Ignorant First Question about adding Hydraulic operated Accessories

[shaley]

I've got a US NAVY Hydraulics manual in PDF format. I can't attach it because it's 5 meg. Here is a link to it.
http://www.metalwebnews.org/ftp/fluid-power.pdf

 

[hill]

Hill, you have gotten some very good advice so far...let me highlight some points:
1. You need a Open Center, Double Acting, Spring Return To Center spool vavle, NOT a Motor Spool valve.

2. You CANNOT "T" into hydraulic pressure lines, you can only "T" the Return To Tank line.

3. That valve you linked is WAY to big for a CUT.

And here is more food for thought, The way I read your initial post:
You only need 3 additional circuits. Remember when your BH is on, the T&T on the 3PH will not be on the tractor. So the most you'll use at once is 1 spool for the grapple, and 2 spools for the T&T.

I wasn't fooling when I put "ignorant" into the thread title, but I know now that the linked valve in my first post will be perfect for operating and aiming the antiaircraft turret guns I'll have mounted atop my ROPS.

Seriously, I agree as to the excellence of Mike's posting here, and as chance would have it I've just come from scanning relevant parts of the US Navy manual linked by Shaley. "Metalweb News" is part of my second home online as I've got a fair machine shop here and doodle around metals considerably. I'd just not given much thought to hydraulics until deciding to buy this tractor which arrived home this last Friday. BTW, Thanks shaley - I happened upon that by pure chance as I hadn't expected it to be in an area that I think of as machining related. Looks to be as good as all of the other US Navy manuals I've encountered over the years, even easier to understand then some.

About the number of circuits: I hadn't realized the nature of this 'in series open system' or the significance of the need to reconnect opposite male and female connections when removing the hoe or the loader. Good thing that all I've had time to do so far with the tractor is to give some of it a coat of wax and to remove most of the 'babysitting' warning labels - after studiously internalizing their messages, of course. Those things just piss me off.

The hydraulics are very interesting to me. Adding the mentioned additional tools make them that much more interesting. Hope this thing isn't the one that breaks the bank!

 

[patrick_g]

Hydraulics is interesting stuff, a lot more like electronics than many suspect. Unfortunately as a sort of beginner level hydraulics guy, I have to translate a lot of the hydraulics into electronics equivalents to feel comfortable and be sure I understand what is going on. May not work for the next guy but it helps me.

I would be so proud that my head would burst if I knew more than a small fraction of what the hydraulic gurus here know.

Pat

 

[shaley]

Here is a good explanation of series - parallel hydraulic circuit or commonly called open center with power beyond. This is how most tractors and mobile machinery are configured for the advantages stated in the article.

 

[MJPetersen]

Thanks guys for the compliments, but I do not believe that I am an expert in hyd and I certainly am not a teacher of hyd--well except I guess on this forum. I did spend 12 summers working as a mechanic on heavy equipment in Alaska where I grew up. My expertise lies in an area totally unrelated to tractors. I am a missionary with a PhD in Old Testament Interpretation.

Pat is right that sometimes it helps to think of hyd like electrical. That works most of the time except when you have oddities like the series\parallel valves.

Shaley posted an excellent diagram of a series\parallel setup. I have never seen such a setup as a whole system, but the better backhoe and loader valves are setup this way. You want to be able to lift and curl at the same time on a FEL and on a backhoe often you are working two spools at one time; boom\swing, boom\dipper; boom\curl or even 3 or 4; boom\swing\dipper\dump. With our smaller volume pumps when trying to do too much you will run out of flow to operate too much at one time though.

One other thing that the diagram points out too is that the pump for our systems is a fixed displacement pump (normally a gear pump, but vane is also possible), the closed center systems have a much more complex pump that has a variable displacement (a multi piston pump on a wobble plate). They maintain the pressure by varying the flow as necessary. Some JDs and bigger machines have this kind of system.

At any rate, I am glad that I could be of some help.

Mike

 

[hill]

Here is a good explanation of series - parallel hydraulic circuit or commonly called open center with power beyond. This is how most tractors and mobile machinery are configured for the advantages stated in the article.

All of the above has brought me along quite a ways, I think, and everyone may take a bow for having been able to budge the reluctant old brain of mine.

Shaley, once again a very valuable pearl in the latest diagram. Am I wrong to think that it depicts the internal passage 'wiring' of most of the gang valves on the market?

 

[MJPetersen]

I would not say most, but many. One of the after-market (build it yourself) backhoes advertises that they use such a valve and that their competition uses the straight series valve (no two valves can be simultaneously used).

mike

 

[hill]

Hmmm, I have a Kubota B7800 with front loader and backhoe. I also have wild seemingly impossible dreams.

With but one power beyond outlet, the one used by the backhoe from the loader joystick valve how can additional outlets be obtained? That would seem to be the prerequisite to any idea of additional features. Can I daisy chain power beyond valves by routing the one PB circuit to another valve of however many spools that also has a power beyond outlet of it's own AND through that to the backhoe (or T&T)?

Are people making up their own high pressure hydraulic hoses and piping? If so, what's it take to tool up to do it? I'd imagine that the hose and fittings cost a good bit, but don't you also need pretty specialized crimpers, flaring equipment, and the like?

 

[kennyd]

Can I daisy chain power beyond valves by routing the one PB circuit to another valve of however many spools that also has a power beyond outlet of it's own AND through that to the backhoe

Yes, that is what the PB is for.

Are people making up their own high pressure hydraulic hoses and piping? If so, what's it take to tool up to do it? I'd imagine that the hose and fittings cost a good bit, but don't you also need pretty specialized crimpers, flaring equipment, and the like?

Usually no, they are made at a shop. The crimpers that install the end are thousands of dollars. There are however "re-usable" hose end that you can put on yourself, but I think of them more as a temporary repair than a permanent solution (that is just MY opinion).

You can find the crimpers and lots of other good stuff at DHH

 

[hill]

Yeah, I was afraid of that. $1400.+ is a bit too much to spend for a one time use of a crimper like that, and having hoses made can be very expensive depending on the available makers. It'd be bad to mis-measure my need and have to keep buying to get a fit and that is altogether possible.

I've seen in the info posted in the Kubota section(s) that rear remote hydraulic kits are available from the dealer that include necessary hosing and the option of additional spools for the kit valve. The list price is some $600. for a basic setup and dealers don't necessarily charge list prices. Mine sure didn't when they sold me the machine. Maybe this is the way out of the headaches that seem inevitable, although in most things I enjoy the project as much as the benefit derived.