JD Squared 3 - Page 11

Animportantruleofbendingisto,ifpossible,alwaysmakethebendsclosesttothecenterrstand
workyourwayout.Thisallowsyoutomakemeasurementcorrectionsbetweenbends.Basedonthisrule,
place a mark at the center of the rollbar tube. This is shown Figure 21.
BEND 1:
The rst bend will be the
upper right side bend. Referring
toFigure20,theupperdimension
of the rollbar is 50”. From the
center of the rollbar to the outside
ofthebendis25”(50”dividedby
2). Lay the tubing to be bent on
theoorandholdthetemplate
with the scribed side parallel
totherollbartubinganddirectlyaboveit,asshowninFigure21.Thescribedsideofthetemplatewill
alwaysfacetowardsthecenterofthetubingbeingbent.Usingatapemeasure,slidethetemplateleftor
rightuntilitis25”fromitsoutsideedge,shownbytherightarrowinFigure21,totherollbar’scentermark.
Usingamarker,drawasmalllineontherollbardirectlybelowthescribedline.Takenoteofwhatside
of this mark the bend needs to be and draw an ‘X’ there so that when you load the tube into the bender
you’llbebendingonthecorrectside.Sincethedesiredbendisonly70
o
andthetemplateis90
o
,you
willhavetouseyourbestjudgementofwhenthetemplateis25”out.Thisgetseasierwithexperience.
Now,loadthetubeintothebenderandmaketherstbend.Don’tforgettooverbendalittletoaccount
fortubespringback.Forthismaterial3to4degreesshouldbesufcient.SinceallJDSquaredbenders
are equipped with degree of bend indicators this is easily accomplished. Once you know the correct over
bendrequired,youmaywanttorecorditforfuturereference.
BEND 2:
Place the template above
the rollbar tube with the template
line facing bend 1 as shown in
gure22.Usingatapemeasure,
position it for the desired 50”
outside to outside of the two
top rollbar bends. DO NOT
use the tube’s center mark
as a reference and place the
template 25” left of center. The
reasonforthisisthatiftherst
bendwasnotmadeattheexactrightspottoachieve25”fromcenteryoucancorrectfortheerrorinthe
secondbend’sposition.Onceagain,sincethebendwillbe70
o
andthetemplateis90
o
you must use your
judgementastowheretopositionthetemplate.Placeamarkontherollbartubeexactlyunderneaththe
template line. Load the tube in the bender so that the bend will be made on the CORRECT side of the
tubeandmakethe70
o
bend.
Erasethecentermarkontherollbartube.Usingthetapemeasure,placeanewcentermarkexactly
midwaybetweentheoutsideofthetwobends.Why?Let’ssayyourmeasurementshowsthetwotop
bendsarereally501/4”wideinsteadofthedesired50”.Inthatcase,youroldcentermarkcouldbeoffby
asmuchasa1/4”.TheNEWcentermarkcorrectsthiserror.That’sthecoolpartabouttemplatebending.
Yourerrorscangenerallybexedwiththenextbend.Alsonotethatifyouhadnotstartedyourbending
from the center of the rollbar you would not have been able to make the correction. Every bend adds a
littlemoreerrorandyouendupwitharollbarthatdoesnott.
25”
50”
Figure 21 - Template positioned for 1st bend.
Figure 22 - 2nd bend position
Tube’s
Center Mark
Template Line
Template Line
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