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Hydraulics Guru's needed for a little advice


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#16 skyrydr2 ONLINE  

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Posted November 22, 2011 - 05:27 AM

Yup, you are going to have some issues for sure! The verticle shaft will pose to be a real challenge getting the pumps mounted. For the large pump you could use a snowthrower frame/belt drive system and mount it out front, thus giving you dome extra balst as well. But ground clearance could also factor in... Your going to need to do some serious pondering for sure.

#17 Toolpartzman OFFLINE  

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Posted November 22, 2011 - 05:42 AM

You are closer to a solution than you might think. Tudors splitter experience and re-visiting your original goals provide important clues.---i.e. Splitter Cylinder 18"?- what length logs?-Likely not much shorter than 18 means a single stage pump will work OK- The 2 big heat makers are relief valves and flow controls, compounded by the length of time they are active. Reduce that use in either of your 2 functions reduces reservoir requirement and money.
Most Importantly; I would suggest treating your design considerations separately by each of the 3 jobs, list all options separately, then find the answer that's common ,( or the best fit) to both. Simplify your requirements for single acting or double acting actuators. This further simplifies the mix of control valves ($) Each function acts alone. You'll never be tilling and splitting logs etc at the same time, so finding the control which is common to all means saving $$$---------------Hope this helps----LeeB

#18 Toolpartzman OFFLINE  

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Posted November 22, 2011 - 05:44 AM

I meant the 3 functions-not 2.

#19 dave8338 OFFLINE  

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Posted November 22, 2011 - 09:57 AM

Very good info, guys ! ! ! The pump mounting will be tight, no doubt about that. As for getting rid of the excess heat, generated by the hydro motor and the relief valve, I have a few ideas on that. Nothing too costly and if done on the low pressure return line, I can go with heat sinks on the tank. The real heat maker is going to be the tiller.

#20 cp7 OFFLINE  

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Posted November 22, 2011 - 11:42 PM

Please don't take offense but you really need to be looking for a different machine. First and foremost your transaxle isn't rated to handle a three point or ground engaging rear attachments.
Take a look at a Case Ingersoll garden tractor. They have done all the R&D that your wanting to attempt. They do all that your wanting to with as little as a 10hp engine. You can usually find them pretty cheap because not many really understand the brilliance and simplicity of their design.

#21 nra1ifer OFFLINE  

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Posted November 23, 2011 - 12:02 AM

Please don't take offense but you really need to be looking for a different machine. First and foremost your transaxle isn't rated to handle a three point or ground engaging rear attachments.
Take a look at a Case Ingersoll garden tractor. They have done all the R&D that your wanting to attempt. They do all that your wanting to with as little as a 10hp engine. You can usually find them pretty cheap because not many really understand the brilliance and simplicity of their design.


:ditto: I would love to have a Case tractor. Would definitely use a rear tiller and a wood splitter, and the Case would be a good source of power.

#22 TUDOR OFFLINE  

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Posted November 23, 2011 - 06:53 AM

You are closer to a solution than you might think. Tudors splitter experience and re-visiting your original goals provide important clues.---i.e. Splitter Cylinder 18"?- what length logs?-Likely not much shorter than 18 means a single stage pump will work OK- The 2 big heat makers are relief valves and flow controls, compounded by the length of time they are active. Reduce that use in either of your 2 functions reduces reservoir requirement and money.
Most Importantly; I would suggest treating your design considerations separately by each of the 3 jobs, list all options separately, then find the answer that's common ,( or the best fit) to both. Simplify your requirements for single acting or double acting actuators. This further simplifies the mix of control valves ($) Each function acts alone. You'll never be tilling and splitting logs etc at the same time, so finding the control which is common to all means saving $$$---------------Hope this helps----LeeB


Good plan!

Unfortunately there are 2 totally different tasks involved, each requiring valve spools with different functions.

Note:
There is a terminology problem that I may be creating here. Most people understand that open center valves are needed for GT hydraulic circuits. The correct term is open circuit. Open center actually applies to the work ports, not the throughput of oil through the valve body.

In this particular situation, the splitter requires a spring loaded, auto centering, closed center, open circuit spool. Spring loaded and auto centering are what most of our valves do. The control lever pops back to center when we let go of it. The spool is closed center because it needs to hold the load and open circuit because the oil has to pass through the valve body to the next component.

The tiller requires a detented, open center, open circuit spool. Using a detented spool allows the operator to set the spool in an operating mode and it stays there rather than having to constantly hold it in place. The open center spool will allow the tiller motor to wind down instead of stopping abruptly since the work ports are open to each other, and usually to the pressure port or the return port as well. A closed center spool can be used, but when the valve is centered the oil stops in the work ports and there is no relief valve to deal with any overpressure created by the rotating mass of the tiller as it comes to a very abrupt stop. It's open circuit because .....

I'm sorry if this causes any confusion, but there are 2 circuits in a valve, and in this instance especially, both must be differentiated. The term in general use is simply inadequate in this situation and the use of correct terminology can keep everything clear.
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#23 Toolpartzman OFFLINE  

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Posted November 23, 2011 - 08:06 AM

To add to Tudor's control valve explanation: Its best and easiest for those new to hydraulics to first learn a few basic circuit symbols because they depict VISUALIZE flow paths, and terminology is secondary. Closed/open in electronic and hydraulic terminology are opposite----Common Mobile valves in multiple valve stacks further confuse the issue.-----Imagine, or better yet draw a schematic "valve position" box, that is one box for each position of a single hand valve--i.e. A double-acting cylinder has 2 Ports--A and B, the 4-way valve driving this cylinder has at least 4 ports--the A and B to feed the cylinder, and a P and T--Pressure (from pump) and Tank (return line) connection----If you refer to schematics---can't show it, %%^^&&#@sorry.--its simple though-- In NORMAL or centered valve position (of a 3-position valve) most common ag apps "block" or Close the valve to flow at A or B (lock the cylinder)-but only the A/B ports are blocked, P is allowed to flow directly to the T port--(or directly on to the next valve). Industry refers to that as a Tandem Center because, though A/B are "closed", P remains "open" to Tank.

Hope I haven't further confused the issue, but If someone here can upload a simple circuit dwg with a brief explanation of the flow paths it is the simplest way to understand what is actually happening, because unlike an electrical circuit, a hydraulic circuit is largely pictoral, and virtually eliminates unclear terminology.----in the meantime I'll try to lay one out---later today. Its making me cranky, because every a soul here could be comfortable with hydraulics in less than an hour, using a basic circuit.:wallbanging:
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#24 skyrydr2 ONLINE  

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Posted November 23, 2011 - 09:05 AM

Bob, your spot on in theory , for the tiller motor , just need a detented open circuit closed center valve and use only the detented circuit to pressurize the motor, return the oil directly to tank, far less heat will be generated and thus much less chance of a popped seal. If a Case tiller is used then there really is no worries as their motors are not as "tight" as an industrial unit. then the OP can use that valve for other things as well cutting down cost, only thing needed is an extra return line and quick connect, with less chance to hook things up backwards, especially if he makes the return line larger (highly recomended).Also this valve can used for a remote app like the splitter.And If he gets even more creative, can make a lock out for the detented extra travel and use this valve for anything like power angle, or power tilt or even ..... the uses are endless :thumbs:

#25 ducky ONLINE  

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Posted November 23, 2011 - 09:10 AM

Here is a link to some great hydraulic info.
Fluid Power Information Center-(Hydraulic,Pneumatic,Electro Controls,Hose,Automation)
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#26 Jehtro OFFLINE  

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Posted November 23, 2011 - 09:30 AM

I'm with Cp7 on this, I had a 116 for years. I ended up selling it because the transaxle was getting stuck in gear. That was just from mowing and snow blowing. Changed over to a Bolens G14

The L-Brigs has got the HP, but the machine is not heavy enough.

My father in-law pulled a selfpower tiller with a 111 and took the axle out of it.

Tiller work is hard, I would hate to see you put all this time into it, and then end up getting a bigger machine anyway.

#27 ducky ONLINE  

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Posted November 23, 2011 - 09:37 AM

Here is a pic that will better explain valve centers
valves3_4.jpg
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#28 Toolpartzman OFFLINE  

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Posted November 23, 2011 - 03:39 PM

Thankx Ducky . Davey, Here's a simplified circuit using the 4-way as a 3 for the on board deck lift. I Finally figured out how to upload it--I think. Also, even though your pump is a fixed displacement (1 or 2 stage), being able to change engine input speeds allows for some speed control. The main 4 -way is shown with the return detent for the splitter valve with auto return. This will also drive the tiller motor, providing P to A is the tiller drive side.----I've not considered your specific flow and pressure numbers which would have be plugged in, however this may be an inexpensive way to get where you want to go.---LeeB---OK ,so here goes...CircuitDwg.jpg

#29 ducky ONLINE  

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Posted November 23, 2011 - 03:49 PM

It looks like you will be deadheading you B port when you try to lower your deck.

#30 Toolpartzman OFFLINE  

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Posted November 23, 2011 - 04:25 PM

Pumps Off when lowering the deck.




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