Bending Tubing up to 90 Degrees

Tue, 31 Aug 2021 14:48:53 GMT

go to see Welding Machine for Bending Tubing up to 90 Degrees

I posted this over on the H-F Tools comment site with pictures of the result. If you are in a pinch and can work with 90 degrees or less of bend (can you accept sleeving and welding/rosette welding two pieces together in your build to get more angle?). Like the Tubing Notcher issue, after some proper prep, I had good success. It will only do up to 90 degrees IMHO, but it will do it acceptably well, no wrinkles, with the aforementioned prep. To avoid duplication, here is the link to the write up:http://weldingweb.com/vbb/showthread.php?t=23668 Attached Images
Reply:It would not be acceptable in my work. Sorry.There are many plans available on the net to make tubing benders that really work, but the die sets still cost around $200 each .The hydraulic jack, the steel to make the frame. and some bushings. It is a $500-600 project BUT you get professional results.AWS certified welding inspectorAWS certified welder
Reply:I have to agree with Donald. You can either buy pre-bent 90's for most tube, or have a shop bend some up for you. But to bend it vwell yourself, you just have to have a good bender. And with the cost of raw steel now, it is more practical to just buy a bender than make your own. Pro-tools and JDSquared use chromoly for their parts, so the cost of the arms would be very expensive to make yourself. Best bet is always buy one used on the offroad sites. They are up for sale all the time.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Rog, it simply fits a niche. Yuh can't beat the real deal IF you can justify it financially, and, the steel price thing today....holy cow!This setup works fine for our crawler since that is a slow speed rig to begin with. If my son was building a Pre-Runner, high speed Parnelli, Bronco endoing at 120 mph kinda thing, no way I would consider sleeving and splicing. I'd never let him drive it.
Reply:Originally Posted by cranestThis setup works fine for our crawler since that is a slow speed rig to begin with.
Reply:Moon Rocks, NV
Reply:O.K. for a bumper hoop maybe.  I couldn't even imagine the amount of time spent packing tube with sand to build an entire chassis!!   A typical VW sand rail chassis has about 30 bends and over 150' of tube.  The last custom crawler chassis I built had close to 100 bends and over 300' of tube!  A simple rotary draw bender (PT-105, JD2) is a small investment when looking at the total cost of building a complete rig.
Reply:Correct, for that much work you would obviously justify a pro bender. If I ever crank a full chassis I wouldn't dream of trying to sand pack all that, though, a commentor earlier passed the link to a guy who made one small mod that cured the flattening issue. He doesn't sand pack and has built some beautiful roll cages. He goes by Joescustroms or something like it.
Reply:I cut my teeth on an old HF hand cranker/kinker. It worked well for the amount of money that was invested(I bought it used by the way). I've since upgraded, but always wondered could a person upgrade to an air over hydro style HF jack to get away from the hand pump. That's what I grew tired of.
Reply:Here is the link to the H-F bender guy on "Got Trikes" as well as directly on You Tube. He is using the bender with no "Cap Die" and bending full length tubes for sand rails, etc. Similar to me, he is using sand fill but, unbeknownst to me, he has discovered that wet sand packs tighter. His bends/cages are fine with no cap die. Check this out:[ame]http://www.youtube.com/watch?v=GWT3N3m4bE4[/ame]
Reply:Wow...that was a 7min + video which had been edited for time. By the time that guys makes 2 bends in a tube, I could have half a cage done...with better results as I have multiple CLR choices for my TUBING bender. I'm all for saving money but using a tool that wasn't designed for a specific application, especially when it comes to roll-over protection and safety doesn't make sense to me. The amount of time it takes to modify that PIPE bender, pack each tube with sand, pump that ram 1000 times for each bend, clean the tube and test fit a piece just seems ridiculous.A base JD2 bender is about $600 including a die. Is safety and hours and hours of wasted time only worth $500?http://all-a-cart.comWelding Cart Kits and accessories
Reply:Apparently to a few. And, I don't see safety as an issue at all. Time is probably the biggest issue. A real garage guy with no deadline and, probably more realistically, no paying customers, can continue to plug along and set up, bend, clean, notch, etc, etc. Nobody in a production shop could make a living doing this. Water will seek it's own level.
Reply:I've never worked with round tubing. So maybe I'm asking a wierd question.I noticed in the lead off pic on this thread that the bend looked as if the dia. of the tubing had been changed at the 90 (slightly reduced).  Is this normal to have the metal drawn like this?
Reply:Originally Posted by farmersammI've never worked with round tubing. So maybe I'm asking a wierd question.I noticed in the lead off pic on this thread that the bend looked as if the dia. of the tubing had been changed at the 90 (slightly reduced).  Is this normal to have the metal drawn like this?
Reply:Agree fully!
Replyook at it this way. . . . the $500 this guy saves by not buying a decent bender can be used to buy a nicer casket for his son and/or himself.  Sorry, but that method doesn't fly with me either.  Maybe I've got more to live for, but I figure if I can't afford to do something regarding the safety of my family or my self THE RIGHT WAY, it just won't be done.  Just because the NASCRAP guys back in the day built cages that way doesn't make it right.  Consider the HUGE improvement in crash survivability due to the improvements in cage construction methods and materials.  Is that a mere coincidence?  I doubt it.  When you bend a tube like that where there is that much deformation, the tube's strength in bending is very severely compromised.  In order to restore the lost strength along that load path, you need to add more tubes or use a larger tube (both in diameter and wall thickness.)  Most people like our friend won't do that, because that adds to the cost and complexity of the fabrication, and the cheated bend is usually hidden by a body panel or isn't in direct line of sight of the driver.  Hey, out of sight, out of mind, right?  But here's the problem with this situation.  If you apply a force tangential to the bend with both ends of the tube welded to FIXED positions (non-moveable) then the result would be similar to that exhibited by a properly bent tube.  However, if the legs of the tube carry through similarly bent tubes, the net result becomes the longitudinal shift of the common tube as one bend collapses and the other flattens.  What this means is the cage fails and somebody becomes hurt or dead.  The only way to prevent that is to trellis the cage with straight sections forming triangles.  The problem with that is that it makes driver/passenger ingress and egress difficult if not impossible.A vehicle with bends that look like that would NOT get a logbook signoff, nor would it EVER pass tech in my world.  What I don't understand is why a guy wouldn't buy a proper bender USED, then sell it again in good condition for close to the same money when he's done?  And no, the physics of rock crawling are NOT different than those in road racing, nor are the economics.BK
Reply:Any bending will deform the tube, no matter what method is used.   Even a mandrel bender.  Generally any bend over 30 degrees will significantly effect the strength.  Rock/dune buggies aside,  most cages built for racing purposes have very few bends.
Reply:You lose a ton of strength in that tubing once you kink it.I bought a HF pipe bender to try out once. I returned it within an hour. I then went online, found some plans, and built myself a hydraulic tubing bender. I have about $600 between 2 dies and about $150 in materials to build it. The results are of professional grade benders.Well worth it if you ask me:1-5/8x0.125Miller Syncrowave 180SDMillermatic 175
Reply:Originally Posted by jetenginedoctorLook at it this way. . . . the $500 this guy saves by not buying a decent bender can be used to buy a nicer casket for his son and/or himself.  Sorry, but that method doesn't fly with me either.  Maybe I've got more to live for, but I figure if I can't afford to do something regarding the safety of my family or my self THE RIGHT WAY, it just won't be done.  Just because the NASCRAP guys back in the day built cages that way doesn't make it right.  Consider the HUGE improvement in crash survivability due to the improvements in cage construction methods and materials.  Is that a mere coincidence?  I doubt it.  When you bend a tube like that where there is that much deformation, the tube's strength in bending is very severely compromised.  In order to restore the lost strength along that load path, you need to add more tubes or use a larger tube (both in diameter and wall thickness.)  Most people like our friend won't do that, because that adds to the cost and complexity of the fabrication, and the cheated bend is usually hidden by a body panel or isn't in direct line of sight of the driver.  Hey, out of sight, out of mind, right?  But here's the problem with this situation.  If you apply a force tangential to the bend with both ends of the tube welded to FIXED positions (non-moveable) then the result would be similar to that exhibited by a properly bent tube.  However, if the legs of the tube carry through similarly bent tubes, the net result becomes the longitudinal shift of the common tube as one bend collapses and the other flattens.  What this means is the cage fails and somebody becomes hurt or dead.  The only way to prevent that is to trellis the cage with straight sections forming triangles.  The problem with that is that it makes driver/passenger ingress and egress difficult if not impossible.A vehicle with bends that look like that would NOT get a logbook signoff, nor would it EVER pass tech in my world.  What I don't understand is why a guy wouldn't buy a proper bender USED, then sell it again in good condition for close to the same money when he's done?  And no, the physics of rock crawling are NOT different than those in road racing, nor are the economics.BK
Reply:Is a bend stronger/weaker than the same tubing notched and welded to a sleeve, and the sleeve welded around the other piece of tubing?  For 90's."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersammIs a bend stronger/weaker than the same tubing notched and welded to a sleeve, and the sleeve welded around the other piece of tubing?  For 90's.
Reply:Originally Posted by 737mechanicYou talk like it reduces its strength to zero and provides no protection what-so-ever which is the farthest from the truth. No matter how strong you build something it can always be built stronger. Just because a tube has been flattened out some in a bend doesn't mean it does not provide adaqute strength and protection for its original function. I have seen people build roll cages from 1.5 diameter tube and are plenty fine with that but 1 3/4 or even 2 would have been stronger but would probably not be necessary. I would rather have a cage built from 2 in tube and have some flattened bends that have 1.5 in tube with pretty bends that look good.BTW if there wasn't any cost effective way for the average person to bend tube would you refuse to drive or ride in a vehicle that had a cage bent with flattened bends. If you say yes then you would not have raced or went rock climbing in anything 30 or 40 years ago because almost all of them had flattned bends and they never worried about it.It wasn't until madrel bending became common and then hossfeld came out with a cost effective bender and now we are all spoiled and think that the only right bend is one with almost no deformation and even though thats how we all want our bends it isn't always necessary.
Reply:All the hype about safety, doing it right or wrong is pretty interesting since we didn't really have a final application in relation to the bend in the original post other than "making a bend". Not every bend needs to withstand a 226 mph slam into a concrete wall. If a guy wants to add (key word = add) a psuedo roll over bar to the back of his pickup you can't tell me it absolutely has to meet some secret welders society specs or it becomes magically dangerous some how.  A truck is just fine off the lot the way it is but somehow becomes a killer truck with the addition of a home made light bar and the builder is now responsible for all deaths and/or injuries in and around the vehicle? Come on now.
Reply:Originally Posted by jetenginedoctor And no, the physics of rock crawling are NOT different than those in road racing, nor are the economics.BK
Reply:These  chassis all use bends. I defy anyone, that is anyone, to walk up and tell whether they are Mandrel or not. The way tech is done now, a density measuring device reads the wall thickness in the tube(s) and bends. The reason the minimum tubing size is specified is because, even with the simplest benders (kinking excluded) it is sized heavy enough to compensate for the bend.Stew Attached Images"hysics might be the same but the energy sure isn't." BINGO!!!That's why it is called C-R-A-W-L-I-N-G. Having wrenched on Sprinters that have endoed at race speeds, they aren't even in the same star system.Stew
Reply:Originally Posted by cranest"hysics might be the same but the energy sure isn't." BINGO!!!That's why it is called C-R-A-W-L-I-N-G. Having wrenched on Sprinters that have endoed at race speeds, they aren't even in the same star system.Stew
Reply:Originally Posted by RojodiabloUsually, for a welded corner, you miter the 2 sides, and then flat cap one, if not both, and then weld them together. If I have a rig I am doing this on, I cap one side, and then weld the other tube to the cap also. The cap will keep the corner from compressing. It may get bent, but it can not flatten out done this way. Sleeve seams can be very, very good. Difficult to say what application is the best. It would depend on the overall package, and the intended use for it. Done properly, you would have no problem.
Reply:Originally Posted by cranestThese  chassis all use bends.  I defy anyone, that is anyone, to walk up and tell whether they are Mandrel or not. The way tech is done now, a density measuring device reads the wall thickness in the tube(s) and bends. The reason the minimum tubing size is specified is because, even with the simplest benders (kinking excluded) it is sized heavy enough to compensate for the bend.Stew
Reply:Originally Posted by SandyAll the hype about safety, doing it right or wrong is pretty interesting since we didn't really have a final application in relation to the bend in the original post other than "making a bend". Not every bend needs to withstand a 226 mph slam into a concrete wall. If a guy wants to add (key word = add) a psuedo roll over bar to the back of his pickup you can't tell me it absolutely has to meet some secret welders society specs or it becomes magically dangerous some how.  A truck is just fine off the lot the way it is but somehow becomes a killer truck with the addition of a home made light bar and the builder is now responsible for all deaths and/or injuries in and around the vehicle? Come on now.
Reply:Originally Posted by Brad BlazerKinetic energy = 1/2 mV^2Road racing V^2 = 10,000 Rock crawling V^2 = 25 Physics might be the same but the energy sure isn't.
Reply:Originally Posted by jetenginedoctorNice reading comprehension.  The application is described above.  Go back and read.Thanks,BK
Reply:Originally Posted by 737mechanicYou talk like it reduces its strength to zero and provides no protection what-so-ever which is the farthest from the truth.
Reply:Originally Posted by cranestThese  chassis all use bends. I defy anyone, that is anyone, to walk up and tell whether they are Mandrel or not.
Reply:Originally Posted by SandyGet over yourself.
Reply:Originally Posted by jetenginedoctorWhat's wrong, still couldn't find it?
Reply:Okay, a member wants to continue the discussion, and he notes there is still some good information to share. So, let's hear it, and please keep it from getting personalI'll start it back up: When bending a tube, wether using a pull bender like a hossfield type, or a HF style push bender, or the old torch and apply leverage bend, be careful of over-bending, and then pulling back. This has made for some great looking bends on a few of my projects, but there have been some pretty weak-suck fractures at that bend back point. Maybe a combination of a weld close by, or the tube thinning out from the pulling back. But any way I look at it, an 85lb, 35" tire shooting through the desert at 70mph off the back of my truck was NOT the intended result from the otherwise great looking bend I made in the tube.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Wow I leave for a few days and come back and this thing has gotten personal. First I want to apoligize for upsetting you jetenginedoctor[quote=jetenginedoctor;211334]Show me where I said that?I never said you said that. What I did say is the way you talk you would think there is no strength left in a bend if there is any flattening at all. I got that assumption from your statement Look at it this way. . . . the $500 this guy saves by not buying a decent bender can be used to buy a nicer casket for his son and/or himself
Reply:Originally Posted by 737mechanicSandy What she said.
Reply:Originally Posted by 737mechanicWhat she said.
Reply:Originally Posted by BurnitFYI Sandy is a Dude.
Reply:Originally Posted by ZTFabI said the same thing to a buddy of mine at the bar the other night....
Reply:"My suggestion is you put away your pom-poms and leave the engineering to. . . . US engineers."Brilliant prose all around. Hopefully people who notice the PE in my profile will realize that not all engineers are so insecure that they feel the need to constantly flame every opinion that is not theirs.Lincoln SA200, HH135, Lencospot, HF80 Inverter, Rockwell 11x35 lathe, HF drill mill, Kama 554 tractor w/ FEL & BH, Belarus 250AS, lot's of Chinese tools
Reply:Originally Posted by ZTFabI said the same thing to a buddy of mine at the bar the other night....
Reply:Originally Posted by Brad Blazer"My suggestion is you put away your pom-poms and leave the engineering to. . . . US engineers."Brilliant prose all around. Hopefully people who notice the PE in my profile will realize that not all engineers are so insecure that they feel the need to constantly flame every opinion that is not theirs.