Help with my device deformability 2

[surgeon2016]

Hi everybody,

For a personal project, I am trying to make a wire cable holder that can hold the cable and then you can bend the holder with your fingers into the configuration you want. I included an image below and I'm trying to get the holder to bend laterally into whatever angle you want and to stay in that place. Was wondering if anybody can offer me ideas on materials or structures I can use to help me achieve that goal? I'd greatly appreciate it - thanks!

 

[BUGGAR]

Lead is easy to shape. Is it still legal?

 

[surgeon2016]

Haha, thanks for your input. I was hoping I could make it hold it's configuration and be able to reconfigure it into a larger/smaller angle if needed. Kind of like what gooseneck tubing does.

 

[MikeHalloran]

AFAIK, lead is still legal, and remarkably ductile, but you have to be careful about the forms of waste you generate, particularly metal vapor and finely divided solids.

There exist some filled epoxies that you mix by kneading with your fingers. For a few minutes, the mixed product is ductile enough to form with your fingers or simple tooling, and then hardens to become rigid.

Many plastics can be formed by hand when heated, but for most of them you will need serious gloves.


I'm a little fuzzy on what sort of configuration you intend to produce with your fingers from the simple preform you have shown. Can you take a shot at illustrating a few typical configurations?


Mike Halloran
Pembroke Pines, FL, USA

 

[surgeon2016]

Thanks for your input, Mike. I was hoping I could make a little device that looks as below: which you can bend the end of it laterally to 30 or 60 degree angles and stay in that configuration, and then be able to change it to a different angle if you want it to. I'm not sure if you can make a solid material that can behave that in that way, so was wondering if you knew of anything.

 

[tygerdawg]

You might investigate malleable polymers that can be cured with ultraviolet energy. I think the dental industry does some innovative & interesting tasks with UV-curable polymers and luckily I have not had need to experience it first-hand. But once cured, cross linking takes place and the form is permanent if that works for you. Of course, as always, I reserve the right to be totally & embarrasingly wrong about this.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[MikeHalloran]

If by 'wire cable' you mean a plastic jacket with multiple small stranded insulated copper wires inside, you might be able to make a two-piece plastic thing with a friction hinge or maybe a ratcheting hinge.

If by 'wire cable' you mean a Bowden cable, i.e. a piece of solid music wire sliding inside a coiled steel wire shell with or without a liner, you will need something fairly sturdy in order to resist the cable's tendency to straighten itself.

Lead might be the perfect material for what you want to do, but its presence may scare civilians and/or 'safety people', who come out of the woodwork regularly.

If you can do without the radial 'lay in' feature you have depicted, and can do axial assembly, consider also annealed copper tubing, which in small sizes can be worked with strong fingers, and will withstand a few corrections.

Friction hinges that actually work tend to be fairly bulky.
For reference, I have a couple of mirror extenders that strap onto my rearview mirrors so I can see around a wide trailer. Between the straps and the mirror housings are a couple of articulated struts with friction hinges. The struts are semi-streamlined, with a cross section estimated at 1/2 inch x 1 inch, obround. The friction hinges are maybe 1 inch diameter and 1/2 inch thick (two halves x 1/4 inch thick each), secured by a single central screw. There may be friction hinges of smaller proportions that work, but none come to mind at this instant. I am getting the impression that something that large might not be what you want.

The gooseneck tubing in the photo retains its bent position because it is coiled with some preload between adjacent turns, probably by twisting the preform strip as it is coiled. This preload provides some friction that resists bending, until the metal either yields or wears a bit. They tend to loosen and lose utility after relatively few cycles.

There is a sectional construct sold for positioning coolant streams in machine tools, comprising tubular injection molded bits with ball and socket joints at the ends that allow limited flexibility. The joints are made with an interference fit so they retain position, at least for a while. The interference is tight enough that special pliers are required to connect and disconnect the links, but they might provide something to copy or buy. Those 'coolant hoses' come in several sizes. None that I have seen are thinner than a fat finger.

For further inspiration, wander through a toy store.
I am not kidding; you will find a lot of interesting stuff, much of it fairly well engineered.


Mike Halloran
Pembroke Pines, FL, USA

 

[surgeon2016]

Those are fantastic ideas Mike. Thank you so much. I'm gonna have to make a trip to the store and check these out to see what will work.

The device I'm hoping will hold a .014 inch stainless steel wire that is flexible and doesn't have much recoil ability. I am hoping it will be a device you can hold in your hand so not too bulky.

 

[BUGGAR]

There are full size (12 inches plus wide) cable trays made for buildings that have hinged, curvable sections like you want. You would have to scale it way down. Look up electrical cable trays.

 

[BUGGAR]

Also, I just thought of those steel stud walls using the curvable track sections. Look up light gage steel framing from Dietrich, et al.

 

[MikeHalloran]

I just ran across some plastic that melts at 140F, so you can mold it in your hands:

http://www.jameco.com/shop/StoreCat...mecoall^prodPage~15^page~SEARCH+NAV&CID=FQCAT

Mike Halloran
Pembroke Pines, FL, USA

 

[surgeon2016]

Thanks for the help! Greatly appreciated.

I was hoping to construct a device I can adjust with my hand without the assistance of heat/energy. Much like a paperclip you can bend with your hand, and be able to bend it the other way if needed. I am assuming I will have to lean towards a mechanical construct with hinges and multiple pieces if there isn't a solid piece material that exists for this purpose?

 

[MikeHalloran]

You didn't answer my question about 'lay-in' as a requirement.
If you can tolerate axial assembly, annealed copper tubing seems a likely candidate.


Mike Halloran
Pembroke Pines, FL, USA

 

[Tmoose]

Is this a one time adjustment, or a few times a day for the same part?

 

[Compositepro]

Pure aluminum is pretty ductile with about a 5 ksi yield strength.

 

[surgeon2016]

Really appreciate the input. I'm trying to have it adjust several times in the span of one-two hours and that is it

 

[BUGGAR]

I use a flexible drafting curve - sort of soft plastic wrapped around a lead(?) core that you bend by hand for drafting curves. Breuger (sp?) makes a pin striping layout strip like my drafting curve but with a groove down the middle to guide their pin striping tool. I've got all this stuff if you want me to send a photo.

 

[surgeon2016]

Thank you.