Roll hoop bending

[Coombesy]

Can anyone lend a hand with a few hoop bending questions?

Last year we sent our pipes out to a "mandrel bender"� and we weren't really happy with the results. The pipes were necked pretty heavily, and we paid a fair bit, from memory $450 for both hoops.

Are there any Australian teams willing to share where they get their pipes bent? If you bend your own how do you do it?

A team member has bent some up on a bender that sort of rolls around the die, rather than a press with dies, giving pretty good results, but not perfect. We are thinking of having a crack with filling the pipes with sand and seeing how that goes, has anyone else done similar?

Thanks.

[Coombesy]

Can anyone lend a hand with a few hoop bending questions?

Last year we sent our pipes out to a "mandrel bender"� and we weren't really happy with the results. The pipes were necked pretty heavily, and we paid a fair bit, from memory $450 for both hoops.

Are there any Australian teams willing to share where they get their pipes bent? If you bend your own how do you do it?

A team member has bent some up on a bender that sort of rolls around the die, rather than a press with dies, giving pretty good results, but not perfect. We are thinking of having a crack with filling the pipes with sand and seeing how that goes, has anyone else done similar?

Thanks.

[Rob Littlewood]

Coombesy,

We tried the 'sand method' this year fot the first time and it worked really well. No necking at all.

We did it by getting a tube that is too long, filling it with sand and welding on a metal cap at either end. Then find something of the correct rad, put the tube over it and bend it round.

Then offer it up to a plot of the roll hoop shape or jig to get the correct shape. Cut the exccess ends off, Job Done.

We did it without heating the tubes and it was ok. If you are going to heat the tubes just remember to leave a small gap at each of the caps to allow any water in the sand turning into steam to escape or you may get a bang!!

Have Fun
Rob

[jwill211]

The sand bending techique will get you by, but unless you have done it a few times in the past I'll bet you are not going to be happy with your first try. Be sure to firmly secure 1 end of the tube to something and yank on the other, any movement will throw the bends off slightly enough to give you headaches later. It can be done w/o heat, but just get a good rosebud tip on a oxy/ace torch and heat it to a dull orange and it'll bend much easier than cold.

As for the caps, I pound a wooden dowel in the ends, it seems to hold the sand in and let tiny amts of air out, and if it flys out it probably won't knock you senseless and/or kill you like a metal cap would. Good luck

with all that being said, I'd still get them bent up in a real bender, but give it a shot and be patient.

[Jersey Tom]

We have ours sent out and done. Usually pretty good results, and for front bulkhead, FRH and MRH usually comes out to like 150USD, I think. Could be wrong.

Guy we went to thsi year, local, did a great job. No kinking, real clean work... except he screwed up the FRH, apparently some dimension was unclear, to where we had to cut out a couple inches and reweld it. Wound up gettin the bends for free.

[JagLite]

Sounds good.
But sent out where?
I got a quote from Woolfe for ours.
$1200. Absurd! I asked them if they had put the decimal in the wrong place but they came back with a breakdown of the prices for each hoop that came up with the $1,200 total. Plus shipping of course. We obviously did not have them do ours. Ridiculous.
Tried AutoPower but never got even a reply.
Still looking....

[Bill Kunst]

buy a shark tubing bender. What a joke, these shops must not want the work.

[Kurt Bilinski]

Give Autopower another try. Go to their website and download their design form. Fill it out and fax it back (if you didn't already). Worked for me, they did the bends for my Mini.

[Jevon]

We used a manual bender on our roll hoops with great success. There was no noticable necking or kinking of the tubes, although you may run into problems if you want to do thinner wall stuff. The bender we used is made by pro-tools. The baha team got it a while back and we just needed to get a die for it. Anyway its under $700 which will pay for itself in a few years even if all you bend is a few roll hoops every year. Heres the model we have:

http://www.pro-tools.com/105.htm

Jevon

[John Stimpson]

We have a JD-Squared Model 3 bender, and I've been very happy with it. It really does work great, and I've used it a lot.

http://www.jd2.com/

It's $300 for the bender, and there are a plethora of dies/shoes to bend all different size tubing on different radius's. I can't speak highly enough of this bender with one exception:

When you make the ~150º bend for the top of your roll hoop, the way the tube begins the bend, and exits the bend are slightly different. Hard to describe... Not a big deal, you need to have a picky eye to catch it.

[BStoney]

John:

Can that bender do an 8" radius bend with 1" tube?

[VFR750R]

I've used a similar bender on stainless hardlines at work. I dont' know the bending properties of stainless vs 4130 but I got clean bends down to 5" radius with 1" x .060 tubing. I've also done 7" on 1.5" x .060 tubing with good results, which I think is even more agressive a radius per tube size.

With 1" tubing you guys in the US might want to contact Brown and Miller which do hardlines for cup teams. They have a CNC bender and can do like 1" radius bends on 1" stainless tubing! Frank Weiss Racing Components in Indy also has a CNC bender with the same capabilities. I can't imagine they would charge much for simple bends. Plus any of you should consider CNC bent hardlines for coolant and for dry sump teams oil. You could send them a model of it and they could make it within thousandths of your CAD model. The price would be similar to softline but it's much more robust and maybe cheaper on the cost report. Plus if you make your own hardline fittings and weld them yourselves it certainately would be cheaper then hose ends for softlines.

[John Stimpson]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BStoney:
John:

Can that bender do an 8" radius bend with 1" tube? </div></BLOCKQUOTE>

The biggest die/shoe we've got for it in 1" is a 5.5" radius. There are lots of die/shoes available, you'll have to contact them to find out.

I'll also mention that we've got die/shoe sets for 5/8, 7/8 and 1" that are small radius. We've done hard aluminum coolant lines with the bender with great success. As I mentioned before, we really like that JD^2 bender.

[Matthew Giles]

John,

Did you guy have to sand fill the Aluminum tubes to bend them, or heat them up, or anneal them? I bent some 1.25OD x .125" 6061-T6 tubing with my buddy's bender, but I annealed them first. I'm not sure if it would have worked otherwise, I didn't test it un-annealed.

[Korey Morris]

Go to a local hydraulics shop (ie Parker store etc) and get a minor sponsorship. Our local store did three sets of our '07 (umm now '08) design one Saturday afternoon. The tech said that the .095 4140 had way more spring back than the hydraulic tubing he was used to, but given a good drawing, he whipped them out no problem.

Our only payment was sitting a few cars in their showroom during their counter day this spring and eating burgers and drinking beers with them talking cars. ouch...

Shameless sponsor plug: www.airhydropower.com (http://www.airhydropower.com)

[VFR750R]

Yeah T6 doesn't bend too well. We've always annealed first as well, otherwise it snaps.

I'd also like to add that the bender at work uses external dies and no sand/water/mandrels ect. on the inside and the bends are very nice with no buckling on the inside at 5" radius.

[John Stimpson]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Matthew Giles:
John,

Did you guy have to sand fill the Aluminum tubes to bend them, or heat them up, or anneal them? I bent some 1.25OD x .125" 6061-T6 tubing with my buddy's bender, but I annealed them first. I'm not sure if it would have worked otherwise, I didn't test it un-annealed. </div></BLOCKQUOTE>

Our coolant lines this year were 5/8" x .049" 6061-T6, and they bent around a 2.5" radius die no problem, with no annealing. Surprised me, but hell, whatever.

I've also done 1" x .065" 6061-T6, and 1"x.095" 6061-T6, around 3.5", 4.5" and 5.5" radius dies with no issue, and no annealing.

By the way, you're -T6 is NOT -T6 anymore after bending!!!

[Charlie]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BStoney:
John:

Can that bender do an 8" radius bend with 1" tube? </div></BLOCKQUOTE>

The JD squared and Pro-Tools benders are basically identical, and the dies interchange.

There is a 6" die that I think we used at Auburn, After bending the tubing straightens a bit which gave us about a 6.5" or 7" radius if I recall correctly.

You can make your own dies, or design your car to use standard size radii..

[Drew Price]

We have a Hossfeld No. 2 with the powered hydraulic attachment ( Hossfeld (http://www.hossfeldbender.com/)) , and I bent our front and main hoops on it, 1" x 0.095 4130 with a 3" radius (only 1" dies we had), no crimping, collapsing, etc., they came out really well. I did our seat back tubes the same way, 1" x 0.049, and the harness tube 1" x 0.065 4130. Didn't have to use sand either. It uses a leading shoe following around a 200 degree die, and I just use lots of teflon grease (Synco Superlube) on the leading edge. I make a scale drawing on layup paper and sketch in the radii, and go back and forth between the bender and the drawing matching an angle at a time.

We did 7/8" x like 0.095 6061-T6 hard lines for radiator on a little hand bender, same deal, lots of grease, no sand. It seems like we crack tubing every time when there isn't enough grease on the leading edge, the shoe grabs the outer edge of the tube and splits it right open.

I can send photos of our bends if you're curious, but it's so easy to do yourself I am a little startled that so many people outsource theirs. The main hoop only took about an hour to make after I made the drawing.

Only thing is that's it's a little scary worrying about messing up a 16' length of 4130 for the main hoop.

Best,
Drew

[MikeDutsa]

We got ahold of a guy that does circle track dirt cars, he said he would do it cheap, but when we got there he just showed us his "pipe bend calculator" and we did it our selves. he just asked that we swing by and show him when we are all finished up.

[Coombesy]

Thanks for all the replies guys, looks like it's worth having a play around with the bender (grease it up for a start) until we get the results we want.

[markocosic]

Sand and heat around a plywood former will work fine - but I'd bank on 3 tubes and 3 guys and a full day's work per hoop the first time you do it.

[KU_Racing]

I will back John up on the quality of Kettering's bender. That style is pretty easy to set up, really easy to use, and the bends are very repeatable with enough practice.