Cage Construction?

[Dust]

Those of you building your own racers.
Are you doing this per the SCORE rules (CR33) or does it not apply in C3?

None of the tubing may show any signs of crimping or wall failure. All bends must be mandrel type. The center radius of the bends may not be less than three (3) times the outside diameter of the roll cage tubing.

If so what bender are you using?

Dust

[Blanco]

Those of you building your own racers.
Are you doing this per the SCORE rules (CR33) or does it not apply in C3?

Of course we must follow the CR33 rules..
How could we be exempt? :confused:

Can you re-frase your queston?

I'm probably not the only one thats not sure what your asking? http://www.thewebwheeler.com/forums/images/smilies/shrug.gif

[pigracing]

Jd squard (jd2.com), pro-tools (pro-tools.com) and JMR are a few I see often.
Most garage fabbers seem to be able to get by with just a manual set-up but if you got the money you can get those set with hydrolics.

[Dust]

Of course we must follow the CR33 rules..
How could we be exempt? :confused:

Can you re-frase your queston?

I'm probably not the only one thats not sure what your asking? http://www.thewebwheeler.com/forums/images/smilies/shrug.gif

Thought it was clear enough.
In your picture here:
http://www.class3racing.com/showthread.php?t=224

We see that you are running (unless you changed it) ERW tube... Not DOM.
And in one (lower) pix we see that while it is correctly bent (Seam Location) it is (at least does not appear to be) a Mandrel Bent Tube. The Fab houses that I work with will not Mandrel Bend ERW Tube.
The typical "Amateur" fabricator that buys a Tubing Bender does not buy a $15,000+ bender. Even in my shop I do not have a Mandrel Bender I farm that out.
So, if there is anyone that is fabricating SCORE Legal and you bought a Mandrel Bender what did you buy?
If there is a way to get your cage past SCORE Tech what is it?

Is that clear?

[Dust]

Jd squard (jd2.com), pro-tools (pro-tools.com) and JMR are a few I see often.
Most garage fabbers seem to be able to get by with just a manual set-up but if you got the money you can get those set with hydrolics.

I own the Pro-Tools Hyd Unit and several thousand in dies...
But... It ain't ever going to produce a DOM Bend! Good yes, adequate IMO yes, but not a Mandrel Bend!

[pigracing]

Perhaps i'm mis-understanding your question as well but you asked what type of bender people are using to build a cage and those are a few of the ones i'v always seen people use.

[Dust]

Perhaps i'm mis-understanding your question as well but you asked what type of bender people are using to build a cage and those are a few of the ones i'v always seen people use.

Agreed.
But they are not mandrel benders...

SCORE appears to be specifying Mandrel Bends...

[pigracing]

Ok I ran a search and see what you mean now. Sorry.
I'v never heard or seen anybody do that but i'm pretty sure people have built cage's and raced with score with out using a mandrel like that.
I'm defenatly intrested with what other have to say now.

[Dust]

Ok, maybe I need to get real basic here..
We have discussed the difference between DOM and HREW or ERW tubing.
One is drawn over a Mandrel and the other is not. DOM is SCORE Legal and HREW is not.

SCORE appears to be saying that for a cage to be legal it must be made of DOM AND the bends MUST be produced on a MANDREL BENDER.
Now there are all of the previously listed benders but they are NOT Mandrel Benders and therefore they do NOT produce Mandrel Bends.

When tubing is bent in a Die type bender the outside wall of the tubing on the outside of the bend stretches while the inside wall of the inside of the tubing tends to crush. This is because the inside of the tube is trying to compress while the outside of the bend is trying to stretch.
The Mandrel bender places an inner plug or die if you will that forces the wall thickness to remain the same. As the wall of the inside of the bend tries to compress or bunch up and the outside tries to stretch or thin out the plug forces the material to flow around the tube and the wall thicknesses remain constant.
It follows that the plug must be pulled through the tube as it progresses through (around) the bending dies.

IF SCORE is requiring a Mandrel Bend then the JD, Et Al Benders will NOT produce the requisite Bends...


Ok, I hope that you have a mental picture of what I'm describing and can now understand what I'm asking way back at the beginning.

If you follow this link: http://www.vansantent.com/model_4_bender.htm
You will see the JD bender.
If you follow this link: http://www.vansantent.com/mandrel_bending_machines.htm
You will see a Mandrel Bender.
And if you don't know about this company and you fancy yourself a fabricator you should bookmark this page: http://www.vansantent.com/index.htm

Me

[pigracing]

[QUOTE=pigracing;3753]Ok I ran a search and see what you mean now. Sorry.
QUOTE]

[151FAB]

Dust, this has been brought up many times on other websites and, simply put, the JD2 type benders are fine. Score just wants to make sure you don't have a muffler shop (bottle jack press) or electrical contractor (Rigid benders)built your cage. I completely understand your question and I am pretty sure that even the teams with the largest possible budget have never implemented a true mandrel bender.

You absolutely must use DOM or Chro-mo tubing in the locations the Score rule book mentions; not erw or black pipe, etc. There has never, in all my reading and all the bench racing I've done with the few people I know who have built race vehicles, been an exception made for this basic rule.

I use a JD2 manual bender and have only had a die fail when I was bending 3/8-1/2 wall 1.5" dia tubing with it. Tubing was cold, bender was anchored with the help of a 6000# capacity fork-lift and three guys (600# combined weight) pulling on a ten foot long pipe where the bender handle belonged. We broke the weld between the die and the block of steel the 3/4" pin goes through.

[151FAB]

I just reread my post and have no idea why I told the broken die story? Sorry for the ramble.

[roach]

you guys need to learn how to read rules...............

"mandrel type bends", not "mandrel bends".

pretty much all draw benders are good to go unless you are using something that was designed for pipe and not tube (or muffler shop benders that crush the tube from the center out) the only shop i know that uses (or used) and "actual" mandrel bender was chenowth.

[locopny]

you guys need to learn how to read rules...............

"mandrel type bends", not "mandrel bends".

pretty much all draw benders are good to go unless you are using something that was designed for pipe and not tube (or muffler shop benders that crush the tube from the center out) the only shop i know that uses (or used) and "actual" mandrel bender was chenowth.

I would like to think I would have caught that when I bought my rule book...(just before cage construction started)


So I guess my Harbor Freight Pipe bender is out of the question for cage construction....as is all my BIP...:rolleyes: :D

[3amigo]

So I guess my Harbor Freight Pipe bender is out of the question for cage construction....as is all my BIP...:rolleyes: :D

Dang, there must be a whole buch of the HFT benders in peoples garages.
I have to admit that I own one as well.
I use a jd squared model 3 for my fabrication. It works pretty darn well and is affordable. I have a 1.75" die, but if your rig is over 4000 lbs you will need a 2" die. That would cover 99% of what you will ever have to bend for a class 3.

[locopny]

Dang, there must be a whole buch of the HFT benders in peoples garages.
I have to admit that I own one as well.


You know I was being totally sarcastic-right? I would never consider a pipe cage bent on that Harbor Freight bender.
I only use it to bend large rigid conduit and utility handrails where close is good enough. for that they are ok...
I had planned a 2" cage done on JD2 or Protools bender...