
Screw Cuttin’ Lathe
Season 32 Episode 6 | 26m 46sVideo has Closed Captions
Roy Underhill shows how to use an 1889 foot-driven metal working lathe.
Make your own darn metal screws with this 1889 foot-powered lathe! Roy shows how to cut perfect threads, cones and tapers in iron and brass.
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Problems playing video? | Closed Captioning Feedback
The Woodwright's Shop is a local public television program presented by PBS NC
PBS North Carolina produces The Woodwright's Shop with Roy Underhill in partnership with State Farm Insurance.

Screw Cuttin’ Lathe
Season 32 Episode 6 | 26m 46sVideo has Closed Captions
Make your own darn metal screws with this 1889 foot-powered lathe! Roy shows how to cut perfect threads, cones and tapers in iron and brass.
Problems playing video? | Closed Captioning Feedback
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CAPTIONING MADE POSSIBLE BY FRIENDS OF NCI HEY, HELLO AGAIN.
WELCOME BACK TO "THE WOODWRIGHT'S SHOP."
I'M ROY UNDERHILL.
AND FOOLS RUSH IN.
AND I'M NOT TALKING ABOUT YOU.
I'M TALKING ABOUT ME.
I HAVE HAD THIS WONDERFUL 1887 BARNES NUMBER 4 1/2 FOOT-POWERED, BACK-GEARED SCREW-CUTTING METAL LATHE FOR TWO WEEKS, AND I HAVE THE BOLDNESS TO GO AHEAD AND SAY IT.
I'M GONNA SHOW YOU HOW TO USE IT.
AND I'VE SPENT A LOT OF THAT TWO WEEKS JUST TUNING IT UP, CLEANING IT, FIXING IT, AND TAKING ON EXTRA WORK SO I COULD PAY FOR IT.
BUT I HOPE I CAN MAKE UP WITH ENTHUSIASM WHAT I LACK IN INTIMATE KNOWLEDGE OF THE ART OF THE MACHINIST.
NOW, AS A WOODWORKER, YOU KNOW, I NEED LOTS OF... GOT LOTS OF TOOLS.
YOU NEED SCREWS CUT.
YOU NEED...PARTS MISSING.
WELL, THIS IS A SCREW-CUTTING LATHE, AND YOU CAN SEE HOW IT WORKS HERE.
HERE'S THE TOOL REST.
ACTUALLY NOT THE TOOL REST, BUT THE TOOL CARRIAGE.
AND I SAY CARRIAGE BECAUSE IT'S RIDING ALONG.
YOU CAN SEE IT SLOWLY ADVANCING AS I TREADLE.
SLOWLY ADVANCING DOWN THE CYLINDER AS IT ROTATES.
WELL, LET'S TAKE THAT ON BACK.
I'LL PEDAL THE OTHER WAY NOW.
TAKE IT ON BACK.
AND WE WILL ADVANCE THIS CUTTER INTO THE BRASS ROD, AND WE WILL CUT A SCREW.
AND THEN WE'LL FIGURE OUT HOW IT WORKS.
ALL RIGHT?
READY?
HERE WE GO.
SET THAT IN.
HAVE I GOT A CUT?
ALL RIGHT.
THERE WE GO.
AND NOW WE JUST WORK IT RIGHT ALONG THERE.
HA HA HA HA HA!
YES, SIR.
ALL RIGHT.
AND IT JUST TRAVERSES THERE.
THERE'S A SCREW FEEDING THIS CUTTER LENGTHWISE AS THE METAL TURNS.
NOW I'M GOING TO BACK OFF.
I'VE TURNED A LITTLE SCREW ON THE BACK, AND NOW I'LL RETURN HERE.
ALL RIGHT.
JUST TREADLING IN THE OTHER DIRECTION.
SO WE ALWAYS TRY AND-- I'M LEARNING SOME OF THE RULES.
WE ALWAYS CUT TOWARDS THE HEAD STOCK, AND THAT'S THE PART THAT GRIPS THE METAL AND MAKES IT TURN.
SO NOW I'LL SET IT A LITTLE BIT DEEPER AND GO AGAIN.
AND THERE WE GO.
HA HA HA HA!
ALL RIGHT.
IT JUST CUTS RIGHT ALONG, ADVANCING.
SO WE'RE CUTTING 16 THREADS TO THE INCH, AND I KNOW THAT BECAUSE WE'VE SET THIS UP ON THIS BARNES NUMBER 4 1/2 TO DO EXACTLY THAT.
LET ME BACK IT BACK OFF AGAIN.
IN FACT, I'LL BACK IT WAY OFF, AND WE'LL TAKE A LOOK AT WHAT MAKES THIS THING TICK.
IT'S AN OLD IDEA AND A GREAT ONE HERE.
THE ONE THING IS-- JUST TAKE A LOOK BEFORE I GET DOWN AND SHOW YOU THE OTHER PARTS HERE.
DO YOU SEE HOW SLOW IT'S RUNNING?
YOU NEED A LOT OF TORQUE WHEN YOU'RE CUTTING SCREWS, AND YOU CAN SEE THIS BELT HERE IS GOING PRETTY FAST.
I GOT A BELT JUST WAILING AWAY RIGHT THERE, BUT IT IS NOT CONNECTED DIRECTLY TO THE CHUCK.
SO THE BELT IS SPINNING REAL FAST HERE.
INSTEAD IT'S-- WHAT THE BELT IS DOING IS TURNING THESE BACK GEARS.
THESE ARE THE BACK GEARS HERE.
IT GOES FROM A SMALL GEAR TO A BIG GEAR, SO THAT SLOWS IT DOWN, AND A SMALL GEAR TO A BIG GEAR HERE, AND THAT SLOWS IT DOWN AGAIN.
SO I'M GONNA DISENGAGE THAT.
I CAN ENGAGE IT, SWING IT IN AND OUT, RUNNING IT ON THE BACK GEAR.
BUT LET'S TRACE IT FROM THE BOTTOM UP HERE TO SEE WHAT MAKES IT CUT THE SCREW THREAD.
SO FROM THE BOTTOM DOWN HERE, I'VE GOT THE-- OOP.
MAKE SURE MY CUTTERS ARE STILL IN GOOD SHAPE, BECAUSE THIS THING KEEPS GOING.
YOU CAN'T REALLY DISENGAGE IT.
SO THERE YOU GO.
I'VE GOT THE TREADLES DOWN THERE, AND THEY TURN A SPROCKETED GEAR.
THERE'S A CHAIN THAT COMES UP AND THEN TURNS THE FLYWHEEL THAT I'M TURNING RIGHT NOW, AND IT'S STEPPED SO YOU CAN CHANGE THE SPEED, BUT THEN IT COMES UP HERE, AND NOT ONLY TURNS THE CYLINDER THROUGH THIS STEPPED PULLEY UP TOP NOW.
SO IT TURNS THIS CYLINDER THAT YOU'VE CHUCKED UP IN THE LATHE, BUT IT ALSO TURNS THIS GEAR RIGHT HERE.
THESE ARE THE CHANGE GEARS.
THESE CHANGE GEARS ARE WHAT DRIVES A LONGITUDINAL SCREW THAT'S FEEDING THE TOOL REST DOWN THE LENGTH OF THE TOOL CARRIAGE THERE.
SO TO FIND OUT HOW TO DO THE SCREW-- IT COMES WITH EVERY LATHE-- THERE'S A PLATE ON IT RIGHT HERE, AND I LOOK AT THAT PLATE, AND I SAY, "HOW MANY THREADS TO THE INCH?"
WELL, I'M CUTTING 16 THREADS TO THE INCH.
AND SO I SAY 32 ON THE SCREW, AND I SEE 20 ON THE SPINDLE.
AND THAT'S WHAT I HAVE-- A 20-COGGED GEAR, TOOTHED GEAR ON THE SPINDLE, A 32-TOOTHED GEAR HERE.
THEY'RE INTERCONNECTED, AND THAT'S WHAT MAKES THE FEED RATIO.
SO YOU CAN CUT ANY KIND OF THREAD PITCH THAT YOU WANT JUST BY READING THE TABLE AND CHANGING OUT THE GEARS.
I MEAN, LOOK AT ALL THESE GEARS HERE.
HERE THEY ALL ARE.
SO YOU CHANGE THESE GEARS, WITH THE TEETH AS SHOWN ON THE TABLE, AND THAT'S WHAT LETS YOU DO ANY KIND OF SCREW THAT YOU WANT.
ALL RIGHT.
SO, LET'S CUT ANOTHER.
LET'S GET BACK HERE AGAIN, AND I'VE GOT A NICE, UH... HA HA HA.
THIS IS THE DEAD CENTER DOWN HERE.
I GET SOME OF THE PARTS IN.
LET ME GO THE OTHER WAY NOW.
SO I'VE GOT TO JUST TREADLE THIS WAY, AND WE'LL CUT ONE MORE THREAD.
UH, SO HERE WE GO.
THIS IS THE DEAD CENTER, AND IT'S IN THE TAIL STOCK.
AND I'M TAKING THE CUTTER IN.
TAKE THE CUTTER IN UNTIL I SEE IT TAKE OFF A NICE CHIP, ALL RIGHT, AND THEN JUST RUN IT ALONG LIKE THAT, AND YOU CAN SEE, BECAUSE OF THOSE GEARS, IT'S SENDING THE CUTTER DOWN THE LENGTH OF THE CYLINDER AT A SPECIFIED RATE.
AND BECAUSE WE ALWAYS CUT TOWARDS... FROM LEFT TO...HA HA HA.
FROM RIGHT TO LEFT, WE'RE ALWAYS GOING INTO THE HEAVIEST PART OF THE MECHANISM.
SO JUST A GREAT TECHNIQUE HERE.
ALL RIGHT.
NOW, WHAT MORE CAN IT DO?
BUT WAIT.
THERE'S MORE.
SCREW-CUTTING IS A BIG PART OF IT, BUT NOT THE ONLY THING I NEED TO MAKE ON THE LATHE.
I HAVE TO DO, SAY, CUTTING CENTERS, LIKE... WELL, LIKE THIS IS A CENTER RIGHT HERE.
I HAVE A CENTER IN THIS LATHE, THIS CONICAL 60-DEGREE POINT.
WE NEED THOSE FOR SPRINGPOLE LATHES AS WELL.
SO WE'LL SEE HOW WE CAN MAKE ONE OF THOSE.
I'M GONNA BACK OFF THE TOOL REST, AND LET'S SEE.
WE NEED TO TAKE OUT A COUPLE OF THINGS HERE SO WE'LL GET TO USE IT.
NOW, THIS IS THE STEADY REST.
THIS IS AN INTERMEDIATE STEADY REST RIGHT HERE.
SO I'VE LOOSENED THAT UP.
AND I'VE GOT A 3-JAW CHUCK THAT CENTERS ITSELF.
THAT'S VERY NICE.
IT HAS A SPIRAL ON A PLATE, AND SO THAT EACH OF THESE JAWS COMES IN AT THE SAME TIME AS WE TURN THE SCREW.
SO HERE WE GO.
WE TAKE THAT OUT.
AND NOW WE DON'T NEED THE STEADY REST ANYMORE.
THAT CAN COME OFF.
SO WE'VE GOT THAT RIGHT THERE.
ALL RIGHT.
AND THAT OPENS UP, I HOPE, DOWN BELOW.
AND I SHOULD BE ABLE TO-- OOP.
SEE IF I CAN GET THAT.
THERE'S A LITTLE SCREW THAT HAS TO TURN.
THERE WE GO.
RIGHT.
AND THIS WILL COME OFF.
YOU CAN SEE HOW THIS ADJUSTS TO GO IN TO STEADY THE WORK AT SOME POINT BECAUSE THE VIBRATION IS THE ENEMY OF PRECISION.
BUT WE DON'T NEED IT NOW BECAUSE WE'RE GONNA CHUCK RIGHT INTO... WE'RE GONNA CUT RIGHT UP ON THE CHUCK HERE.
SO I'M GOING TO SET THIS IN HERE.
I'M GOING TO DO SOMETHING A LITTLE BIT SLACK HERE.
I'LL TIGHTEN THIS UP, SO I'VE GOT TO TURN THIS AROUND.
TIGHTEN IT ON ALL 3 SCREWS.
ALL RIGHT.
AND THEN I'M GOING TO TAKE OUT OR DISENGAGE THE BACK GEAR.
SO HERE, THERE'S A LITTLE BOLT RIGHT HERE ON THIS GEAR, AND THAT IS WHAT KEEPS IT CONNECTED EITHER TO THE PULLEY DIRECTLY OR RUNNING OFF OF THE BACK GEAR HERE.
SO WE CAN DISENGAGE THE BACK GEAR BY JUST DOING IT.
THERE.
IT JUST GOES BACK ON A CAM.
SO THOSE BACK GEARS ARE NOW DISENGAGED.
SEE?
NOTHING'S HAPPENING WHEN I TREADLE.
BUT NOW WHAT I HAVE TO DO IS, OF COURSE, NOW REENGAGE THE...
UH!
UH...FRONT HERE, THE HEADSTOCK WITH THE PULLEY, WITH THE STEP PULLEY.
SO THERE WE GO.
I FOUND A LITTLE NICK THERE.
AND WE'LL TIGHTEN THIS UP.
AND THERE WE GO.
HA HA HA HA!
ALL RIGHT.
SO THAT'S GOOD.
ALL RIGHT.
SO NOW, THAT WILL ALLOW US TO TURN.
I DON'T NEED THE TRAVERSING MECHANISM.
I'LL LET IT JUST BRING IT ON DOWN.
BUT YOU SEE HOW MUCH FASTER IT'S GOING NOW?
LOOK AT THAT.
I'VE GOT THE TRAVERSING MECHANISM GOING ON.
I'M GOING TO TAKE OUT-- THERE WE ARE.
THE SCREW-CUTTING TOOL HERE.
ALL RIGHT.
BY UNDOING THE TOOL POST.
AND WE'LL ADJUST THE NEW TOOL IN PLACE HERE.
AND THIS IS A LITTLE SLACK.
I'M GOING TO SET IT ACTUALLY TO AN EXISTING PIECE OF WORK.
BUT WHAT I'M DOING NOW IS TURNING THESE TWO LITTLE THREADED CAMS HERE.
THEY'RE JUST LIKE...ONE SITS INSIDE ANOTHER, THE CUP.
AND THEY ADJUST THE DISTANCE BETWEEN THESE TWO QUITE SOLIDLY.
I PUT THE TOOL HOLDER IN AND SET IT.
I WANT TO SET IT SO THAT IT'S CENTERED OR JUST ABOVE CENTER.
CENTERED OR JUST ABOVE, RIGHT HERE.
AND I'M GONNA GET A LITTLE BIT MORE OF AN ANGLE ON IT.
AND THERE WE GO.
BECAUSE, YOU KNOW, WHEN WE WERE TRAVERSING-- OH, I'VE GOT TO DO SOMETHING ELSE HERE.
AH.
OK.
IN ORDER TO SET THIS PROPERLY, I HAVE TO SWING THIS OVER.
SO LET ME GO AHEAD AND DO THAT.
I'M GONNA MOVE THIS OUT HERE AND PUSH THIS AT 60 DEGREES NOW.
DID YOU SEE WHAT I DID?
JUST SWUNG THIS DIRECTION OVER.
I'VE GOT A LITTLE BIT MORE OF ADJUSTMENT TO DO.
SO I'M GONNA SET IT AT EXACTLY 60 DEGREES, USING THE LITTLE GUIDE RIGHT THERE.
ALL RIGHT.
SETTING IT BACK AT 60.
ALL RIGHT.
AND YOU CAN SEE, IF I HAD SET MY TOOL POST EARLIER, I WOULD HAVE HAD A MESS.
HERE WE ARE.
SO NOW I'LL ADJUST THIS UP.
THEN WE'LL BE READY TO GO.
NOW, BARNES, WHO MADE THIS, THIS IS THE BARNES 4 1/2.
ALL RIGHT.
SO NOW I'LL TRY THAT.
SO I WANT TO BE RIGHT AT CENTER HERE.
THE BARNES 4 1/2.
THEY SAY, "WE DON'T MAKE THIS WITH AN AUTOMATIC CROSS FEED HERE."
WE DO THIS ON THE 4 1/2 WITH THIS SWINGOVER, WHICH MEANS WE CAN'T DO A 4 1/2, AND THEY SAY IT'S JUST MORE USEFUL HERE.
I'LL JUST SHOW YOU THE CATALOG.
THAT'S THE 4, AND HERE'S THE 4 1/2.
AND SO THEY SAY THAT IS A FEATURE, AND IT REALLY IS.
IT'S A GREAT THING.
YOU CAN SEE THIS IS THE 4 1/2.
AND THE WHOLE THING SOLD IN 18...
I'M NOT SURE WHAT YEAR THIS CATALOG IS, ABOUT TURN OF THE LAST CENTURY, PREVIOUS CENTURY.
55 BUCKS.
SO THERE YOU GO.
YOU GET EVERYTHING IN THE KIT.
SO THIS WAS A FEATURE FOR THEM.
NOW IT'S CHANGED THE ROLE OF THE TWO.
YOU CAN SEE THAT THIS CRANK HERE IS NOW THE TRAVERSE.
THAT'S THE GOING BACK AND FORTH THIS WAY.
THIS ONE IS THE DEPTH.
SO LET'S GET IT GOING.
AND I'LL JUST KEEP FEEDING IT IN A LITTLE BIT MORE AND MORE UNTIL IT STARTS TO CUT.
AND NOW WE'RE MACHINING, I HOPE.
ARE WE?
VERY SLIGHTLY WE'RE MACHINING STEEL.
SO BEFORE, WE WERE DOING BRASS BECAUSE IT WAS SO PRETTY.
HERE NOW WE'RE CUTTING STEEL.
AND I'VE GOT THE SPEED WAY UP.
SO WE HAVE A HIGH SPEED AND A SLOW FEED.
ACROSS.
AND BACK OFF THE TOOL.
ALL RIGHT.
IT'S CONFUSING, BECAUSE THE ROLE OF THE TWO LEVERS, THE TWO LEVERS HERE ARE REVERSED NOW.
SO THERE WE GO, SLOWLY WORKING OUR WAY ALONG, GIVE IT A LITTLE MORE.
GIVE IT A LITTLE MORE, A LITTLE MORE.
I'M ABOVE CENTER, SO IT'S NOT QUITE WORKING RIGHT.
THERE WE GO.
ALL RIGHT.
SO WE'RE TAKING A NICE CHIP NOW, RUNNING THAT ALONG, CUTTING A 60-DEGREE CONE THAT WE CAN USE TO MAKE OUR LATHE.
YEAH.
HA HA HA!
OH, IT'S GREAT.
AH, WOOD, SHMOOD, I TELL YOU.
THERE WE GO, RIGHT ALONG UP TO A NICE... NICE SHOULDER THERE.
YEAH!
ALL RIGHT.
SO THAT'S IT.
I'M GONNA BACK OFF BEFORE I GO BACK DOWN IN THERE.
I'M STILL LEARNING QUITE A BIT ABOUT THIS.
BUT NEVERTHELESS, THAT'S THE TECHNIQUE YOU USE.
SO WE CAN TURN THESE WONDERFUL CONICAL CENTERS THAT WE WILL THEN USE TO MAKE SPRINGPOLE LATHES, THE EARLY, EARLY ANCESTOR OF THAT.
OK. NOW WE WANT TO MOVE ON, THOUGH.
I WANT TO DO ANOTHER KIND OF TAPER THAT WE WOULD USE TO MAKE THE CONICAL...
UH, LET'S SEE.
I WANT TO REMOVE THIS PIECE.
WE WANT TO DO THE CONICAL PINS THAT HOLD BOW SAW BLADES.
AND THAT MEANS WE'VE GOT TO SWING THIS BACK.
ALL RIGHT.
AND RESET THIS NOW.
I'M GONNA SET THIS TOOL POST AROUND.
AND THIS TIME, I'M GONNA SET THE TOOL POST TO THE TAIL ADJUSTMENT.
SO I'LL RUN THE FEED MANUALLY DOWN AND SET IT JUST TO BE A LITTLE MORE PRECISE.
I THINK I WAS A LITTLE HIGH ON THAT LAST CUT.
SO I'M ADJUSTING THE CANS DOWN.
AND UP JUST A LITTLE BIT.
ALL RIGHT.
RIGHT THERE.
JUST RIGHT AT CENTER OR JUST ABOVE IT.
BUT NOT AS MUCH AS I WAS BEFORE.
ALL RIGHT.
AND THAT'S STILL A LITTLE HIGH.
I'M GONNA GIVE THIS A LITTLE TWEAK HERE.
SO DROP IT DOWN.
DROP IT DOWN.
AND THERE WE GO.
AND IT'S DIFFERENT FOR BRASS, BECAUSE WE'RE GONNA GO BACK TO BRASS.
I'LL SHOW YOU WHAT WE'RE GONNA MAKE IN JUST A SECOND HERE.
OK.
SO NOW THAT'S AS GOOD AS I'M GONNA GET, I THINK.
ALL RIGHT.
SO THAT'S ALL READY.
NOW, WHAT DO WE NEED TO DO?
WE WANT TO TAKE THE BRASS AND CUT A CENTER IN IT.
SO WE CAN'T TURN ANYMORE ON THIS CHUCK THING.
WE'RE GONNA USE THE CHUCK TO MAKE THE CENTER, BUT WE'RE GONNA TAKE IT OUT AND TURN IT BETWEEN DOGS HERE.
SO I'M GONNA TAKE THE END OF THE BRASS-- OOP.
END OF THE BRASS, PUT IT IN THE VISE, AND I'VE ALREADY CUT IT OFF AND FILED IT.
SO THIS IS THE OTHER END OF THAT THREADED PIECE.
AMD TAKE THIS CENTERING, THIS MACHINIST'S SQUARE, AND RUN CROSS LINES.
I'VE GOT IT IN THE "V" RIGHT THERE.
AND THIS WAY.
AND I'LL TELL YOU, THE PERSON WHO MAKES TWO MARKS KNOWS WHERE THE CENTER IS.
THE PERSON WHO MAKES 4 IS NOT QUITE SURE.
BUT NEVERTHELESS, NOW I'VE GOT CROSSED MARKS THERE.
I'LL TAKE THE CENTER PUNCH AND GET IT IN THERE.
[HAMMER TAPS] AND NOW I LOOK AT IT, LOOK AT IT AND SEE IF IT NEEDS TO MOVE OVER A LITTLE BIT.
AND...THERE WE GO.
ALL RIGHT.
SO, BY ANGLING THE CENTER PUNCH OVER, I CAN DRIVE IT OVER AND CORRECT IT, AND BY EYE, I CAN BRING IT IN TO ABOUT THE CENTER.
SO THAT'S A CENTER PUNCH RIGHT THERE NOW, IN THE BRASS.
I NOW NEED TO COUNTERSINK THAT SO THAT IT CAN RIDE ON THE CENTER.
LET ME SHOW YOU WHAT WE'RE GONNA MAKE, THOUGH.
WE'RE GONNA MAKE THE TAPERED-- HERE'S THE PIN.
A LOT OF PEOPLE LIKE TO HAVE A TAPERED, LIKE A VIOLIN PEG, A TAPERED BRASS PIECE HERE TO GO DOWN THROUGH THE END OF THE BOW SAW BECAUSE IT GRABS A LITTLE BIT BETTER.
SO WE'RE GOING TO TURN THIS TO A LONG TAPER, A HALF-INCH IN A FOOT.
SO A VERY GENTLE TAPER.
SO TO DO THAT, WE'RE GONNA RUN IT BETWEEN CENTERS WITH A DOG AND OFFSET OUR CENTERS.
BUT FIRST WE'VE GOT TO GET THIS THING COUNTERSUNK.
SO I'LL GRAB IT HERE IN THE LATHE CHUCK AGAIN.
AND...OH, GOSH.
THIS IS GREAT.
AND THEN WE'LL TAKE THIS OFF HERE.
I'M GONNA BACK OFF A LITTLE BIT AND SLIDE THIS BACK, TAKE OUT...TAKE OUT...
UH, HERE WE GO.
TAKE OUT THE DEAD CENTER.
ALL RIGHT.
AND PUT IN A SMALLER CHUCK THAT HAS A COUNTERSINK IN IT.
NOW, SEE, THIS IS A VERY SMALL 3-JAWED CHUCK, AND IT HAS THIS COUNTERSINK RIGHT HERE THAT DRILLS AND THE SHOULDERS OF WHICH ARE AT 60 DEGREES.
THAT'S GOING TO DRILL IN HERE AND LEAVE US A PERFECT SHOULDER, ONE HOPES, FOR THE...THERE WE GO.
UH.
THERE WE ARE.
ALL RIGHT.
SO, FOR THE DEAD CENTER TO RIDE ON.
SO WE'RE GOING TO DO THIS METHOD BY WHAT'S CALLED OFFSETTING THE CENTERS.
SO LET ME SEE IF I'VE GOT THAT.
ALL RIGHT.
THAT'S GOOD.
ALL RIGHT.
AND I'VE GOT TO LEAVE THIS TURNED OFF BECAUSE WE NEED TO GET DOWN IN THERE.
ALL RIGHT.
OK. WHAT HAVE WE GOT?
IS EVERYTHING WORKING?
ALL RIGHT.
GOOD.
ALL RIGHT.
THERE WE GO.
SO NOW IT'S WORKING ALONG PRETTY FAST.
AND YOU CAN SEE WHAT'S HAPPENING.
AS I SLOWLY TURN THE BACK WHEEL ON THE TAILSTOCK, THE, UH...
IT'S FORCING THE DRILL INTO THE END GRAIN, AND IT LOOKS PRETTY DARN STEADY RIGHT THERE RIGHT NOW.
SO WE TAKE IT ON IN, FEEDING IT UNTIL WE GET UP TO THE 60-DEGREE SHOULDER AND DO THAT RIGHT IN THE CENTER.
THAT'S GOING TO ALLOW US TO SET THIS PIECE OF BRASS ROD BETWEEN CENTERS.
OK.
THERE WE GO.
YEAH.
ALL RIGHT.
SO NOW I'LL BACK THAT OFF, TURNING THE HANDLE, AND YOU CAN SEE A BEAUTIFUL CONICAL CUT RIGHT INSIDE THERE.
SO A COUPLE OF MORE CHANGES NOW.
WE'VE GOT TO CHANGE OUT A LOT OF THINGS, ONE OF WHICH WE HAVE TO CHANGE IS THE RELATIONSHIP OF THESE CENTERS.
SO I'LL TAKE THIS CENTER OUT.
THE CHUCK CENTER.
AH!
I'LL TAKE IT OUT.
AND NOW I'M GONNA TAKE OFF THE CHUCK ITSELF.
AND THAT'S GOOD.
THERE'S THE CHUCK.
ALL RIGHT.
AND WE'LL PUT...
THIS CENTER IN.
ALL RIGHT.
SO NOW WE'VE GOT A DEAD CENTER AT BOTH ENDS.
LET ME GET THE OTHER ONE.
HERE IT IS.
WE'LL PUT THIS IN HERE.
NOW WE'RE GOING TO SLIDE THESE UP, AND YOU'RE GONNA SEE THAT THEY COME RIGHT TO EACH OTHER.
I MEAN, THEY WERE ALIGNED.
THAT'S THE WHOLE POINT WITH A LATHE.
WE ALIGN THESE TWO POINTS DEAD ON SO THAT WHEN THE TOOL CUTTER HERE IS GOING BACK AND FORTH, IT CUTS A PERFECT CYLINDER.
WHAT HAPPENS, THOUGH, IF WE OFFSET THESE TWO POINTS?
WE'RE GONNA MOVE ONE THIS WAY AND THE OTHER WAY.
AND THAT WAY, IT'S GONNA PUSH THE FAR END CLOSER TO THE SLIDING TOOL CUTTER.
NOW LET ME SEE.
I NEED TO FIND THE LITTLE... OOP.
I LEFT IT ON HERE.
ALL RIGHT.
I NEED TO OFFSET THIS A QUARTER-INCH BECAUSE I'VE GOT ABOUT A FOOT-LONG PIECE OF BRASS.
AND SO WE'LL DO HALF OF THE OFFSET THAT WE WANT.
WE'LL COME OVER A QUARTER-INCH.
AND I'M GONNA GIVE IT JUST A LITTLE MORE, JUST FOR THE SHEER DRAMA OF IT.
BUT I'VE OFFSET THIS ONE TOWARDS ME NOW SO THAT AS WE HAVE THIS TOOL GOING ALONG DOWN THE LENGTH OF IT, IT'LL BE CUTTING CLOSER.
THE ROTATING CYLINDER WILL BE CLOSER TO US DOWN HERE.
NOW, HOW ARE WE GOING TO GRAB IT?
WE CAN'T PUT IT IN THE CHUCK BECAUSE IT WOULD BE BENDING.
SO I'M GONNA TAKE IT OUT OF THE CHUCK HERE, TAKE OUR BRASS OUT OF THE CHUCK.
THERE WE GO.
AND PUT ON THE DOG.
SO WHERE IS MY DOG?
ARF ARF.
WHERE IS IT?
HERE IT IS.
AND I HAVE A LITTLE WRENCH THAT WILL HELP ME TIGHTEN THAT.
AND WE'LL NEED A CROSS ARBOR.
HERE.
OK.
THIS IS GREAT.
SO HERE WE ARE.
I'M GONNA PUT A CROSS ARBOR ON.
AND THERE WE ARE.
NOW, THAT WILL ENGAGE WITH A DOG.
AND I'M GONNA PUT THE DOG DOWN HERE ON THIS END THAT WE WERE WORKING WITH EARLIER AND THREADING.
AND THAT WILL WORK FINE.
SEE IF I CAN GET THAT ON THERE.
ALL RIGHT.
AND TIGHTEN THAT UP.
SO I'VE GOT THIS DOG GRIPPING THE CYLINDER.
IT'S HELD IN THE CENTER DOWN HERE AND THEN HIT BY THIS CROSS ARBOR COMING AROUND, AND THAT'S GOING TO PUSH IT.
NOW I'M GONNA SLIDE THIS END DOWN, SET IT IN PLACE.
LET ME SEE.
I WANT TO MAKE SURE I HAVE ENOUGH ROOM TO GET ALL THE WAY DOWN THERE.
SO I'LL THROW THE WHEEL OUT.
AND THERE WE GO.
BOY, I MENTIONED THE...
BOY, THE GREAT FICTION, AND IT'S BY FAR THE BEST-- NEVIL SHUTE'S "TRUSTEE FROM THE TOOLROOM," WHERE THE MACHINIST GUY, HIS UNCLE, MAKES A BUNCH OF TURNED-METAL LITTLE BABY DUCK EGGS FOR A DUCK THAT BELONGS TO HIS NIECE AFTER...
GIVEN TO HIS NIECE AFTER HER PARENTS HAVE DIED.
IT'S WONDERFUL.
UH, HE RELATES TO PEOPLE THROUGH HIS LATHE.
HA HA HA.
NOT QUITE.
ALL RIGHT.
SO NOW THIS IS GOING TO-- WE'RE SET NOW.
THIS CYLINDER IS ACTUALLY OFFSET THIS WAY TOWARDS THE TOOL REST, FARTHER AWAY DOWN AT THIS END.
SO AS WE GO TO THE... FROM RIGHT TO LEFT, IT WILL CUT LESS AND LESS OF A...THERE WE GO.
OK.
IT'S GONNA CUT LESS AND LESS.
SEE HOW, AS I START TO CUT, IT GOES ALONG, AND THEN IT RUNS OUT.
IT STOPPED CUTTING.
SO SET IT A LITTLE DEEPER, SLIDE IT ALONG, OR RIDE IT ALONG THE CARRIAGE THERE.
AND IT STARTS TO CUT... AND WORKS ALONG.
NOW, TO GET A FINE CUT, I'M GONNA WANT TO MAKE SURE THAT I'M--OOP.
I'VE GOT TO DO SOMETHING HERE.
I NOTICE MY-- THERE.
LET ME SEE.
THAT HAS TO SWING AROUND, TIGHTEN UP.
THERE WE GO.
AND WE'RE GETTING A NICE CHIP, A LITTLE SPIRAL CUT, BECAUSE THIS THING CUTS ON THE SIDE THERE.
IT'S A LITTLE SIDE-SHEARING CUT, WORKING RIGHT ALONG.
OK. WE BACK OFF THE TOOL, GO BACK AGAIN, FEED IT IN A LITTLE MORE, AND RIDE ALONG LIKE THAT.
NOW, IF YOU DO FAST, YOU'LL BE CUTTING A THREAD LIKE THAT.
BUT YOU CAN CUT OFF A LOT OF MATERIAL.
BACK OFF.
IF WE GO SLOW THIS TIME... YOU'LL SEE THAT IT CUTS A BEAUTIFUL, BEAUTIFUL FINISH.
AND LOOK AGAIN.
LET'S LOOK AT THAT OTHER END DOWN THERE WHERE IT'S DRIVING.
YOU CAN SEE WHAT'S HAPPENING WITH THE DOG AND EVERYTHING.
THE DOG IS BEING GRIPPED BY... LET ME SEE.
I'LL SLOW THAT DOWN THERE.
THERE'S THE DOG.
IT'S BEING HIT BY THE CROSS RIGHT THERE, AND BY TURNING ON THIS CENTER, THAT'S HOW WE'RE ABLE TO BE, UH, OFFSET WITH THIS, BECAUSE OTHERWISE, IF WE HAD THIS IN THE CHUCK, THIS WOULD BE A VERY, VERY ROUGH OPERATION INDEED.
BUT THAT ALLOWS US TO OFFSET.
WE'RE JUST TURNING ON THAT CONICAL POINT.
SO HERE WE GO.
I'LL FINISH UP THIS THING.
THERE WE ARE, SLIDING RIGHT ALONG.
I'LL GIVE IT ONE MORE, AND YOU CAN SEE WE'RE STARTING TO GET THE WONDERFUL...
THERE WE GO.
OH, YEAH.
WE'RE STARTING TO CUT THAT WONDERFUL TAPER THAT WE CAN USE TO MAKE TIGHT PEGS.
WELL, THIS IS THE SAME KIND OF LATHE THAT THE WRIGHT BROTHERS HAD WHEN THEY BUILT THEIR AIRPLANE.
HA HA.
YOU SEE NOW WHAT HAPPENS WHEN ONE OF THE WRONG BROTHERS GETS AHOLD OF IT.
BUT NEVERTHELESS, I'VE ENJOYED IT IMMENSELY, WORKING WITH THIS THING, AND I THANK YOU SO MUCH FOR JOINING ME.
WE'LL SEE YOU NEXT TIME, SEE WHAT TURNS UP NEXT TIME HERE IN "THE WOODWRIGHT'S SHOP."
SO LONG.
LEARN MORE ABOUT "THE WOODWRIGHT'S SHOP" AND TRADITIONAL WOODWORKING ON OUR WEBSITE.
YOU CAN FIND US ONLINE AT pbs.org.
CAPTIONING MADE POSSIBLE BY FRIENDS OF NCI MAJOR FUNDING FOR "THE WOODWRIGHT'S SHOP" IS PROVIDED BY... [THUER] [CAR ALARM BLARING] WHEN THE UNEXPECTED HAPPENS, STATE FARM HAS THE TOOLS TO GET YOU TO A BETTER STATE.
PROUD SPONSOR OF "THE WOODWRIGHT'S SHOP."
ROY UNDERHILL IS THE AUTHOR OF "THE WOODWRIGHT'S GUIDE: WORKING WOOD WITH WEDGE AND EDGE," AS WELL AS OTHER BOOKS ON TRADITIONAL WOODWORKING, ALL PUBLISHED BY THE UNIVERSITY OF NORTH CAROLINA PRESS AND AVAILABLE AT BOOKSTORES AND LIBRARIES.
Preview: S32 Ep6 | 30s | Roy Underhill shows how to use an 1889 foot-driven metal working lathe. (30s)
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Hit the road in a classic car for a tour through Great Britain with two antiques experts.
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PBS North Carolina produces The Woodwright's Shop with Roy Underhill in partnership with State Farm Insurance.