Flexible bending cord options for tight acrylic bends

[LePhuronn]

Hi all

I've started experimenting with some hardline bending for my current project because I have some really tight bends to pull off in order for most of the loop to work. I'm using 12mm OD acrylic tube and in places I'm looking ideally at a mere 16mm bend radius in some places. So far it looks theoretically possible to do if I have a flexible enough bending cord. PETG may give more bendability in the tube itself, but that's redundant if the cord itself won't flex.

I grabbed some 9.5mm OD nitrile o-ring cord from fleabay and it doesn't bend that tightly, and if the cord won't bend as I need it then of course the tube won't either.

What other options are there? Would something hollow like fuel line do the trick? I've read a few times that hardliners moved away from hollow tube because it would collapse and knacker a bend. Silicone tubing?

Suggestions welcome, because yay or nay on getting the required small bends will greatly affect the project.

Cheers!

 

[LePhuronn]

Cheers niro

I might be able to train the nitrile cord a little to improve its flexibility, but it takes a firm hand to bend it tightly, by which time I've flat-spotted the inside of the tube.

I did see some rubber bungs on fleabay a while back when I was considering dyeing the tube, so it might be worth trying the water-filled approach. Silicone fuel line is cheap enough so I'll grab a length of that as well.

Still, back to Photoshop and draw up some new bends to see how big a radius I can realistically get away with.

 

[LePhuronn]

could mineral oil be used instead of water? as the stuff used for Ghetto Submerged PCs? should be able to take a lot more heat then water and contain it better

I was thinking this on the bike ride into work. I have a bunch of foam and silicon ear plugs and some Ikea mineral oil so I'll see if I can seal up some tube and expose to heat.

Never bent an acrylic tube in my life, and here I am going down unconventional routes to get unconventional bend radii for my very first attempt! Madness, I tell you

 

[LePhuronn]

Aquarium filter line like a fuel line, the hollow inside will let it bend far tighter...

Yeah, this is what I'm thinking. I recall early in the hardline days people were using hose such as this but things moved to solid core after a while.

I've just grabbed some cheap silicone hose and will give it a shot too.

 

[LePhuronn]

At the end of the day it's just bending tube and it's quite cheap so you have plenty of scope for messing about trying things.

I grabbed 5m of Shakmods tube for £20 delivered as a starting point, but can get about double that for the price from engineering plastics companies online. I'll also give some PETG a go once I'm more confident I can get bend radii down closer to where I need as that's more forgiving to work with.