Trevor Posted April 1, 2001 Share Posted April 1, 2001 On impulse I bought a hydraulic pipe bender from Harbor Freight when it was on sale. I didn't come with (English) instructions.... but I was swayed by the the advertising things like "you can built exhaust systems, roll cages, custom parts..." But it's nothing like the pros use at the muffler shop. It's a simple rig with a 12 ton jack, pushing cast iron shoes between 2 steel roller wheels. In preparation for some exhaust work I put some test bends in a 1" diameter pipe with dissapointing results. once the bends get past 20-30 degrees it kinks in the inner radius of the bend. I tried bending a little and moving the pipe but all I get was a series of small kinks. Visualize the factory exhaust on a '81 Chrysler K car. Looks like junk. Not what I want. I want those smooth "mandrel bends" you get by stretching the outer radius rather than kinking the inner. I want up to 90 degree bends and some complex shapes too. Anybody know how a mandrel works? Can I acheive the nice smooth bends in 2" pipe with my new toy? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 1, 2001 Share Posted April 1, 2001 This is a Mandrel: But seriously, I think the problem comes in the fit of the shoe on the tubing. Its my understanding that Pipe benders and Tubing benders are slightly different due to the way they're measured. The shoe for the two are slightly different from what I've heard. Unless the shoe perfectly supports the contour of the pipe you'll get kinks. Which still ain't as bad as those compression bends which look like a flex exhaust hose on the inside. FWIW. Check Mandrel on the search engines you'll probably find the problem exactly. Regards, Lone Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 1, 2001 Share Posted April 1, 2001 Lone will chime in and show us pictures, I'm sure (he's great at that!), but in general terms a mandrel is a piece that you form something around - kind of like a male mold. My guess is that a mandrel pipe bending machine has a ball on a cable that is slid down the pipe to the region where the bneding will happen. So when the bend is done, you'd pull this ball through the bend at the same time to keep the pipe from collapsing. Lot's of grease is used. Just my wild ass guess. ------------------ Pete Paraska - 73 540Z - Marathon Z Project pparaska@home.com Pete's V8 Datsun 240Z Pages Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 1, 2001 Share Posted April 1, 2001 Lone, that's too funny. We were typing responses at the same time and you DID put up a picture, like I said you would . ------------------ Pete Paraska - 73 540Z - Marathon Z Project pparaska@home.com Pete's V8 Datsun 240Z Pages Quote Link to comment Share on other sites More sharing options...
DavyZ Posted April 1, 2001 Share Posted April 1, 2001 Lone, you may have lost your mind, but not your humor! Man, THAT is too funny! This is a mandrel...BOY THAT IS RICH! Haw haw! Quote Link to comment Share on other sites More sharing options...
DavyZ Posted April 2, 2001 Share Posted April 2, 2001 No no no...a mandrel is another name (formal name) for a baboon! Spelling is actually "mandrill" for the ape, but they are pronounced almost the same. Quote Link to comment Share on other sites More sharing options...
Trevor Posted April 2, 2001 Author Share Posted April 2, 2001 Oh I get it. He puts the pipe in his mouth, and holds one end in each hand........ Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 15, 2001 Share Posted April 15, 2001 Your problem lies in the manufacturer location. If you look closely at your new toy, I feel sure you will find it's origin to be of the eastern most part of the world. namely China or even taiwan. This is not condusive of tools that operate on a very high level. Harbor Freight is cheep cheep. I also go there from time to time, but watch what you buy, some things just aint worth a f#%* Good Luck Tony ------------------ To many projects:74 V8Z,63Nova SS,48Chevy Street rod. www.speedtechcoatings.com Quote Link to comment Share on other sites More sharing options...
Owen Posted April 15, 2001 Share Posted April 15, 2001 That picture scared the hell out of me! Good one! And like someone said,you get what you pay for at Harbor Freight. I bought one of those forks to remove a ball joint and the damn fork ends bent in separate directions! My hydraulic press is holding up pretty well though. Any my $20 disc grinder and $4 one man brake bleeder kit! Haw Haw! Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 15, 2001 Share Posted April 15, 2001 Yeah, some of the harbor freight stuff is cheap, no doubt. Some of it is cheap, but still works ok. I have their cheap metal bandsaw and drill press and it works ok. I wouldn't say its like dead accurate run-out on the drill press, but for doing most things its ok. Their engine hoist worked pretty well, jackstands not bad 6 ton units with cast uprights for cheap. Floor jack, fairly decent for the tonnage and price. $20.00 grinder, hey, its still working and used it for alot of stuff, even included new brushes... such a deal Inspect the stuff well and look for signs of cheap design and stay away from those, and you can do ok there. IMHO. Lone ------------------ http://datsun240v8z.virtualave.net/index.html Quote Link to comment Share on other sites More sharing options...
DavyZ Posted April 16, 2001 Share Posted April 16, 2001 I bought a grinder there--it's decent quality and works well. I don't like the fact that 95% of everything is made in (communist) China. The price many times reflects the quality, unfortunately. I am very selective when I go there and carefully look at what I buy. Even if something is more expensive, I try to buy American when I can, so Sears is my first stop! David Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 16, 2001 Share Posted April 16, 2001 For hand tools, definately I go to Sears, how can you go wrong, no question replacement. (I draw the line on those Bob Villa advertised Robogrip plyers though... should be called Robostrip or Roboslip... ) Lone Ps (Guitar players, the deep sockets work well for playing slide guitar ala the late great Lowell George of Little Feat...) Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted April 16, 2001 Share Posted April 16, 2001 Yea I go to Harbor Freight sometimes also, and you do get what you pay for/sometimes! Years ago when Snap-On was coming on real strong & flooding the market w/their tools I worked in East Dallas for a shop that reguilt hydraulic tools....all the tool trucks would drop their stuff off at our shop for the "Factory Gaurantee" rebuild after a line tech had worn it out...guess what: At first Snap-On was USA made, till the economy began going south-then one by one theay all began showing up as China built/we would sometimes use the guts from a known China made hydraulic tool to rebuild a snap-on unit regardless of whose name was on it. Same thing w/Chicago Pnuematic (or however you spell it); and sears did the same thing/China built but w/Sears's name on it. Not all but most Hydraulic guns you could swap parts w/regardless of whose name was on it w/in that particular model line. I still like Sears when it comes to sockets & ratches; when it comes to Haydraulic Tools-they're all the same w/exception to Ingersol Ran. The reason Snap-On's cost so much is due to their warranty; when you buy a Snap-On Hydraulic tool you're buying a warranty! The number one reason a Hydraulic Tool fails is because most tech's dont "OIL" the gun prior to use & the internal viens burn up. Once the viens burn up then air simply bypasses the viens & the gun gives the feeling of "Lossed Power". Most Hydraulic Ratchets fail from the same non-oiling or they are used to "Untorque" a bolt-the Hydraulic Ratches were never intended to "Untorque" a bolt; instead they were intended to remove or install the bolt after its been "Untorqued" by a breaker bar. About the mandrel; if you want nice "Unkinked" bends; you're gonna half to pay alot more than what Arbor Freight has. Back in FFA when I was young/dumb & full of energy (High School days)...our FFA shop had an electrical Hydraulic Pipe bender that would rotate around a steel wheel as it was bending...this would create that smooth bend finish. Dont know how much one of those would cost but I'm sure it isnt cheap. Kevin, (Yea,Still an Inliner) [This message has been edited by Kevin Shasteen (edited April 15, 2001).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 29, 2001 Share Posted April 29, 2001 That steel wheel is the mandrel...just like an arbor that goes on your die grinder is also called a mandrel...I'm assuming that that is how they make the bends, that wheel probably prevents the pipe from crimping while being bent...I'm assuming that they are replaceable in a mandrel bender to fit the size pipe that is being bent... Quote Link to comment Share on other sites More sharing options...
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