Drive pin or shear pin ?

[xtal_01]

So, I tore into the VV-XVI I was given.

It would not wind ... found the pin under the gear sheared off.

Easily punched it out.

Now, what to put back into the hole?

I read somewhere I should use piano wire.

This is very hard, tempered spring steel if I am right.

I asked myself what was the purpose of this pin?

If it is only to drive the gear, then piano wire will work great.

If it is not only to drive but also to act as a safety if the unit is over-wound, then this would be a mistake.

If you want it to shear, then it should be a softer material ... say a soft nail or ????

Any guidance on this?

Thanks ... Mike

[JerryVan]

You do NOT want it to shear. Doing so risks spring breakage. Piano wire may be too brittle, but would probably be fine. Honestly, I've used a cut off nail in the past, (crude as that may seem). Otherwise, a piece of mild steel would be fine**. If you wanted to go deluxe, maybe a piece of 4140 steel.

**Apparently, that's what Victor used. However, this is a common problem, so maybe an upgrade is best.

[Jmcmahan67]

I’ve replaced two such pins before, and would also not recommend that you use piano. You need a 3/32 steel pin made of 304 steel. Would recommend Albany county fastener as a supplier from whom you can purchase online

[Jmcmahan67]

3/32 x 1 inch to be exact. I may have shaved a tiny bit of the length off when I got them, but I don’t know that it’s absolutely necessary.

[Jmcmahan67]

Actually.,, I have a few extra pins. Assuming you are in the US, if you send me your name and address via private message, I can drop a couple of pins in the mail to you…. No charge.

John

[JerryVan]

I’ve replaced two such pins before, and would also not recommend that you use piano. You need a 3/32 steel pin made of 304 steel. Would recommend Albany county fastener as a supplier from whom you can purchase online

Sounds like an excellent choice.

[xtal_01]

Thanks guys!!!!!!!

I knew you didn't want it to shear easily (so nothing like brass or aluminum) but I was afraid if the pin was hardened, it would never shear. If this some kind of protection against over winding, then I didn't want to do any damage.

Being a northerner, we do this for our snow blowers. There are shear pins (I think there is one in the prop of a boat also) that are made to break before doing any damage to the unit.

I have seen guys put grade 8 bolts in and rather than destroy a $5 pin, they break a chain or destroy a gear.

Thanks so much for the advice!

Mike