Broken boom

[673moto]

Any tips on how to fix this?

 

[Delmer]

Grind it out, weld it up. Don't break it again.

 

[Coaldust]

My goodness, shame on the mess. A busted boom and broken dreams all up in here. Looks like it’s been messed up for awhile.

 

[Nige]

Inspect it frequently and you might find the crack before it grows so big next time.
As above, get all the hydraulic lines out of the way, get the boom off the machine, then take some more good photos of the damage.

 

[John C.]

Looks like an articulated boom section where the break is. Depends on age and where the machine came from. Call the dealer and demand a new boom under warranty. The break is a design failure. Another cause might be a sloppy joint that wasn't taken care of which impact loaded on a seam.

The proper repair in my mind would be to dismantle the boom section from the main boom and stick, get it all pressed back in place and do the welding thing. Add fish plate on the sides when the broken stuff is all back together. Replace sloppy pins and bushings in the joints as required. Reassemble and go back to work to pay for it all.

 

[673moto]

Oh man, you guys are the best.
Had a rough day but at least you guys will set me straight.
It’s 100% my fault for not noticing earlier... this machine is like a red headed stepchild so I kinda just beat it up without any regard for its wellbeing.

I’m a hack of a welder but I know some real professionals... should have that aspect under control.

the break is right on the bushing for the pivot... will all that heat from welding distort the bushing?
My guess is yes. ..

 

[Tugger2]

the needs to be stripped of all lines and cylinders and removed from the machine so you dealing with a single piece .pull or press that crack tight .creative use of a good porto power jack and some strong backs should accomplish that. once its tight gouge it out clean it up and weld it up . this shouldnt hurt the bushing bore judging the distance of the crack from the bore in the picture. you may want to consider a doubler plate running back to the bushing bore and tapering out maybe a foot to 18" down the boom. this reinforcing welded to the bushing hub may make the bushing go out of round,but it quite likely is beaten egg shaped already . You may need it built up and bored anyhow . If your welder works on booms he will know the procedures.If not ask in here we can all help with details as to rod type beveling and reinforcing plate design.
Its only an excavator boom they arent hard to fix.Just takes a creative welder I threw this picture in of a boom off an old 172 Hitachi road builder boom with a couple of cracks in it that neede fixing. we cut right apart ,fabbed up new sections with some 50,000 yield plate and a paint job . off it went back to work

 

[Camshawn]

IC weld on utube has some video on repairing excavator booms.

 

[uffex]

Good day
Maybe an idea to check that the machine is not over stressed by the attachments and the operator is aware of the swinging boom limitations, better to prevent that repair may be a little late with that advice.
Kind regards
Uffex

 

[673moto]

Good day
Maybe an idea to check that the machine is not over stressed by the attachments and the operator is aware of the swinging boom limitations, better to prevent that repair may be a little late with that advice.
Kind regards
Uffex

Good point, Uffex...
This machine is gray market and kind of different. .. the cab/body/motor/hydraulics/tracks are a Deere 35d but the boom/arm are from a 40series machine that I’m having trouble identifying.
The issue could be the mismatched structures...or it could be that I’m a **** operator!!

 

[673moto]

If anyone has any guesses on the boom/arm setup I’m all ears... would be nice to know where to get parts

 

[Nige]

TBH looking at the physical size of it and where it goes from and to, rather than attempting a welding repair it might be easier/cheaper to simply replace it provided you could identify the Part Number and also track one down. Personally I'd go that way first.

 

[JLarson]

Airman is Japanese. I've only seen one branded mini here, that one looked Kabota like, we do see some of their Airman compressors but I think that's a whole different section.

If you brought that to us we'd probably strip it, pull the boom then cut that end square and rebuild the end, little bit of new plate, a pin boss and then bevel and backer strip connection maybe plate it depending on how it looks/gets used. I'd bet that existing boss is hammered.

 

[Vetech63]

Should have painted it yeller when ya got it! LOL

 

[Nige]

If you brought that to us we'd probably strip it, pull the boom then cut that end square and rebuild the end, little bit of new plate, a pin boss and then bevel and backer strip connection maybe plate it depending on how it looks/gets used. I'd bet that existing boss is hammered.

That makes sense. I was wondering myself about the feasibility of stitching both ends of the existing boom on to a new center section.

 

[John C.]

I would get some measurements done and start checking on other makes for that articulating boom. My guess is they were all made by a sub contractor and then installed on any make that wanted one of them. Pin distance, diameter and type of bearings would be the considerations.

 

[Tags]

I wonder if you do some measuring if you could find a standard boom from a machine being parted out that would fit. You would lose the articulating boom though. I bet if you have a competent welder near you he could put it back together. Especially if you disassemble and reassemble yourself. You’ll probably need new pin and bushings though.

 

[JLarson]

That makes sense. I was wondering myself about the feasibility of stitching both ends of the existing boom on to a new center section.

A little bit more time probably that way.

On a lot of stuff I've found you can cut and replace just as quick or quicker then sitting there and gouge/air arc/touch out old weld trying to reuse/fix, especially if you can source off shelf bosses or use stock DOM tube sizes.

 

[uffex]

Good day
Sorry, no offence to the operator.
Kind regards
Uffex

 

[BluewaterLa]

From the looks of the cracks developing perpendicular to the main larger crack there is going to be metal fatigue.
I would not waste my time trying to grind / gouge and weld that back up.
I would cut the sections of metal out, use backer plates and weld up new metal. This would be stronger than dealing with smaller cracks and metal fatigued areas that will fail yet again under load.

Side note using fish plates over an existing repair weld will only cover up any new cracking / failure in the welds or metal until the issue is severe enough to cause a larger failure / break.
This was done on my mini ex stick. Once I removed the fish plate just to have a look in an area thought to have no issues, well there was severe issues to deal with so no go on the fish plate.