How to make the curve on a backhoe bucket?

[jim_wilson]

I'm contemplating welding up a backhoe bucket. I've got some use for a 24" or even a 30" bucket - and they are available out on the market - but they're darn expensive. It doesn't seem like a very complicated project - except for one thing: how to bend the steel that makes up the main part of the bucket.

making the "sides" , getting a cutting edge, making the mounting brackets - etc. - those are all pretty straightforward. But the "back" of the bucket typically is a semi - semi-circle shape.

I can see how this might get stamped out in a press - which I don't have. I can also see how this might be done in a plate-roller - but it would have to be a big one for the gauge of steel that typically gets used in a bucket. I'm wondering if there is some other way - or if maybe I just need to find a metal shop with a big plate roller and have them do it.

 

[BukitCase]

"I'm wondering if there is some other way - or if maybe I just need to find a metal shop with a big plate roller and have them do it."

That would be one way - or you might get lucky (as I did) and find a 4 foot "clean out" bucket for a mini-excavator on CL for $75. Mine had the tabs cut off (who cares in this case) and the guy was cleaning out stuff he didn't need any more. Lucky me.

My case 580 has a 2 footer and I built a 6" from C channel and 1/4 plate, but need a "toothless" 18" for foundation trenches. This will leave the rest of the "pre-curved" section for a 12" and a "toothed" 18 if I need them, all from the one 4' bucket.

If you're desperate you can do a "pseudo-curved" bucket by welding narrow strips together, each at a slight angle. Probably won't clean out quite as good, but there have been a couple of posts here in the last 6-8 months of guys doing just that.

You would cut out the sides, then use 1-1/2 or 2" flat bar cut to same length as your bucket width, tack everything in place, then back-stitch everything to keep warpage to a minimum.

HTH... Steve

 

[jim_wilson]

"I'm wondering if there is some other way - or if maybe I just need to find a metal shop with a big plate roller and have them do it."

That would be one way - or you might get lucky (as I did) and find a 4 foot "clean out" bucket for a mini-excavator on CL for $75. Mine had the tabs cut off (who cares in this case) and the guy was cleaning out stuff he didn't need any more. Lucky me.

My case 580 has a 2 footer and I built a 6" from C channel and 1/4 plate, but need a "toothless" 18" for foundation trenches. This will leave the rest of the "pre-curved" section for a 12" and a "toothed" 18 if I need them, all from the one 4' bucket.

If you're desperate you can do a "pseudo-curved" bucket by welding narrow strips together, each at a slight angle. Probably won't clean out quite as good, but there have been a couple of posts here in the last 6-8 months of guys doing just that.

You would cut out the sides, then use 1-1/2 or 2" flat bar cut to same length as your bucket width, tack everything in place, then back-stitch everything to keep warpage to a minimum.

HTH... Steve

I've thought about doing that - but all the excavator buckets I've found were always big money - to the point where I'd be better off just buying a new bucket.

I've been searching Craigslist for buckets - I know what the interchange is for my hoe (Kubota BH77) - but there just isn't that many out there.

 

[GLyford]

Depending on how thick you intend to make your shell, one way I've seen people describe it is to chain the bucket shell to a rigid frame or structure, with the shell welded onto the straight part of the sides leading up to the curved section. Bolt or weld an attachment to the free end, and start pulling it into the curve as much as you can with a come-along or chain tensioner, then weld. It might only be an inch or less at a time. You could help speed it up a little by heating the bend line, which would also help preheat your weld. Bend-weld-bend-weld and so on until done.

 

[jim_wilson]

Depending on how thick you intend to make your shell, one way I've seen people describe it is to chain the bucket shell to a rigid frame or structure, with the shell welded onto the straight part of the sides leading up to the curved section. Bolt or weld an attachment to the free end, and start pulling it into the curve as much as you can with a come-along or chain tensioner, then weld. It might only be an inch or less at a time. You could help speed it up a little by heating the bend line, which would also help preheat your weld. Bend-weld-bend-weld and so on until done.

Yeah - I was thinking of that too - I figure I could make "jig" of a sort - bolt the sides and one end of the main plate to the jig - then basically weld my way around until I've got it all held together.

 

[jmc]

Jim, when you said making the sides would be straightforward, I had a flashback to the bucket on my Case 480F. Without walking out there and checking it with a square, my recollection is that the sides are angled such that the bucket opening is wider than the bucket width deeper down into the bucket. It's classic cutter design where they build in a clearance angle so the body behind the actual cutting edge does not drag. It might be subtle or it might be my imagination.

 

[BukitCase]

Here's the more pertinent (I hope) threads out of 1449 results of a search of this forum on "backhoe bucket weld home made" - may be some "gems" somewhere, good reading for the next "rainy day"...

http://www.tractorbynet.com/forums/build-yourself/267513-diy-excavator-bucket.html

http://www.tractorbynet.com/forums/build-yourself/164970-12-backhoe-bucket-pics.html

http://www.tractorbynet.com/forums/build-yourself/233975-smaller-backhoe-bucket.html

http://www.tractorbynet.com/forums/build-yourself/111905-smaller-backhoe-bucket.html

http://www.tractorbynet.com/forums/build-yourself/65175-lets-talk-about-bh-buckets.html
(describes a bending method)

http://www.tractorbynet.com/forums/build-yourself/24676-built-me-bucket.html

http://www.tractorbynet.com/forums/build-yourself/267730-back-hoe-digger-bucket-theory.html

Rain's stopped, guess I better "GOMA" and do something useful... Steve

 

[mrmikey]

To save yourself a lot of grief and wasted time, find a welding/fab shop with a brake. Take them a template with your plate and ask them to brake it, shouldn't take more than 1/2 hour but you may get dinged more depending on the minimum, it'll be the best $100 you spent.....Mike

 

[Stimw]

I made this 6" bucket for my Hoe out of 3/16" steel.
I have a 1' press brake for my 50 ton Ironworker and I just bumped the curve until I got the profile I needed.
I made a pattern of the side of my regular bucket out of cardboard, chalked it on flat plate and cut it out with my Plasma Cutter.

As stated, a good fab shop can bend the back for you for a reasonable price.
They should have the metal plate too. A good shop will have "drops" from other jobs in their inventory so you don't have to buy a full sheet.

 

[Arc weld]

A lot of backhoe buckets use a compound curve. A steel supplier with a plate roller could maybe form it but a bending brake could make it just how you want. If it was a narrow strip you might be able to form it yourself but a wide piece like a bucket, get it formed. There's a reason new buckets aren't cheap but often you can find used ones pretty reasonable.