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Overly Complex Hydraulic System

Provience

Kill!
Joined
Jul 8, 2009
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15
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Gatesville, TX
I need a repository over here, big thank you to everybody who helped me get to this point from before. None of my ideas are original and i'm learning as i go, if i've got something wrong or you feel mis-represented, feel free to correct away! I'm going to try to put up my current plan, why it is what it is and explain why i'm doing something overly complex for no apparent reason.

First things first, this is my most current schematic that i'm building around:

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Walking through it: this is a dual pump system; to a Danfoss OLS 120 valve to control a Danfoss OPSU steering valve; to a Danfoss OLS 80 valve controlling a Hydroboost; to a Brand single spool dual acting flow control valve controlling a MileMarker 10.5K winch; to a filter/cooler/reservoir.


No, this won't be done anytime soon. This is what it looks like at the moment :flipoff2:

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Wait a second!? How did you end up with 2 pumps? what happened to running a single large pump like a gear pump or a variable displacement pump like a piston or vane?

Well, lot's of things. Every single variable displacement pump that i looked at is poorly fitted. the variable displacement vane pumps all tended to be small capacity, so they wouldn't do so well for low speed functions and they have lower max RPM's than fixed vane pumps. A variable piston pump would be dope and could even be made to work, but one small enough to tolerate a ~4k rpm swing that a gas engine can easily make is still a ~$4k unit just by itself. Variable displacement would be the ultimate way to go if you want maximum performance with minimum drag on the system, but you'd want to have a substantial budget and a narrow input RPM. anybody running a diesel race car? that would be the application for it.

and next i looked at using a larger capacity gear pump. my "ideal" output target was ~15 gpm at ~1500 rpm engine speed. that takes a 1.9 cubic inch displacement pump depending on pulley ratio, and honestly, that is a whole bunch of pump to sling fluid around the system. It would be awesome to run that single pump and set it up with a pressure compensated unloading valve, so that it could dump excess without needing to hit full system relief pressure and thereby keep the heat and horsepower load down, but an unloading valve up to the task is ~$1k just by itself. there is nothing cheap about them and those were mostly what i could find used. I'd expect a custom spec'd one to be at least $1k and probably a bit more. This is probably not the worst way to go, but it isn't the easiest. Adding a flow control valve that does more than just split the stream is another couple hundred bucks. To mimick a variable displacement pump, it could be rigged cheaper and be much more tolerant to RPM fluctuations, those gear pumps might lose efficiency over their rated RPM, but there are plenty of people running the absolute shit out of them for it to be not much concern.

So dual pumps. 15 GPM at 1500 rpm is still the target. There is a whole aftermarket out there and plenty of O.E.M. options for running 4-8 GPM from a fixed vane pump that can handle the RPM swings. My steering valve is 'rated' at 6.3 GPM, no reason to feed it any more than that. So 6 GPM on tap at nearly all times is plenty doable for 1 pump. Turns out, 12V pulley clutches are "only" a couple hundred bucks, and i can get one setup on a gear pump that will give me ~10 GPM at 1500 engine RPM. 10+6=15 GPM at 1500 engine RPM. for "only" $700 assembled, but the advantage is that i'm not sending the full volume of fluid through the system all the time. This is the cheapest and easiest way to mimic a variable displacement system that i've come across.

CB-X High Performance Steering Pump – Radial Dynamics (radial-dynamics.com) 6 gpm just off idle

1.45 cu in Rexroth Hydraulic Clutch Pump 6 Groove Pulley For Serpentine Belt | Clutch Pumps Hydraulic | Hydraulic Pumps | Hydraulics | www.surpluscenter.com 10 gpm on demand

and here is a link to a handy hydraulic HP to PSI calculator. this is why slinging around 15 gpm constantly isn't ideal and variable flow to match my variable load is the goal.

To find hydraulic horsepower, use the equation:
HP = (PSI X GPM) / 1714

PSI = Pressure in Pounds per Square Inch

GPM = Flow Rate in Gallons per Minute

Hydraulic Horsepower Calculator (calcunation.com)



to try and keep my post length manageable, i'm going to attempt each section in their own post. give me a bit.
 
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Next up, pressure gauge, because they are handy.

0-2000 PSI gauge will not only let me know how i'm doing for neutral pressure, which is the no-load system loss or parasitic loss, but it will also let me know how hard the steering is actually working to do stuff. Let's say the pump relief is 1200 PSI, if i have 500 psi neutral, then i've really only got 700 psi to do work with, depending on a few things.

2000 PSI 2.5" LF BM Pressure Gauge Dynamic CF1P-140-D | Pressure & Vacuum Gauges | Pressure Gauges | Air & Pneumatics | www.surpluscenter.com


and then we get to a big part of why this is overly complicated, the first Dynamic Load Sense Valve. OLS120

this is the neutral pressure drop for a given flow rate and balance bar. I'm going to be on the 7 bar "B" scale. while the pump may be making a whole bunch of volume and passing it internally, sending 6gpm vs 15 gpm through this valve saves me ~30 psi at neutral and ~20 psi under load. The "Min" line represents the pressure drop when the unit is doing work. The 7 bar vs 10 bar is the standby/ready pressure that the valve holds so that it can react when it senses a load.

OLS 120 Dynamic P Drop.png


Here is a chart from the Danfoss OSPU book for min. standby pressure. 7 bar won't get me a full 4x amplification at 80 rpm steering wheel input, but it should get me a 3x at that same speed. I.E. sitting at idle in a parking lot, if i turn the steering wheel quickly, i should still get a pretty fast (comparatively) reaction from the tires. Standby Pressure is why the OLS120 has a much higher neutral pressure drop compared to a min. working pressure drop. once you are steering, the valve will regulate as much flow as it needs to do what it thinks you want based on the steering input rpm and the load (pressure) that the rams generate, while bypassing everything else.

min standby pressure.png



alright, so Load Sense valve on the steering is a requirement for the danfoss flow amplification units. easy enough, but why the heck would you want a flow amplication steering unit and not a static displacement system like literally everybody else in the world uses? because fawk'em :rasta:

Sizing of steering unit to Cylinder to determine steering ratios. How many turns of the wheel equates to how many degrees of steering or how much lock to lock.

Volume of a hydraulic cyclinder with a ram: Pi*r^2*L

Hydraulic Cylinder Calculations - Womack Machine Supply Company

With shaft, don't forget to subtract the shaft from the cylinder volume.

I'm using surplus center 1.5"x8"x0.75"shaft cylinders, and i'll be using 2 of them, limited to 6" stroke

Shaft side is 1.33 sq in * 6" for 7.98 cu in per side and 15.96 cu in total volume.

blind side is 1.77 sq in * 6" for 10.62 cu in per side and 21.24 cu in total volume.

turning each way will have me powering 1 blind side and 1 shaft side, nets 18.6 cubic inches

OSPU Steering valve at 60/240 is 60cc (3.66 cu in) displacement min and 240cc (14.64 cu in) displacement max amplification

Here is a chart out of the book using the same unit but with a different valve, but it shows how the OSPU "ramps" output based on steering RPM input

OSPU Linear.png



what that means, is that if i turn the wheel at a slow rate, less than 10 rpm or so, i'll have about 5 turns lock to lock (18.6 cylinder volume/3.6 displacement) and that would give a high degree of fine tune correction. low sensitivity steering. If i turn the wheel quickly at 100 RPM, i'll have 1.2 turns lock to lock (18.6/14.6) and that would give quick steering. Stuck on top of a rock and want to saw the tires back and forth while they spin? rip the wheel as fast as you can and saw away.

If that is too slow, then it would be very easy to tie the two shaft sides of the rams together and only power the blind side of the cylinder. that puts "slow" at 2.9 turns lock to lock (10.6/3.6) and fast at 0.75 turns lock to lock (10.6/14.6)

options are nice, hopefully being able to "control" how quick the steering is based on steering wheel input RPM makes for a more enjoyable driving experience than something that is sensitive based on engine/pump RPM. at least, that is the idea anyways. just don't get pissed off and whip the wheel driving through traffic, or literally everybody will die.

what danfoss calls dynamic flow amplification, eaton call q-amp. nobody is using it that i can find, probably because it is added complexity and cost and not needed and less predictable :rasta:
 
I really want to run hydroboost brakes. takes up less space than a large vac. booster, i'm already going to be running a funky hydraulic system, gives much better assist than manual or vac assist.

Of course, hydroboost units are small and restrictive and don't play well with high volume flows. heck, the OEM's even think that brakes are more important than steering and in a panic situation will divert all the pressure to the brakes and leave you with unassisted steering. not a big deal if you have regular steering gear box, really sucks when you are relying on cylinders to steer.

OLS80 priority valve to the rescue. Because there isn't much need for standby pressure for the brakes as it has it's own reserve canister, i'm planning on sticking with a 4psi bar and throttling it with a 1/4" supply line and possibly a restrictor orifice. Hydroboost works with 1 gpm, it really doesn't take much to activate. using this valve will keep the fluid bypassing in bulk and when brakes are applied and a load is sensed, via resulting pressure drop, the valve will pass along as much fluid as it needs to keep it satisfied. at least, that is the theory anyways. this seems like a better option than trying to open up the internal passageways to accomodate higher flow. if the hydroboost doesn't like have the main throughway blocked off completely, then it is easy enough to set it up with a small leak

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using an 80's GM hydroboost with a 1-1/8" master cylinder, should move a silly amount of fluid for whatever brakes i end up with.

Hydroboost cutaway

hydroboost-cutaway-jpg.2922942.jpg


so that's what i'll mess with to see what it can be restricted to and still be functional. ideally, closed center, but it that isn't possible, then as small a leak as will function
 
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alright, so off of that, now we get to the joys of the winch and the second pump. Not pictured in the diagram would be a pressure relief valve for this circuit, which is isolated with 1 way check valves so that each pump doesn't try to overpower the other when not running or what-have-you.

both pumps feeding into the SDCF755TM184LF1 control valve. this will lock and hold in neutral and offer some better metering control compared to the basic on/off style spool control, but not as good as some more precise options. Trade off is the finer option controls from Brand don't offer neutral blocking, which is something i do want in the winch.

tm spool.png


DCF TM Pressure Drop.png




Being able to run the winch at ~6gpm from the main pump or 15 gpm with both pumps will give further control as well.

But why a hydraulic winch? everybody knows those are slow piles of crap and any halfway decent electric will smoke them :rasta:


Mile Marker is, as far as i can tell, the ONLY hydraulic winch company that is making a 2 speed winch and the only ones who advertise their performance at 3.5 gpm flow to give real world expectations. :beer: to them. 17.9 cu in is the motor size for the unit i've got

HW MM 12k.png



The Warn hydraulic winches use a smaller displacement motor, such as 4.9 or 4.6 cubic inch, and a higher ratio ~36:1 to get their performance numbers. also note, they show 10 and 15 gpm line speeds

HW warn 12k perfm.png


ramsey hydraulics uses a larger motor and 5:1 ratio similar to Mile Marker, but with a 24 Cu In motor, but they list their speeds at 15 gpm.

hw ramsey 12k.png



What kind of nonsense can we draw from this mess of information?

Well, the Mile Marker in LOW, being the same gearing and slightly smaller pump than the ramsey should pull similar enough to guestimate. not bad for full load performance.

If 3.5 gpm gets 5.6 Feet per Minute (which is rather slow) and 25 FPM at 15 gpm, then our unloaded (milemarker says under 2500lbs in high) line speed should go from 31 fpm to ~130 fpm on the first wrap. that's damned fast, for a winch anyways :rasta:

hw ramsey 12k.png
 
:eek: Wow. Bringing the tech for sure!

I like the hydraulic winch idea, but haven't really gone beyond "You know, a Milemarker with one of those Scott's pumps would be nice..." :laughing:

Subscribed!
 
And that point, the only what's next is running a the whole she-bop through a filter that has the attribute "efficiency beta 1000" of 22 micron or better. or so :rasta: something like a donaldson P162766 is a little spin on filter that is 23 micron...close enough

Buy Donaldson Filters | Official Donaldson Cross Reference and Ecommerce System

there are a great many variety of filter heads that screw on, as long as it has a bypass provision then it can't really be complained about. it is more important to keep the fluid moving.

adding a cooler is always nice, from the calculator up above, 15 gpm at 1800 psi, which can be considered my "max" flow, will require just shy of 16 horsepower. If i run a cooler in the 12-18 HP dissipation range, should be just fine. probably better to run more rather than less. grainger shows a 16x14" air cooler with SAE#12 fittings as a "18 HP" removed cooler. well plenty.

after filter/cooler comes reservoir, and despite the best efforts of real professionals to make nice units, the odds are very good that i'm going to end up with some strange shape and go with a larger capacity unit and put a few screen grids inside to help force out the air, because of space restrictions.
 
alright, well that is basically the tour of the system in my mind. I'm going to try and put a bunch of formula and basic stuff in this post so that i can keep them all together. These are things i reference because i'm not smart enough to measure them or perform trig in my head :flipoff2:

Hose sizing considerations. Hoses are sized based on velocity, sometimes you can enlarge the size in a thing, such as bigger pump inlet, and sometimes you can just reduce them for ease, such as the 7/8" hole in my steering valve, which will get a 1/2" hose shoved into it.

Handy pocket chart for figuring ideal hose size, and then adjusting from their based on space and components

hose velocity is found by v=(0.3208*gpm)/hose cross section

common hose cross sections: 1-1/4” hose CS = 1.226 1” CS = .785 ¾” CS = .4416 5/8” CS = .306 ½” CS = .196 3/8” CS = .110 3/16 CS = .076 ¼” CS = .049

Most fluid power handbooks recommend rule of thumb line velocities in Feet Per Second (FPS). Pressure Lines 20-25 FPS Return Lines 10-15 FPS Suction Lines 2-4 FPS

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calculating HP for pressure and flow

Hydraulic Horsepower Calculator (calcunation.com)

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GPM through orifice @ whatever pressure, orifice with no depth

TR-G93-01.pdf (munciepower.com)

muncie power link, if you want to learn more about anything related to mobile hydraulics

calculating internal displacement of a gear or vane pump

Cubic Displacement Calculator - Metaris Hydraulics

Formula for Vane Pumps: CIR = 12*W*(L+D)/4*(L-D)/2

in case you want to scab a pump from a junkyard and figure out generally what the displacement is, so you know how much you need to underdrive it, so you can determine how much to drill out the orifice, so that you can match up to the rest of your system.

CBR Steering Pumps - OEM Applications? - irate4x4

a whole bunch more information on messing with "stock" pumps for flow and such in that thread

Calculating "turns lock to lock" or "turns per degree of steering" is pretty straightforward.

Volume of Cylinder / displacement volume of steering valve = Turns

1 cubic inch = 16.38 cubic centimeters

converting pump flow into gallons per minute is also straightforward

cubic inch displacement of pump * revolutions per minute / 231 = GPM flow

1 gallon = 231 cubic inches (close enough)



edit: this is a cool chart, another "use a straight edge" to estimate maybe close enough pressure drop and flow through a hole

Fluid Power Data.qxd (hyvair.com)

hydro press drop chart.png
 
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:eek: Wow. Bringing the tech for sure!

I like the hydraulic winch idea, but haven't really gone beyond "You know, a Milemarker with one of those Scott's pumps would be nice..." :laughing:

Subscribed!

I wonder if Scotts Custom Off Road - SCOR High Performance Steering Products would hook up a 12v clutch to one of his pump setups and ship it out as part of the kit? it'd make for a nice unit

thanks :laughing: trying to condense a 100 page thread down to a few posts and otherwise get the pertinent information took a while. I'm sure i left out a ton of nuggets of information in all the sidetracked stream of consciousness expressed over there.

biggest thing is, be mindful of how much approximate fluid you are trying to circulate, control it a bit, use pressure relief valves for safety, use large enough fluid lines to avoid starving stuff, use enough fluid or cooler so that it doesn't get heat soaked


edit:

I should toss this in here as well, this is my generally close-ish price list. it isn't cheap, could be a bit cheaper in some areas, could be a helluva lot more in others. obviously if i just wanted to do a standard open center full hydro setup, it could be done for way less. but to get the same performance out of an electric winch would be much more expensive and i'd have to deal with manual brakes, which suck even when good :flipoff2:

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Alright, This was an interesting post near the end of the other thread. It is basically the "what if i wanted a simple circuit just for steering?" and thoughts behind it. again with the goal being to have enough flow to make the steering valve happy, keeping it as consistent as possible to have consistent steering, sending the excess fluid to a cooler/reserve with the hopes of not adding any extra pressure as wasted energy



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#1) fixed displacement pump of your choice, this depends on what size steering unit you choose. for simplicity sake, let's just assume it will be crank driven at a 1:1, so math output from shaft speed of about 800 rpm -5500 rpm. this is where the Scotts Custom Off Road mounts come in handy as he has the snout support bearing and various pulley sizes and locations already worked out

#2) Priority Flow Control Valve with Pressure Relief. Based on the Prince Hydraulics RDRS-150-16 (0-16 gpm) and RDRS-175-30 (0-30 gpm). these are ~$125 on amazon. These will allow the priority flow tobe set to whatever GPM your steering valve requires and allow the rest to go down the extra flow path. With the internal and adjustable pressure relief, even if something becomes damaged or blocked in the steering valve, this will provide a system relief. You want the EF line to be, essentially, as large a diamter as can fit (at least the diameter of your outlet) and as straight a shot as possible. This is what will keep your neutral pressure down, as you won't be attempting to send full volume of fluid through the steering valve #

3) Open center steering valve. Pulling some numbers from Midwest Steeering, a 9.67 cu in valve wants 4.2 GPM and a 24.17 cu in valve wants 10.6 gpm. so size the pump based on how resonably quickly and closely you can get to these numbers. Some variation is fine, that just means your steering will be a little bit slower. so if you are putting out 3 gpm at idle and hit 4gpm at 1500 rpm, you just might not even notice. bypass everything else. these will be sized on steering preference and cylinder volume just like normal. difficult thing is trying to get the GPM requirement from the MFG without a few phone calls.

#4) steering cylinder or cylinders, size and volume to determine steering valve to determine flow division to determine pump size

#5) Filter with 2 in and 1 out or a simple spin on filter, but with a Y style connector. the goal is to get as low crossover as possible between the two return lines. any extra pressure added to the return is just going to hurt efficiency. something like a donaldson SP15

#6) reservoir, a gallon or better is going to give enough that it should be good. small cooler optional edit: What is the good thing about adding the flow control valve? not just the pressure relief, but the PSI drop.

Let's go ahead and say that we are running an open center steering valve requesting 4.5 gpm (the 9cu in midwest valve) danfoss OSPD is going to be similar, so let's use that chart posted above. It shows the Neutral pressure drop around 100 psi for 4.5 gpm (eyeballing it). i'm not sure what the pressure drop will be for the RDRS vavle, but because it is a pretty straight shot and compensated against the controlled flow side, it shouldn't be much more. let's say out filter wants 25 psi pressure drop. so the Controlled Flow side will want 125 psi, fitting and such will add some resistance, but the Excess Flow line shouldn't be any higher restriction than the Controlled Flow side

let's say we are using a 0.83 cu in gear pump. .83*5500=4565 cu in is 19 gallons at max output. 19 gallons at 150psi (125+a few for whatnot) calculates to 1.663 HP. if we didn't have the priority flow valve, 19 gpm is about 275 psi through our steering valve. this is pretty close to the verified real world claims of 15 gpm resulting in 300psi neutral, that calculates to 3.048 hp.

doesn't seem like much. this is where the weight to hp link comes in to play :rasta: let's say our car weighs 4400 lbs and makes 350 hp. gives a weight to power ratio of 12.57 if that is our 'no bypass' power, then saving 1.5 hp gives 4400lb/351.5 is 12.51 still no difference right?

Well, if we take out same 350 HP and want a 12.51 WPR, we would need to drop weight to 4378 lbs. Adding a small valve and a few lines can result in the same sort of efficiency gains as removing over 20 lbs :rasta: beats the hell out of adding an "air swirler" into your intake :flipoff2: Internally regulated pumps, like the common style options or the trophy truck versions, are essentially doing the same thing, except that by keeping the fluid inside the pump, it doesn't get the chance to cool as it goes through the system or get filtered. The tradeoff is that the lower fluid circulation volume means smaller suction hose and fewer parts.

EDIT: Throwing this information in here as an edit and concerning ITEM #2 Priority Flow Valve...https://www.sunhydraulics.com/model/YREM Sun Hydraulics offers a few variations of Priority Valves that are slightly more complicated than the Prince Valve part number that is shown above.

These Sun Hyd units are likely much more close to the style that ZAG added and offer some potentially worthwhile improvements, considering the price is likely still reasonable. Quote: Customer must specify a flow rating. Factory set flow ratings are within +/- 10% of the requested setting. The tuneable control option provides +/- 25% variation from the nominal factory pre-set flow. Turn the adjustment clockwise to increase.

Bypass flow is not available until priority flow requirements are satisfied. instead of the more basic % diverters, which i'm concerned the RDRS Prince may be, the Sun YREM (for example) will satisfy Priority Flow to a set rate of GPM, instead of 20% of output. If your Steering Valve wants 7 GPM for happy access to flow at all maneuvering speeds, order from the factory at 7 gpm, all flow from the pump will be Priority Flow until 7 gpm are satisfied, and all remaining flow will be diverted.

If you have no additional restrictions, this means that your total system pressure should not ever be more than the neutral pressure going through your steering valve or the amount that the steering requires. By limiting the flow going through the steering valve at Neutral, you can be assured that you are not generating the waste that forcing higher flows than required does generate.




can this compete at all with a standard "psc full hydro kit" ? I dunno, probably all about the same price once all said and done. biggest thing, in my opinion, is matching your cylinder volume to your steering valve volume, and then making sure that your steering valve housing is sized properly for your pump. with all the stock and aftermarket pumps that are available, finding a steering valve that will be happy with your flow shouldn't be much of a problem.
 
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interesting reading...if you need a another MM 10.5 hydro, im using one as a doorstop. Slow as fuck (ran a dedicated pump, 1500psi, 4.0gpm) and if the truck stalls...
 
interesting reading...if you need a another MM 10.5 hydro, im using one as a doorstop. Slow as fuck (ran a dedicated pump, 1500psi, 4.0gpm) and if the truck stalls...

it's like a puppy, yes i want it, no i don't have a use for it or space to give it a good home :laughing:


edit: as for the "if the truck stalls" yeah i know there is that. an an electric winch can run for a few minutes before it destroys the battery, which might be enough to get whatever done that needs to be done. I would *like* to toss a set of quick disconnects on the winch lines, and then i could hook it up to a hand pump. slow? you wanna talk about slow? :laughing: now that would be slow! Tradeoff, i could pump a handle for 12 hours straight and eventually get out of a 10' long mud hole without causing any further damage to anything
 
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i could hook it up to a hand pump. slow? you wanna talk about slow? :laughing: now that would be slow! Tradeoff, i could pump a handle for 12 hours straight and eventually get out of a 10' long mud hole without causing any further damage to anything

:lmao: I had never thought of that! Now I'm picturing some guy trying to keep his electric winch going without the engine!

IMG_4955.jpg
 
a hydraulic winch has some big advantages, but they come with big tradeoffs as well. as somebody who is running a long wheelbase for tire for belly, something like 122"x37"x 18", i hope that the advantages work in my favor for hydro.


edit: another note of comparison

Warn ZEON 10 Platinum

Load (lbs) Line Speed (FPS)
0 44
2000 18
4000 12
6000 10


New Warn 8274

0 88
2000 21
4000 10.6
6000 11.9

as far as electrics go, a gigglepin GP100 will probably kick ass, but a 15 gpm milemarker *should* beat everything else, and be easier on the whole system in the event 6 rigs need to winch straight up a waterfall :rasta:

Gigglepin GP100 TwinMotor Competition Winch (gigglepin4x4.net)
 
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Yeah there a ways to increase efficiency....good info
 
My favorite part is the clutch driven pump for high speed lock out.
You have a lot going on and it brings flash backs to the endless work on my old buggy. Try to keep it simple if at all possible and have a plan for if a part fails. Good luck!
 
My favorite part is the clutch driven pump for high speed lock out.
You have a lot going on and it brings flash backs to the endless work on my old buggy. Try to keep it simple if at all possible and have a plan for if a part fails. Good luck!

yeah, i don't have a good solution for that :laughing:

in my head "damn, i really don't want to just start slamming a high volume pump on and off while at idle" on the other hand, fuck it, A/C compressors spin in neutral at those RPM's all day long :laughing:

cruising car-part and looking at the front of my rig...hmm...i could fit 3 P-pumps on there at 5 gpm each, put 2 of them on clutches and ease in to it a bit more :smokin:

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1 pump with 1 clutch and 1 set of lines for only ~$200 more than 2 clutches and 2 junkyard pumps + extra idler doesn't seem like too bad of a deal.

the permco 520226 CLAIMS it is designed around 120 lb-ft, 1800psi at 10gpm would be ~10.5 hp, at ~1500 rpm would be 36 lb ft, so IN THEORY it should survive :laughing:

520226 6 groove serpentine Clutch 120 lb.ft. | Permco Pumps

i'm certainly still open to ideas if you have any. my last rig was easy and simple stuff, so i'm trying to do more experimental things this go 'round.


edit: well dang, I can get a new A/C compressor with clutch for $130 or apparently the junkyard will sell them for <$50
Torque Transmission Capacity of Car Air Con Pump Electromagnetic Clutch (practicalmachinist.com)

according to some random person on the internet, they hold up just fine to 5 gpm at 1800 psi with engagement at over 4k rpm. so, should be fine. well, certainly $50 fine

p-1091-we.ashx (warnerelectric.com)

link to everything there is to know about 12v clutches
 
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This might be a bit cleaner diagram for a simple circuit. i sent off an email to see if i can get actual price quotes for the Eaton LS valves

hydraulic circuit simple eaton LS.png


1) 1.52 cu in Dynamic GPF2025PC Hydraulic Pump ITEM NUMBER: 9-7794-BPRICE: $125.50 from surplus center, Summit sells a keyway pulley for $70 that is 5.9" diameter. Stock LS crank pulley is ~7.75" diameter. gives us about a 25% overdrive at the pump. 600 engine idle rpm/0.76 overdrive = 790 shaft rpm*1.52/231 = 5.19. So we'd be about 4.5--5 gpm at idle. if we go up to a 1.83 cu in pump, we'd be about 5.5-6.3 gpm.

2) eaton prfd-16-u-a-12t-065-00. this is the part number for their priority dynamic load sense compensated adjustable valve, for 8gpm with 1800 psi pressure relief, 65 psi standby


Flow controls section H screw-in cartridge valves (SiCV) catalog (eaton.com) page 54 of that link

hydraulic circuit simple eaton pfrd pg1.png

hydraulic circuit simple eaton pfrd pg2.png


3) Char-Lynn
200-0803-002
Steering Systems - Series 10
M/C: ADRA21A54AEA00111900AACAA3AAA10B

14.1 cu in disp load sense, non-reactive steering valve.

apparently the reason everybody uses the series 10 is because the series 5 maxes out with a 8.9 cu in displacement valve.

4) Trail Gear dual ended cylinder with 2.5" O/D body and 1-3/8" shaft, displacement of 3.42 cubic inch per inch, nets 27.36 cu in per 8" travel. puts it just under 2 turns lock/lock with the 14.1 cu in valve above

5) reservoir with 2 in and 1 out.



this handles pressure relief and flow control, this does everything that the internally regulated pumps do, but on the outside. note the much larger lines required to circulate the fluid, but it lets you use the cheap and common gear pumps and have plenty of fluid to not have to complain about slow steering, and it will also generate bookoo pressure. obviously the gear pumps aren't "intended" for side loading, so build your mount with an intermediate shaft to take the side load off, or toss a spare pump in the trailer for when it starts leaking out of the front bushing....eventually.


But is it really cheaper?

1) 1.57 or 1.83 cubic inch gear pumps are available as cheapos from surplus center for $125 or $210 for less aluminum (under 2k psi, aluminum shouldn't be a problem) pulley is another $70
2) i'll update when i get my actual price quote back, but probably $250-300 for the priority valve
3) also, waiting on quote, probably around $1k for a load sense steering vavle
4) trail gear sells this ram with mounts and ends and such for $500
5) just as an example, summit sells the PSC 2 in 1 out reservoir for $200. not sure it will handle the larger line sizes well.

maybe $100 in hoses?

$2,170


PSC currently sells their "trail series full hydro" kit for $2,025, which is similar but with the 9.8 cu in steering valve and their modded p-pump.
 
As you can tell from the other thread I'm not extremely well versed in hydraulics yet so I'm still sponging stuff like this up. Too cool. I didn't know you could create variable displacement orbital/valve systems like outlined at the beginning of this thread that displace more fluid as you turn harder to decrease lock to lock under extreme situations. May be an interesting sensation to get used to, but I could see its purpose.

On this latest simpler system it's cool to see the actual manufacturer chart for that external pressure compensated flow control valve. From reading the top right "operation" blurb though, it sounds like the primary ports 2 and 4 still need external pressure relief protection. I wonder if they have a version of this valve with the integral relief to simplify further and be truly like our steering systems?
 
and since i'm having fun drawing in sketchup for a bit, i figured i'd try my hand at recreating Hydraulic Steering 101 – Radial Dynamics (radial-dynamics.com)

should go without saying, all prices current at time of writing ONLY


hydraulic circuit simple radial dy 1.png


so kind of like this

hydraulic circuit simple radial dy.png


1) CB-X pump 6 gpm internal regulated $480

2) Relief valve (combo unit)

3) PSC Eaton/Char-Lynn 14.1 CU IN Open Center Steering/orbital valve $655

4) sticking with the Trail Gear 2.5"x1.375"x8" cylinder kit $500

5) High flow filter, 23 micron Beta1000, either 12 or 20 or 30 GPM depending on who you ask :flipoff2: $400

6) 3" high flow inline finned cooler $325

7) 3.5" Vortex Reservoir de-aerating pressurized $545

Total $2,905

proven to run upside down while taking heavy abuse.

comparison for finned vs finned coolers heat dissipating capacity

RD_Fun_Tube_CFD_720x.png?v=1585618416.png
 
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As you can tell from the other thread I'm not extremely well versed in hydraulics yet so I'm still sponging stuff like this up. Too cool. I didn't know you could create variable displacement orbital/valve systems like outlined at the beginning of this thread that displace more fluid as you turn harder to decrease lock to lock under extreme situations. May be an interesting sensation to get used to, but I could see its purpose.

On this latest simpler system it's cool to see the actual manufacturer chart for that external pressure compensated flow control valve. From reading the top right "operation" blurb though, it sounds like the primary ports 2 and 4 still need external pressure relief protection. I wonder if they have a version of this valve with the integral relief to simplify further and be truly like our steering systems?

yeah, i'm sure to be super safe and stuff they'd want pressure relief on the controlled flow side, but the steering valve being non-reacting should mean that you will break your knuckle before the system sees enough pressure to damage the valve :laughing:

their concern is specing it out for something that is going to hammer fluid back and forth, that would need it's own relief. this will relieve across at the specified cutoff limit, i think 1800psi is what i picked for my price quote
 
yeah, i'm sure to be super safe and stuff they'd want pressure relief on the controlled flow side, but the steering valve being non-reacting should mean that you will break your knuckle before the system sees enough pressure to damage the valve :laughing:

their concern is specing it out for something that is going to hammer fluid back and forth, that would need it's own relief. this will relieve across at the specified cutoff limit, i think 1800psi is what i picked for my price quote

Haha I wasn't as concerned for the health of the valve, but the safety aspect when that wrist breaker rock sneaks up on ya at 30mph that could spike the system through the roof (and try to break your hands as a bonus lol). I actually thought I had heard of people shearing pump shafts before as well, but I don't know how much merit there is to that in reality
 
Haha I wasn't as concerned for the health of the valve, but the safety aspect when that wrist breaker rock sneaks up on ya at 30mph that could spike the system through the roof (and try to break your hands as a bonus lol). I actually thought I had heard of people shearing pump shafts before as well, but I don't know how much merit there is to that in reality

better not get no wrist breaker rocks with a closed center non-reacting valve :flipoff2: that's their big tradeoff for not having and "self correcting" tracking.

that's when it get's into the question there, how much would you want the system to tolerate? let's say the orbital/steering valve is rated for 4k psi and the cylinder is rated for 3k psi. Do you set a relief valve on those lines for 2800 psi and say "rather than blow out or past the seals on the cylinder, let's relieve" but, hell, then you don't know really what the knuckle or whatever will take on a hit. So if you hit a boulder at 30 mph, do you want the tire to flop around or are you hoping that your tire balls will hold up to the smash and let the tire sidewall try and take it all?


edit: as for shearing pump shafts, absolutely that would be possible. the valves can only react but so fast and i'd wager the internal pressure relief valve is nowhere near as capable of handling the volume of fluid a cylinder could shove back into the system that an external relief valve could handle. you could consider that a safety feature of the way the radial dynamic diagram is setup in post #23 for folks wanting to run load reacting steering valves.

Even if you wanted to run just a modded stock pump and a cheap (or no) cooler, that filter/relief combo would still provide benefit. of course, a big hit to the shaft is still going to whip the steering wheel pretty good, so thumbs out anyways


edit2: just taking on some notes from Danfoss

Oil temperature Oil life will be drastically reduced because of oxidizing if the operating temperature exceeds 60 °C [140°F] for long periods. A rule of thumb is that oil life is halved for each 8 °C [46.4°F] in excess of 80 °C [176°F] . Impurities in the oil, e.g. particles or water, will further reduce its life.

min. rec'd oil temperature 86*F

viscosity rec'd 12-80 mm2/s = ISO 12 to 80, or ISO 15 to 68 to stay within limits oil grade

and this is why crisbee1 recommended previously Mobil DTE 25 with it's fancy pants ISO 46

i've always been kind of curious what "too hot" actually is for hydraulic oil and such, temporary over 140 isn't bad, 180+ is bad, change the oil eventually. makes for a good reason to put a system together and run it for a bit while monitoring the temperature in, say the reservoir, and seeing what it is actually doing.

VISCOSITY CLASSIFICATIONS (premiumgrades.com)

ISO derivations.


OSPB/OSPC/OSPD Open Center and OSPB Closed Center Steering Units Technical Information Manual (danfoss.com)

alright, going to put up some comparisons for some basic stuff again, just to have the notes. the Danfoss OSPC is the steering valve size that is small enough to work with OEM style power steering pumps. Drill out the relief to 5/32" (roughly) and overdrive as needed if slow on idle, should get 4 gpm depending on the displacement of the pump, but that should be enough to function the two small steering valves with consistency below :confused:

Midwest Steering sells the OSPC 100 OR (open center load reacting) for ~$450. P/N 150N1298 - 100cc = 6.10 cu in
Polish company "Perfect Hydraulic" sells OSPC 80 ON (open center non reacting) for ~$150 P/N 150N2150 - 80cc = 4.88 cu in

So obviously then these would be well paired with a smaller cylinder/shorter stroke or what-have you. Nice side effect, smaller valves and smaller flow equal low neutral pressure.


Neutral Pressure Drop - the OSPC is likely comparable to a series 5 eaton

just for reference, the OSPB is a smaller (no feature) unit than the OSPC and the OSPD is a larger (dual meter) unit than the OSPC

Click image for larger version Name:	OSPC Neutral Drop.png Views:	0 Size:	51.6 KB ID:	253043


specs on some various valve options, and hence why 100cc is about max for a "stock modified pump"

Click image for larger version Name:	OSPC specs.png Views:	0 Size:	41.9 KB ID:	253044


Click image for larger version Name:	OSPC specs 2.png Views:	0 Size:	74.4 KB ID:	253045


beware of stupid european only part numbers, not available in the US, hence the polish ebay supplier


and finally, if you are looking to size some of those valves up to various cylinders, here is a slightly modified chart from Trail Gear for reference. The bottom cylinder is a PSC unit

Click image for larger version Name:	hydraulic ram specs.png Views:	0 Size:	57.8 KB ID:	253047



50cc = 3.05 cu in
80cc = 4.88 cu in
100cc = 6.10 cu in
120cc = 7.32 cu in
160cc = 9.76 cu in
200cc = 12.20 cu in
250cc = 15.25 cu in
315cc = 19.22 cu in
400cc = 24.40 cu in
500cc = 30.51 cu in (and wants about 18 GPM to be happy)
 
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well, that above post should have been broken in two :homer:

Basic Hydraulic Formulas | Flodraulic Group

Cylinder Time (secs) = area (in²) x cylinder stroke (ins) x .26 / flow rate (gpm)

Cylinder Flow Rate (gpm) = 12 x 60 x cylinder speed (ft/sec) x area (in²) / 231https://flodraulic.com/formulae/basic-hydraulic-formulas
https://flodraulic.com/formulae/basic-hydraulic-formulas

Hydraulic Cylinder Speed Calculator (baumhydraulics.com)

hand formula above, handy online calculator. why does this matter? Because fuck a flow meter, disconnect your cylinder, even if using just an assist ram, and see how fast it will cycle with no load. then either work the formula backwards or whatever, and you will know what your actual, real world GPM output is after all efficiency loss and everything. how accurately can you time half a second? I dunno :flipoff2: realistically, if you are able to have the cylinder meet or exceed whatever you can actually produce via the steering wheel, then you are likely getting "enough" volume.
 
This was a lot to take in. Very impressive planning. My question is why does the excess flow from the brake priority valve tie into the output of the clutched pump? If that pump (16) is working and the winch loads up, increasing pressure, would that not dam up the EF from (13). wouldn't it make more sense to run EF from (13) to the reservoir and have the winch run off pump 16 independently? Other option is put the 2 check valves on the pump outlets and tie them together, either one or both pumps can run the system, and everything cascades, steering, brakes, winch without restriction.

I may have messed up something in the theory of operation though
 
This was a lot to take in. Very impressive planning. My question is why does the excess flow from the brake priority valve tie into the output of the clutched pump? If that pump (16) is working and the winch loads up, increasing pressure, would that not dam up the EF from (13). wouldn't it make more sense to run EF from (13) to the reservoir and have the winch run off pump 16 independently? Other option is put the 2 check valves on the pump outlets and tie them together, either one or both pumps can run the system, and everything cascades, steering, brakes, winch without restriction.

I may have messed up something in the theory of operation though

EF from the priority valve for the brake booster passes through to then pump fluid to the winch control valve, because the "main line" (EF from the priority valves) is only ~6 GPM from the small constant pump, and i want ~15 gpm so the winch isn't god awful slow, i'm tying the clutched pump there.

this way, i only need to activate the clutch when i want to run the winch, if it happens to fail when i need it most, then i'll still get the slow flow from the regular pump, and i'm not needing to send the full ~15 GPM through all the valves, which was the original plan for 1 big pump. Let's me easily plan on running smaller lines and avoids the extra PSI lost from sending 15 gpm vs 6 grpm through the 2 priority valves

Not shown in that drawing, but yeah i would need to put a pressure relief valve AFTER the check valves and BEFORE the control valve for the winch, and then set that for whatever the relief pressure is for the 6gpm pump. if that is 1800 psi, then so be it. that way, if the winch hits that high of a load, it shouldn't block it and 'hide' that, the whole thing will stop and bypass. that way i could carelessly just disengage the big pump near the end and run the winch all the way in until it hits bypass pressure :laughing: Easier to vent some hydraulic pressure for a moment than it is to run 300 amp load from the battery

Thank you for the feedback :beer: it is a ton and all over the place :rasta:
 
Are there specs on that Scott’s pump somewhere. The link referenced earlier has price only.
 
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