Tractor backhoe - homemade

[4570Man]

I found my Kubota pins to be fairly hard, and my Deere pins, soft.

Pins on my JD310J are soft. The pins in my Kubota BH90 were a little harder but still pretty soft.

 

[Kyle_in_Tex]

The bushings I'm talking about are those that are welded in place in the structure. I could see mounting the structure on a large boring mill, boring the old one out, and welding in a new one? A costly adventure.

 

[sandman2234]

I would hope the pins are softer than the bushings welded into the structure, makes it easier to replace when worn.
David from jax

 

[BFreaky]

This is what I'm talking about. Replaceable bushings. It's always better to raplace this, it costs 2$, new hardened pin costs 20 at least...5 minute job...so... Every serious machine has this....at least over here

 

[Kyle_in_Tex]

This is what I'm talking about. Replaceable bushings. It's always better to raplace this, it costs 2$, new hardened pin costs 20 at least...5 minute job...so... Every serious machine has this....at least over here

That looks like a great solution. Do they slip in place, or do you need some liquid nitrogen?

 

[rScotty]

This is what I'm talking about. Replaceable bushings. It's always better to raplace this, it costs 2$, new hardened pin costs 20 at least...5 minute job...so... Every serious machine has this....at least over here

I think we are getting tangled up in word usage here. The problem is that Engish doesn't seem to have a specific word for weldable bushings versus replacable sleeve bushings like you are showing in your picture there. And that's a problem because English-speaking mechanics tend to simply call both of them a "bushing" - and count on the context to make it clear which type is being used. To add to the confusion, both types of "bushings" are usually ordered as a precision fit, either the pin itself, or to the plus its replaceable sleeve bushing. Both in ID and OD.

Freaky, when you wrote back in post #1021, "...usually I put all the bushings in place, push a pin through and weld it all in place."
Well, when I read that I just kinda assumed that you were talking about weldable bushings of the kind that are that are welded into place as the main support at the ends of the pins. Over here, those kinds of weldable bushings are usually a loose fit OD to allow some self-alignment to the supporting structure, and also very close to pin or pin+sleeve bushing fit on the ID of the bushing. These weldable bushings can be one long bushing welded at the ends, or a bushing at each end of the pin welded into the supporting structure. BTW, I like your weldable support bushing way of doing things in #1021.
Another advantage in the case of something like a boom or dipper stick, The hard bushing can have a thinner weld flange so it ends up having a a cooling rate to match the boom material. That way we can use hard bushings - and a softer pin. At least that is what I was trying to get to originally.....

And I agree about the preferred use of sleeve bushings. Most better machines come with them. It is also common here to have them available in various thickness to compensate for wear to the pins.
rScotty

 

[BFreaky]

Oh don't worry, I understood right away what you said. I understand English just like my native language. Well, I always weld outer bushings with the pin in place. That's the only way to get it straight after welding without the need to use line boring machine or bohrwerk machine. It turns out great but you have to weld them last, after welding all the plates in place even if they are really thick. Good weld can bend any plate. Anyway, I find it much easyer to change sleeve bushings because they are cheap and easy to change.

 

[dfkrug]

I think we are getting tangled up in word usage here. The problem is that Engish doesn't seem to have a specific word for weldable bushings versus replacable sleeve bushings like you are showing in your picture there. And that's a problem because English-speaking mechanics tend to simply call both of them a "bushing" - and count on the context to make it clear which type is being used. To add to the confusion, both types of "bushings" are usually ordered as a precision fit, either the pin itself, or to the plus its replaceable sleeve bushing. Both in ID and OD.

Yes, that is right. That is why I try to call all the close-tolerance stationary elements that experience rotating cylinders inside them, "bearings". A stationary section of tubing that has a stationary element inside (e.g. a pin), is a "bushing". The latter are usually welded in.

The former, called sleeve-, plain-, solid-, split-, or friction-bearings are usually interference fit. Those are terms from the makers. They are made of bronze, copper, steel alloys, sometimes with coatings. You should not get them too hot. On the cylinders I just got from China, the solid bearings in the cross-tubes are 12-13mm thick, which I have not dealt with before. Bearings do not have to have balls or rollers inside them.

Photo here is some sleeve bearings I bought from ASB on the US East coast. The shipping was more than the bearings.

 

[4570Man]

The bushings in my backhoe are press in but it’s a lot heavier than the bushing listed above. And you’d probably need a crane or second backhoe to take it apart.

 

[Renze]

The standard in real construction machinery (10 ton and above, so excluding compact machinery and jobsite wheelbarrows like TLB's) is hardened pin and hardened bushing with grease grooves.