Mini pipe bending

[Matt Stevens 1Participant @mattstevens1]

Hi All,

What does everyone recommend / use for bending small diameter pipes for models? I am particularly thinking about 2x applications….1) Bending a small 1/8" pipe into almost a 1" circle for a boiler blowoff and 2) pipework for a stuart Triple which has has quite tight 90deg bends from diameters around 1/4" (i think)

There doesnt seem to be much ont he market for this type of thing, do people make their own tool? Any pictures if the answer is yes to that…

Thanks

Matt

[Matt Stevens 1Participant @mattstevens1]

[EmgeeParticipant @emgee]

Hi Matt

There have been a couple of designs in the ME over the years, I have plans somewhere but unable to share publicly in case of copyright infringement, if you search the ME indexes for Tube Bender I'm sure the relevant issues will be highlighted.

Emgee

[Former MemberParticipant @formermember19781]

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[Former MemberParticipant @formermember19781]

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[Nick Clarke 3Participant @nickclarke3]

Only used them twice but these (bending springs halfway down the page) **LINK** worked OK

There is a pipe bender there as well, but I have not tried that personally

[Mike ClarkeParticipant @mikeclarke87958]

I have a set of mini bending springs like the ones mentioned above which work quite well for simpler pipe bends. I also made a mini bender which has proved a joy to use…..the plans were posted on Model Engineering Website a few years back.

 

 

Edited By Mike Clarke on 19/02/2020 20:52:12

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[old martParticipant @oldmart]

There is another way, filling the pipe temporarily with a low melting alloy such as Cerrobend:

**LINK**

[Paul LousickParticipant @paullousick59116]

There are lots of tube benders on ebay for bending tube but are normally limited to a 90 deg or 180 degree bend. (as shown in the links above). The tube can also be filled to prevent it from crushing as it is bent. Plunbers use fine, dry sand to fill copper tube prior to heating with a gas torch prior to bending but this would not suitable for small tubes. Instead a low melting point metal alloy could be used instead.

One such product is called "Cerrobend" and is available with a melting point of 70-150 **LINK**

Another option is to fill the tube with water and freeze it before bending around a former.

Paul

[Matt Stevens 1Participant @mattstevens1]

wow….that stuff is not cheap!

I wonder if freezing water would damage the pipe? I guess the pipe could be annealed, plugged at one end, filled with water and propped upright while freezing allowing expanding water to come out the top to prevent damage?!

[SteviegtrParticipant @steviegtr]

I bought this a few months ago at Lidl. Something like £9.99. Cheap tat but looks ok. Would do your 1/4" I guess.

Steve.

[SteviegtrParticipant @steviegtr]

If you cannot find anything look on ebay for brake pipe bender.

Steve.

[not done it yetParticipant @notdoneityet]

I have one of the original CZ metal benders. Never tried it for a continuous close spiral but likely to manage everything really well. Chronos have recently re-invented it – at a cost of around £104. Mine was just over £30 when new and is a magic little tool. I have made a couple of extra mandrels when needed.

**LINK**

[JasonBModerator @jasonb]

For the Stuart the bends are a lot tighter than most commercial benders can go down to. For similar plumbing I have used various end feed plumbing fittings that can be cut down and silver soldered to straight lengths, things like street elbows, full and half crossovers are the most useful.6, 8, 10, 12, 15mm etc.

Another option is to make the bend from solid with a couple of well positioned holes drilled with a ball nose milling cutter and again solder the pipe on before shaping the external profile, this is 6mm OD with a 2mm internal "bending" radius.

Edited By JasonB on 20/02/2020 07:12:33

Edited By JasonB on 20/02/2020 07:13:24

[nigel jones 5Participant @nigeljones5]

I have several different benders but the Dubro is by far the best for small sharp bends.

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