I'm planning on buying a JD2 model 3 bender in the very near future and i've been looking at information i received from tools for bending. great information. anyway, they have a tooling selection guide.

it tells you what mandrel you should use to give mandrel bends with a rotary draw bender depending on the wall factor (tube OD / wall of tube) and the D of bend (centreline radius / tube OD).

anyway, i'm going to use the bender to do up a roll cage for my gen1 crx and i know it'll be totally fine without a bender (1.75" tube with 0.102" thick wall). the figures will be well in the range on the table where a mandrel slug or plug is not required.

but i'm also considering making a header for my other car. the header will be made from 1.75" mild steel with 0.063" thick walls. now, according to tools for bending, i dont have to use a mandrel slug or plug to get suitable bends.

my question is this, has anyone tried bending 1.75" pipe with a 0.063" wall on the jd2 model 3? if so, how did it look? can you post a picture?

if no body has done this, could someone please give it a go for me if you have some 1.75" pipe lying around? it would be immensely appreciated.

 

bump??

 

may be a type-o, but jus to let you know, cage should be .120, not .102" wall thickness. and just to be safe, buy .134" wall thickness..youd be surprised at how much tubing varies in wall thickness when your talking about a certification or not...

 

0.102" is the minimum requirement for the cage for my class of racing. no need to go any more than the minimum required when you're drag racing and weight is everything

 

yeah, dont go bigger than you need, i believe that .120 wall is the rule around here, but if its .102 there go with it...i think anything over .100 is overkill though, the nascar team im about to be doing fab work for uses .095 tubing that they turn down to .090, and most drag racers arent going to be going 200 mph like they do

in any event if the cage is built properly, it shouldnt be an issue

and forking out the money for chromoly's weight difference may be worth it, depending on how stiff the competition is down there

 

i've only got a mig so i cant use chromoly (cm has to be tig'd here and i assume it's the same there). although ms will weigh more, i'll be well under minimum weight and will be adding ballast anyway, so no real need to go cm.


but can anyone help me with the 1.75 and 0.063" wall on a model 3 bender question?

 

so what would be the best dies to buy. im getting the model 4 in the next few weeks.
ill probably get 3 die sets.

what would you guys suggest as norms for cage rules?

1 is reserved for some stuff for my truck
and the other 2 are open...
anyone have ideas?

 

I had one I sold a while ago.

I never tried exhaust tubing but I would worry the material is too think and wouldnt last thru the bend.

There is a 4x4 guy who wrote an article on how to bend cages.. Great stuff and really simplifies CLR and all that stuff..

I bought a program from Bend tech that made it much easier as well. It told me where to start and how much to bend! well worth the saved tube!

 

yeah i thought exhaust piping would be too thin as well, but check this out : http://www.toolsforbending.com...t.pdf

if you have a look on the last page it talks about tooling selection guide (referring to mandrel slugs). on a 1.75" pipe and 0.063" wall, the wall factor is 27.7. the D of the bend (5.5" radius) = 3.14. plotting that onto the chart with ferrous metal says no bending slug is required.

so in other words, a mandrel bend *could* be obtained from a model 3 bender on 1.75" exhaust pipe

 

still looking for some help please...