pipe bending help
pipe bending help
(OP)
Hi i have recentley purchased a 16 ton hydraulic pipe bender for use in my garage, i was hoping to manafacture a roll cage for my landrover. The kit seems simple enough, a bottle jack in a frame with a selection of dies and a pair of adjustable top rollers, the problem is there is no instructions with the kit and when i try to bend steel tube in kinks at the point where the top rollers make contact with the tube, i'm not sure if you are suppose to start with the rollers at the bottom holes and work up to the top or vice versa, can anyone help me,Im avionics by trade so a bit dull when it comes to mechanicle, also it says it does 180 degrees (3 x 60 degrees) not sure how to do that, i only actualy need to go to 90 degrees,cheers jimm





RE: pipe bending help
From experience bending conduit both rigid (pipe) and EMT tubing, you need a better bending rig if going to a 90. You also cannot go less than 5 times the pipe radius.
IF it is exhaust tubing then a muffler shop can bend it. They will NOT generally attempt pipe or rigid conduit.
you may try packing the tube full of sand TIGHT and drive wood plugs in ends to prevent wall collapse. Sometimes it works sometimes not. There is a material called low melt melts at around 100 F. If you pour that in the tube you can do real tight bends then melt it out. But it is not cheap.
IF you are doing water pipe ie sched 40 then an electrical shop with a power bender may be willing to bend it for a fee of course ASSUMING you can tolerate the wide sweep.
Dan Bentler
RE: pipe bending help
RE: pipe bending help
This type of bender will always "kink" or locally buckle and flatten the tube wall. A better bending rig has "shoes" or saddle blocks, i.e. blocks about 1 tube diameter long with a semi-circular groove in it that matches the tube o.d. These are held by pins in place of the rollers, to help support the tube wall during bending and reduce distortion/buckling. Go visit a local auto muffler shop, and ask to take a look at their tube bender in operation. You might want to try and get a local machine shop to make a pair of saddle blocks to replace the rollers with.
RE: pipe bending help
RE: pipe bending help
RE: pipe bending help
If you are rotary draw bending and using a mandrel and wiper die you can achieve a far tighter radius than compression bending
Anything less than 4.5D you will need a mandrel
1D needs a 2 ball mandrel and a wiper die
RE: pipe bending help
1. You will always have a small kink at the apex of the bend with this type of bender, but you can minimize it with a few techniques.
2. That bender should bend 90 degrees in one shot.
3. You should never have to move the rollers once a bend is started.
Place the rollers according to the size of the pipe you are bending. For example, if you are bending 2" pipe and the bender range is 1/2"-2" then the rollers would be set all the way out. Grease the rollers and the bender die. If you are still getting kinks where the rollers are located, you may want to polish or custom fit the rollers. If the pipe is kinking in the center, then make a strap to secure it to the bender die so it doesn't move away from the die as you are bending. good luck.
RE: pipe bending help
RE: pipe bending help