Author Topic: Metal spinning  (Read 4770 times)

Offline RussellT

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Metal spinning
« on: August 10, 2015, 04:34:28 PM »
This is my first attempt at metal spinning (not counting the one 10 minutes before this where I overdid the annealing and the metal went too soft  :doh:).

I have a car radiator which is leaking from the join with the filler neck - I've soldered it once and a professional has done it once and it's leaking again.  This time the rest of the radiator is a bit tired so I plan to get it recored.  I want to try and stop this leak properly and I think a flange that bridges the joint might give it sufficient extra strength.  Here's a picture of the filler neck.  In spite of the bracing piece it cracks the solder underneath the neck.



I could turn a flange from a bit of bar but I haven't got any and it would be expensive.  I have got some brass sheet though so I thought I'd try metal spinning.

Here is the setup to try it. The former is from the scrap box (a collet chuck which I took too much off).  The brass sheet has been fitted to it with a hammer and a jubilee clip.  I drilled it in the lathe.



This is the lever arrangement.  The toolholder isn't clamped to the toolpost and the toolpost has been oiled.  The bar has a rounded end from a test of a ball turner.  The bar is just resting on the toolholder slot.



This is the result.  It took much less force than I expected.  I annealed it twice.



And here it is parted off and cleaned up.



I'm encouraged by this experiment - it didn't feel like I was abusing the lathe much - and the result was OK.

The next step is to make a former the correct size.



Common sense is unfortunately not as common as its name suggests.

Offline rythmnbls

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Re: Metal spinning
« Reply #1 on: August 10, 2015, 06:50:09 PM »
I've done a little bit of spinning. One tip I was given was to use a small ball bearing mounted on the toolpost as the pressure point.

Here's a couple of pics, material is 316 stainless...





Regards,

Steve.



Offline ieezitin

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Re: Metal spinning
« Reply #2 on: August 10, 2015, 06:54:39 PM »
Nice job...

look forward to the repair with interest.

Anthony.
If you cant fix it, get another hobby.

Offline ieezitin

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Re: Metal spinning
« Reply #3 on: August 10, 2015, 06:57:50 PM »
yo..

i looked through your complete library of the turbine you built.. you ought to think about publishing the build on here looks rather interesting.


Anthony.
If you cant fix it, get another hobby.

Offline rythmnbls

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Re: Metal spinning
« Reply #4 on: August 11, 2015, 06:58:02 AM »
Thanks Anthony,

I did a build thread on HMEM a year or so ago, I assumed that most of the modding / machining community had seen it as I see participation by the same folks on all these sites.

Here's a link http://www.homemodelenginemachinist.com/showthread.php?t=17433

Apologies to Russel for the hijack :)

Regards,

Steve.

Offline RussellT

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Re: Metal spinning
« Reply #5 on: August 11, 2015, 08:16:36 AM »
No problem Steve.  Thanks for the tip.  Your setup makes mine look very crude.

Thanks Anthony.

I thought about using a bearing as Steve suggested but my test piece seemed OK so I tried the same way again.  I made a former out of a bar and had another go.  I annealed it twice and this time I made an effort to clean up the surface that will be soldered while the part was still in the lathe.

Here's the result.





There's a slight flat on one side but that's Ok as one side will need to be fitted against a seam.  I left the clearance around the neck generous as that will hold a fillet of solder.  I think this will work.

Russell
Common sense is unfortunately not as common as its name suggests.