I was all set to cut the grass and enjoy a beer on the deck wen done and this happened

[muncybob311]

Here are some pics after a bit of cleaning. The QA plate looks OK? I cannot see any stress fractures?

 

[ponytug]

Here are some pics after a bit of cleaning. The QA plate looks OK? I cannot see any stress fractures?

I think you were just really unlucky. I also suspect that there was probably a metal defect in the axle, and you clipped it just right to shear it. I can't see any sign of a pre-existing crack that spread in any of your photos.

I think that in the hands of a great welder with the right tools, anything can be welded. That said, I think that welding at your break is a high stress location and I think it would require cutting enough of a gap to weld in, and then a great welder, but even then there will be a heat affected zone that will be prone to failure. I wouldn't go that route if it were me.

I suspect that the repair is a new axle, then gouging or plasma cutting the old end out of the Q/A plate, and then welding the new one in. That would be fairly easy for a competent welder, and would get the heat affected zone away from the highest stress area.

Good luck!

All the best, Peter

 

[RayIN]

I think that in the hands of a great welder with the right tools, anything can be welded

Yep. I watched a man weld 2 sections of aluminum wrapper out of a pack of Pall Mall's together.
Others were betting on the outcome. That Navy-trained welder won nearly $1,000 with that feat.

 

[CliffordK]

That looks like a pretty wicked grain structure, but I'm not quite sure what what it would be like to break the unbreakable.

I assume the part with the nut can just be knocked out towards the nut... hopefully. Then once off you can try to salvage the nut.

That is an interesting method to use a short sleeve between the base plate weld and the pivot point which effectively isolates the heat affected zone.

Would rounding the corners slightly on that short sleeve help reduce the single point stress riser?

A good machinist should be able to build the part from scratch. Basically sizing and threading a rod. And then get it welded on. I'd do it all in the machine shop.

I'd be tempted to go with steel that wasn't the original steel that failed.