View Full Version : Hydraulic pipe bender for cage construction, good/bad?
I hear people say not to use a hydraulic pipe bender, but to use a mandrel or draw roller type. What's the reasons behind this?
All I can think is it may want to kink the tube and the guides aren't as precise. Surely if bending thick wall tube and/or filled with sand it should be up to the job?
What's the word from those who have built cages or even braces?
I want to buy a bender [har har] shortly and have been looking at this type
Am I missing something? (http://cgi.ebay.co.uk/NEW-12-TON-HYDRAULIC-PIPE-BENDER-UP-TO-2-DIAMETER_W0QQitemZ110484621409QQcmdZViewItemQQptZL H_DefaultDomain_3?hash=item19b9658861)
Jon_nova1
22-02-10, 12:44 PM
people say to use mandrel because you get equal width throughout the bends
I'm not sure if these work the same way but my dad has a copper tube bender for plumbing stuff, and it ends up looking like this:
http://www.wintonmachine.com/products/images/BentCopperTubing.jpg
Not sure if it's hugely obvious but the tube necks inwards at the bends.
Ah, like when you bend copper and get the flat spots? I remember that from college .
Mark seems to be on about the same thing.
16v Nova Kev
22-02-10, 12:48 PM
i have heard if you fill the pipe up with sand it wont distort as much.
Aye sand will help loads, plus the CDS will be quite thick walled so I would think it wouldn't 'flute' like the copper.
[EDIT] That pic wasn't there when I posted. lol
Aye sand will help loads, plus the CDS will be quite thick walled so I would think it wouldn't 'flute' like the copper.
It's a magnification of forces though, all you're doing is the same process on a bigger scale with more force... I wouldn't be surprised if they look exactly the same, did you get my offliner on msn about CDS btw?
we have an auto one at work, but we dont have the right size for roll cage bending. if only we did lol.
i wouldnt do for the one above tbh. with something as important as a rollcage. its got to be perfect. and by the time you have faffed about buying that one, the metal which is well expensive, and cutting it all. you could of bought a new one for less lol
Can't buy a cage BMX. Trust me. So that's not an option lol.
I'm looking into buying CDS without the scene tax from a couple of local suppliers too, so I reckon I can get the price down a bit. Even if not, I will be building it in stages so won't feel the sting as it were lol.
Bar the main hoop and front legs, a lot of it is straight sections so IMO it shouldn't be so bad. If the only issue is the 'throating' or WTF it's called (I will remember) lol. Then I don't see that affecting the structure TBH. It will be tied into every conceivable point on the chassis anyway.
It's a magnification of forces though, all you're doing is the same process on a bigger scale with more force... I wouldn't be surprised if they look exactly the same, did you get my offliner on msn about CDS btw?
Mark, I never mate. Haven't been on MSN for a few days so your present may be waiting for me. :) BTW Custom Cages haven't rang me back - there's a surprise! lol
Jon_nova1
22-02-10, 01:03 PM
Metals cheap if you go to the right places, steel stockholders, I got 6ft of box section for £40:eek:
Exactly. Where I get my tube/sheet from at present is the cheapest around. Just need to see what price he comes back with for suitable CDS.
It pays to shop around doesn't it. :)
Custom cages appear to be a cheap supplier for CDS was all it said, 12.40ish for 1.5m? Not sure if they will supply it without you buying one of their cages though. Obviously can't do the long sections like that but it will do for a lot of the triangulation.
Ah right mate, cheers for that. I seen it in their 'club cages' area. I get the feeling it's additional to buying cage sections from them though.
I am interested to know if I could collect the CDS (in a van) in any meter lengths I want.
Jon_nova1
22-02-10, 01:08 PM
it certainly does pay to shop around, going to B&Q would give me 1 metre for the same price!
B&Q is only used in an 'It's 8pm and everywhere halfway decent and fairly priced is closed and I'm desperate for whatever' kind of way. lol
The Simps
22-02-10, 01:28 PM
Don't know if its worth trying your local exhaust maker/powerflow dealer.
I asked my local one and he said they'd mandrel pipe pipe for me for not alot. As long as you know what to bend it to.
Mandrel results in a lot less loss of diameter through out a bend. Hence why intercooler hard pipe kits are mandrel bent.
Not a bad idea Simps. I get the feeling there will be a lot of faffing on though so it may not be the most economical idea. Certainly one I will bear in mind though fella. :thumb:
I get ya Mike. I can't even find a mandrel on eBay. I bet the're a fortune?
Will look on Google when I get a minute.
I get ya Mike. I can't even find a mandrel on eBay. I bet the're a fortune?
Will look on Google when I get a minute.
There not actually as i was gonna buy one when i had a Nova lol lol you can em for about £80 IIRC.
http://shop.ebay.co.uk/?_from=R40&_trksid=p3907.m38.l1313&_nkw=hydraulic+pipe+bender&_sacat=See-All-Categories
Was slightly confused about the above as none are listed as mandrel benders, but nor did I know what mandrel bending was so I looked it up, it seems what you want is any old pipe bender and something like:
http://www.bendtooling.com/product%20mandrel%20assy%20aluminum-bronze%202.JPG
To support the inside, although what most people refer to as a mandrel bender is a massive 12 tonne hydraulic thing that will do 180 degree bends lol
Guess I'll shortly be finding out how good these (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=170449946936&ssPageName=STRK:MEWNX:IT) are. lol
I also found CDS for £4.79 per metre plus vat from a marine engineering place.:thumb:
brainsnova
22-02-10, 04:57 PM
i ll make you a 28mm copper roll cage its worth a packet lol
i really do think it will be cheaper in the long run to buy just the hoob and front legs from custom cages. because if you bend it in the wrong place or it crushes or anything then that piece is scrapped. plus the cost of the bender aswell!!
i really do think it will be cheaper in the long run to buy just the hoob and front legs from custom cages. because if you bend it in the wrong place or it crushes or anything then that piece is scrapped. plus the cost of the bender aswell!!
It's not for a nova, it's a cage for a primera being built from diagrams/pics he has of the works cages, there's not an off the shelf solution available
with that bender, do you have the right Dia bender, if its to small it wont fit and to big and itll ruin it.
and the right tubing for rollcages is not cheap.
there is a certain size for proper spec rollcages. is it 32mm or something with a certain thickness wall.
and it has to be CDS as you say which is no seams. so its more expensive to manufacture lol.
leave it to the experts IMO. like burgo said, get a couple of hoops from the cage place and cut the straights your self. EDIT, in reply to the above comment, ok take in some drawings, say what you want for the hoops and get them made custom.
also when bending, take into consideration how much the tube stretches when you bend it lol. other wise you will measure the size and them come up short :)
It's not for a nova, it's a cage for a primera being built from diagrams/pics he has of the works cages, there's not an off the shelf solution availablei know it is:confused: im sure i found one the other day. ill go have a looksie
i know it is:confused: im sure i found one the other day. ill go have a looksie
Limplamp is looking for a replica of the actual works cage though, pretty sure whoever did them might have something to say if custom cages were churning them out! He also said to me on msn the closest thing from custom cages is a cage for an almera lol He also doesn't have exact sizes for anyone to bend it up to reliably despite having tech drawings he's not found anyone who can dimension them up (old autocad files), so it's going to be a line it up in the car and see what happens job.
Limplamp is looking for a replica of the actual works cage though, pretty sure whoever did them might have something to say if custom cages were churning them out! He also said to me on msn the closest thing from custom cages is a cage for an almera lol He also doesn't have exact sizes for anyone to bend it up to reliably despite having tech drawings he's not found anyone who can dimension them up (old autocad files), so it's going to be a line it up in the car and see what happens job.so gonna go pete tong.
matt_vaughan
22-02-10, 05:38 PM
Not necessarily. Chances are you will make a few mistakes though. My dad had 3 attempts at making the rollover hoop for his Locost, although he hadnt used one of the benders before and was doing it "ad-hoc" lol
Came out fine in end though, using one of those 12 tonne jobbies.
There's a way you can turn them into a mandrel which stretches the tubing at same time as bending, instead of just crushing into one side effectively. I'll see if my dad has the link.
All Limp needs is the correct size die for whatever diameter tube TBH. The rest is a case of angles, measurements an maths.
matt_vaughan
22-02-10, 05:44 PM
Problem is the way those tube benders work above means that 'can' kink the tube quite easily. Its a case of trial and error really. I'm sure the less the angle the less chance of kinking the material though.
lol this is what i was studying at uni today, all about mandrel pipe benders lol
And for CDS for the rollcages your going to need a proper hydraulic mandrel pipe bender.
Got shown this VIDEO (http://www.youtube.com/watch?v=KiHSTFKHRjg) and if you work out all the angles you can measure the angle of bend you need. So i would say yes you could use it.
Hope this helps.
matt, if you could find a link to adapt the bender that would be awesome mate!
BMX, I will use the correct size tube and die. Yeah it's pricey but I think I'm sorted in that area.
Burgo I will be making it with my mate who's a plumber/gas fitter so he has over ten years bending experience (lol)
Mike, that's it mate - hopefully. lol
MK, cheers dude. You're right I have pics and CAD fles, also don't forget this
http://i895.photobucket.com/albums/ac157/itsallac0nspiracy/Roll%20cage%20info/Picture022-1.jpg?t=1266861369
LOL
We used it to have a measure up before. Looking like around 28 metres for the whole lot.
Cheers everyone who has replied. TBH there isn't that many bends in this design IMO.
fook me, rather you then me,
those two bends coming down to the dash, one either side will be so shallow and long i reckon they will be hard to bend by anyone.
the top two with the curve will be a PITA.
and you have just reminded me of a locost build thread i once read about a bloke with a pipe bender who make massive bend lol.
ill have a hunt for it
http://www.locostbuilders.co.uk/viewthread.php?tid=54042&page=8
that should load the right page, go from there and have a read, he does some massive long shallow bends.
Hadn't seen your straw mock up before, looks top notch, and after seeing that I wonder why you bother with cds tbh, get cracking through the capri sun/ribena packs I reckon lol
That looky like an FIA International Spec cage. Gonna be some epic bending for you Limp lol lol
This is never gonna work hth
To develop/reverse engineer a full international cage takes a good couple of weeks full time work with all the right equipment. And that bender wont do the job properly I can guarantee you.
As for replicas of works cages, there's no real drama in doing it at all copyright wise, I've done quite a few now including copying the original audi quattro cages in steel as the original aluminium ones are now illegal for competition.
As for using 32mm tube. NO NO NO NO NO. Only for the X in the hoop and roof and possibly minor support bars
what size is the proper rollcage stuff?
The Simps
22-02-10, 10:56 PM
Isn't 1 3/4" common for most bars and 2" for main hoop?
Who said anything about 32mm tube? If it was me it was certainly a typo lol.
No harm in trying. The bender was buttons, and after a couple lengths of tube I will know how feasible this actually is.
i wrote 32mm, that is what i was guessing at for the rollcage tubing. i think its 42mm for the bigger and 38mm for the smaller.
get a blue book. and follow that lol.
and my mate said make sure you get the certificates for the steel, so if you do race it, you can proove you have used the right steel.
new regs are 50mm main hoop, majority of the cage 40-45mm, 38 for less critical tubes and 32 for minor tubes iirc. But yeah, blue book is the one to go by. Also be careful on your thicknesses. 2.5mm main hoop, 2mm main cage, 1.6 secondary tubes
Cheers for the info Sturge. May get some tube tomorrow if the supplier has it in and my budget bender tips up from eBay - BMX I hope you never packaged it. lol
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