General Twist Information

GeneralTwistInformation
By DennisLiggett
Overview
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Twistwork is spindlework even if you put a twiston a bowl.
Twistwork is purelydecorative.
All twistworkweakensthe structureof the finishedproduct.
I n t w i stw o rksa n d i n gi s a sh apingtool.
All Twistwork can be definedby 4 key elements
1. Diameter: The diameteror widthof the object. Not the circumference.
Twistsare alwaysa functionof the diameter.
2. Bines: The numberof beadsthat spiraland run the lengthof the twist.
3. Pitch: The distancebetweenthe tops or apexesof the same binein
relationto the material.Generallydefinedas the slopeof the line.
RibbonEtc. These are factorsthat
4. Other: Graduated,Open,Laminated,
affectthe appearanceand strengthof the Twist.
N o m e n cl a tu re
a n d Gu i d e l i n es
.
Si n g l eT w i st: H a s o n l yo n e bineand one hollow.Sometimescalleda Bar ley
Twistbut not often The TraditionalPitchis 1 to 1lztimes the diameterof the
material.The depthof the hollowshouldbe approximately
1/3 of the
diameterof the material.This is a weak structure.
.
DoubleTwist: Usuallycalleda BarleyTwist. lt has two binesand two
hollows.The traditionalpitchof a doubletwistis 2 timesthe diameterof the
material.The depthof the hollowshouldbe approximately
la of the diameter
of the material.
Tripfe Twist: Has threebinesand threehollows.The traditionalpitchis 2 Yz
to 3 time the diameterof the material.The depthof the hollowshouldbe
approximately
1/6 of the diameterof the material.
Four Start Twist: Has 4 binesand 4 hollows.The traditionalpitchis 4 times
the diameterof the material.The hollowsshouldbe between1/6 and 115of
the diameterof the material.
the
CableTwist: 8 to 9 binesand the samenumberof hollows.Traditionally,
"V"
rope
had
8
A
twist
traditionally
shaped.
hollowsor troughsshouldbe
pitchis 3 to 4 timesthe diameterof
binesand a cablehad 9. The traditional
t h e ma te ri a l .
Layout of the Twist.
verticaland diagonallinesto
MarkingOut: The processof drawinghorizontal,
definethe characterof the twist to be created. Horizontallines (withthe lathe
bed)consistof StartLinesand otherlinesto easethe creationof diagonallines.
Verlicallinesconsistof Pitchand BineSegmentLines(aroundthe circumference
a n d D i a g o n aLl inesconsistofBineApexlines,Cut Linesand
o f t h e c yl i n d e r),
of Horizontaland Verticallines
the BineWidthControlLines. The combination
piece
paper
graph
wrappedaroundthe
of
shouldbe viewedas creatinga
spindle.In a full layout,the Diagonallinesare the apex of the bine,(2) widthof
the bineand the bottomof the hollow.This requires4 startlinesfor each bine.
l n a p a rl i alla yo u t,w h i chi s u su allyused,onlytheapexof the bineand the bottom
of the hollow(cut line)are used. The partiallayoutrequires2 startlinesfor each
bine.
(withthe lathebed)that are usedto start
Start Lines: Linesrunninghorizontally
the bineapex,binewidth linesand the cut controllines(hollow).The numberof
linescreatedcan be more than the numberof binesand hollowsbut it is always
a multipleof the numberof bines. Example,for a doubletwisttherewouldbe 4
StartLinesfor a partiallayout,one for eachof the 2 bineapexesand one for
eachof the 2 hollows.
Pitch Control Lines: Verticallinesrunningaroundthe circumference
of the
workpiecethat are a multipleof the diameterand are usedto definethe typeof
twistbeingcreated. Example: a doubletwistshouldgo aroundone time in twice
the diameter.So the PitchControlLineswouldbe at a lengthof twicethe
diameter.This space is calledthe PitchControlSegment.
Bine SegmentLines: Verticallinesthat are usedto dividethe PitchControl
Segmentsintoequalpartto makethe drawingof the diagonallineseasier.
Bine Apex Lines: Diagonallinesoriginating
at the Startlinefor the top of the
bineor beadand drawndiagonallyto reachthe same Startlinewhereit crosses
the pitchcontrolline. This linewill be the top of the bineas it worksits way down
the cylinder.lt will alwaysbe the top of the bine. When cuttingand sandingthe
bine,this line is alwaysleft.
Bine Width Control Lines: A diagonallinecreatedbetweenthe BineApex
Lines
andtheCutControl
Lines
todetermine
thewidthoftheBineanddefines
the appearanceof the bead. Used in full lay out mode.
Cut Control Lines: The diagonal linesthat are marked out from the Starl Line to
the intersectionswith the Piich ControlLines that indicatethe bottom of the
hollowas it works its way down the cylinder.
Otherdefinitions:
Open Twist: A single,double,triplesor four-starttwistthat has a holedrilled
downthe centerof tne twistis calledopen. Usually,OpenTwistsare stretched
to increasestrengthunlessvery strongwood is
(thebinesegmentis lengthened)
used. The numberof bines,widthof the binesand the stretchof the twist
the strength.The thinnerthe binethe morethe bine shouldbe
determine
for strength.Do not attemptto opena twistuntilall of the finishinghas
stretched
beendoneon the top of the bines. Thereare no hardand fast rulesfor open
twistsbecausethis is mainlya modernapproach.SomeVictorianfurniturehad
opentwiststhat were doublesand stretched.Sometimesopen twistsare used
and then splitto createvery stretchedsimplertwiststhat would be very hardto
p r o d u cesi n g l y.
Rulesof thumb for Open Twists that work:
o Double Open Twist: For a 1 Tz"diametercylinderof materiala 3/8" hole
in recommended,For a 3/S"diametercylinderof materiala 1/8"holeis
recommended.Note:thatthe holedrilledin the centerof the cylinderis
actuallymuch smallerthan it willappearwhenthe twistis finished.
. Triple Open Twist: For a 1 Tr" diametercylinderof material,a 3/8" hole
or largeris recommended.The reasonfor the largerhole is that 3 bines
providegreaterstrengthand if thinbinesare desired,a Yz"or 5/8" holeor
la rg e rca n b e d ri l l e d .
. Four Start Open Twist: For a 2" diametercylinderof material,a 5/8"hole
i s re co mme n d e d .
threebinesand threehollows.lt can
RibbonTwist: Twistthat has traditionally
have2 bineand 2 hollows,but this is very,veryweak and lookslikean old drill
bit. The binesshouldbe pointedor slightlyrounded.The roundingdependson
the application.For example,a canewill receiveabuseovertime and the bines
needto be rounded.A spindleon the otherhandshouldnot receiveabuseand
can be pointedor have a slightflat on the bine. The traditionalpitchis 3 times
the diameterof the materialwith 3 bines. The BineAoex shouldbe
approximately
1/8"wide or less. Actually,cut and sand up to the bineapex line.
Thereare no BineWidth ControlLineson a RibbonTwist. This is one of the
easiertwiststo hand make.
TraditionalTwist: The bineapexalwaysends at the same StartLinethat it
starts.This is one of the majormethodsof determining
if the twist is madeby
h a n dor w i tha ma ch i n e .
TaperedTwist: A standardtwist of any descriptioncut on a taperedcolumnor
spindle.
A truetapermustbea straight
edge.
GraduatedTwist: The methodis usedto describeand explainthe markingout
withthe changingdiameterof
of a twistwhichis measuredand cut in accordance
the material.A GraduatedTwistis eithera taperor irregularshape. The
methodof layingout is to measurethe diameterat the end of each
traditional
binesegment,layingout onlyone binesegmentat a time. Measurethe new
diameterat this point,and lay out a new binesegmentbasedon the new
diameter.Continuethis approachuntilthe end of the materialto be twisted.
Note: Thiswill not changethe horizontallinesjust the verticalones. The result
of this is as the materialgetssmallerin diameterthe twistsget tighter.
twist'spitchis a functionof the diameterof the
Strengthof a Twist: Traditional
material.Reducingthe pitchwill makethe objectlessstrong. Stretching(or
the pitchwill makethe twist
lengthening
the binesegment)the twistor increasing
the
twist
slightlywill strengthen
in
thin
twisting,
stretching
stronger.Sometimes
stretchingthe twistwill
the material.Sometimeswhen usingsoftmaterials,
the material.Sometimeswith opentwists,the pitchis stretched
strengthen
dramatically
to increasethe strength.
Right-handedand Left-handedTwists: Righfhandedtwistsare cut from right
to left,lookingare the twist horizontally.When lookingat the twist verticallythe
twistgoes from the lower left to the upperright. Left-handedtwistsare cut from
leftto right. Differenttwist(rightand left)are usuallyusedon tablelegs,bed
posts,mirrorimagesof goblets,candlesticks,
or pineappletwists. Also this is
usedon staircasesdependingon the visiblesidethat is prominent.In other
words,tableswherethe twistspointedtowardeachother,were put on the legs
thatwerethoughtto be seenthe most. The otherway the twistswill pointaway
fromeachother. On bedswhereflameswere used,the flameswere attached
witha dowelso that they couldbe changedto accommodate
different
placementsin a room, On staircasesthat are againsta wall,the twistswere
placedto that they followthe stairsup. This requiresa lefthandedtwistson
stairsthat are on the rightand a righthandedtwistfor stairsthat are on the leftof
an entryway.
Notes:
It is important
to markthe samestartsideof eachspindlefor placement.
When
theyareinstalled
thewilllookright.
Whencuttingwiththetraditional
saw,gouge,or rasp,it is extremely
important
to
alwaysrotatethe materialto avoidflat spots.
The correctsandingprocedures
will even out minorchangesin the depthof the
hollows.Sandingin twistwork is a shapingtool.
The saw cutsare not for depth. They providea placefor the side materialto
breakoff intowhen usinga gouge.
Be extremelycarefulat the startand the end of the cut lines. Peopletendto
i n s p e ctth e sea re a si n d e ta i l .
all twistwork was endedby a cove. Somefactoriesor shops
Traditionally,
developedtheirown way of endinga twist. Someusedbeadsand somejust
taperedthe material.This taperingis extremelydifficultto get even all the way
aroundbut can be used successfullvon ribbontwists.
to givethe
To twista bowlor a finale,the pitchmustbe variedconsiderably
the twistwill look likea straight
of a variablemovement.Othenruise,
appearance
broken
to vary the pitchradically.
the
rules
must
be
lines. Sometimeson bowls
A Ram'sHornis a graduatedsingletwistthat only has one end attached.The
graduatedmethodof layout.
otherend finishesin a point. lt usesthe traditional
and
finaleon staircases
on the cornersof clocks.
It is usedas an upside-down
A Pigtailis a graduatedsingletwistthat onlyhas one end attached.lt does not
graduatedmethod. lt stretchesthe twistas it gets smallerto
usethe traditional
giveit strength.lt is used on hollowformsas a finale.
The singlepointtwistis a twistwith 2 differenttypesof bines. One is a round
overand the otheris a ribbon. On a regularsinglepoint,the layoutis 1.5times
the diameter,insteadof 2 timesbecauseof the differencein the binewidths.
A doublepointtwistis a roundedoverbineand a binethat has two points,which
are usuallycreatedby splittinga binewith a 3 startfile. The layoutis as a
double.
The bannertwisthas the appearanceof a ribbonthat goes arounda pole. lt is
"cutline"and the "bineapex line"with
laidout as a double. You cut betweenthe
a flat cutterinsteadof on the cut line. Caution:do not cut deeplyon the flats.
twists,a cylinderwas gluedover a waste
Sometimes
to developspectacular
materialwith rabbitglue. Rabbitglueis verywatersoluble.A twistis created,
thenthe materialis put is waterand the twistedcylinderis removedand glued
piece
permanently
ofwoodcanbe
ofwood.Thentheotherpiece
toanother
howthe twistwas made.
if notimpossible
to determine
twistedandit is difficult
to takeverysmall
twist,it is important
Whendrillinga holefor a laminated
hole.
amounts
andkeepthe drillbittip coolto drilla straight