Bandsaw Circle Cutting

circle-cutting jig

band saw Circle-Cutting Jig In just an afternoon, you can build a simple accessory that makes creating perfect circles a snap.

The band saw is without a doubt one of the most you rotate it through the cut. An adjustable pivot versatile tools in the shop, especially when it comes pin that’s mounted in this base, as well as a heavy- to cutting curved or round parts. And with the jig duty aluminum bar, work together to allow you to you see above, you can even cut perfectly shaped cut circles up to 38" in diameter. circles quickly and reliably. Finally, a unique stop system lets you align the The jig’s base is made from phenolic plywood. pivot pin with the front edge of the blade. This way, This type of plywood has a durable, slick surface the jig automatically stops at the correct point for you that makes it perfect for supporting a workpiece as to begin rotating the workpiece for the cut.

1 WoodsmithPlans.com SN11324 ©2012 August Home Publishing Co. All Rights Reserved. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z AA BB C C DD E E F F GG HH I I J J KK L L MM NN OO P P QQ RR SS T T UU V V WW X X Y Y Z Z AAA BBB CC C DDD EEE F F F GGG HHH I I I J J J K KK L L L MMM NNN OOO P P P QQQ RRR SSS T T T UUU V V V WWW X X X Y Y Y Z Z Z CL

EXPLODED VIEW OVERALL DIMENSIONS: (24!/2" x 24!/2" x 24!/2")

PART NAME

CALLOUT Sizing the Base. To get started, 1 you’ll want to measure the width PHENOLIC PLYWOOD TOP VIEW PROVIDES A DURABLE, and depth of your band saw table. SLICK SURFACE END VIEW I sized the jig base 4" larger in both A B C D E F G H I J K L M directions to provide solid support SIDE VIEW A B C D E F G H I J K L M N O P Q R S T U V W X Y Z for the workpiece (Figure 1). BASE N O P Q R S T U V W X Y Z (18" x 18" - #/4" Ply.) AA BB C C TOPDD EVIEWE F F GG HH I I Locate the Runner. An alumi- (CROSS SECTION) AA BB C C DD E E F F GG HH I I J J KK L L MM NN OO P P QQ RR num runner rides in the miter slot J J KK L L MM NN OO P P QQ RR SS T T UU V V W W X X Y Y Z Z to align the jig for the initial cut STEP 1: XXXX SS T T UU V V WW X X Y Y Z Z AAA BBB XXXXXXXXXXXXXXXCC C DDD EEE F F F into the workpiece. (I’ll talk more SECOND: MARK AAA BBB CC C DDD EEE F F F LOCATION FOR GGG HHH I I I J J J K KK L L L about that later.) To locate the run- RUNNER GGG HHH I I I J J J K KK L L L MMM NNN OOO P P P QQQ RRR MMM NNN OOO P P P QQQ RRR ner, place the base on the saw X X X SSS T T T UUU V V V WWW SSS T T T UUU V V V WWW X X X table with the left side of the base FIRST: POSITION Y Y Y Z Z Z C BASE FLUSH WITH L Y Y Y Z Z Z C flush with the edge of the saw table. INSIDE EDGE L OF TABLE After marking the location of the “QUOTE MARKS” miter slot, cut a shallow dado sized EXPLODED VIEW OVERALL DIMENSIONS: EXPLODED VIEW to fit the runner (Figure 2). You can NOTE: EASE ALL EDGES !/2 !/2 !/2 OVERALL DIMENSIONS: WITH !/16" CHAMFER (24 " x 24 PATTERN" x 24 ") (24!/2" x 24!/2" x 24!/2") temporarily install the runner to complete the next step. PART NAME w/LETTER A B(firstC timeD E used)F G H I J K L M N O P Q R S T U V W X Y Z FIGURE CALLOUT AA BB C C DD E E F F GG HH I I 2 CALLOUT J J KK L L MM NN OO P P QQ RR TOP VIEW TOPSS TVIEWT UU V V WW X X Y Y Z Z DDD EEE F F F END VIEW AAA BBB CC C CUT DADO FOR ENDGGG VIEWHHH I I I J J J K KK L L L RUNNER AND " TEMPORARILY SIDE VIEW SIDEMMM VIEWNNN OOO P P P QQQ RRR ATTACH WITH SCREWS #8 x 1" Fh SSS T T T UUU V V V WWW X X X WOODSCREW TOP VIEW Y Y Y Z Z Z (CROSS SECTION) !/2 TOP VIEW C #8 x 1 " Fh (CROSS SECTION) L WOODSCREW #8 x 2" Fh 1!/4" 1!/2" 1#/4" a. STEP 1: XXXX XXXXXXXXXXXXXXXWOODSCREW STEPEXPLODED 1: XXXX VIEW XXXXXXXXXXXXXXXOVERALL DIMENSIONS: #/4 !/2 !/2 !/2 FIRST: XXXXXXX (24 " x 24 " x 24 ") XXXXXXXXXXX FIRST: XXXXXXX XXXXXXXXXXX PART NAME w/LETTER RUNNER (first time used) (#/4" x 18" - #/8" Alum.) !/16 #/4 #8 x " Fh “QUOTE MARKS” WOODSCREW “QUOTECALLOUT MARKS” PATTERN PATTERNTOP VIEW Making a Saw Kerf. The next 3 END VIEW task is to create a kerf in the base. FIRST: SLIP SIDE VIEW This kerf locates the end of the RUNNER INTO stopped groove that will be used to MITER SLOT TOP VIEW house the adjustment bar. (CROSS SECTION) Cutting this kerf is a simple mat- STEP 1: XXXX ter. Just turn on the saw, set the XXXXXXXXXXXXXXX runner in the miter slot, and push FIRST: XXXXXXX the base forward into the band saw XXXXXXXXXXX blade. Proceed slowly, so you don’t #8 x 1" Fh SECOND: CUT SAW WOODSCREW cut too far into the piece. Once the KERF UNTIL BACK EDGE #/4 #8 x 1!/2" Fh 3 EXTENDS " PAST BACK back edge of the base extends ⁄4" EDGE OF TABLE WOODSCREW !/2" #/4" #8 x 2" Fh 1!/4" 1 1 “QUOTE MARKS” !/2" #/4" past the back edge of the table, you WOODSCREW #8 x 2" Fh 1!/4" 1 1 can stop the cut, as shown in Figure WOODSCREW

3 at right. At this point, you can turn NOTE: THE DIAMETERPATTERN OF THE BIT your attention to making the adjust- AND THE DEPTH OF CUT DETERMINES THE SIZE OF YOUR WORKPIECE ment bar, which we’ll show you how to do on the next page. WASTE !/4" 2 WoodsmithPlans.com SN11324 ©2012 August Home Publishing Co. All Rights Reserved. !/4 FULL DIAMETER OF BIT USED END VIEW TO ROUT PROFILE FENCE

#8 x 1" Fh WOODSCREW #8 x 1!/2" Fh WOODSCREW #8 x 2" Fh 1!/4" 1!/2" 1#/4" WOODSCREW

CUT SAW KERF UNTIL BACK EDGE OF BASE THE DIAMETER OF THE BIT IS FLUSH WITH EDGE NOTE: NOTE: THE DIAMETER OF THE BIT OF TABLE AND THE DEPTH OF CUT DETERMINES THE SIZE OF YOUR WORKPIECE AND THE DEPTH OF CUT DETERMINES THE SIZE OF YOUR WORKPIECE

WASTE WASTE !/4" !/4" !/4 FULL DIAMETER !/4 FULL OF BIT USED DIAMETER END VIEW TO ROUT OF BIT USED PROFILE END VIEW TO ROUT FENCE PROFILE FENCE

NOTE: THE DIAMETER OF THE BIT AND THE DEPTH OF CUT DETERMINES THE SIZE OF YOUR WORKPIECE

WASTE !/4" !/4 FULL DIAMETER OF BIT USED END VIEW TO ROUT PROFILE FENCE A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A B C D E F G H I J K L M AA BB C C DD E E F F GG HH I I Q X Z N O P R S T U V W Y J J KK L L MM NN OO P P QQ RR AA BB C C DD E E F F GG HH I I SS T T UU V V WW X X Y Y Z Z J J KK L L MM NN OO P P QQ RR AAA BBB CC C DDD EEE F F F SS T T UU V V WW X X Y Y Z Z GGG HHH I I I J J J K KK L L L AAA BBB CC C DDD EEE F F F MMM NNN OOO P P P QQQ RRR GGG HHH I I I J J J K KK L L L SSS T T T UUU V V V WWW X X X MMM NNN OOO P P P QQQ RRR Y Y Y Z Z Z CL SSS T T T UUU V V V WWW X X X Y Y Y Z Z Z NOTE: SEE SHOP SHORT CUTS EXPLODED VIEW FOR CUTTING GROOVE FOR OVERALL DIMENSIONS: MAKE PIN FROM !/16" ADJUSTMENT BAR (24!/2" x 24!/2" x 24!/2") FIGURE DRILL BIT AND EPOXY (PAGE 5) EXPLODED VIEW attaching the 4 INTO HOLE OVERALL DIMENSIONS: (24!/2" x 24!/2" x 24!/2") END OF GROOVE PART NAME w/LETTER ALIGNED WITH (first time used) !/2 SAW KERF 1 PART NAME w/LETTER Bar & Stop (first time used) CALLOUT #/8"-WIDE PART NAME !/16"-DIA. With the base complete, you’re SLOT CL ready to add an adjustment bar that CALLOUT TOP VIEW locks in the cutting radius. Lastly, !/4"-20 x 1" THREADED !/2 ROD FASTENED END VIEW 1 you’ll add an adjustable stop. This WITH EPOXY TOP VIEW !/8 stop correctly positions the pivot pin 3 END VIEW relative to the blade. It also prevents #/4 1 the jig and workpiece from lifting off FILE EDGES OF SIDE VIEW TOP VIEW BAR SMOOTH (CROSS SECTION) the table once you start the cut. PIVOT ADJUSTMENT TOP VIEW Adjustment Bar. The first thing a. (CROSS SECTION) XXXX !/4" PIN BAR STEP 1: 5 -20 XXXXXXXXXXXXXXX to do is cut the ⁄16"-thick aluminum INSERT KNOB DRILL AND bar to length. I took the time to file w/WASHER STEP 1: XXXX XXXXXXXXXXXXXXX FIRST: XXXXXXX TAP FOR XXXXXXXXXXX !/4"-20 off the sharp edges before drilling BASE THREADS and tapping all the holes (margin Then, I routed the adjustment slot at FIRST: XXXXXXX 11 RUNNER XXXXXXXXXXX drawing). The tapped holes allow the router table (Figure 4). You can A B C D E F G H I J K L M for a wide range of adjustment for fasten the adjustment bar in place SIDE VIEW N O P Q R S T U V W X Y Z “QUOTE MARKS” the cutting radius. with a studded knob and washer. AA BB C C DD E E F F GG HH I I Figure 4 and the margin draw- Now would also be a good time to “QUOTE MARKS” J J KK L L MM NN OO P P QQ RR ing show all of the hole locations reinstall the runner on the bottom. go ahead and install the threaded PATTERN SS T T UU V V WW X X Y Y Z Z in the adjustment bar. The pivot Stop Assembly. When using insert while you’re at it. %/16"-THICK PATTERN AAA BBB CC C DDD EEE F F F 1 A B C D E F G H I J K L M ALUMINUM pin is made from a ⁄16"-dia. drill bit the jig, it’s important that the pin is After fastening the block to the GGG HHH I I I J J J K KK L L L ADJUST- MENT ground to a point. It’s glued with directly aligned with the front edge underside of the base, all you MMM NNN OOO P P P QQQ RRR N O P Q R S T U V W X Y Z BAR epoxy into the aluminum bar. The of the blade’s teeth (see page 4). need to do is install the hardware. SSS T T T UUU V V V WWW X X X AA BB C C DD E E F F GG HH I I remaining holes are drilled and This prevents the blade from bind- This starts with a short length of Y Y Y Z Z Z J J NN OO P P QQ RR 1!/2 KK L L MM 1 tapped for a ⁄4"-20 thread. ing and results in a smoother cut. aluminum bar. It’s longer than SS T T UU V V WW X X Y Y Z Z !/2 Groove & Slot. You can set the To accomplish this goal, I made the the mounting block and creates AAA BBB CC C DDD EEE F F F EXPLODED VIEW GGG HHH I I I J J J K KK L L L bar aside for now and get to work on stop assembly shown in Figure 5. a “hook” to keep the jig in place. OVERALL DIMENSIONS: 2 the stopped groove for the bar. And The assembly starts with the You can see how it’s installed in (24!/2" x 24!/2" x 24!/2") MMM NNN OOO P P P QQQ RRR #/8 SSS T UUU V V V WWW X X X there’s a slot located at the end of the mounting block. Its thickness Figures 5 and 5a. T T #8 x 1" Fh 5 PART NAME w/LETTER Y Y Y Z Z Z CWOODSCREW groove for the adjustment knob that matches the thickness of the band Next comes the knob assembly. (first time used) L !/2 #8 x 1" Fh #8 x 1 " Fh sets the radius. I removed the run- saw table (Figure 5a). Drill the Begin by cutting the threaded rod WOODSCREW WOODSCREW PART NAME DRILL AND !/2" #/4" COUNTER- ner to make these two tasks easier. through hole for the threaded rod to length and using epoxy to fasten EXPLODED VIEW#8 x 2" Fh 1!/4" 1 1 SINK OVERALL DIMENSIONS:WOODSCREW FOR #8 Fh Routing the stopped groove is and the two screw holes used when a knob at one end. After the epoxy CALLOUT !/2" #/4" (24!/2" x 24!/2" x 24!/2") WOOD- easy (see Shop Short Cuts on page 5). attaching it to the base. You can sets up, you can spin on a locking #8 x 2" Fh 1!/4" 1 1 SCREW WOODSCREW knob before threading the rod into TOP VIEW %/16 PART NAME w/LETTER "-THICK the insert in the mounting block. (first time used) ALUMINUM END VIEW STOP BAR Final Adjustment. The last thing PART NAME 5 MOUNTING BLOCK 1!/2 (1!/4" x 1!/2" - 3") to do is install the jig on your saw SIDE VIEW CALLOUT and make some adjustments fol- TOP VIEW !/4"-20 x 8" lowing the process detailed on the (CROSS SECTION) TOP VIEW 1 THREADED ROD next page. Once everything is set up, you’ll soon discover how easy STEP 1: XXXX END VIEW !/4"-20 XXXXXXXXXXXXXXX THREADED it is to cut perfect arcs and circles in #/4 C INSERT #8 x 1 " Fh L no time at all. FIRST: XXXXXXX WOODSCREW XXXXXXXXXXX TOP VIEW a. (CROSS SECTION) !/2 SIDE VIEW !/4"-20 INSERT RUNNER KNOB FASTENED STEP 1: XXXX WITH EPOXY “QUOTE MARKS” XXXXXXXXXXXXXXX

FIRST: XXXXXXX XXXXXXXXXXX #8 x #/4" Fh STOP BAR PATTERN WOODSCREW (1!/2" x 5" - %/16" Alum.)

!/4 #/8 "-20 THROUGH "-DIA. !/4" WASHER KNOB HOLE “QUOTE MARKS”

3 WoodsmithPlans.com SN11324 ©2012 August Home Publishing Co. All Rights Reserved. PATTERN NOTE: THE DIAMETER OF THE BIT AND THE DEPTH OF CUT DETERMINES THE SIZE OF YOUR WORKPIECE NOTE: THE DIAMETER OF THE BIT AND THE DEPTH OF CUT DETERMINES THE SIZE OF YOUR WORKPIECE WASTE #8 x 1" Fh !/4" WOODSCREW !/4 FULL WASTE DIAMETER OF BIT USED !/4" FULL END VIEW TO ROUT !/4 PROFILE DIAMETER FENCE #8 x 2" Fh 1!/4" 1!/2" 1#/4" OF BIT USED WOODSCREW END VIEW TO ROUT PROFILE FENCE #8 x 1" Fh WOODSCREW

#8 x 2" Fh WOODSCREW

NOTE: THE DIAMETER OF THE BIT AND THE DEPTH OF CUT DETERMINES THE SIZE OF YOUR WORKPIECE

WASTE !/4" !/4 FULL DIAMETER OF BIT USED NOTE: THE DIAMETER OF THE BIT END VIEW TO ROUT AND THE DEPTH OF CUT DETERMINES PROFILE THE SIZE OF YOUR WORKPIECE FENCE

WASTE !/4" !/4 FULL DIAMETER OF BIT USED END VIEW TO ROUT PROFILE FENCE Using the Circle-Cutting Jig Perfect Circles. After cutting the Setting up the jig and using it is center of the pin to the outside edge workpiece to shape, a little sanding is pretty simple. The photos guide of the blade’s teeth. all it takes to remove the saw marks. you through the process. Cutting. You’re almost ready to Initial Setup. The most impor- start cutting, but first you need to tant part of using the jig is making drill a centered pivot hole in the sure the pivot pin is aligned with workpiece. This involves drilling a the front edge of the blade. This is a stopped hole on the bottom face. matter of adjusting the stop to con- With the saw off, slip the work- tact the edge of the table and lock- piece over the pivot pin. Now you making a straight ing it using the locking knob. can turn on the saw and get ready cut until the jig stops Set the Radius. The next step is to make the cut. against the table. Then, you can to set the radius for the desired cut. While holding the workpiece begin rotating the workpiece into Here, you’re measuring from the steady, slide the jig forward, the blade to cut a perfect circle.

{ Aligning the Center Pin. Use a { Setting the Radius. To set the radius, framing square to align the pivot pin loosen or remove the adjustment knob and with the front edge of the blade. After adjusting the stop underneath so that the slide the bar so the pivot pin is located at the threaded rod contacts the table, lock it in place (inset photo). desired radius and tighten the knob.

{ Straight Cut First. After drilling a { Perfect Circles. Once the stop contacts the band saw pivot hole (inset), place the workpiece table, you can start rotating the workpiece into the blade in a on the jig. As you make the cut, hold the clockwise direction. The key to a smooth edge is to maintain a workpiece straight until the jig stops. consistent feed rate throughout the cut.

4 WoodsmithPlans.com SN11324 ©2012 August Home Publishing Co. All Rights Reserved. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z AA BB C C DD E E F F GG HH I I J J KK L L MM NN OO P P QQ RR SS T T UU V V WW X X Y Y Z Z AAA BBB CC C DDD EEE F F F GGG HHH I I I J J J K KK L L L MMM NNN OOO P P P QQQ RRR SSS T T T UUU V V V WWW X X X Y Y Y Z Z Z CL

EXPLODED VIEW OVERALL DIMENSIONS: (24!/2" x 24!/2" x 24!/2")

A B C D E F G H I J K L M PART NAME w/LETTER (first time used) N O P Q R S T U V W X Y Z PART NAME AA BB C C DD E E F F GG HH I I J J KK L L MM NN OO P P QQ RR CALLOUT SS T T UU V V WW X X Y Y Z Z AAA BBB CC C DDD EEE F F F TOP VIEW GGG HHH I I I J J J K KK L L L END VIEW tips from MMM NNN OOO P P P QQQ RRR SSS T T T UUU V V V WWW X X X SIDE VIEW Our Shop FASTEN STRIPS IN PLACE Y Y Y Z Z Z C AROUND ALUMINUM BAR L TO FORM TEMPLATE TOP VIEW FOR ROUTING (CROSS SECTION) EXPLODED VIEW GUIDE OVERALL DIMENSIONS: STEP 1: XXXX JIG BASE (24!/2" x 24!/2" x 24!/2") XXXXXXXXXXXXXXX FIRST: XXXXXXX PART NAME w/LETTER XXXXXXXXXXX GUIDE (first time used) ALUMINUM Shop BAR NOTE: XXXXXXX PART NAME XXXXXXXXXXX TEMPLATE CALLOUT “QUOTE MARKS” DOUBLE-SIDED Short TAPE TOP VIEW GUIDE PATTERN a. END VIEW SIDE VIEW GUIDE TOP VIEW Cuts GUIDE (CROSS SECTION) !/4

WASTE STEP 1: XXXX DADO XXXXXXXXXXXXXXX CLEANOUT JIG BIT BASE FIRST: XXXXXXX XXXXXXXXXXX

NOTE: XXXXXXX XXXXXXXXXXX #8 x 1" Fh WOODSCREW Fitted Groove #8 x 1!/2" Fh “QUOTE MARKS” WOODSCREW The adjustment bar on the band bar in position on the base, then #8 x 2" Fh 1!/4" 1!/2" 1#/4" saw circle jig rides in a stopped fasten hardwood guides around it WOODSCREW groove. To cut the groove, I used using double-sided tape. PATTERN my router and simple guides. As I used a dado cleanout bit to rout you can see in the drawings above, out the groove. The bearing on the I assembled the guides around the bit follows the guides. All that’s aluminum bar, guaranteeing a per- left to do now is square up the cor- fect fit. All you need to do is set the ners with a chisel.

#8 x 1" Fh WOODSCREW #8 x 1!/2" Fh WOODSCREW #8 x 2" Fh 1!/4" 1!/2" 1#/4" WOODSCREW

5 WoodsmithPlans.com SN11324 ©2012 August Home Publishing Co. All Rights Reserved. MAIL Project Sources ORDER SOURCES The circle-cutting jig doesn’t take long to build, especially if you have all of your Woodsmith Store 800-444-7527 supplies ready to go. You can find the 5 1 ⁄16" x 1 ⁄2" aluminum bar (8975K18) at 1 McMaster-Carr McMaster-Carr. You’ll also need ⁄4"-20 in- 630-600-3600 1 sert knobs (DK-1204) and ⁄4"-20 through mcmaster.com knobs (DK-1210), both of which I found Reid Supply at Reid Supply. The Kreg jig/bar fixture 800-253-0421 (KMS7303) can be purchased from Kreg reidsupply.com Tool. And I got the phenolic plywood Woodcraft (131170) from Woodcraft. 800-225-1153 woodcraft.com

Kreg Tool 800-447-8638 kregtool.com