stupid simple manual bender idea...

[fledgling666]

tell me why this is dumb...

just basically a flat plate with the die and guide mounted to it and the crank bar attached to the die (somehow). the plate could be bolted down flat to a work bench or the bottom T could be bolted to the garage floor. i know it's a super simple MSPaint drawing, but i'm sure you can get the idea. so, question is.... is there something about this design that wouldn't work? AND- where would be the best place to put the handle if this isn't a dumb design? thanks.

http://i274.photobucket.com/albums/jj258/fledgling666/bender.jpg

[raskal]

where would be the best place to put the handle if this isn't a dumb design?

hmmm how long do you think you handle will have to be to bend a reasonable diameter tube?
:p

[fledgling666]

hmmm how long do you think you handle will have to be to bend a reasonable diameter tube?
:p

i'm not an engineer:p

just a guy thought something like this might work. all I need it for is to bend 1.5x.120 HREW.

[87JeepWrangler]

hmmm how long do you think you handle will have to be to bend a reasonable diameter tube?
:p

x2. im assuming you(fledgling666) haven't done much with manual benders. the handle works on a compound leverage system, not just a 4' handle welded to the die. thats the just 1st problem.


second, all points where the pivot points are will not be in double sheer. there's a reason all the other manufacturers of benders use huge pins in double sheer.

your idea needs a lot more work before it will work

[PTSchram]

Years ago, I worked for a tubing company that made brake lines, etc. They used exactly that style bender for tiny tubing with thin walls.

Once you got to a point, you wouldn't be able to exert enough force to bend the tubing, otherwise, it would work fine.

[300sniper]

it would probably work fine for tube up to 1". maybe 1-1/4" x .063". i am basing this on the fact you can bend conduit by hand in that fashion. you would have to be a bamf to bend 1-1/2" x .120" tube that way.

[oldjeep]

Looks like a conduit bender, but as others have said the lever would have to be insanely long and strong to bend something like 1.75 x .120 tubing
http://www.northerntool.com/images/product/images/144214_lg.jpg

[fledgling666]

hmm... i'm beginning to see where the main flaw is. the reason i was having trouble envisioning the leverage (why i stuck the handle right on top, out of ideas...) is because it should be out the other side of the die, right into the floor, the way i have it drawn. so, instead, i'm basically going to order a die, and build sorta the same type manual bender as the JD2 but with the bottom arm (that would mount to the stand) as a wide, flat plate i can bolt to my workbench. i won't need as many holes or pins and such, but i will need to figure out a racheting system of some sort. thanks.

[guidolyons]

Xeleventy billion, unless you are bending EMT conduit

Problem #1 = not enough leverage

Problem #2 = Flat plate base could limit multi-plane bends

Problem #3 = Single shear mounting, even the cheaper verticle style 90* one shot benders have 2 side plates

If you want to build your own bender, built a gottrikes bender.

[PISSCAT]

I am the most crap ass fabricator ever, so I may have no fawking idea what i am talking about but here it goes.
You could use a rocker link(MTB tech) and achieve better leverage ratios. Make an L shape with the pivot at the intersection of the L. short end goes to the die and then the long end could get a straight handle. The ratio of the short compared to the long end of the L should be your mechanical advantage.

[Old Blue]

a 1 1/4 emt bender has a 5 foot handle, and is hard to bend. Anything larger than that and it can't be done by hand without assistance (electric,hydro).

[fledgling666]

Xeleventy billion, unless you are bending EMT conduit

Problem #1 = not enough leverage

Problem #2 = Flat plate base could limit multi-plane bends

Problem #3 = Single shear mounting, even the cheaper verticle style 90* one shot benders have 2 side plates

If you want to build your own bender, built a gottrikes bender.

i ordered the plans for that months ago. read everything. it's a pain in the ass. too much involved. i wanted something really simple. in the end, i'll build it and i'll post it.

[guidolyons]

Go for it. Post pics.

[PTSchram]

Go for it. Post pics.

LOL, you're too kind. I was gonna tell him not to bother. If it's too much trouble to make a real bender, it's obviously too much trouble to bend tube!

[fledgling666]

LOL, you're too kind. I was gonna tell him not to bother. If it's too much trouble to make a real bender, it's obviously too much trouble to bend tube!

so, you'd rather there be NO innovation, just follow what's been done before?

[oldjeep]

so, you'd rather there be NO innovation, just follow what's been done before?
Too much work and then innovation :laughing:

Like the man said, make sure to post pictures :)

[ROXROES]

Did a little math, at work so I don't have my bender to do "exact" calc's.

Figured from the main pivot point to the hinge point for the ratchet arm is 3". Then figure you have a 4' lever, that your pulling on which applies a moment to another arm that is probably 20" in length that applies a moment to the pin that goes thru the die with its main pivot point thru the center of the die. Then I figured to do more than 90* bend on 1.75 OD .120 wall I can put 100 lbs of force on the handle, maybe more, I don't know. I weigh about 180ish and find myself smoothly pulling not yanking on the handle to get it to bend.

So using these calc's that means with 100 lbs of exerted force on the handle you have roughly 8000 lbs of force being applied to the pin thru the die to rotate it. If your putting about 150 lbs of force on the handle that means your puttin about 12,000 lbs of force. Now when I get home I could get accurate measurements and rework these numbers but I'm just trying to show how much force it takes to bend tubing. Hence why copperhead fab recommend you put the HF 8 ton ram on the bender. :D

Possibly you could rig something up with a HD hand winch and cable and pullies but the mechanical linkage that these benders use is probably about as simple as you'll find to apply the necessary force manually. Now if you use a simple hand pump hydro cylinder, you could make something like the link below has:

http://www.pro-tools.com/200.htm

[braxton357]

Cons: Having to use a whole stick of tubing for the lever arm. Pros: Being able to use the lever arm as a giant angle gauge!

[fledgling666]

Too much work and then innovation :laughing:

Like the man said, make sure to post pictures :)

yes. innovation is what we here in America use to make things easier, less complicated, more convenient, etc. that is the number one thing that drives invention. well, that, and necessity, but necessity is taken care of, there are already benders on the market. now, the innovation comes in the smaller, easier, more convenient and less complicated package. just like that oxy-clean shit, i'm gonna be on TV screaming at you to buy my bender because it's better in some miniscule way than all the others.:flipoff2:

[mike_belben]

i made a manual bender similar to that for 1" OD. you'd need a heavy bench bolted to the floor and about a 10foot lever for 1.5" though.

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02441.jpg

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02442.jpg

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02475.jpg

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02473.jpg

[Mechanos]

If your objective is to save some money, then I say fail. By the time you buy a die, the material and spend all that fab time, you will more than likely have spent as much or more than if you just buy a bender. If you're just bore and want to fawk around with an idea, then do it.

[roverjohn]

yes. innovation is what we here in America use to make things easier, less complicated, more convenient, etc. that is the number one thing that drives invention. well, that, and necessity, but necessity is taken care of, there are already benders on the market. now, the innovation comes in the smaller, easier, more convenient and less complicated package. just like that oxy-clean shit, i'm gonna be on TV screaming at you to buy my bender because it's better in some miniscule way than all the others.:flipoff2:

A history lesson and a dictionary might help before you start 'innovating'. The tube bender you think you are going to come up with have already been built and have been shown to only work on light weight stuff. You can't just scale stuff up and expect it to work unless you live in the same world as Popeye and if you do keep plenty of spinach handy.

[Travis Waldher]

Ah, you fail.

Because in this case you CAN scale this up and expect it to work.

Unfortunately, it would be such an ungainly beast it would be a bitch to use.

:flipoff2:

[46/71 Hybrid]

i made a manual bender similar to that for 1" OD. you'd need a heavy bench bolted to the floor and about a 10foot lever for 1.5" though.

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02441.jpg

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02442.jpg

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02475.jpg

http://i65.photobucket.com/albums/h205/mike_belben/shopstuff/DSC02473.jpg

That's interesting, where'd you get the die from?

[dopeassjackson]

looks like he made the die. nice job that thing bends tight.
the die in the thread starter is only supported on one side so the bolt/pin that would attach it to the big plate would have to be preaty tight. i would add another side to the bender.
if your looking for a cheap way to bend tube theres a harbor freight tube kinker modification that can turn out was seams like some decnt bends.

[mike_belben]

actually, my experience with using a single bolt has been good.. i bet i could bend without a nut on the thing at all. once you load the die, the tube finds its center in the shoe and thats it. mine DOESNT work as well with the center bolt tight than it does loose for this reason.

correct, i made the die.

those saying it can't be done, you're just guessing. :shaking: i know this because i've bent 1.75x .120 wall in another homemade manual bender.

[300sniper]

actually, my experience with using a single bolt has been good.. i bet i could bend without a nut on the thing at all. once you load the die, the tube finds its center in the shoe and thats it. mine DOESNT work as well with the center bolt tight than it does loose for this reason.

correct, i made the die.

those saying it can't be done, you're just guessing. :shaking: i know this because i've bent 1.75x .120 wall in another homemade manual bender.



how long was your cheater bar to bend 1.75x.120? did you compound the leverage at all or was it the same way as the other you just showed?

[sami-stine]

the JD2 bender is about as cheap as it gets! they use a 5 foot bar on it and it builds alot of force. we can bend 1 1/2 x .120 wall and only use about three feet of the lever. there unit works so well i cant see any need to build my own. its kind of a wast of time and funds to build one. i would rather use my time to build my rig or one for my wife or 7 year old girl.