Soft roll pins?

[dobbslc]

As the title really, where can I get soft roll pins from?
It's for the saddle drive / lead screw on my lathe, I've mashed two bevel gears last year and luckily only sheared a normal steel pin recently.
I know be careful, but a soft breakable pin will save much grief in future!!!
Thanks

 

[daleyd]

Can you turn a solid one out of some brass or Aluminium?

 

[MattF]

I keep various remnants of smooth brazing rods knocking about for things like that. Easily cut to length and fairly soft.

 

[gordon stephenson]

You could always turn a mild steel pin and drill out the centre leaving enough wall for a bit of strength and maybe even put a split in it.

 

[Robotstar5]

Roll pins aren't normally soft, you should ideally use a shear pin, which as the name suggests are designed to break in shear.

I've seen the results of using a roll pin instead of a shear pin in a capstan winch, it broke part of the casting away instead of shearing

 

[Cobbler]

Some of the smaller older outboard motors used shear pins on the propellor to protect the prop & gearbox if you caught it on something. I don't know if there still used, but should still be available from boating places.

 

[rory1]

Brass pins are the norm for shear pins in this application

 

[The_Yellow_Ardvark]

Get a dead fire extinguisher.
Rip the head off.
Pop the top handle up, underneath you will see a plunger.
It will push out.
Turn it down to size.
A nice soft brass pin.

 

[dobbslc]

A shear pin!
That's what I need!!! I couldn't think of the name.
I might be able to turn down a bit of alloy it's only about 3.5mm diameter.

 

[Pete.]

Can't get away with some 3.2mm tig rod?

 

[Wendelspanswick]

Tirfor winches use shear pins in the handle to stop them being overloaded, they normally come with a few spares in the handle.

 

[wristpin]

If you can find the right diameter round "wire" nail it will be soft enough to give the desired level of protection. I have fond memories of when a student with a holiday job feeding the front elevators of static pea viners for Birds Eye we Sussed that working like stink to overload the elevator would shear a pin in the drive and the resident " engineer" would be busy sawing up two inch lengths from ordinary six inch nails.

 

[bricol]

Shear pins we design into mechanisms that need them simply have a necked down portion in the area of where the interface between shaft and boss. Ie a deliberately weakened area

 

[dobbslc]

I've just turned up a bit of alloy that seems to work ok and should be weak enough to give if I crash the bloody thing again.....