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Mcgyver
05-05-2007, 06:54 PM
I made this a few years, ago but used it today and have never taken photos of it so thought you guys might like to see it.

occasionally when making models, one has to bend copper tubing. the typical tube bender, while successful in creating a bend, is not up to the task for modeling as 1) it won't work to a small enough radius and/or 2) distorts the shape of tubing around the curve - ie not a smooth transition from curve to straight on both the inside and outside curves. Thus began a bunch of experiments and reading on to produce a decent bend in a tube.

What I came up with has two unique (well they were to me anyway) features. 1) the outside die, rather than being a round die like the inner is straight. 2) the outside, straight, die, gets tightly pressed against the inner die, sandwiching the copper tube between them. This done via an eccentric axle. If you look in the pic, you’ll see the straight die, then a cylindrical spacer. It's this cylindrical spacer that is on an eccentric shaft.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbuniquefeatures.jpg

Here a bend is being set up. The tube clamp shows a larger allen key setting the orientation of the clamp along a tee slot, while the smaller one clamps the tube itself. I made slit spacers for different sized tubing. In the main pivt, about the round die, there are spacers such that it is firmly bolted to the base, yet free rotate.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbsetup.jpg

here's a shot after completing the first and second bends. the tube was annealed for these bends

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbfirstbendcomplete.jpg

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tb2ndbend.jpg

Mcgyver
05-05-2007, 06:55 PM
(stupid image limitation)

here's a close up showing the fairly decent shape that is maintained. ideally the bend looks like 1/4 of a torus without kinks or ploughed-up leading edge to the bend.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbcloseupofbend.jpg

of course, if you're going to make a tube bender, you're going to do so for all sizes of tubes and radii. Should I ever commit a heinous crime, I consider this important work towards my insanity defense. It handles tubing from 1/8 to 3/8 by 16th’s

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tboverview.jpg

after cutting to length and some emery and polish work, here's the finished product. It’s sitting on the block to which it will one day be attached. Imo it turned our well, its a .5" centre radius bend in a 5/16 tubing. Still, the Stuart plans (this is for a triple expansion) calls for a 5/16 centre line bend, the accomplishment of which still eludes me, even with this rig. perhaps filling with cerro or something.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbresults.jpg

Tony
05-05-2007, 07:11 PM
holy smokes, mcgyver, thats some pro looking work there.. good job.
some of those surfaces look hardened?

-tony

Ken_Shea
05-05-2007, 07:43 PM
That is a very neat set up McGyver, nice job.

Looks very complete :D

Carld
05-05-2007, 07:58 PM
Very nice set of benders. Someone in the future is going to think they have a factory made set.

Rich Carlstedt
05-05-2007, 10:20 PM
Very Nice WOrk !
They have the straight sections in "Large" Commercial benders
They are called "Shoes"
A shop my company had doing work for us used them when bending
our pipes. They could bend a 3 1/4" Stainless Pipe with a 7/8" bore and get a 6 inch radius ( or 7 5/8" C/L) for us.
Obviousely when you do something like that, You have to pay the vendor for making the custom shoes and rollers.
Rich

h12721
05-05-2007, 11:06 PM
Mcgyver,
(this is for a triple expansion) calls for a 5/16 centre line bend, )

Check your print, it is 4 5/16 CRS.
Hilmar

dp
05-06-2007, 12:21 AM
Lots of eye-pleasing workmanship detail work there. Very nice and just a little bit, no, a lot old school. Well done.

Buckshot
05-06-2007, 04:24 AM
........That is fabulous work. It shows a lot of attention to detail and the final finish is just great. Looks just like the kind of old time craftsmanship that's very hard to find these days. Except by dedicated individuals :-)

Rick

Evan
05-06-2007, 04:42 AM
Excellent job. I'll be posting pics of my sort-of-like-a-Hossfeld bender I recently built when I make a few more dies and have some work from it to show.

abn
05-06-2007, 04:59 AM
Consistently impressive, your work looks great!

Mcgyver
05-06-2007, 06:13 AM
thanks very much guys, appreciate the kind remarks. around here its just another hunk of metal dad spent hours messing with so its good to show it to people who get it. nothing is hardened, figured its low duty cycle and bending copper. I will probably use casenit on some parts, ie the top 3/8 hex on the pivot is starting to get dinged up. The finish is just the wipe on blue done to help fight rust.

Hilmar, that tube shown is 4 5/16, what i was referring to was the print requirement that the bend be to a 5/16 radius along the centre of the tube - was i missing something?

laddy
05-06-2007, 07:16 AM
Phenominal, I have settled with the ugly crude bends over a dowel, Yours looks fantastic!!!

Your Old Dog
05-06-2007, 07:32 AM
Nicely done Mac!

h12721
05-06-2007, 09:04 AM
No You don't. I was. Sorry.

Hilmar

A.K. Boomer
05-06-2007, 09:25 AM
Nice work, looks like you also know the value of a good finish on the bending peices to they dont bind or tear the material being bent, I also was fooled by the "color" of the metal and thought for sure that you put it through a hardening process...

Evan
05-06-2007, 09:44 AM
The easiest way to harden those sorts of dies is to make them from 1040 medium carbon steel to begin with. It machines much nicer than mild steel and to harden simply heat to red and water quench. Stick in kitchen oven for an hour at 500F and it will draw it back to a spring temper. Nice colors too.

BobWarfield
05-06-2007, 10:03 AM
Great tooling as usual McGyver!

How did you cut the radius in each die? Custom ground form tool? Some funky inside out ball turner? Just curious.

Also, shouldn't you give a picture of your "tubing unbender"? I seem to recall you have such a thing, and it seems to go with the bender.

Best,

BW

Mcgyver
05-06-2007, 11:45 AM
more pics! here's the device i used to cut the radii. hardened a bit of drill rod with a clearance taper to it and then after hardening, surface ground it down to be the right dia. it work reasonably well, had I known about the 'up and over' style using a boring head and tangential cutter, might have gone that route

http://i20.photobucket.com/albums/b201/michael0100/tangentialradiuscutter.jpg

yeah, the tube comes in coils which isn't much good for my purposes. you can straighten it by tieing one end off to a tree and the other to a bumper, but that reduces the dia and is a pita in my urban environment (I'm sure the neighbors already think I'm certifiable, let alone if they keep seeing me out tying crap to a tree and to my car).

so i made this mill. the two upper rollers are adjustable. orginally they locked into position via a threaded collar and spanner (shown in the pic) however this wasn't positive enough so i added the hex screws to keep them in place. the middle roller, while it has a sprocket, pretty much idles. it works well and is powered used the table crank from my mill.

here's a few shots of it

http://i20.photobucket.com/albums/b201/michael0100/tube%20straightener/tubestraightener.jpg

http://i20.photobucket.com/albums/b201/michael0100/tube%20straightener/tubestraightenerwithrolls.jpg

http://i20.photobucket.com/albums/b201/michael0100/tube%20straightener/tsback.jpg

BadDog
05-06-2007, 01:30 PM
Unbelievably nice work. I don't think I could do work that nice, clean, and professional if my life depended on it. Very nice...

cynic
05-06-2007, 01:35 PM
Really, really nice Mcgyver!

Looks like you could incorporate a mandrel into the setup pretty easy too.

Errol Groff
05-06-2007, 06:11 PM
Let me add my compliments to the quality of the workmanship! The tools look great and your photographs convey this to the max.

How about a word or two on your photo techmiques. I did a properties check on a couple of the pics and see that they are posted as quite large files which certainly adds to their appearance.

When posting pics for the NEMES web site I try to keep photo sizes smaller to help out the guys with slow dial up connections but large size photos certainly look nicer.

Errol Groff

Dawai
05-06-2007, 06:23 PM
Rigid, or Other brands instrument tubing benders can be had cheap.
I broke the flat bar in my 5/16th bender.. I do need to repair it.

A vise mount bender such as you built thou costs around $1200, a little more fancy perhaps with a crank handle and a degree wheel. Good job on yours.

Bending 5/8" .060 wall stainless will make your chest muscles stick out.

Weston Bye
05-06-2007, 09:39 PM
No chance of stealing Mcgyvers thunder here... I submit my lowly home made bender, offered as a good example of a bad example.

http://img.photobucket.com/albums/0803/Weston/e861d391.jpg

Well, not so bad, it works for the purpose. Still, shows Mcgyvers excellent work, by comparison.

Mcgyver
05-07-2007, 02:58 PM
thanks gents, Wes, its whether it works that counts. different style than mine, wonder how it would be on small radius stuff? I don't claim superior design, other than what i can goggle, what i come up with is without the benefit of the tricks and tips of the trade.

David, if i tried stainless, something would break. either the bender or a chest muscle. then again it wasn't 1200 bucks either :D

Errol, All pics are done with a nikon p3 point and shoot. I would like a digital single lens reflex, but haven't splurged yet. size are usually to 600 so it fits a browser - a fraction of what the originals are. i take at max size so i can crop if i want. understand your point about pic, its a compromise either way.

What I've found is the trick for getting decent P&S results is 1) the P3 at least lets me control the aperture so i set at the highest F stop and 2) use a tripod and no flash. Exposure times are long, but the pics are decent. The frustrating part with P&S is that you can't control focus and the screen really doesn't convey how well focused the shot was. If I doubt the quality of focus, I usually take many shots moving the camera slightly each time, figuring that if I give the autofocus enough different samples, one will be ok.

dsergison
07-16-2008, 08:24 AM
wow mcgyver, that is cool.

JMI
07-16-2008, 10:38 AM
... The finish is just the wipe on blue done to help fight rust.


Simply beautiful. Gives me something to aspire to.

As for the bluing, is this a gunsmithing blue? Like a Birchwood Casey product?

Thanks

Jim

Lynn Standish
07-16-2008, 11:58 AM
in the photo on Page 2 of this thread looks like the same solution I came up with for a KDF 5C collet boring bar holder.

kf2qd
07-16-2008, 12:14 PM
Worked for a while for a company that built air conditioner coils. They put very tight bends in copper by using a mandrel on the inside of the tube that had a floppy ball bearing (for lack of a better description) that was positioned so it was just at the point where the tube wanted to collapse as it was bent. Still used the inside radius block and the straight shoe on the outside of the bend. Did 10 & 12 foot hairpins out of 1/4, 5/16, 3/8 & 1/2 copper tube, six hairpins at a time. 5/16 was the most common and they bent it with 1 & 1-1/2 inch hole spacing.

urrutia
08-16-2016, 12:32 AM
(stupid image limitation)

here's a close up showing the fairly decent shape that is maintained. ideally the bend looks like 1/4 of a torus without kinks or ploughed-up leading edge to the bend.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbcloseupofbend.jpg

of course, if you're going to make a tube bender, you're going to do so for all sizes of tubes and radii. Should I ever commit a heinous crime, I consider this important work towards my insanity defense. It handles tubing from 1/8 to 3/8 by 16th’s

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tboverview.jpg

after cutting to length and some emery and polish work, here's the finished product. It’s sitting on the block to which it will one day be attached. Imo it turned our well, its a .5" centre radius bend in a 5/16 tubing. Still, the Stuart plans (this is for a triple expansion) calls for a 5/16 centre line bend, the accomplishment of which still eludes me, even with this rig. perhaps filling with cerro or something.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbresults.jpg

Buenas amigo me encanto su maquina me ayudaría en fotos mas detalladas para yo fabricar una copia de su hermosa maquina. gracias espero su pronta respuesta

flylo
08-16-2016, 01:15 AM
Yea what he said(I hope):confused: That bottom one looks like a 7/8" dia solid SS door handles for glass doors. I bought the elect/hyd bender but only have the 7/8" dies but the bottom pic looks exactly like the ones it bends.

metalmagpie
08-16-2016, 01:20 AM
Another of McGyver's old threads turned into a zombie!

Richard P Wilson
08-16-2016, 04:38 AM
(stupid image limitation)

here's a close up showing the fairly decent shape that is maintained. ideally the bend looks like 1/4 of a torus without kinks or ploughed-up leading edge to the bend.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbcloseupofbend.jpg

Nice work, both the bender and the

of course, if you're going to make a tube bender, you're going to do so for all sizes of tubes and radii. Should I ever commit a heinous crime, I consider this important work towards my insanity defense. It handles tubing from 1/8 to 3/8 by 16th’s

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tboverview.jpg

after cutting to length and some emery and polish work, here's the finished product. It’s sitting on the block to which it will one day be attached. Imo it turned our well, its a .5" centre radius bend in a 5/16 tubing. Still, the Stuart plans (this is for a triple expansion) calls for a 5/16 centre line bend, the accomplishment of which still eludes me, even with this rig. perhaps filling with cerro or something.

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tbresults.jpg

Nice work, both the bender and the pipe! My drawings for the Stuart triple, dated 1955 show a 5/16" inside radius, so on 5/16 dia pipe, that would be 15/32" centre line radius, near enough to 1/2" for me! I've got to do a similar pipe for the No3 compound, but on 1/2" dia, luckily no bend radius specified.

Richard D
08-16-2016, 10:27 AM
I wonder how much time went into making that? Excellent workmanship.

Willy
08-16-2016, 10:47 AM
Buenas amigo me encanto su maquina me ayudaría en fotos mas detalladas para yo fabricar una copia de su hermosa maquina. gracias espero su pronta respuesta

Exactly my thoughts as well.:)
I remember seeing this beautifully executed project when it first appeared here. Although I did not comment on it then I must now as it truly deserves an encore appearance.
Well done, almost too nice to risk marring it up by actually using it.

Edited to add:

I should have included the translation from Google translate....


Good friend I loved your machine in more detailed help me to make a copy of your beautiful machine photos. Thanks I hope your prompt response

SpoonerandForker
08-16-2016, 11:00 AM
Should I ever commit a heinous crime, I consider this important work towards my insanity defense. It handles tubing from 1/8 to 3/8 by 16th’s

http://i20.photobucket.com/albums/b201/michael0100/tube%20bender/tboverview.jpg



I think you qualify for that defense, and I hope to have the room next to you in the boobie hatch. That is exceptional work and a pleasure to see. Thank You for positing the eye candy.

Mcgyver
08-16-2016, 02:13 PM
thanks guys.....a real blast from the past :D. I'd thought to make some drawings and send it in to George for consideration....its percolating somewhere in the 500 item to do list

George Bulliss
08-16-2016, 02:21 PM
thanks guys.....a real blast from the past :D. I'd thought to make some drawings and send it in to George for consideration....its percolating somewhere in the 500 item to do list

You need to retire so you can find more time for work:D

mdavi
03-02-2018, 02:49 PM
I know this is an ancient thread (at least in today's terms), but this is of great interest to me. Any way of sharing some photos? This have been erased by the photobucket monster.