Vinpetrol
Well-known member
Is it possible to get a pair of 50mm bucket pins drilled for grease ways and a groove carved out of pin faces to allow grease to move along the pin and then the pin end countersunk and threaded for a grease nipple ?
S
Smiffy
Well-known member
For the most part very easy to drill the duct and tap it. The hard part is making the groove helical to properly grease the pin.
Can be done with a mill and a dividing head but will be shakey. Or if someone has a CNC machine then easy. My dad made a piece of kit to mount on a conventional lathe for doing for doing helical grease paths
Can be done with a mill and a dividing head but will be shakey. Or if someone has a CNC machine then easy. My dad made a piece of kit to mount on a conventional lathe for doing for doing helical grease paths
Vinpetrol
Well-known member
Cheers Smiffy at least I know now it can be done .
doobin
Well-known member
I’ve never seen a pin done like this. Only bushes. I’d assume Vins bushes already have helical greaseways if OEM spec.
Any small engineering shop will be able to drill, counterbore and tap a grease way in a pin.
S
Smiffy
Well-known member
It's not very common, I don't think I've seen it on plant, have seen it on automotive and static machinery but vin asked for a groove.
Vinpetrol
Well-known member
It’s on one of the other hitachi pins in the machine .
I thought I’d seen it on bucket pins in the past but maybe I’m mistaken .
If I didn’t do the grooves along the pin surface would the grease holes across the diameter need to be in line with the bushes or would the grease push out around the bushes if the holes were in the centre of the pin filling the void between the bushes
I thought I’d seen it on bucket pins in the past but maybe I’m mistaken .
If I didn’t do the grooves along the pin surface would the grease holes across the diameter need to be in line with the bushes or would the grease push out around the bushes if the holes were in the centre of the pin filling the void between the bushes
S
Smiffy
Well-known member
Should just push out regardless. No matter what the groove in the bushes will only line up with the grease hole at one particular point of articulation. And I can't recall a machine ever specifying at which angle you grease everything
Vinpetrol
Well-known member
So a hole across the centre of the diameter of the pin should do the job , then the grease will push through the bosses ?
S
Smiffy
Well-known member
Thats what is usually fitted to machines yes.
Gecko
Well-known member
If you think about it, a helical groove doesn't need to be precision machined.
Nothing in the groove will be in contact with anything (other than grease), so there is no reason you shouldn't cut the groove with an angle grinder.
Nothing in the groove will be in contact with anything (other than grease), so there is no reason you shouldn't cut the groove with an angle grinder.
Shovelhands
Well-known member
Why is it necessary to grease it via the pin? Can the joint not be greased via the bosses? I know pin end greasing is convenient but it does weaken the pin.
S
Smiffy
Well-known member
Not necessarily. A hollow pin can potentially be stronger than solid. Although I don't know the maths of pin size and wall thickness v shear force and bending moment
Shovelhands
Well-known member
It’s not the hole through the middle that weakens it, it’s the cross drilling.
A
AHPP
Well-known member
I was about to say that. Just follow a wrap of tape or something to keep it neat.
S
Smiffy
Well-known member
If it gets to the point it's snapping round the grease hole then the bushes are so far gone I'm not sure what the point in greasing it is
Bri963
Well-known member
A lot of OEM pins are cross drilled. Does weaken them at all as the shear forces don’t line up with the cross drilling.
Shovelhands
Well-known member
I’ve had pins break through the cross drilling in the past, OE pins. I’ve also got lots of things with pin end greasing that are fine. In my opinion a cross drilled pin in the wrong position has the potential for failure. Many areas will be fine, but a few places I’d rather not have cross drilled pins, bucket pins are probably one of them. But that’s only my opinion.
Bri963
Well-known member
Can’t say it’s something I’ve ever seen or had happen, but one thing I’ve learned is never say it can’t happen. What application was that in? I had a solid pin in a shovel bucket linkage go, across the shear face. Went perfectly square. In the days before I took pictures Unfortunately.
Left hooker
Well-known member
My 5t Hitachi's are greased pins with no groves while pin is smooth just a little counter sink around the grease hole
V8Druid
do it as well as you can,but learn to do it better
my little Fleming walker used to kill the boom to dipper pin regularly on the grease hole .. but was a 5mm hole in a 25mm pin ... (last one I broke digging a ditch along the field beside the driveway here - keep the water at bay and in the field 'til I let it out where I wanted it) ... reduced the hole to 3mm and it lasted for the remaining 3/4 of the length and a few other scrats with it since ... was a PITA ... rest are the same through drilled, but never gave trouble
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