Old Ford disc repair

[mongobird]

I have a 1950's Ford disc that I use for yard and garden work. It's heavy enough to do pretty much what I want it to. However it broke last year with disastrous results. The angle bracket which held the three point pin cracked and failed, and the disc swung so that the discs shredded the calcium filled turf tire. I replaced both tires, as I had bought spares back in the 80's when I bought the tractor. Now it's time to repair the disc and put it back to work.

The break was from fatigue at the corner of the angle bracket holding the pin in place.

I admit that I am a bit concerned about a similar failure, and taking out calcium filled (or worse) tires.

My plan is to replace a segment of angle bracket which is welded to the disc frame, by grinding off the old, and welding on a new piece. I don't have quite the same size material yet. I thought it would be better to use new material than repair the existing.

What I am trying to figure out is how, rather than simply using heavier material, to prevent a similar failure, with perhaps a redundant structure.

That's an idea, but I don't have allot of experience fixing things like this, and no experience creating redundant structures. Any pointers or ideas?

[ryanjones2150]

Build it back the way it was and pay attention to your implements and repair them before they break.

[mongobird]

Still figuring how how to put a hole for the hitch pin into 3/8" angle iron. No big bits in my bin.

[Aeronca41]

Are you familiar with Silver and Deming drill bits? The name comes from the machine shop that invented them (I think in the hometown of our very own AAMetalmaster if you have looked at other posts on this site). They have a 1/2" shank, but the rest of the bit is way bigger, and you should be able to find the right size. Safest if you have a drill press to use them, and clamp the work to the table. Try MSCDirect.com. They have expensive American-made ones, and the ever-present Chinese versions; check on the prices. Just about any industrial supply house should have them. Use lots of cutting oil to keep it lubricated while drilling.

Or, you could just lay out the hole size you need, drill all around the inside of the perimeter with smaller bits so the outside of the holes you're drilling just kisses the diameter you need to make, and finish off the inside with a large rat tail or small half-round file. I'd rather buy the big bit.

If you can post some pics of the problem with the disc, it will probably result in more suggestions and discussion than you can imagine.

[mongobird]

My younger brother has a plasma cutter, and I was considering having him cut the hole, with me providing a template.

The drill bit solution is what I used for tractor rims, but they are expensive.

[Noel]

Grab a few 6010, crank the current a blow a hole. Although a cutting torch would work a bit better, your buddies PAC, how big a hole are you talking anyways? Cut it bigger weld a pipe in for a bushing of the hole size? I'm sure Amazon will sell one bit for cheap? I looked. 1/2" shank x 1" = $20. End the suffering.

[Bob Miller]

If you get the hole bored in your angle, you can put a gusset at every 90* joint.
Grind out all the cracked welds and re weld.
Then put your gussets in across the corners.