Tube Bending Springs.

Stilldrillin · Tube Bending Springs.

A handy little package, just been delivered.
Never seen these mentioned on here before.

CJW steam, Hastings. £7.65.

toxx

.... yo, David!

How do they work?

Stilldrillin

Slide em over the pipe at the bend position.
The steel spring supports the tube, keeping from kinking as it is gently bent into a radius.

The same as a real plumber`s pipe spring, but on the outside of the pipe.

johnreid

I have used bigger ones, just take it slow and annealing might still be needed. However the radius of bend without kinking is greatly improved with them. If you have tubing to experiment with, you can find your limits.

Mister Occlusion

Just bought a set a few days ago on ebay cuz I'm tired of waiting for the hobby shop to get theirs in....besides, they only ordered 2 and 1 is already spoken for..sheesh.

barry1946

Looks like a "must have" to me!

toxx

... yeeees!

A MUST HAVE!!!

bessytractor

I keep looking at these and thinking that I will eventually succumb!

Wilescoman_123

looks good shame they dont make one for 1/8 pipe or do they?

johnreid

They do make tubing benders for 1/8" such as the Dubro
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXE228&P=7
I have seen these on Ebay too, maybe there is a source for them where you are.

Mister Occlusion

steamgranny

Have a set from CJW too, since completely ruining several lengths of tubing

Have used them twice & nice smooth bends on pipes now, with no kinking

But I'll let you into a secret. I'd had my eye on a set for sometime without thinking to bookmark & after ruining brass tubing as mentioned & in frustration, I did a far too hasty search & ordered what I thought were same only to discover on delivery they were for full size copper pipes

I now have a brand new, very heavy & completely useless set of enormous plumber's pipe benders

IndianaRog

I have had a set of the K&S tubing benders for some time...found they work beautifully on soft copper tubing and reasonably well on brass tubing without annealing (add a drop or two of oil to the spring to make things flex around the tubing smoothly).

Next time I use them I might try annealing brass tubing first with heat...then do the bending. Bottom line they are a good tool to have in hand when working with small tubing and small bends.

Reid

Mark not sure you want or need a full universal joint like that cited example.

In reality what you want is what I'll term (I don't know the name), a shaft alignment joint.

I don't have a picture at hand. The Violano Virtuoso uses this, though,
and it forgives slight shaft misalignments beautifully,
without noise, wear-out or hassles:

Shaft Aligner:

Two identical disks set-screwed to the output and input shafts.
These flat disks have two features: a lip or flange on their periphery,

and two steel dowel pins at nine and three.

The coupler is a disk of dense piano felt.
It is retained, captured between the two flanged disks by the aforementioned circumferential lip
(think: jar lid, only about the size of a quarter or half dollar.

The coupler is that felt disk sandwiched in between.
It has four holes punched through (like a button sort of)
The holes are at 3, 6, 9, 12 o'clock, and register with the pins
of the driving and driven disks.

The device is so simple that it can be made by a home hobbyist
It could possibly be made most simply by re-machining a pair of larger transmission-type pulleys.

If you can't do what Rog did for his coupling system,
this other way is probably your best mechanical bet.

Just in case you pursue this avenue, I do have the dense felt in my stock of piano felts.

----
Tube bending: the spiral benders are grand for gentle radii.

For more acute bends, a pipe (and I presume a miniature pipe would be the same deal)
can be filled with molten metal, and then bent to tight radius with impunity, presuming you have annealed the tubing, and copper excels for bending, of course.

IndianaRog

Reid, I know what I'm ordering next from the Small Parts folks...that bismuth alloy sounds perfect for situations like we often find ourselves in trying to make snug bends in tight spots.

Wow, just never heard of the stuff.

thanks,
Rog

johnreid

I had to sell all of my tools a few years back due to medical bills, but, I remember having a couple of these and they worked great, they were not inexpensive, but would reliably give you good bends without flattening the tubing. When one is paid to install tubing and his work is exposed for all to see, benders and the likes are a necessity. I thik mine cost me somewhere in the neighborhood of $50
http://www.stridetool.com/tools/hose_tubingtools/tubebenders_04.html

Note that for 1/8" tubing the radius of the bend is 3/8" that is a fairly tight bend

Mister Occlusion

That's the stuff I need... But not for casual mucking about

Guy at the hobby shop suggested loosely chucking the tube in the vice and bending it parallel with the faces (with the bend forming inside the jaws). I can see how that might work, but you'd no doubt still end up with wrinkles on the inside bend.

IndianaRog

I bought one of those tubing benders with the plier like handles that John pointed us to. They did a beautiful job, but covered limited tubing sizes (3-4) and cost a fair bit for a good one. My mistake was NOT buying one that made tight enough radius. I think I like the bismuth idea and the small hobby tubing springs...cheap and I probably can't screw it up!!

Graham-Jilly

I have a set similar to the ones john pointed us to. I use them for bending aluminium tube to make folded dipoles

Mister Occlusion

Reid

Wallace

I like the idea of Springs.

Pipe can be filled with fine dry sand, heat the area that needs bending, and bend without any kinking.

The hardest part though is filling such a small diam pipe with sand.

johnreid

The type I was referring to was for 1/8" pipe, it was real useful when more than one bend was needed on the same piece of tubing. There are also similar ones that are sometimes found a plumbing supply houses. I repaired machinery that had some small tubing that carried coolants, lubricants and air.

IndianaRog

Small Parts Inc. has a fabulous website if you have not visited of late...they do sell stuff I have never found elsewhere.

http://www.smallparts.com/

My only gripe with them is their flat rate shipping charge by FEDEX when a 41 cent stamp on an envelope would handily cover a few gaskets I once ordered. I even put in my order instructions to skip the $8 FEDEX shipping and go the USPS route, but to no avail...a FEDEX truck shows up with a box in hand...inside the box my 4 gaskets weighing next to nothing and costing less than shipping charge.

Maybe they just couldn't modify their system, but for future orders, I need to get enough stuff to justify the shipping charge. Other than that issue, they are great to deal with, have the impossible to find and send it fast.

johnreid

There are lots of places that are that way, I was wanting to order a Mamod Safety Valve from Ministeam but the minimum shipping and handling ( in the neighborhood of $12 ) is more than what a Safety Valve costs.

Reid

Sounds like they morally owe you eight dollars of credit, Rog.

That sure would yank my chain. But if they don't have a runner to
run things to the PO, then it got glossed-over.

However, you'd think they'd offer options. But, on the other hand,
the PO is hell for tracking packages, and plus, the insurance is hardly collectable, not for many months.

So I dunno. It would still yank my chain too had that happened here.
It's the no-explanation, no apology aspect. Somebody dropped the ball there.

johnreid

Too bad we dont know someone that only lives 15 miles away from that place

Mister Occlusion

Last week I finally got a web order in at small parts., They were supposed to email me with a shipping quote. Never heard from them.

I *still* need some 5/8" brass square tubing and so far they are the only source I can find.

Anyone got any other web stores in NA that sell raw materials? I'd like to get some telescoping sections of fine copper tubing too, instead if using brass for steam lines.

Reid

johnreid

In fact, I was just teasing, Reid.
Factory made items are not going to be done the time consuming manual ways, I assume that a pneumatic tool is used to form Wilescos bends.
One thing that I do not like about Wilescos is that on the ones I have seen, soldering is done on the engines steam lines after it has been assembled. Thus, if one wishes to disassemble it he has to unsolder some parts. Just a personal gripe I guess as I also assume that those joints are probably soft soldered and not that difficult to work with, but still an area that could be improved on.

Minor1PJG

I used the full sized springs when fitting a new gas pipe to a gas fire in a house I was living in as a student. Made a lovely job of bending the pipe.

Shame the flue at the back of the fire was cracked and the poisonous CO could have killed me and my girlfriend.

Of course I din't find this out until a routine visit from the gas board 3 months later and he condemed it and disconnected it. Lucky it was Spring by then so not so cold.

It just goes to show being able to do something and being competent are two very different things

That Bismuth looks like great stuff when bending our small diameter pipes

Bogstandard

Over many years of small tube bending, I have tried everything mentioned here, and a few that haven't. None of them compare to a correctly made tube bender, and if anyone has a bit of a workshop I can supply plans for such.
But seeing that most of you won't have a workshop, and only want to bend a bit of pipe every now and then I will run over a couple of pitfalls that you might experience with a couple of these methods.

Bismuth low temp metal (called Cerobend in the UK) is very good, if you can get it into the tube in the first place. With larger tubes there is no problem as you can ladle it in, but with small tubes you need to immerse it into the molten metal to get the tube full, then blank the ends off while still immersed, and this is at a working temp of near boiling water. Can be a little dodgy.
Very fine dry sand or salt can be used to good effect if you want to pursue the packed tube method.

Bending springs are great, until you need a fairly tight bend, then getting the springs off again without restraightening the pipe can sometimes lead to grief.

Now here are a couple of tips to help make nice bends.

ALWAYS anneal the metal before bending, without it you are asking for trouble. Just heat the pipe up to a cherry red (dullish red)and drop it into a bucket of water. Most of the time I can do the bends in my fingers to the desired radius (not by grabbing both ends and just bending, but by forming the bend with your fingertips) with no sign of collapse. If you feel the tube going stiff you need to stop straight away and re-anneal, even if you are half way around forming a bend.

If you don't fancy doing it with your fingers, try this method, it works very well when you just want the odd bend.
If say you want to bend a 1/8" pipe thru 90deg. then just get a piece of thinnish wood and file the radius you want onto the corner of it. Then just file a small groove on the edge of the wood around the radius you have just filed. Anneal your metal, grip the tube on the top of the wood and resting on the groove that you filed. Then it is just a matter of bending the tube around the corner using your fingertips in an action as though you are trying to push the pipe into the groove while following the corner profile. It takes a lot longer to try to explain it rather than doing it.

One thing you must remember when bending pipework, very sharp bends are NOT possible even with bending machines, the reason being is that metal can only stretch and compress so much, especially with the thin walled tubing that you use, going over this limit will usually result in a collapsed or split bend. The only way around that problem is to use a cast or machined bend.

If you do a lot of tubing runs, it pays to buy in bulk, I usually buy 5mtrs at a time, it works out to about 1/3 the cost of model shop tubing.

I hope this might help a few of you with the odd bend that needs doing.

John

tmuir

Thanks for that.

In a few months time I may hit you up for plans to make a tube bender.

gavsr70

Just an idea I had that I've never tested

- would filling a pipe with finely milled salt support the bend?

You could then wash the salt out afterwards.

Wallace

johnreid

On Large pipe compressed air works, I used to have a PVC pipe bender that worked on heat, but to avoid flattened pipe, I would plug the ends of the pipe before heating. I agree with what was stated above, a channel in the radius of the desired bend is a major step in the right direction, commercial bending tools have such a channel or should I say groove in them,

Cedge

Wallace
Salt works great. The natural cubic shape keeps it from shitfing about under pressure and allows it to bind nicely inside the pipe. Heat won't hurt it and it washes out easily.

What I use are these. http://www.shopatron.com/product/part_number=786/101.0
All I can say is they work well enough for me that I'll be making several of copies in different diameters and bend radii.

Steve

Stilldrillin

Look what I found in me bits box!
Don`t know where it came from.

!/8" dia copper with .054" steel wire all the way through.

I guess you bend as desired, then pull out the core.
Not tried it out, yet.

tmuir

Nifty item to find lying around.
Let us know how it worked when you bend some up.