Bend enough tubing like that, and you wont have the energy to care.The old trick to bending tubing is to fill it with sand to keep it from collapsing. I have to wonder thow if the sharp grains of sand might cause scratches on the inside (as they are squeezed around the curve) that might become stress-risers?
The trick to a tubing bender..... If its mechanical, it has to mounted to the floor or something substantial, if its powered, it bends against its own mass, so you can roll in the corner of the shop when you are not using it. Mine is mounted on a engine stand that I cut the top off of, rolls around wherever I need it, and plus I can put in the back of the truck, etc. Basic hydraulic stuff can be pretty cheap if you shop around.Wow, thanks for all the good info guys. Looks like I will just stick to cutting and welding for now, but I will check out some of the info you have shared. I would like at least a basic setup someday, when I, too, have the floor space
Did I really type "thow"??? Must have been a really bad day!The old trick to bending tubing is to fill it with sand to keep it from collapsing. I have to wonder thow if the sharp grains of sand might cause scratches on the inside (as they are squeezed around the curve) that might become stress-risers?
Building one from scratch might not be too bad if you have something to copy from, but by the time you work everything out, you still will have some money in it. The metal to make the dies is not something you can find easily because of the thickness needed. Then you have to machine the radius which is going to require special tooling or purchase dies from a manufacturer. You really are probably better off dedicating some time to working "overtime" and taking that money and buying a bender. Then it has more value if you ever want to sell it. Actual cost is what you paid minus what its worth after you have it a while, not just the initial cost. I recently bought a JD2 bender and its well made. The larger dies are expensive. One of the claims they make is that to prevent bends from wrinkling, you have to prevent the slight springback when you reset the bending die to complete your bend. They have a catch which prevents this springback....so if you build one, you may need to check out a pro bender. There are always ways to make benders that will handle smaller diameter tubing, but when you move up to exhaust pipe sizes, you need some power. I tried the pack it with sand method on a 1 7/8 exhaust pipe andI guess I don't really need one yet, and I definately don't have the room until I build the other half of my shop, but sure would be handy. It's a real pain ordering things here, at least as far as time is concerned. Makes simple projects take a long time
You might look at the DC motors with speed controllers on Ebay. There are lots of them on Ebay and with a little searching you can find one with a control,maybe a reduction gear, and 110 Volt plug in. The one in the picture is 230 volt single phase 3/4 hp 20 to 1 gearbox for $144. They produce a lot of torque.I built one years ago. The inside dies I made on a lathe. There is one for each OD of tubing. I made them for 7/8 thru 1-1/2 diameters. They drop onto a 600/1 ratio gearbox with a 2-3/4 diameter keyed output shaft.
There is a half round section about two inches long that goes around the outside of the tube and clamps it to the inside die. I bought the outside die from Parker Hanifin . It is a straight 2-1/2 " square by 12" long hardened bar
with one tube size in each face. The bar is slid up to butt the clamp backed up by a row of 3" diameter cam followers with 1-1/4" mounting studs and tapered roller bearings. The input shaft on the gearbox has an
automotive flex plate on a taper loc hub adapter. I just spin the flexplaste with my foot to power the bender. It was tested by just bending cold rolled steel shafting. If I use it again I will mount a starter motor to run
on the flex plate with the starter bendix locked. I also need a better scale of larger diameter to measure bend angle. The current one is a degree wheel for setting motorcycle timing.
Have tried many times thru my life everytime a total failure, last time I even welded a threaded plunger that I screwed down to ultra-compact the sand, no good. I have also tried many other tricks such as springs inside the tube, it helps but complicated.The old trick to bending tubing is to fill it with sand to keep it from collapsing. I have to wonder thow if the sharp grains of sand might cause scratches on the inside (as they are squeezed around the curve) that might become stress-risers?