double helix

[Beanmetalworks]

hi got to make a double helix that is 2meters tall by 750mm diameter got few ideas as how to do it just seeing if anyone had suggestions?

 

[Windy Miller]

One for Chunko I think. I seem to remember him doing a double helix some while ago...

 

[Engineer1964]

Basically its 2 spirals connected, see the picture below

What i would be inclined to do would be to get one of those companies that can roll a helix to the size that you need and you need 2 of them, I have used this company in the past

http://www.anglering.com/metal_bending_methods/spiral_and_helical_bending.php

 

[KemppiFrog]

I found it not too difficult when bending the handrail for a spiral staircase. But I did have the stair as a mould. Lots of tweek and try. It was about 180cm diameter, so rather bigger. Yours should be less of a prob. Now I would roll it on the machine as a coil, then stretch it out, followed by some 'correction'. Some maths might help to get the coil size, relative to the spiral.
Bon chance
KF

 

[Beanmetalworks]

i was thinking what about if i got a 750mm tube 2 meters high and got the flat and heated it and bent it round the tube in the desired postion?

 

[Dev]

Or 1 metre and moved it along, 750mm tube can't be cheap

 

[Beanmetalworks]

to be honest the tube isnt as much as thought it would be but just the method is what want idea for? was thinking if you had the tube could you plasma cut the helix out of it?

 

[mike 109444]

how thick does the metal have to be?
You could cutout/makeup 2 spring like coils (see chunko's ring maker) (20 x 5mm strip?) then pull out to form the spiral.

 

[Beanmetalworks]

i think looking at more like 100mm by somthing like 6mm its got to look chunky

 

[Beanmetalworks]

i tryed a piece of 50mm x 8mm bending it around a smaller diemeter tube got quite nice result

 

[chunkolini]

Do you mean something like this?
I was recently asked to make a collection of spirals by someone I think is a time waster but I came up with this.


About 1m in diameter, made of 15x3mmm strip rolled up flat on it's edge on my powerbender. It works a treat but would sag horribly if any heavier. Hence the strings.

You could do it in flat strip rolled into a coil, roll it flat them stand on the bottom and lift the top coil and it will open up to it's finished shape like this.
Edit, this was bent up on it's flat edge as well.

Could be scaled up and opened put with a forklift.
I am sure it would work rolled edge up, then opened up vertically as well but not tried it.
Designed and made by one the customers to my sculpture classes.

The double helix I made is here.
Made of chains of pennies with short bars linking the pairs.

Fabricated as a series of barbell shapes and welded together. Not saying ho i did it, that is the challenge.

Beanmetalworks you have PM.