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I Forge Iron

Show me your Improvised Cone and Other Mandrels

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Part of a large water valve 

insert from a wire rope fitting (I believe; other suggestions?)  bolt/nuts so it can be held in a postvise.

Test sample. (from Quad-State one year)

Structural steel pin& wrench, the wrench end was forge welded to fit a hardy hole and bent 90 for ring work

bull pin (I have one with a hardy stem welded on but it's at the other house---I hope)

More when I get a chance to visit my shop...

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On the rare occasions I actually need a true ring I make a jig. For one or two I cut it from plywood for enough to burn the plywood beyond useful I torch one. The same circle cutter works for my saber saw as does for my torch.

Not a mandrel cone and I've only ever worked where there was one in the shop and we didn't use it. I wish I'd asked but . . . 

Frosty The Lucky.

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I like a cone as I can get close to the right shape and then forge weld the ends (lapping them) and then heat and drop on the cone and true it up.  Making some of the spiders used for cooking in Scappi's Opera becomes simple---now to make some of the oval ones....wish I had an oval mandrel much bigger than my bracelet one...

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Tip the ring on a cone and it's elliptical, reverse and true it's oval. Just because I've never used a mandrel cone doesn't mean I don't know about conic sections. Well, okay I read a LOT of sci fi and the best is written by scientists. I don't recall the author, Heinlein maybe probably described orbits in terms you don't have to be good at math to understand or figure. 

Tipping a ring on a cylinder is an easier way to form an oval but a cone is more versatile size wise.

Nobody go saying Frosty thinks there's such a thing as an oval orbit! I brought it up to describe part of the process.

Frosty The Lucky.

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Actually, now that you say that I realize that's exactly what it is. I work in CNC machining but I am a "lathe guy" so I know about mills only from what I pick up by osmosis. And now that I looked back I see you have a very similar item. So thank you for giving me the idea to place the locking grooves into the vise. :D






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5 hours ago, LaneSiders said:

that's exactly what it is.

There is more bonus consideration to be had.  First, if you can see the butt end of the broken tool from the threaded end, you are in luck.  If you can not, you may still be in luck.  These Shrinkers are designed to be thermal cycled thousands of times...

Bring the xxxxxx end to a low red heat, and the carbide may either fall out, or be drifted out. Be sure that the heat travels the length of the broken stub.  

Now you have a piece of 1" dia tungsten carbide with excellent hot working properties, as a fuller, for example.  Shrinkers are coolant quenched in many systems, so the carbide is quench-tolerant at those lower temperatures....

These things are made from 8xxx and 9xxx alloys, amongst others...  use a junk file first, as the case can be wicked hard.

I think I will break out the big abrasive saw, and report back...

You have two cone mandrels for the price of one (flip flip)!

Robert Taylor

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