a question for you cage fabricators- how do you keep tubes where you need more than one bend planar? im trying to get the rollhoops for the sae car bent, but before i waste bunches of tubing, i thought id ask how you guys keep things (at least close to) planar.

 

We used a "portable" bender on the floor of the shop (ouch - knees) and every bend required the application of a little brute muscle - from two guys - to tweak it back into a plane. No biggie, really...

K

 

Work from a flat surface. If the bender is level , then make sure first bend is level and in the same plane as your inside shoe, your bend should come out flat, otherwise use Kirk's method.

 

So you don't use expensive stuff to try and get a shape that you want, use electrical conduit as the template and then bend the good stuff.

 

make a line down the length of the tube. this line will be your plane. make sure this is in the same spot in bender.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicrr &raquo;</TD></TR><TR><TD CLASS="quote">make a line down the length of the tube. this line will be your plane. make sure this is in the same spot in bender. </TD></TR></TABLE>

i like this idea!! i just have to scribe the die where the line is, then keep it on that line. qed

 

I use magnetic torpedo levels, 2, make the first bend, go the second bend, use the level near the first bend, level it out. Place second torpedo level on other end. Finish the last of the bends. Works everytime!

 

sorry to bring this back from the dead, but what kind of tube bender are you guys using?

 

we use a manual mandrel bender.

scribing a line, btw, is not exact. the tube twists a little as it bends

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondan00b &raquo;</TD></TR><TR><TD CLASS="quote">we use a manual mandrel bender.

scribing a line, btw, is not exact. the tube twists a little as it bends</TD></TR></TABLE>

Is that the type with a hydraulic jack with a die and rollers above it? or is it more elaborate than that?

 

We used a level for our FSAE car. You probably won't get it exactly perfect, but when it is welded in the chassis it will be okay if it is jigged properly. You will never get the chassis perfectly straight, deflection of 1/8" or more is not unusual since it warps when welding anyway.

What school do you go to?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Afazz &raquo;</TD></TR><TR><TD CLASS="quote">

Is that the type with a hydraulic jack with a die and rollers above it? or is it more elaborate than that? </TD></TR></TABLE>


its not the type with a jack and rollers- those dont really work, and they can pinch the tube. it's kind of like this: http://www.mittlerbros.com/Tubebender180.htm except that one is hydraulic, and ours isnt.


and if you were asking me, angry joe, i go to UIUC

 

More FSAE guys?? Me too. Carnegie Mellon here, it's only our 3rd year in it and i'm a freshman, so we're all still learning.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Angry Joe &raquo;</TD></TR><TR><TD CLASS="quote">We used a level for our FSAE car. You probably won't get it exactly perfect, but when it is welded in the chassis it will be okay if it is jigged properly. You will never get the chassis perfectly straight, deflection of 1/8" or more is not unusual since it warps when welding anyway.</TD></TR></TABLE>

Our chassis guy(s) run(s) the torch over the welds for a few minutes while it's still on the jig, so it doesn't tweak when you take it off. My only chassis experience is grinding bars though, so that's just my observations.

 

Look for a Greenlee 882. It is a portable hand pump model. It is reasonably simplistic. You should be able to rent it for approx $35 a day.

Rick