A great success!

arrow · Feb 16, 2014

Traskblacktail said:
Arrow, your thread on a "great success" is also a great success; invaluable information being shared here, thanks!

Thanks Trask. Since you have the same machine as I, I do not know if you have what's considered a "fast dump" position. Mine goes real slow when in dump mode. When I push it further right, it goes slow a bit faster. It supposed to take 2.5 seconds to dump but where they measure the dump "position" is beyond me. From the full curl lock position , my loader takes almost 5 seconds to reach full dump lock. Anywhere else, 5 seconds would be fast (like 0 to 60) but watching a loader take this long is rather maddening.

k0ua · Feb 17, 2014

Arrow, lets think this thru. All the regen position on the spool does is make connection from the pump port to BOTH sides of the curl/dump cylinder. Both the Cap end and the Rod end at the same time. Say you are fully curled and don't have any fluid in the cap end (or very little) and the rod end of the cylinder is full minus the displacement of the rod itself. So in a normal powered down dump (first position on the spool as you push it to the right). The fluid in the rod end is opened to the T or tank port, and the Cap end is is open to the P or pump port and starts to fill with the flow from the pump. The rod end starts to empty back to the tank. All well and good, and the time required depends on the volume of the cylinder and the flow rate of the pump. Of course in your calculations remember that the flow is divided between the two cylinders that need to be filled. So when we go into regen by pressing the spool further to the right, we are closing off that return to tank, and making connection to the pump onto both sided of the cylinder, both the cap end and the rod end. Now remember the equation F=PxA so the Force on the cylinder is equal to the Pressure times the Area. Now you might ask if you apply the pump flow to both sides of the cylinder, how can that work at all? Well we have less Area on the rod end due to the fact that the rod itself removes that area the fluid is allowed to act upon that end of the cylinder. So with the same fluid Flow applied to the cap end and the rod end then the force will be greater in the cap end vs. the opposing force on the rod end and the rod will begin to extend from the cylinder. Now since the fluid that would normally go to the tank is available and is connected to the same pump port, the only amount of fluid that has to be made up by the pump flow is the amount of fluid the rod displaces. Remember the rod is moving out of the cylinder past the seal. So the total amount of fluid needed to extend the cylinder is the volume of rod only. This means that in a given amount of time the rod will extend faster because the 7 gallon a minute pump or what ever it is on your tractor will have a smaller volume of fluid in a given time to get the cylinder extended.

So Long story short, IF the spool valve is making the hydraulic connection to both the Cap and Rod side to the pump at the same time, and a gauge would be able to determine if it is doing that by applying a gauge to the curl and dump hose connections and seeing if the pressure rises in both at the same time. Then the cylinder MUST extend faster due to the above principals I outlined. Keep in mind you do not get something (faster cylinder extension) for nothing, because the amount of force the cylinder can exert while extending in this regen mode is much much less. So you have traded extend force to for extend speed.

My hypothesis is that your spool valve does NOT do this properly, because if it did, then the cylinder rod would extend faster from the cylinder. This is the whole concept of regenerative extension.

There is not likely to be anything wrong with the hoses, QC's or cylinders as they all work normally in the normal dump and curl operations. It has got to be the control valve spool.

Now perhaps someone with REAL hydraulic experience will comment. What do I know, I am an electronics/telecom guy.:laughing:

arrow · Feb 17, 2014

k0ua said:
Arrow, lets think this thru.

So Long story short, IF the spool valve is making the hydraulic connection to both the Cap and Rod side to the pump at the same time, and a gauge would be able to determine if it is doing that by applying a gauge to the curl and dump hose connections and seeing if the pressure rises in both at the same time. Then the cylinder MUST extend faster due to the above principals I outlined. Keep in mind you do not get something (faster cylinder extension) for nothing, because the amount of force the cylinder can exert while extending in this regen mode is much much less. So you have traded extend force to for extend speed.

My hypothesis is that your spool valve does NOT do this properly, because if it did, then the cylinder rod would extend faster from the cylinder. This is the whole concept of regenerative extension.

There is not likely to be anything wrong with the hoses, QC's or cylinders as they all work normally in the normal dump and curl operations. It has got to be the control valve spool.

Now perhaps someone with REAL hydraulic experience will comment. What do I know, I am an electronics/telecom guy.:laughing:

You know James, if I were Noah, i'd choose you to ride the ark. You are "Ark Worthy" in my mind. Thank you so much for your detailed explanation. I'd like you to put a picture in your head. Pretend you just said the above looking down to a three year old.... or perhaps Kelly Cuoco from Big Bang, you would then realize "what the **** am I doing explaining this to this apparent doofwaft" Its just not worth it James.. My "whatever I have" in my head does not put stuff like this together without great consternation. Don't get me wrong, I appreciate all of it and maybe after a couple of hours it would sink in.

So, you think something is wrong with my control valve?

k0ua · Feb 17, 2014

I do tend to ramble on.

I went out and tested my Kioti.. It was 1 second difference from full curl. to load completely dumped comparing regular dump to regen dump. Just 1 second. is it worth it to worry about.. I am not sure. But the regen dump works on mine, and apparently does not on yours. I tested it at idle and at 2000 rpm. For some reason it might have been a fraction of a second over 1 second difference at idle. Of course the overall times were slower at idle than at 2000. but I am talking about comparing the times. Now I did not have a stopwatch, or anything like any kind of instrumentation. This was me saying to myself, one thousand 1 one thousand 2. My dump at 2000 was about 2.5 seconds on regen and about 3.5 seconds with standard dump. But I bet I have a faster flow pump (10 gallon a min not including the Power steering section.) than on your Mahindra, and my cylinders probably are about the same size.

As for your valve, I can't for sure say,, perhaps with lower flows, you just don't notice much increase. Say it was 1/2 a second, would you notice that? or did you say it actually seemed slower? I can't remember without going back and reading your responses. I am not any authority on this anyway, I am going on what I read and think I understand.. I do get a bit "wordy". Perhaps I should look into writing books.

Good luck with it Arrow.

k0ua · Feb 17, 2014

I just looked up your specs on your pump and loader.. Of course I don't have the exact dimension of your cylinders, but you can lift about 250 more pounds than my tractor, so I am guessing you cylinders are slightly larger. Or of course the pressure relief could just be set slightly higher. But you pump capacity is somewhat less, at 7.8 Gallons a minute vs mine at 10 gallons a minute.. SO especially if your cylinders are larger, then I can easily see why your loader takes longer to cycle than mine. Higher pump flow means faster operation for a given cylinder size, but larger cylinders mean you can lift more, but take longer to do it. And since you have less pump flow, and possibly larger cylinders, no question your tractor would be slower than mine.

PS. I haven't given up on explaining stuff like this to you, because I believe you can understand it and it helps me to understand it also, when I try to explain stuff to others.

And I know you are smarter than Kelly, because you have a tractor..:thumbsup:

k0ua · Feb 17, 2014

By the way I looked up this "Kaley" person, and I am betting your don't look Anything like her!

arrow · Feb 17, 2014

k0ua said:
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PS. I haven't given up on explaining stuff like this to you, because I believe you can understand it and it helps me to understand it also, when I try to explain stuff to others. And I know you are smarter than Kelly, because you have a tractor..:thumbsup:

I have a tractor but Kaley has other stuff. If you had a choice James as to who you would want in the room to explain hydraulics to between she and I, there is no doubt in my mind you'd pick me. (does that show you how smart I am?)

Thanks James for the in depth and real world comparisons. At least i know why my fel is such a turtle.

k0ua · Feb 17, 2014

arrow said:
I have a tractor but Kaley has other stuff. If you had a choice James as to who you would want in the room to explain hydraulics to between she and I, there is no doubt in my mind you'd pick me. (does that show you how smart I am?)

Thanks James for the in depth and real world comparisons. At least i know why my fel is such a turtle.

I dunno, I looked up her picture, and I might just enjoy explaining regenerative extension to her!.:laughing: