Small Excavator boom attach

admin

I got a call to weld this, but when I arrived the piece was shot.  I suggested we cut it off and have a new one made.  He had a new one burned out of a little thicker material.   The alignment rod was supplied by the customer.  There are 2 bearings under the top one, so if the rod slides in, the hole is where it is supposed to be.   I ground a bevel on the machine side, then fit the piece.  I welded the bottom first.  Not much room, I have to bend the rod and it was overhead.  3/32 7018  85 amps first pass then 1/8" 7018 135 amps second pass.  Then I took the gouge to it and finished the bevel.  I also went down to the weld on the underside.  Clean up with a grinder and fill with 7018.  5/32 at 90 amps for the first couple passes then 1/8 at 150 amps for the rest.  All rod was Lincoln Excalabour right out of the oven.When I welded the bottom side first, It tilted the piece down.  Since this was a one sided bevel, I tapped it down a little more. It pulled back up a little past center and took a couple of good whacks with a sledge and a piece of wood on top.   When all was finished, that alignment pin slid right through the hole with NO effort.  I got lucky.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Newbees take note on how a pro works!  Even grinds away the paint before cutting the defective part off to get a cleaner cut.  Think about how much more important is it to have clean material to weld together before posting your practice welds for evaluation.  I wanted to point that out as it's the first thing that I noticed - even before seeing the break.Thanks for another great example of 'real world weldin' thread David.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Thats weird i have a bobcat 331 and the piece you fixed on yours is plate mine is cast. I'm curious what model and year that hoe was. i notice that is a bobcat and has me thinking now is this the piece you fixed?
Reply:That be exactly it.  This had steel plates welded to the frame.  that is just what it looked like, broke in the same place.  Give the cast the spark cast.  Ya never know till you look.  If its cast steel,  you could do the same repair.  If its cast Iron, yer SOL.I'm thinking its cast steel.  The piece is welded to the frame isn't it?Its not the same machine, your swing cylinder is on the other side.  This one was new in 2000. Duaneb55, I cleaned the torch tip right before I used it.  And thank you.David Last edited by David R; 05-10-2009 at 09:25 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:bobcats were built by some other company for  a while . I think it was komatsu but not sureinsert thoughtful quote from someone else2000 Thermal Arc 300GTSW 3.5 hours1946 Monarch 20 x 54 Lathe1998 Supermax 10x54 Mill2004 Haco Atlantic 1/2" Capacity Lasernot mine but i get to play with it
Reply:When Bobcat first came out with the mini-x, they were built overseas.  They started making their own around 1990-1991, I believe.
Reply:Originally Posted by David RThat be exactly it.  This had steel plates welded to the frame.  that is just what it looked like, broke in the same place.  Give the cast the spark cast.  Ya never know till you look.  If its cast steel,  you could do the same repair.  If its cast Iron, yer SOL.I'm thinking its cast steel.  The piece is welded to the frame isn't it?Its not the same machine, your swing cylinder is on the other side.  This one was new in 2000. Duaneb55, I cleaned the torch tip right before I used it.  And thank you.David
Reply:Nice repair.  I worked on a lot of bobcat equipment over the years. I was scratching my head, trying to figure out what machine this was.   Soon as landman said something, it hit me, this is a older bobcat 331.  With the square sheet metal.Lincoln 300 Vantage 2008300 Commander 1999SA250 1999SA200 1968Miller Syncrowave 200XMT350MPA/S-52E/xr-15Xtreme 12vs Millermatic 251 w/30A  Millermatic 251 Dialarc 250 Hypertherm 1250 GEKA & Bantom Ironwokers