Oneway Wolverine Arm if you want with my Yellow 4x7x2 Raptor Jig. See page 6 of my blueprints .

I like my custom arm solution because it has a secondary bevel pivot point and it is hard to slip out of the small pivot points. The pivot point, in the Oneway Wolverine Arm is to big in my not so humble opinion. You can easily slip forward in the Wolverine Arm and screw up your grind.

The built in “secondary bevel” pivot point means you NEVER need to adjust the arm in/out. Thus you can put a stop block on it. Set it & forget it!

You should be able to get most of what you need at local hardware store and/or your local steel supplier. HOWEVER, you really need a FULLY THREADED cap screw. This may be hard or impossible to find locally. You may need to order it from McMaster ( item #90044A150.

Drilling holes in a steel or aluminum bar on edge is not easy. I recommend grinding a little flat spot, so the drill has a flat spot to start on. Use a center drill and a drill press vice.

Cut the slot in the little stop block by drilling a hole and then cut slot with a hack saw. Or, you really don’t need the slot! Use the white jig below to set your arm length. Then, temporarily clamp the stop block to the arm with a C-clamp. Drill a hole all the way thru the stop block and arm and install a #10 bolt. See stop block in photos below.

Photo: Primary Bevel Example (4x7x2_arm_primary_usage) Primary Bevel Example

Primary bevel pivot point in use example. Used to sharpen the primary bevel on a gouge. See photo.

Photo: Secondary Bevel Example (4x7x2_arm_secondary_usage) Secondary Bevel Example

Secondary bevel pivot point in use example. Used to sharpen the secondary bevel on a gouge. See photo.

4x7x2 White Jig

Photo: 4x7x2 White Jig (4x7x2_jigs_page5)

The 4x7x2 White Jig is used to setup "The Pivot Point is 4" below CENTER of Wheel" and "The Pivot Point is 7" from FACE of Wheel" in 4x7x2 system.

Cut the white jig out of 1/4" x 6-1/2" x 12" piece of plywood. Follow the drawing and directions on page 5 of my blueprints .

Photo: White Jig Example (4x7x2_white_jig_usage) White Jig Example

The White Jig in use. See photo. Follow the directions on page 5 of my blueprints.

4x7x2 Raptor Jig (Yellow Jig)

Photo: 4x7x2 Raptor Jig (Yellow Jig) (4x7x2_jigs_page6)

The 4x7x2 Raptor Jig allows you to use my Red, Green, or Blue Vari-Grind jigs in a Oneway Wolverine V-Arm or any other DIY arm.

Photo: Raptor Jig Usage in Wolverine V-Arm (4x7x2_raptor_jig_usage2) Raptor Jig Usage in Wolverine V-Arm

The pivot point in the Wolverine V-Arm is typically more than 4" below the center of an 8" grinding wheel. This means you need to move the V-Arm in closer to the wheel. i.e. make the pivot point less than 7" from face of the wheel.

The Raptor Jig is magic. It keeps the same grind angle AT THE WHEEL when the pivot point is NOT 4" below center of wheel or 7" in front of wheel. It adjusts the distance from pivot point to grinding wheel so it is always the same value. The value required by my 4x7x2 system. See "Wolverine Arm Example" above or on page 5 of my blueprints .


  • The 4x7x2 Raptor Jig is very similar to the 4x7x2 White Jig. It is just a cut down version of the white jig. With one very important change. There is a back cut angle on the 4×7 pivot point that allows it to work in Wolverine V-Arm.
  • I STRONGLY prefer my "4x7x2 Custom Arm for Wolverine". See page 4 of my blueprints . It just works better. The pivot point on my custom arm is more secure. You can't accidentally slip forward in it.

    My custom arm also has a "secondary bevel" pivot point. Thus you never need to adjust the arm in/out. Thus you can put a stop block on it. Set it & forget it!

    If you want to grind a secondary bevel with the Wolverine V-Arm then you have to slide it forward. Thus you can NOT put a stop block on it. If you want to use it for other things then you can NOT put a stop block on it.

  • 3-in-1 Travel Jig

    Photo: 3-in-1 Travel Jig (4x7x2_sharpening_jigs_15)

    Carrying three jigs when I go to a demo or class takes up to much space and weight. Thus, I made a 3-in-1 Travel Jig.

    3 different arms with just 1 jig head. See photo. Notice that the 3 arms are different lengths and have different hole patterns.

    If you want to make one of these then do the blue arm first. Drill holes in the blue arm and jig head on center. Then do the green and red jigs. Use the same (just one set of) holes in the jig head. You can see in photo that the green arm hole is a little to left of center and red arm hole is a little to right of center. i.e. the jig arms go at different angles.

    DIY Vari-Grind Jigs

    Photo: DIY Vari-Grind Jigs (diy_ellsworth_jig)

    I am not a big fan of DIY versions of the Vari-Grind Jig or Ellsworth Jig that are ubiquitous on the web. I rather have a steel or aluminum jig for something that I use all the time, over and over.

    If, I was going to make a DIY jig. I would make it like the red one in above photo. Simple and straight forward block of wood. Aluminum or steel rod and 5/16-18 thumb screw. The wood block is 1-1/2" thick x 2-1/2" long x 2-1/4" tall hard maple.

    Notice the angle cut on the block of wood where the rod goes into the block. Green arrow in above photo. This makes it easy to drill the hole for the rod. I would adjust the length and angle of the rod in one of my "4x7x2 Vari-Grind Setup Jigs". See page 2 of my blueprints .

    The thumb screw needs to come down from the top. NOT up from the bottom. When the thumb screw comes down from the top it goes between the flutes on the gouge in the jig and holds it steady with the flutes up. Grind and polish the end of the thumb screw so it does not screw up the flutes in the gouge.

    The designs all over the web that try to recreate the metal vari-grind jig in wood are CRAZY. Doomed to failure. You can't make the wooden joints strong enough or rugged enough. The Oneway vari-grind jig was designed as something that could easily be made (welded up) in STEEL. You need a completely different solution for wood.


    Photo: History (4x7x2_sharpening_jigs_16)

    I Use What I Recommend!

    I now use 3 custom vari-grind based jigs in my studio. I no longer use the Ellsworth style ones that I made from scratch long ago. My new red, green, and blue vari-grind based jigs are the same as the old Ellsworth style ones.

    Long ago (20 years ago?), I realized I really liked the Ellsworth Sharpening Jig. It is easy to use. No dorking around with jig arm angles on my vari-grind jig, etc. Thus, I decided to make two similar Ellsworth style jigs for the Stirt Bowl Gouge and Hosaluk Detail Gouge grinds that I really like to use all the time. I made my jigs and I was happy.

    Then I started teaching students in my studio and I ran into a problem. Students would come to my studio and fall in love with my quick and easy grinding jigs. I struggled with how can students make there own version of my grinding jigs. Helping each student make 3 custom Ellsworth style jigs was to time consuming and error prone. I often had trouble getting the angles and everything just right.

    In the mean time, I tried over and over to come up with a one size fits all jig. Or an easy set up that required just one or two vari-grind or Ellsworth style jigs. I drew things out (grinding wheel, etc) on paper and dorked around. I tried full size mock ups with an old 8" CBN wheel. No luck! If you want to keep a simple 2" gouge projection in front of the jig. Then, changing 4×7 arm, does not work well. Not worth the trouble. You MUST change the jig arm angle and length! 4x7x2 with 3 jigs is the best solution!