Excavator Boom Busted

[W Welding]

Got a call today for a crack in 490 John Deere Excavator Dipper boom.
Almost completely broke off.

[grnxrymnky]

that looks like fun.........there was a post in the last couple days concerning a broken excavator stick and the pros and cons of fish plates on top and bottom or on the sides...........it was labeled something like metal surgery i think.

i look forward to watching the progress of your repairs.

good luck,

jim

[turbo38t]

Nice.....I repair lots of those.....looks like it's right at the end of a repair?

Got a call today for a crack in 490 John Deere Excavator Dipper boom.
Almost completely broke off.

[Daniel]

I've seen one of those not too long ago . Look on my metal surgery thread.
You can see exactly why the boom failed. The add-on cylinder anchor plate look like it was welded right across the top and that little fishplate design is not really properly design and welded.
Good luck with the project. I love doing this kind of job. Keep posting the progress.

[Black Wolf]

Yup, my thoughts were very similiar to Daniel's when I viewed the pictures.... Kind of a No-Brainer having a failure right where all the lines of stress are concentrated.

Previous re-pads are completely wrong - Sharp corners are a really bad idea. Should have been larger to spread out the load over the entire side of the boom.

I am terrible with drawing diagrams and posting them. but as mentioned, we have another thread on here illustrating a MUCH better design for re-pads (fish plating) for a repair like that.

Keep us posted.

[welder_one]

NICE!!! I live everyday of my life to find projects like that. last week (i didnt take any pics, but should have) i came across a 330 link-belt and they tore the boom foot right outta the boom.... clearing trees sideways.... that was a fun time for me.... need any help? i travel...lol

[MMW]

Most of the time you get a call. "Can you come fix my machine? Operator says it has a small crack in it. Shouldn't take more than an hour or two." Have fun.

[W Welding]

Made progrees today on the repair. Boom was twisted and rolled.
Go it lined back up, cut out area around cracks.
Welded backing plates in, started repairing the cracks. Had to remove 4" on right side from jagged crack replace with a new piece. Welded both sides up clamped and tacked side fish plates on.
Tomorrow will remove the thumd cylinder attach fitting, repair crack install new plate on front and reinstall thumb attach fitting.
Thanks for all the comments guys.

[Black Wolf]

Much Better... MUCH, MUCH, Better....

Only comment I would have is Don't be affraid to put LARGER holes (2" - 3") in a fish plate of that size to weld it to the boom.

I probably would have put 3 equally spaced 3" holes in a piece of that size, but that is just ME...

As it stands, I will still give you 10/10 over the previous repairs.

Keep it up.

Hey, WHERE are the pictures of the welding truck in the background? LOL

[davinci2010]

Made progrees today on the repair. Boom was twisted and rolled.
Go it lined back up, cut out area around cracks.
Welded backing plates in, started repairing the cracks. Had to remove 4" on right side from jagged crack replace with a new piece. Welded both sides up clamped and tacked side fish plates on.
Tomorrow will remove the thumd cylinder attach fitting, repair crack install new plate on front and reinstall thumb attach fitting.
Thanks for all the comments guys.

Now that's a fishplate! Nice work.