ok so i have a manual thumb on my ductile stick it keeps on shifting upward then i cant line up the hole on the bracket . how can i fix it from moving i got the nuts down tight even broke two wrenches in the process the botom bracket slides about 3/4 over to the left . i got i back once with the help of a 5 lb persuader . its like that bottom plate dont want to stay put . guess the bolt stretches just enuff to shift it when i grab rocks or logs the plates even bending at the bolt holes
New Grade 8 bolts and thicker top & bottom plates (to stop them distorting as your photo shows) would be my first thought.
Yair . . . As above, I reckon Nige is spot on. Those clamps are no where near adequate . . . I wouldn't even think of welding on the flex area of that stick. As a side note to new posters with a problem . . . this post from bobbyblades is a classic case of the value of pictures. Cheers.
A question... Looks like washers between the clamp & stick. Why ??? Seems like the washers reduce the surface area to resist movement. Can you remove them ? One more tip after you do as Nige says.. Place a piece of coarse emery cloth between the clamp plate and the stick. The cloth helps prevent slippage.
I would agree with the others but have one more thought what if you would take a piece of 3/4 x 2 or something if the sort and weld on edge close to the bolts to keep the plate from bowing like it has Sent from my XT1585 using Tapatalk
That was a good catch on those washers. I would keep it simple, take out the washers, and replace the back straps with wider and particularly thicker material. Then, if that doesn't fix it, go deeper into these suggestions.
Hey, you need more surface area, (friction area) longer plates top and bottom and more bolts putting a bite on the boom,
I had a heel on a log loader doing the same thing. Thicker plates welded to the heel and I used three bolts instead of two on each side. Lasted for 20+ years without moving.
You could also weld beads on the bottoms of your plates, parallel to your stick. Would act like skid plates, you would have to straighten them first, as stated, thicker plates would help also. If you got it back with a 5 pound persuader, then it will surely move again.
Yea those washers are acting as furniture sliders. It's about surface area that is in contact and the torque of the fasters that will keep it in place. If the plate is not moving in parallel and only off to the side you could also weld something on the back side of the 3 hole plate to keep it in line. A guide more or less.
the stick has a crown on the top and bottom and when i had installed without the washers the gap on the sides was more pronounced and only the center areas made contact and it shifted even worse / so i added a few washers on the corners to see if i get more "surface area " to hold /grip but it still moves if i back off on the nuts the plate straightens out and the gap is even bigger so what if i get two strips bar stock 3/8 thick maybe 3/4 x 6 long and weld on each side bottom plate parrallel ? act as skids that top part seems to stay put but the bottom one has shifted due to the force from the thumb as i grip things i was gonna maybe weld a chain on the bottomplate and run it around the end of the bottom end of stick and back up to the top plate and weld it there thus stopping any rearward movement ? or just get a ratchet strap and tie it off in up position when not in use as a last resort if the plate was thicker it would still slip no?
If the stick has a crown, then how about marking your plates and grinding "that area where the plate sits...flat, removing the crown. Do you think that would harm the structure?
I'd take some advice you've already got, thicker plates, better bolts. I'd then grind clean mating surfaces, coat with red locktite, and put it together. Is there something at the bottom end you could add a long bolt on each side to tether it, preventing slide. Another thought is since you have a tapered dipper stick, weld a four sided box to fit over it, instead of the bolt arrangement you have. Extend a hoe versions have a welded steel bottom half of the dipper. Willie