Topic: To halo-bar, or to not halo-bar?

So, we've started the roll cage build. This is my first "from scratch" build. I've installed pre-bent/notched cages, figured this would be "more fun".

Main hoop is bent and fits great. John and I were thinking that we'd attempt to bend the a-pillar bars as a continuous piece that went from floor to main hoop.

I just attempted one, and it's quite difficult to attain 3 axis curves on a tube. My team mate feels that this is a bit safer, verses a "halo-bar" build.

Personally, I think a halo-bar with a-pillar uprights connected to the halo bar is an easier build, and will be just as strong. In my eyes; it's the same amount of welds, assuming that a upper crossmember bar is welded between the two a-pillar bars near the windshield.

Both of these assume that we'll gusset weld a-pillar at upper corners, and gusset bar to a-pillar of actual chassis. 

What are your thoughts about this?

Thanks,

Tom.

(blog @ http://www.kumkrautracing.com/blog/post … t-1).aspx)

2 (edited by RobL 2009-05-23 08:54 PM)

Re: To halo-bar, or to not halo-bar?

I've done both. 

Halos are easier because most of the welds, specifically the ones on the halo to main hoop, can be done outside the car and can be inspected better.  Generally, the easier something is to build, the less likely it is to get fucked up and the stronger it is going to be.

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3 (edited by jad3675 2009-05-24 07:36 AM)

Re: To halo-bar, or to not halo-bar?

After yesterday's ordeal with the a-pillar bar, I'm leaning towards a halo bar too.  My main concern was the a-pillar to halo bar weld - if it failed, and buckled in, it would get all stabby-stabby with the driver.

Take a look at this a-pillar bar - I think if we attempt this, we'll just be wasting tubing.
http://img.photobucket.com/albums/v521/iflytii/roll%20cage/cage_04-29-07_fitted_1.jpg

John

Re: To halo-bar, or to not halo-bar?

Well, both are ok, whatever is easiest.. Since this is Lemons and not other rulesets, tie that cage in every where. A pillar, roof, b pillar, struts front and rear etc..

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Re: To halo-bar, or to not halo-bar?

Bending tube is Fun !  Bend-tec or bend-tec pro is  great software helps a lot

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Re: To halo-bar, or to not halo-bar?

fabtoys wrote:

Bending tube is Fun !  Bend-tec or bend-tec pro is  great software helps a lot

Yeah, I'm thinking about purchasing Bend-Tech EZ3D now, assuming my second attempt on front hoop doesn't work out.

Re: To halo-bar, or to not halo-bar?

I use Bend-Tech and still prefer a halo.  Bending a multi-plane a pillar/roof bar is easy with the software.  The problem is taking accurate measurements of lengths and angles from the top corner of the hoop, along the roof, down the A pillar, and to the floor where you want to land the bar.

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Re: To halo-bar, or to not halo-bar?

The front one piece main hoop will be a serious pain an car with a super angle back A pillar ,Going to us a bunch of tube with or without   the Bend tec program right .
I'm doing a halo to rear main hoop 
Even though in SCORE and Nhra says its Ok  to do an A pillar to rear main hoop .

I might just go TOPLESS  !!!

Pit Crew Revenge Racing   Rolling chicanelimo,95Lamdspeeder,Gimp Pimp Cadi,300zx Car show kaboom!! 90 Wagovan, mazda v8 Lemons LOGO TATTOO!  Aces 84 Cadi Eldo Briattz I O E WINNER
Class C win with LemonOdy Cannonball Run Whambulance !EX K Captain
Lemons Trophy Truck ShaGuar Baby!