Small Backhoe Thumb

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My youngest has been wanting a thumb to go on his Backhoe. It's one of the sub-frame add on hoes, 1 ft wide bucket, about 9 ft reach. Not 100% sure about the reach and depth specs. The outer boom material is like 3/16ths" cold rolled channels seam welded into a tapered box about 4 & 1/8th inch wide, tapered about three inches in height from the top end to the bottom end. Couple of pics of what it went on. Attached Images"The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Here are a few pics of the thumb basically together, locked up and clamped up to my shop boom to check the fit and swing of the various parts. The claw itself is only 18" long. Made out of some 3/8ths scrap he brought over. Pure crap scrap. Intermittent layers of cement, rust,cement more rust. The base mount is of the same crap 3/8ths. Considering the boom is only 3/16ths it should be okay. The eyes and such are all 1/2 inch material, 3/4 inch bolts and pins. Attached Images"The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Here is is all mounted up, welded on and even painted with a rattle can setting around the shop. Color came out close considering. The existing paint is oxidized and scarfed to heck so anything is good. Attached Images"The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Since this is a welding board I'll show a few of the final welds on the boom. They came out like hammered crap. Operator error no doubt. A nice rounded edge to fill on the boom side so that was good. Did a verticle up on the 1st pass and filled the gap, dug into the mounting plate and all was well to there, the vert ups weren't bad for my limited talents. Then I decided I wanted to do a verticle down to fill it on out and smooth things. Things went to heck. I generally can do better. Hobart flux core, .035.. Didn't have any .045.. Probably should have  waited till Monday to get some. After I was all done the wind completely stopped just before dark, so I guess I could have waited. I like my flux core tho. Attached Images"The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:It's nice to see a pup in pics again  Head in the bucket is pricless.  Heelers are great pups, mine was a heeler mix.The tubing that makes the connection from the arm to the thumb is interesting.  I think the addition of the extruded tubing from the square tubing to the outside of the thumb will go a long way in reinforcing the connection.  It will help to keep the load localized near the thumb plate.  And help to spread wear along the entire length of round stock you used for the pin.  I did the same thing with the eye on the cylinders when I made my loader, but the distance from center to outer thingy was shorter.It's the distance from center of the pin to the outer part of the thumb that bothers me.  Adding a gusset from the center piece of square tubing to the outer edge of the extruded tubing would be great.  BUT it would positively crap up alignment at this point.  Any welding along those pieces of extruded would pull it like crazy.  The pin would bind.I did my ear thingys by welding the ears in, then reaming them after welding.  It was a PITA, but it worked.  Adjustable hand reamers, precision ones, are available from WT."Any day above ground is a good day"http://www.farmersamm.com/
Reply:That's pretty slick, It's a shame I didn't have it today after cutting back a 20 some foot lilac bush...Matt
Reply:It looks good Sandy"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersammIt looks good Sandy
Reply:The coolest thing about the use of the seamless pipe etc. is the way it spreads the load, and makes alignment easier.  Your holes can be off in the square tubing, or the plate, but you can smoogie(tech term) the holes and seamless to fit.  Pop the pin in, line it up, and tack, then weld with the pin in.  SMOOOOOOOOOTHI had to use very good, EXPENSIVE , cold drawn extrusions on my pivots because they were constantly moving pivots.  With your static thumb you don't need that kind of precision. Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Looks good SandyAttachment 50949I'll bet the "fold-in" took more more than a few minutes to figure out.Good LuckLast edited by denrep; 10-19-2010 at 11:45 PM.
Reply:Originally Posted by denrepLooks good SandyI'll bet the "fold-in" took more more than a few minutes to figure out.Good Luck
Reply:Impressive for sure. I am wanting on for our dedicated JD backhoe but we are looking at $400 for a 32" one unmounted.
Reply:Nice job Sandy.....Mike
Reply:Very nice Sandy.  Awesome job! The boy owes you big time! 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:Very good lookin' job, Sandy. That should stand up any punishment that hoe can hand out.                         MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:Ya' have a good life Sandy, Blue Tractor... real nice backhoe with goodies on it you fabricated well,  and a heeler who likes to supervise.  IF? my heeler ever comes into heat she'd be having BorderCollie/Aussie X Heeler pups I suppose. My wife is not real keen on mine, CrazeeKellie is friendly,  likes to "heel" the wife by licking her heel, no biting just a lick... Wife does not like her heel licked atall  I say "you love that li'l dog don't you?" Wife scowls a bit.Lincoln Power MIG 215Lincoln WeldPak 3200HDLincon ProCut 25Lincoln WeldanPower 225 AC/DCIf all else fails... buy more tools
Reply:Looks sharp Sandy. Two thumbs up!I crack myself up...
Reply:Thanks for the kind words guys. Duane, I've already told my boy,,, when I get old and my mind turns to mush and I start wandering around aimlessly,,,, that's when the payback starts. Of course he says that'll only be about another off year going by the symptoms. "The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt