7 Tonner thumb suggestions

[Storrsy]

Brilliant looking work mate.
What do you make of the geometry of the thumb having a seperate pivot point? Does the end follow the bucket round well? or do you end up with missalignments? The RSL ones do look nice becuase of how thin they are, hence less weight and less in the way, but does the thinness not provide a disadvantage sometimes in reduced surface area, or for grabbing brash?

Generally I don’t have a problem with the geometry. It all seem to work pretty well and easy being able to change the position of the thumb to suit which you can’t do with a fixed braced grapple.
There is definitely a sweet spot where it’s easiest to pick things up and the bucket and thumb marry up well- on my 3 and 5 tonner this is roughly half reach. But remember when your grabbing something that the thumb and bucket aren’t going to be together anyway as you have the space of what l ever it is your grabbing.
Doobin has a good point of course, if your doing dedicated handling tasks- it’s going to be hard to beat a proper grab with its own ram and hitch. (Not the fixed grapple type) but for me it’s rare that I don’t need to use the bucket at the same time- digging stumps, raking brash, digging out and placing rocks etc so I find the thumb perfect for this. And it’s light- don’t even notice it there really.

 

[honey_badger]

Got this never been used just stole the pin holder for the hydraulic thumb I bought of Polishbuilt

Where abouts are you? Might be interested, not 100% yet though.
I like the look of the one you've got mounted to your machine, its basically what I was thinking of making originally, how well does it fold up to the dipper?

 

[honey_badger]

Flowfit do this one now that says `internally drained` so guessing no case drain needed.
Flowfit 6 Way Hydraulic Solenoid Diverter, 3/8"" BSP Port Size, 12V DC, 50 L/Min Flows, Internal Drained | Solenoid Diverter Valves | Solenoid Spool Diverter Valves (flowfitonline.com)
Was thinking of getting one for a rotator on my timber grab, mounted on the hitch bracket, no case drain appealed.

Ideal thanks, will these reduce the flow drasically though? Don't really know much about hydraulics. Looked it up and it seems like the jz70 has 170l/m pump flow rate. Also think pipes are 3/4? Not checked though thats just off the top of my head

 

[honey_badger]

https://www.mhs.co.uk/hydraulic-item.php?key=1760
Something like this has slightly more flow and larger ports? Or am I thinking I need more flow capacity than I actually do?

 

[V8Druid]

https://www.mhs.co.uk/hydraulic-item.php?key=1760
Something like this has slightly more flow and larger ports? Or am I thinking I need more flow capacity than I actually do?

that's the same thing .... nice unit - hard to find 3/4" ones ..... but you WILL need a case drain line, direct to tank, for that "G plug must be removed"

 

[honey_badger]

that's the same thing .... nice unit - hard to find 3/4" ones ..... but you WILL need a case drain line, direct to tank, for that "G plug must be removed"

View attachment 22590

Just spoke to someone from summit. From what I gathered, using a diverter block like that I coud wind up breaking things becuase there wouldn't be a pressure release in the system when the diverter was closed?


However I then had a look at the block in the machine -

and then this schematic

And to me, it looks like all 9 that are there on the schematic are there on the block? Could this be simpler than I'd thought?

 

[V8Druid]

Just spoke to someone from summit. From what I gathered, using a diverter block like that I coud wind up breaking things becuase there wouldn't be a pressure release in the system when the diverter was closed?


However I then had a look at the block in the machine -
View attachment 22591
and then this schematic
View attachment 22592
And to me, it looks like all 9 that are there on the schematic are there on the block? Could this be simpler than I'd thought?

there is no closed as such with a 6x2 diverter ..... P & T are either open to A & B or C & D .... no totally closed position .... plus as you say, each service has its own PRV

 

[Giles]

Where abouts are you? Might be interested, not 100% yet though.
I like the look of the one you've got mounted to your machine, its basically what I was thinking of making originally, how well does it fold up to the dipper?

Manchester or Sheffield

 

[Shovelhands]

there is no closed as such with a 6x2 diverter ..... P & T are either open to A & B or C & D .... no totally closed position .... plus as you say, each service has its own PRV

I’m guessing what they mean is, if the diverter was in the position to operate the bucket ram, there would be no relief on the circuit connected to the thumb. If the bucket was crowded against the thumb then there would be no relief and no give.

 

[V8Druid]

I’m guessing what they mean is, if the diverter was in the position to operate the bucket ram, there would be no relief on the circuit connected to the thumb. If the bucket was crowded against the thumb then there would be no relief and no give.

but the bucket circuit'd relieve and vice versa when switched to the thumb ram .... yes there'd be relief on both circuits if the thumb was operated by an Aux circuit, but only in operation ... with the spools closed neither would relieve ...... no different to pulling hard on the bucket with the dipper circuit .... the bucket circuit would not relieve with the spool inactive.

 

[Shovelhands]

but the bucket circuit'd relieve and vice versa when switched to the thumb ram .... yes there'd be relief on both circuits if the thumb was operated by an Aux circuit, but only in operation ... with the spools closed neither would relieve ...... no different to pulling hard on the bucket with the dipper circuit .... the bucket circuit would not relieve with the spool inactive.

The bucket would likely have mechanical advantage over the thumb though, and bend things before the it reached the relief pressure
I also think the individual circuits are protected via the ARV‘s when spools are closed.

 

[V8Druid]

The bucket would likely have mechanical advantage over the thumb though, and bend things before it reached the relief pressure
I also think the individual circuits are protected via the ARV‘s when spools are closed.

would depend on the block's architecture James, but you'd not want circuits letting go on ARVs when pulled against .... pretty sure the individual ARVs are there to protect the circuits in operation, not being over stressed whilst in motion

 

[Giles]

Where abouts are you? Might be interested, not 100% yet though.
I like the look of the one you've got mounted to your machine, its basically what I was thinking of making originally, how well does it fold up to the dipper?

Manchester or Sheffield which ever is easiest

 

[honey_badger]

Okay I’ve gone quite deep in to this now and I think I’ve figured

Manchester or Sheffield which ever is easiest

cheers, I’ll bare you in mind. Still trying to get hydraulics figured at the moment though

 

[honey_badger]

Could someone help me figure out what the circled numbers and letters refer to? (The ones with the letter above the number and letter) Are they outputs/inputs, and if so how do I read them? I can get most of this now but that part is still confusing me. Think I’ve figured a way to turn on an additional block service if I can just connect the correct parts to the correct places with a diverter in line.

 

[CPS]

Just spoke to someone from summit. From what I gathered, using a diverter block like that I coud wind up breaking things becuase there wouldn't be a pressure release in the system when the diverter was closed?


However I then had a look at the block in the machine -
View attachment 22591
and then this schematic
View attachment 22592
And to me, it looks like all 9 that are there on the schematic are there on the block? Could this be simpler than I'd thought?

It looks like you have spare service on the valve block

 

[honey_badger]

It looks like you have spare service on the valve block
View attachment 22640

Yup. Should've realised that earlier, top one is hammer and one below that is boom sideshift, which I'm not equiped with, so I was planning to run boom sideshift out to the end to get a progressive control for the thumb out there. Think i've almost got it sussed how to plumb it up to activate.

 

[CPS]

Yup. Should've realised that earlier, top one is hammer and one below that is boom sideshift, which I'm not equiped with, so I was planning to run boom sideshift out to the end to get a progressive control for the thumb out there. Think i've almost got it sussed how to plumb it up to activate.

looking at it there is servo hoses connected already, |Id trace those back as there is a good chance there is a valve fitted somewhere to control them

 

[V8Druid]

looking at the schematic there is a 6 x 2 diverter (13) in the swing circuit to presumably run boom swing, which you say you don't have ?

 

[honey_badger]

looking at the schematic there is a 6 x 2 diverter (13) in the swing circuit to presumably run boom swing, which you say you don't have ?

Yeah I don't have that. I was thinking to put a small 6x2 from flowfit in there, I think I am pretty close to sussing the piping too.