Ibis Tek Lightbar brackets are not off-road worthy

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Ibis Tek Lightbar brackets are not off-road worthy

Postby icentropy » Wed Feb 29, 2012 2:46 pm

Howdy, this is a quick post just to warn anyone with an ibistek 78" light bar that the stock brackets (two sheet metal ones that attach to the windshield) are not able to handle even moderate off-road use.

I just got back from a weekend trip out to the desert. The lighbar snapped off the windshield on the third day! Since the day I mounted it I noticed the whole bar would move side-to-side quite a bit but never gave it too much thought. I figured I'd get around to securing it better some day. Well apparently it couldn't wait because on a dirt road last sunday, the right side of the lightbar itself snapped off. upon inspection the other side had stress cracks as well as both support brackets. You all might know aluminum does not fatigue well so a month of pavement driving and a few days of desert off-roading were all this thing could take before it gave way. I plan on making new brackets out of .25" tempered Aluminum that should keep the entire structure steady enough to avoid this problem, but since the light bar itself broke i'll not how to fix that as well.

So if any of you have an ibistek that is moving side-to-side i would suggest removing it ASAP and strengthing up those brackets before you break the bar itself. Wish i had.

On the other hand, the light coming out of the bar was awesome. the 6 HIDs worked perfectly, no issues at all and i was very happy with the lighting at night. I am still happy i bought and upgraded it, just wish i had upgraded the brackets before it caused damage.
1994 AMG Hummer 6.5NA HMC4 (lots of stuff)
1997 AMG Hummer 6.5TD slantback(w/light performance upgrades)
Ibis Tek FPB, MASTC, ESC, and HID light bar (Sold)
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby Readyman » Wed Feb 29, 2012 11:45 pm

Please post some pics of the stress cracks and breaks, so I can figure out the reinforcing needed.
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby STUDENT-DRIVER » Wed Feb 29, 2012 11:49 pm

Not new to me, I made me some out of 1/4" stainless steel:

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I break it, I fix it!
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby Readyman » Thu Mar 01, 2012 12:01 am

Were they rockin' on the raised threaded inserts in the pillar?
Yeah, that's nice Student Driver


icentropy wrote:Howdy, this is a quick post just to warn anyone with an ibistek 78" light bar that the stock brackets (two sheet metal ones that attach to the windshield) are not able to handle even moderate off-road use.

I just got back from a weekend trip out to the desert. The lighbar snapped off the windshield on the third day! Since the day I mounted it I noticed the whole bar would move side-to-side quite a bit but never gave it too much thought. I figured I'd get around to securing it better some day. Well apparently it couldn't wait because on a dirt road last sunday, the right side of the lightbar itself snapped off. upon inspection the other side had stress cracks as well as both support brackets. You all might know aluminum does not fatigue well so a month of pavement driving and a few days of desert off-roading were all this thing could take before it gave way. I plan on making new brackets out of .25" tempered Aluminum that should keep the entire structure steady enough to avoid this problem, but since the light bar itself broke i'll not how to fix that as well.

So if any of you have an ibistek that is moving side-to-side i would suggest removing it ASAP and strengthing up those brackets before you break the bar itself. Wish i had.

On the other hand, the light coming out of the bar was awesome. the 6 HIDs worked perfectly, no issues at all and i was very happy with the lighting at night. I am still happy i bought and upgraded it, just wish i had upgraded the brackets before it caused damage.
1985 M1036 TOW Missile Carrier
1998 Gatesville, TX IROAN rebuild
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby icentropy » Fri Mar 02, 2012 8:30 pm

Ok finally had a chance to kinda clean out the hummer from the trip and take some pics.

Here's where the brackets were starting to crack
Image

Here's the cracking end of the light bar (hard to see right on the edge)
Image

Here's where the lightbar broke off completely
Image

And the broken sad lightbar :(
Image

Now it's time to start fixing....
1994 AMG Hummer 6.5NA HMC4 (lots of stuff)
1997 AMG Hummer 6.5TD slantback(w/light performance upgrades)
Ibis Tek FPB, MASTC, ESC, and HID light bar (Sold)
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby axemann » Fri Mar 02, 2012 9:10 pm

What about rubber mounting them like they do with off road racing lights to cut back on the vibration?
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby icentropy » Fri Mar 02, 2012 9:18 pm

axemann wrote:What about rubber mounting them like they do with off road racing lights to cut back on the vibration?

might very well be a good idea. I'm going to start with .25" aluminum brackets and see how that does, then maybe add some .25" rubber spacers between the brackets and the bar. Lastly if needed i'll add a center brace at the clearance lights. One way or another this sucker is gonna be mounted well and not give me any more trouble :D well at least not of the same variety.
1994 AMG Hummer 6.5NA HMC4 (lots of stuff)
1997 AMG Hummer 6.5TD slantback(w/light performance upgrades)
Ibis Tek FPB, MASTC, ESC, and HID light bar (Sold)
WWW.ICENTROPY.COM
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby Readyman » Sat Mar 03, 2012 12:07 am

Wow,
IbisTek really missed the ball on this product. Wonder which legislator they paid off to get these approved for purchase by Uncle Sam.
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby icentropy » Sat Mar 03, 2012 7:18 am

yeah, probably didn't sell that many or perhaps only sold one large set which then started faling off the trucks and the rest were shelved and we ended up with them :D

Eitherway, the lightbar is IMO a good product, it's the $5 brackets that caused all this. I appreciate the idea of "the lighter (no pun intended) the better" but you just can't cut weight on certain things and expect them to hold up.
1994 AMG Hummer 6.5NA HMC4 (lots of stuff)
1997 AMG Hummer 6.5TD slantback(w/light performance upgrades)
Ibis Tek FPB, MASTC, ESC, and HID light bar (Sold)
WWW.ICENTROPY.COM
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby Action » Sat Mar 03, 2012 10:08 am

Wouldn't you need to use more than just one rubber washer per bolt to isolate the bolts from the metal?

Like the headlight mounts, the front and rear bolts do not touch each other.

Like the hardtop mounts that have a rubber mount above and below the mody brackets.

etc.

Maybe you could find something similar to the headlight mounts....screw them into the lightbar, then push into holes of a mounted bracket, hold in place, then install the second bracket over the studs at the other end?

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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby Ozhumvee » Sat Mar 03, 2012 2:10 pm

You may also get away with replacing the aluminium bits with the same thing in steel, aluminium doesn't handle stress and vibration at all well in sheet form.
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby actionpaintball » Sat Mar 03, 2012 5:21 pm

Standard rule of thumb [very generic] is that steel is 3X heavier, and 3X stronger (tensile) over aluminum.
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby tanhmmwv » Sun Mar 04, 2012 12:48 am

THANKS for posting this!
I just got mine 2 weeks ago.
painted it so far and now am in the process of fabbing up an " L" bracket.
I am trying to bolt on the windshiled frame, at the 2 rubber bumpers, and go to the IBIStek bar.
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby icentropy » Sun Mar 04, 2012 9:08 am

actionpaintball wrote:Standard rule of thumb [very generic] is that steel is 3X heavier, and 3X stronger (tensile) over aluminum.


The rule of thumb i've always used is aluminum is you have to use 50% more aluminum to come up with the same amount of strength. And by using aluminum instead of steel you'll end up saving around 1/3 of the weight because of the added thickness. This is in comparison will low carbon mild steel.

If you bump up the aluminum to a reasonable quality such as 6061 and temper (or buy tempered) to T6 the ratio gets better. 7050 or 7075 to the T7 temper is basically just as strong as mild steel so you are saving the full weight amount, but you can't really bend or weld T7 material without loosing a large amount of the strength. The correct way to make things out of aluminum is the way AMG made our bodies and rail guards. It's all made out of 6061-0 temper, bent, welded, etc. THEN heat treated to T6 so the whole structure is quite strong.

The aluminum on the light bar and the brackets was plenty "strong" to hold up the bar. Its the side-to-side motion that fatiqued the aluminum to the point of failure. Stop the side to side motion one way or another and the problem will go away. IMO, the easiest way to do that if you still had the whole setup and hadn't mounted it, would probably be just to make some 45° angle brackets (stiffeners) on the corners, that or just make brackets so thick that they keep the assembly ridgid enough to not move. That's not really the correct way to do is as you're basically just overcoming a bad design with excessive use of material but heck that's what i'm gonna do mostly due to lazyness :D.
1994 AMG Hummer 6.5NA HMC4 (lots of stuff)
1997 AMG Hummer 6.5TD slantback(w/light performance upgrades)
Ibis Tek FPB, MASTC, ESC, and HID light bar (Sold)
WWW.ICENTROPY.COM
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Re: Ibis Tek Lightbar brackets are not off-road worthy

Postby fsutterbadass » Sun Mar 04, 2012 9:57 am

That thing just needs something to support it in the middle.....a bracket and nutsert kit that goes in the windshield frame between the glass sections....and you could drill some pass through holes in the center glass hold down that would allow bolts to pass through into the nutserts and mount a bracket there.
just my 2 cents.

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