Hydraulics questions, non truck related.

[shady]

I have a 2015 Bobcat T590 skid loader.
I'd like to make some attachments for it, like a grapple claw for my smooth bucket, and a log splitter.

The auxiliary hydraulics have a 3400-3550 psi pressure relief according to the specs. So to me that means they will put 3500 psi to the cylinders.
Most all the cylinders I've found say 3000 max.

I know theres a built in safety factor, but it seems like it's pushing it.
I do get that there should be no reason I'm pushing it to the pressure relief for a long period. Sooo should be fine. it's all the times I'm splitting a log or something and it's at 3300 that I can't tell that gets me thinking.

But just wondering if that's normal/ok?

I have found some 3500 psi cylinders, but they do cost more and there's of a less size selection.
If the 3k ones are ok, I'd rather go with them.
I already have 4k hose and access to a sweet crimper I've used a few times. So I'm good there.

One more option i thought of was, can I just put a 2800 or 3k pressure relief between my aux lines, so the cylinder just kind of stops when I hit 3k?

 

[76zimmer]

Ask Parker hydraulic?

 

[shady]

Could do that

 

[kennyw]

You can add an additional pressure relief but it may cause problems if your system normally runs above the setting as it will be flowing fluid. Do you know the normal operating pressure of the system?

Looking around online, in not seeing any spec other than the 3500 +/- 50 psi pressure relief. I would make sure all cylinders and hydraulic parts are designed for 3500 psi minimum. Anything less and it is going to cause issues with other hydraulic systems.

 

[shady]

I've looked up a few other brands and styles of skid loader since posting this. Almost all have 3500ish relief valves for the auxiliary hydraulics. And every attachment I've found from any manufacturer runs 3000psi cylinders. So I'm going to just go with the 3k stuff I guess. It has to be ok, or there wouldn't be so many with those ratings

 

[kennyw]

I've looked up a few other brands and styles of skid loader since posting this. Almost all have 3500ish relief valves for the auxiliary hydraulics. And every attachment I've found from any manufacturer runs 3000psi cylinders. So I'm going to just go with the 3k stuff I guess. It has to be ok, or there wouldn't be so many with those ratings

If the system is designed to normally run under 3000 psi, you will never have an issue. Most do not run near the pressure of the relief valve. But, I would expect the relief valve to be below the component level pressure rating for safety. I.e. design a system to run at 1000 psi and use a 2500 psi pressure relief on 3000 psi components. That is how companies I worked for designed things. The 3500 relief pressure makes me think the components are rated for 4000 or higher in the skid steer but the system runs between 2000-2500 psi normally.

 

[CT-BLAZER]

The log splitter is easy...control its own control valve ,& quick disconnect lines...

The valve will only use the 2500 psi or such as you set it for, the rest will be returned... This will generate additional heat from that valve.

Some machines have multiple pumps+ different pressure & volume.

For the price of a stand alone splitter ($2k) , I would NOT run a diesel machine to split fire wood.

The hydraulic grapler is a standard production item...I doubt it could be replicated for less than what an off the shelf unit costs

 

[shady]

If I split wood it's for like a half hr. And I almost never run the throttle wide open like a lot of guys do. I'm usually barely off idle or half. Which is another reason I'm thinking the 3k would be ok.
I only split maybe once a year for my fire pit, and it's only whatever wood we get from trees that come down in the yard or we cleaned up for someone else. So not worth buying a good stand alone that would take up more space. I wanted to build a stand-up one that I could roll a log under and hit the handle quick, spin, repeat. Then when I'm done, lean it again a post by the wood rack and strap it to it for storage.


I get a lot of steel basically free from work. Anything that goes in our semi sized scrap dumpy can be bought for $5. $200-300 cylinder, and some near free steel is way cheaper than the $2k they want.

The grapple I can make my way. Put mounts on both buckets, plus my pallet forks. Then use it on any of them with the pull of a couple pins

All I want is basically a 2' wide centered tine and make the mounts as wide as the forks would let me. Single cylinder. I actually have some 2" DOM I was thinking of bending up to make the main tines.
Then some 3/8" sawteeth on the inside to hold stuff.

 

[kennyw]

If I split wood it's for like a half hr.

A simple splitting maul is probably the smallest, most efficient tool for that task if you are worried about storage space and cost

 

[Blue85]

If I split wood it's for like a half hr. I only split maybe once a year for my fire pit, and it's only whatever wood we get from trees that come down in the yard or we cleaned up for someone else. So not worth buying a good stand alone that would take up more space.

Two words: "splitter rental". No maintenance, no storage. $50/day. Heck, I've done 4 cords by hand in a fall. My splitting axe and maul hang on the wall taking up very little space. Plus, as they say "you're warmed twice". But when you get into the trunk splits on old oak or maple trees hydraulics are the answer.

 

[shady]

A simple splitting maul is probably the smallest, most efficient tool for that task if you are worried about storage space and cost

I actually like doing that, but can't for long. Motorcycle wreck 15 or so years ago messed up my shoulders. I still do it here and there. But as I get older I find it hurts my arms and shoulders a lot quicker. Last time I did it I had to keep my arms at my sides and walk up to doors so my nose almost touched to grab the handle, then walk backwards. I physically couldn't reach out, grab the handle, and pull it.

Two words: "splitter rental". No maintenance, no storage. $50/day. Heck, I've done 4 cords by hand in a fall. My splitting axe and maul hang on the wall taking up very little space. Plus, as they say "you're warmed twice". But when you get into the trunk splits on old oak or maple trees hydraulics are the answer.

I actually didn't even think of renting one.
I borrowed a buddies before, but he's kind of an anal dude and I felt like I was on egg shells. And I LOVE fabricating chit so my mind just went there first lol. The whole "I built that!" Thing

I have almost all the steel to do it. Guy I know has the 'I 'beam laying around if I want it. I have the hose, fittings, and quick connects. So all I really need is the cylinder. Which is what started this thread lol.
But renting one would probably be simpler in the long run.