Narrowing Excavator Buckedt

admin

Ok, here's what I have.  I have a Komatsu PC 200-8 we bought new a little over a year ago.  It came with a new 36" bucket, and a used, bent 24" bucket.  I've welded the 24" bucket back together 3 times now.  Every time, it cracks somewhere else.  It it JUNK.  And of course, laying utility lines, the 24" is the one I use most of the time.  The mounting ears are in good shape on this bucket, and the lip with the shanks is in good shape too.  It has the ESCO shanks that uses the heli-lok teeth, which is the tooth system I prefer.I also have a Case 125b Excavator, which I plan on selling.  It has several buckets with it, one of which is a 28" heavy duty bucket which is in very good shape.  2 out of 3 of the shanks have the ends broke off, and that's the only thing wrong with it.What I'm thinking about doing, is remove the ears and lips off both buckets, cut 5" out of one side of the 28" bucket (the 24" bucket actually measures 23" outside to outside at the lip) weld the side back on, then install the ears for the 200 and the 24" lip with the tooth system I like.I know it sounds like a lot of work, but if I sell the good bucket with the machine, I MIGHT get a couple hundred extra dollars out of it, but would probably just be throwing it in on the deal.  Then to buy a new 24" bucket for the 200, I'm looking at somewhere in the $5000 to $7000 range.The 125 is a little bit bigger machine, but the height and depth of the 2 buckets is very close, so I think it's feasible.If I do this, I'll be doing the work myself.  I've changed ears on several buckets over the years, as well as re-built lips, and changed shanks.  So I'm not new to this type of deal, although I've never narrowed a bucket.  I don't see it being a big deal, since the ears will be off of the bucket anyway, so I don't see why I can't just narrow one side the full amount, instead of taking half out of each side.  Then after it's narrowed, then install the ears in the correct position.Anybody ever done something such as this?  Am I crazy for trying it?  How would you weld it all back together?  I've always done things like this with 7018 stick before, but this much welding, I'm thinking about wire.  I have a 300 amp wire machine, and if I went this route, I would run E71T-1 Dual shield with 75-25 gas probably.  I have a lot more experience with 7018 though.As for material, I have plenty of wire (5 0r 6 big spools that have never been opened), or going with stick, I have some 50 pound cans of 8018 that have never been opened.  so that's covered either way.I know this is a rather long post, but I'm hoping someone here has done something like this, and can give me some insight on this.  I'll try to get some pics of the 2 buckets, to give a better idea of what I'm talking about.
Reply:How are you going to cut them apart?
Reply:Originally Posted by slagmaticHow are you going to cut them apart?
Reply:HandT - A bucket's ear location is very critical to operating geometry. And of course the bucket edge (or teeth) must not be able to roll into the stick, or the bucket mount bind at the link. With that in mind, the two buckets may have much different profiles, and require different mounting angles to place the ears at their correct location; thus making the ear transplant difficult. If the Komatsu ears need too much re-work to fit the Case bucket, it may be easier to build new ears rather than to remove and reuse the Komatsu ears. You probably should build a template of the Case profile, clamp it to the Komatsu bucket,  and see how it compares for a match-up, and clearance, throughout the bucket's complete cycle.As to taking a cut out of one side only - that sounds like a good plan. You'll want to study the bucket's design to be sure that it doesn't have a "back-bone" centered at the mounting ears. If so, you may have to take two cuts , or widen the centered reinforcement.Good LuckLast edited by denrep; 03-28-2010 at 09:45 PM.
Reply:Don't forget the bore alignment for the pins attaching the bucket to the boom linkage.  Are the bores the same size for both machines?  How do you plan to keep them in alignment during welding and while cooling down?  Even if everything was the same size and properly lined up, it is doubtful that the pins would fit without a lot of interference after welding.  Think about possible bore shrinkage from heat and pulling from weld shrinkage.  Too much would require buttering the bores on the ears and then line boring and facing or line boring and facing everything and using oversize pins. Something to consider."The man of great wealth owes a peculiar obligation to the State, because he derives special advantages from the mere existence of government."  Teddy RooseveltAmerican by birth, Union by choice!  Boilermakers # 60America is a Union.
Reply:Originally Posted by denrepHandT - A bucket's ear location is very critical to operating geometry. And of course the bucket edge (or teeth) must not be able to roll into the stick, or the bucket mount bind at the link. With that in mind, the two buckets may have much different profiles, and require different mounting angles to place the ears at their correct location; thus making the ear transplant difficult. If the Komatsu ears need too much re-work to fit the Case bucket, it may be easier to build new ears rather than to remove and reuse the Komatsu ears. You probably should build a template of the Case profile, clamp it to the Komatsu bucket,  and see how it compares for a match-up, and clearance, throughout the bucket's complete cycle.As to taking a cut out of one side only - that sounds like a good plan. You'll want to study the bucket's design to be sure that it doesn't have a "back-bone" centered at the mounting ears. If so, you may have to take two cuts , or widen the centered reinforcement.Good Luck
Reply:This is the bucket I want to modify. Attached Images
Reply:And this is the junk bucket.  This is last year, when the lip broke.  I've dug a lot of rock with this bucket since I welded it back together.  This time, the sides down by the lip broke, and where the lip is welded to the bucket cracked.  Not in any of my previous welds, all new places.  Before I got the bucket, it has been twisted.  Looks like someone had it in a rock trench, with their tracks crossways, and tracked sideways with the bucket in the trench.  I can't figure out how else it could have happened.  It wouldn't have been worth fixing last time if I hadn't had just put $500 worth of new teeth on it...And no, I didn't weld it back together with the little Lincoln in the picture.  I used it to tack the lip back on, before firing up the big welder, just because it was handy. Attached Images
Reply:Are there any heavy equipment auctions around your area?  I'm in Indiana and I've seen plenty of excavator buckets sell for under $1000.  Unless you just got to have one now, I'd keep my eye's open and try to find the right used bucket in good shape.Miller 250x & Lincoln V205-TSmith Oxy-Prop torch
Reply:I like the idea of only one side.  No need to cut both, its a 24" bucket.I would tack things together with that little mig and make sure the pins go in easily and try the bucket for function before putting the snot to it with stick.  With big enough rod and enough amps it won't take that long with stick.I welded shanks on a JD 690  bucket with a 250 amp mig and one shank broke off at the weld so I got to do it over for free.  Stick from then on for a job that big.Just do it!David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:This seems to me to be more trouble than its worth. Why not just give the one you have a major rebuild beefing up the places it has a tendency to break?
Reply:Originally Posted by ChuckAre there any heavy equipment auctions around your area?  I'm in Indiana and I've seen plenty of excavator buckets sell for under $1000.  Unless you just got to have one now, I'd keep my eye's open and try to find the right used bucket in good shape.
Reply:Originally Posted by David RI like the idea of only one side.  No need to cut both, its a 24" bucket.I would tack things together with that little mig and make sure the pins go in easily and try the bucket for function before putting the snot to it with stick.  With big enough rod and enough amps it won't take that long with stick.I welded shanks on a JD 690  bucket with a 250 amp mig and one shank broke off at the weld so I got to do it over for free.  Stick from then on for a job that big.Just do it!David
Reply:Originally Posted by lars66This seems to me to be more trouble than its worth. Why not just give the one you have a major rebuild beefing up the places it has a tendency to break?
Reply:i leave the pins in the ears when welding to help prevent movement or warping of the hole. they can be a mongrel to get out again sometimes but it minimises a lot of distortion. (cover the exposed part of the pin in masking tape or grease to stop spatter, and be careful where your return lead goes so you don't get stray arc between the pin and the bush/ear).
Reply:You'd actually be smart to do it rather than drop the 5-7k on a new bucket. The last PC 200 LC I owned I ended up throwing cab guarding, a computer, and a Waratah HTH 230 log processing head onto it, however I think you could do this either with 7018 or wire as you stated. I'd be in he same boat as you as well since I'm super used to 7018 as well. Make sure to do as stamp says though and leave the pins in the ears to minimize the movement and distortion.