Bending steel

[Robin GrahamParticipant @robingraham42208]

Again not an ME question , but I'm sure I'll get some good advice here. SWMBO has taken a shine to the rustic light fittings below, but they're from a USA supplier which won't export. So obviously I think – hmm – could I make something like? I can do the turned bits, and can weld, but I have no idea about forming the globe shape (which is 8 inches in diameter). Any ideas? If it involves buying some tooling that's OK! Especially as I have a birthday coming up…

Regards, Rob

[Robin GrahamParticipant @robingraham42208]

[Ady1Participant @ady1]

There's a cheapie one we discussed a while back

**LINK**

However for professional "copy" type bending the more expensive gear would make life easier

The company that sprung to mind for me are metalcraft

homepage

It's all very interesting and clever stuff and you're going to spend lotsa money if you get into it

(I find myself salivating when I watch the videos)

Edited By Ady1 on 06/02/2016 00:45:08

[pgk pgkParticipant @pgkpgk17461]

What size rod/wire do you think this is formed from? You can buy 4mm fencing wire (note galvanised you'ld need to clean at welds). that would bend around timber formers

I'm guessing that a heavy duty enough steel frame from rolled up sections and you could cold form the stays around that just using long lengths and clamping at the intersections – say 4-5mm hot roll. Just need to make the bending rolls first and then the pattern.

There's a good chance the original is made from tube – or it could get heavy. I know my OH would take one look and shake her head at a dust trap like that..

(or make it out of wicker and spray with hammerite)

[HopperParticipant @hopper]

You could probably bend them by hand around a suitable former – a bowling ball maybe?

[michael darbyParticipant @michaeldarby61557]

In solid steel ,that would be a fair weight . It could easily be done in plastic, using a hot air gun for the welds.then spray it with a can

[Ian PParticipant @ianp]

Not quite the same as yours but this might give you some ideas. Its SS and the joints are spotwelded

Ian P

[BazyleParticipant @bazyle]

You don't actually want a metal bender as per first link for these curves as they do sharp angles. you want bending rolls – like a formit . or make something incredibly simple from a bit of turned bar ends but we won't tell if it turns out you need the full machine.

BTW it would look a lot better if you avoid the equatorial joint and load the bulb from above.

Edited By Bazyle on 06/02/2016 09:46:03

[davebParticipant @daveb17630]

Our local store has LEDs, halogen and low energy fluorescent but no incandescent. The price for a single low energy bulb, the nearest equivalent to our 40 Wall candle bulb was over £8.00. So, more than £64 just for the living room.

The steel cage to keep these things in sounds like a good idea, there's a lot of cash invested in them.

I eventually managed to buy 24 incandescent bulbs for less than the price asked for one low energy bulb.

[An OtherParticipant @another21905]

Seems to me that the globe is made up of about 16 lengths of wire all the same shape, distributed around the sphere. Would it be possible to make a jig for one piece (probably take a bit of faffing to get the shape right), then just make as many as you need. Also probably need a jig to hold them in place for welding, but if you are going to turn the top and bottom finials, it shouldn't be hard to drill them to support the wire in the correct place using a divider in the lathe. Bending 4 or 5 mm wire by hand is not so hard. Agree with Bazyle – attach it to the fitting at the top so it can be dropped to fit the bulb – much better than the ugly equatorial break.

[SillyOldDufferModerator @sillyoldduffer]

Closer inspection reveals that the wire globe is made from two hemispheres bolted together. I'm entirely ignorant about such work, but couldn't you rough out a half-sphere template from stacked discs of wood and bend the wire around nails banged strategically into it?

You can buy old-style filament bulbs in the UK for decorative purposes. I can't remember where I saw some on sale recently but it may have been B&Q or Maplins. But they're on the web too, LINK .

Regards,

Dave

[Robin GrahamParticipant @robingraham42208]

Thanks for all your replies. Seems that the 'wire' bits (I was thinking maybe 4mm black iron) could be hand bent cold, but TBH I don't rate my chances – whenever I've tried that sort of thing I have always ended up kinking it. I like look of the Warco Formit rolls suggested by Bazyle, but from their web page it looks like it may be for sheet work – couldn't see any reference to wire bending. But if there's a simple way to do it using turned bar ends, please do tell me!

Dave, I like the look of those caged bulbs, but max 40W? Hmm. I'm hoping LED technology will move on, they are getting cheaper and better looking – surely that's the way things will go.

Rob

[duncan webster 1Participant @duncanwebster1]

Not directly relevant, but Toolstatio have a really good offer on LEDs. I've bought a load of 10W at 5 for a tenner and they are pretty good. No idea wat tungstenequivalent, but one is plenty for a not too big room.

[frank brownParticipant @frankbrown22225]

To get that appearance looks difficult to me. They are not lines of longitude, slewed around to get the angular effect. They are bent side ways(along the line of latitude )as well. i would try and find a drum, then free hand draw the "sideways" bend shape on it. Once the "sideways" off set has been determined, make a jig up from jigsaw cut chip board and laminated, so you are make a short section of half the drum. Side guides are now required, router cut groove? Big nails pushed into predrilled holes? Wooden blocks screwed on? I would bend the semicircles with a couple of inches of extra flat bits at the ends . So at the top and bottom have a big washer with a huge hole in it, so the flats can be clamped to them , then spot welded then the excess cut off. Hope SWMBO appreciates the work involved.

Frank

[Raglan LittlejohnParticipant @raglanlittlejohn]

I've drawn a simplified version of this using Design Spark, I left out the equatorial joint as suggested by Bazyle.

I used a helix of 600mm pitch. There are 14 x 3mm wires in each direction. Bit of a job in Design Spark as it has no 3d mirror function.

I think annealed 3mm brass would do, maybe formed over an old bowling ball or similar. The joints could be soft soldered.

John.

[Howard LewisParticipant @howardlewis46836]

Seeing the required end product, my thought was Bending Rolls.

If you want another project, why not make some? The G H Thomas book (Model Engineering Techniques – from memory) has text and drawings in Chapter 18 for a 10 "wide set. I've just finished making a 12" set based on this geared design. If SWMBO complains about the leadtime for her lights, explain that you are making the tools to do the job. Hopefully, she will realise that it is not a "can you just" job.

Howard

[John McNamaraParticipant @johnmcnamara74883]

Hi Robin

Steel ?

It may be bronze or patinated brass.

maybe 6 to 8mm x 2mm flat I don't think it is wire. I wonder if it is rivited?

If I were making it I would first do the harder bend along the thin axis of the bar creating the S shapes then the easier spherical bend.

This is quite a process for a one off.
Lots of jigs. and special parts to make.

Regards
John

[BazyleParticipant @bazyle]

The larger Formit has grooves in the rolls for wire forming. Don't know about the smaller. Remember the ends remain straight for an inch or so in this type of former. It is better to use the longest wire possible and cut up after forming. Practice with coat hangers though wire ones are becoming collector's items so might need to be kept for their true purpose in life – replacement car aerials.

[Neil WyattModerator @neilwyatt]

Looks like No.8 Wire to me (Kiwis will know what I mean).

The equatorial break is so you can make it over a hemispherical wooden former. Just a case of pins in the right places and bend it by hand?

Challenge will be to get bulbs that look right.

Neil

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