What is the best method to make an aluminium tube of 13 OD,280 length and having a reduced cross section at one end? One 'piece' of the foldable cane used by blind people for example

280 long? In mm that's awful short? In cm that's pretty long , in " you gotta be kidding?

Ian

13mm? 13 Inches?

The general way in production is to use a swaging machine with dies shaped to the OD you wish to achieve. It can be done cold, warm or hot.

In general one must support the tube while the reduction occurs or it will buckle/fold so just hitting it with a hammer  is not a good way to go.

 

I suggest a search for tube swaging on youtube.

 

Ric

In 2 or 3 dimensions?  In 2 dimensions just hit the end of the tube with a hammer, presto cross section reduction.  Channeling Thomas P. on this one.

280 long? In mm that's awful short? In cm that's pretty long , in " you gotta be kidding?

Ian

Its 280 mm long. and cross section at end needs to be reduced.

13mm? 13 Inches?
The general way in production is to use a swaging machine with dies shaped to the OD you wish to achieve. It can be done cold, warm or hot.
In general one must support the tube while the reduction occurs or it will buckle/fold so just hitting it with a hammer is not a good way to go.

I suggest a search for tube swaging on youtube.

Ric

Thank you Sir; it is of 13 mm diameter OD which has to be necked down to 10 mm. i have tried using screw press and necking die, using mandrel but the component is cracking at one end or in some cases just buckling,twisting.


13 mm diameter OD which has to be necked down to 10 mm. i have tried using screw press and necking die, using mandrel but the component is cracking at one end or in some cases just buckling,twisting.

wHITE CANE.pdf

Some alloys will crack,,find out wot you have and see if it is one of them...pieces marked T6 will break

Welcome aboard, glad to have you If you put your general location in the header you might be surprised at how many of the IFI gang live within visiting distance. That and some questions have regional specifics we just can't take ito account without knowing where you are.
 
If your necking die isn't working cold try marking it with a black Sharpy (black felt marker) heat it with a soft flame till the marks turn clear and or go away, then quickly swage it in the dies.
 
That's what I'd try. However I doubt I'd take a commission like this, too many shops around that do this every day. The guys who run electrical conduit have swages and presses for doing exactly this. Larger diameter and I'd refer it to a muffler shop. That's just me though.
 
Frosty The Lucky.

Instead of swaging down try 10mm tube and expand. try tallow as a lubericant.

I anneal aluminum on a regular  basis, as Frosty said heating just enough to burn off a sharpie marker line will get you the temp you want, then water quench it, we always use a layer of soot from the OA torch then burn it off and quench,  to anneal sheet sections for cold working, this is the age old standard for panel beaters making cars and airplanes ,  In my experience 6061 T6 is what most of the off the shelf Al tends to be, and it will always crack if you try to do enough shaping to cause any real forging at all,  once annealed it will be amazingly softer, and will cold work a lot before work hardening too much, I regularly use forms made from wood or body filler to hammer form the aluminum because it gets that soft and workable,  annealing will make a huge difference it may even leave the part a too soft after you are done working it depending on the intended application.   I usually work 3003 grade but have used this for 6061 many times for bar stock and some tubes,

What is the best method to make an aluminium tube of 13 OD,280 length and having a reduced cross section at one end? One 'piece' of the foldable cane used by blind people for example

I have done a process where the cutting tool is just below the tube and fed in longtitudina direction. The tube diameter is progressivey getting reduced.