Cat 304 broken boom ear

[MMW]

Having trouble loading pics. They look ok when I am logged in but are small when not logged in? If you click on them they get bigger.

Got back today & this was waiting for me in front of the shop. At least they stopped before they broke it completely off. Other side is still good & cylinder is ok too.

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[MMW]

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[ryanjones2150]

I was an equipment operator outside of Seattle for a few years while I was putting myself through college before I became a fireman. Have a lot of hours in a machine like that. Never saw someone break an ear off a boom arm. <br />
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I'm interested in seeing how you go about this repair. Seems like I remember some of the equipment had right on the casting "do not weld"....but it might have been a backhoe boom.

[MMW]

I plan on veeing it out, pre heating, then welding it like normal. The casting is welded onto the boom so it's obvious it can be welded. The alternative is to order a new casting from Cat & weld that on so I don't really see the difference. I'll probably plate the outside on both sides but haven't decided that yet. Going to cut a spacer to hold the id for the stick & keep the pin in while welding/cooling to hopefully hold the dimension.

[Bls repair]

Are pin and bushing tight ?If not may not line straight

[ryanjones2150]

It was probably an old 580 I saw that do not weld thing on then...<br />
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Get any back story on how the crew broke it? Might have been a crack in that casting from the get go. Looks pretty clean and fresh in the pictures, except for maybe down at the bottom. Hard to tell from the picture angle. <br />
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What alloy are you planning to use? Some fancy schmancy maintenance rod or just 7018?

[MMW]

Took awhile to get it aligned correctly but after that it welded fine. Ran some string down the sides to try to keep it centered.

[MMW]

Vee'd it out, tacked it up', then welded alternating from inside to outside.

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[MMW]

Won't let me post more pics tonight. I'll try again tomorrow, frustrating.

Trying this morning & still getting an error when I try to post more pictures.

I'll try again later. Why is it so difficult?

[ryanjones2150]

Bet you didn't think the hard part of that repair would be posting pictures of your victory.

[MMW]

No I didn't. Try again. One picture will not load & that was part of the problem.

Welded in & out. Plate welded on.

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[MMW]

All done & customer is very happy. I give up on trying to make these photo's large. It comes up on the preview but then they are still small when you post..

[MMW]

Before & after.



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[MMW]

I don't claim to be an expert, just working from experience so this is how I did it. Disconnected stick & dropped it down to give me room to prep the area, veed it out. Reinstalled the stick with the broken ear using pin to help align it. Measured from numerous areas, dropped string lines down each side to check also, used a level & "eyeballed" it. Once it was set to my liking I tacked the outside & removed the stick again. Cut a spacer the right size to take the place of the stick, reinserted the pin & clamped it all together. Pre heated until my spit sizzled & then did a root on the inside, ground in from the outside using the edge of the grinding wheel until I hit my root pass from the other side. Welded two passes on the outside & then alternated passes in & out until done. Ground off the outside & welded on a plate, then also welded a plate on the other ear. Let it cool, then cleaned it up & hooked everything back up. Final measuring shows I am very close & looks perfectly aligned to the eye. This would have been more difficult out on a job site & probably wouldn't of turned out as well. I used 7018 rod. Time will tell if it holds up but I don't see any reason why it won't.

[Olivero]

Yeah, seems like a very thorough and decent repair. I would probably have done the same thing myself. I might not have thought of the plate but that seemed like good assurance. Would take quite some effort to wreck that.