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simplejim

homemade hydralics

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simplejim
heres a silly question. why can't i use a auto power steering pump for a hydro pump? could it run off the same belt as my starter generater? would it have enough power ? has anyone tried this? it just seems like it would be cheap and i like cheap. simplejim

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Dutch
You sure can use a PS pump. It can run it off any belt as long as it turns in the proper direction and has sufficient belt contact (wrap). It should have enough power to operate a lift cylinder on a garden tractor, but would not be able to operate something like a log splitter efficiently. The pump may be cheap (even free), but you'll have the expense of control valves and cylinders. I started a PS pump project at one time. Had it working in the "prototype" stage with 2 manual control valves, but wanted 3 control valves. Decided 3 manual valves would be too cumbersome, so decided to use solenoid valves and a high capacity pump when (if) I resume the project.

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StinKy
I have a project stashed away and it's based on a hydraulic motor. I have been told a motor can pump also (reverse rotation). The motor is off an industrial finishing machine and is small enough to fit nicely in the original pump space on the old A/C's & Simplicitys. It will need a separate reservoir and that will require some extra engineering. I dont know enough about hydraulics to run the lines and valving so will need to get advice from a couple local fellows who do. Dick

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Stoneheartfarm
Hey, if you get this PS pump thing working let me know. I sure would like to add hydro lift to my B210. No more horsing the plow and mower deck up. Not sure where I'd put the pump since I don't think I have the pump space you guys are talking about. Mine's been re-engined with a Tecumseh OH160. SHF

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HubbardRA
I have mentioned it before in some previous discussions, that a friend of mine has built hydraulics for two tractors based on a power steering pump. a power steering pump normally has a built in pressure regulator set at 1500 psi. If needed theis can be changed or completely defeated, since it is usually a ball and spring. My friend eliminates the bypass on his designs, but says that if you deadhead a cylinder you will kill your engine instantly. When designing you own system, remember that the force produced by the cylinder is the pressure in pounds per square inches multiplied by the square inches of the piston. If you want to work with a smaller pressure you will need a larger piston in the cylinder. A power steering pump flows a relatively small volume of fluid, but should be adequate for garden tractor applications. Just remember to remove the factory reservoir and replace with a larger tank. The tank must have sufficient volume to handle the difference in the cylinders when extended and retracted, handle hose volume fluctuations, and some excess fluid to prevent foaming. If the unit starts whining after being run for a short time, this means the fluid is foaming and air bubbles are flowing through the pump. More reservoir is required in this case so that the air can escape from the fluid before it is returned to the pump. Rod H.

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djarvis949
As recall, about 30 years ago , Dodge had a pickup called a 'SNOWFIGHTER', 4x4 with a slant 6 and a 'Meyers' plow that used a 'Sawinaw'(GM) PS pump to operate the plow. It might be worth looking into just to see how they did it. Don

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jlasater
The old Windolph crawler I have has been retrofitted with a power steering pump of unknown make/vintage. It appeared to work too well as the hydraulic cylinder is blow. The cylinder looks identical to large air cylinders and I don't think it was designed for this kind of use, but I could be wrong. Picture of it at http://www.wheatfarm.com/crawler/image6.jpg

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RandyM
If you want to simplify the design a little, you could go to a hand hydraulic pump provided you don't mind a little excercise. I saw a rig like that on a full sized tractor that lifted a small bulldozer blade. I think it would be practical on a garden tractor where you do not need the volume of fluid that a big cylinder would take.

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thedaddycat
I have talked to folks here at work who tell me a hand grease gun can put out up to 10,000 psi. I know that one time when I was greasing the throttle rack on one of our turbines I came across a nipple that had the grease hardened and it would not take any grease. I put the grease gun between my knees and used my legs to try getting it to go. When the hose on the gun blew out the grease hit the control room window about 15 feet away! The operating mechanism on a hydraulic jack is very similar to a grease gun, and they can generate many tons of force.

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powermax_paul
A hydraulic gear motor can be used as a pump also. As far as power steering pumps are concerned, IMHO you'll save half the cost of the cylinder if you just buy a cheap hydraulic gear pump from Northern or Baileynet.com. If you use a gear pump at higher pressure you can use a smaller cylinder. Just make sure the pump input bearings can handle the side loading of a belt drive. Paul

Paul Kjorlie, The Norwegian

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dirtsaver
Jim if you can find an old oil furnacetake the pump off it to use. The Sunstrand mini pump, I think it is model A, works great and has the high pressure adjustment inside. just find a hi-pressure tank and controls and set it up. This pump is not much biggerthan a coffee cup and has flange mtg holes so you can make a bracket to fit about anywhere Larry

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DDB
Simplejim, I have seen this questions asked many times. Many people have said they know of someone who has done it or think it can be done, but I have never seen a good how to (what pump/cylinder(s)/hose and tank size/math etc.) article on how it was done. Myself I have looked at this subject but because at this time I do not need a hydraulic system, I never followed it to the end. This is my two cents worth: 1) HubbardRA gave you some good advice, and he was right by saying you would need a bigger tank, since most older "Power Stearing" (PS) come with the tank as part of the pump here's two ideal's on the subject: a) This would be the cheepest: I had a 83 Chevy Suburban with a 6.2L diesel. The PS pump not only did the stearing but also the brakes as well (diesels do no have vacuum for power assist). To increass the volume of fluid they mounted a second tank above the standard PS pump connected by a rubber hose (Just remove the PS cap and find a hose that will fit over the OD of the pump) go find a GM manual to see this system. This ideal should work for any of the old time pumps with the tanks attached to the pump (Note: I have not done it myself but it seem simple enough). b) I work for a OME supplier that have engine dyno's. Since when you test an engine on a dyno you do not want any of the asseriesy (Alt, PS, AC) on the engine I got a PS pump from a Chrysler 3.5L motor. As you may know the cars of today with constant engineering have found a way to pack 10 pounds in a 5 pound bag. The PS pump on a 3.5L is a pump only with the tank mounted somewhere else in the engine bay. I have a Chrysler pump but I would also look at GM and Ford to see what they have. 2) This is problely the best advice any one can give you, "If you want to play with hydraulic's you must learn for your self how it is done". If I said to us a 1/4" ID hose on your project and the hose blows in your face because it was to small you will get heart, not me. I would and have gotten the 4 book book Hydraulic study course from "Surplus Center" 1-800-488-3407. They also have lots of hydraulic parts for sale. I hope my two cents were worth the read. Good luck and let us know how your project worked out and why not wright an article on how you did it. Dave

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HubbardRA
Hey Guys, I was not talking about a grease gun pump to operate a complete fronet end loader. It was only an answer to the hand pump suggestion. Hydraulics is relatively simple, but sizing is important. I have a hydraulic system for tilting my trailer that uses two bottle jacks one was made into a pump only and the other was converted to cylinder only, so the cylinder coulg go underneath and the pump on the trailer tongue with an external reservoir. When Paul suggested increasing the pressure so that a smaller cylinder could be used, you must keep in mind that the higher pressure the pump is putting out, the more load on the motor. If you have a 8-10Hp engine you will want a lower pressure pump and a larger cylinder that you would use if you have a 16-20Hp engine. My friend who has built two tractors with hydraulics told me that a power steering pump will require 16-18Hp to drive it if smaller cylinders are used. Remember that the pressure in the system is relative to the load being lifted and the size of cylinder doing the lifting. A power steering pump has a built in 1500 psi bypass. He has defeated the bypass on his tractors, and if he stalls the system on a heavy load it will instantly kill his engine. One thing about hydraulics, if the sizing is going to be trial and error - then have plenty of money on hand because hydraulic parts are not cheap if you are buying them new. Remember that pump pressure and volume, cylinder size, hose size, leverage on the mechanical parts, load being lifted, and engine size all play a part in the design. If you can't calculate the sizes, then start with something that is known to work with small horsepowers - a power steering pump. Rod H.

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Kent
I'm a bit confused here with people being so concerned about the cost of the hydraulic pump. The factory L-12 loader used a 1.5GPM at 2000 RPM, and 1500PSI (L-10 was 1250 PSI). Northern Tool has a pretty wide selection of pumps in the $100 to $200 range that will exceed those specs. Compared to the cost of the lift cylinders (especially if you use dual action cylinders), the lines, filters, etc., this price doesn't seem out of line to me -- when you'd be getting a new part that you could match the specs to your specific needs. Here's their selection: http://www.northerntool.com/cgi-bin/ncommerce3/ExecMacro/NTE_search.d2w/report?cgmenbr=6970&cgrfnbr=&KEYWORDS=hydraulic+pump&PHOTOS=on&START_ROW_NO=1&TOTAL_ROWS_FOUND=16&PAGECOUNT=1 Personally, I'd look at a 2-stage pump designed for use on small engines. This page doesn't show max pressure (only flow) but their printed catalog does, unless I'm mistaken: http://www.northerntool.com/cgi-bin/ncommerce3/ExecMacro/NTE_LLSEARCH.d2w/report?PHOTOS=on&prlngth=1012.0000 I realize that part of the "fun" is in making something work -- but if I were going to spend the time and money to build one of these, I'd want to have a pretty high confidence level that it WOULD work.... My 2 cents. The foot-draggin' Clubhouse Custodian...

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Dutch
Kent, You're right...... "Fun" aside, unless one has access to ALL components needed for free or cheap, the pump should be the least concern. Why go through all the engineering for very limited results? That's why I abandoned the PS pump project I was working on. I'm surprised no one has linked to Karl Brandt's hydro lift page. Karl started with a hydraulic tractor, and added cylinders and valves. (very nice job too) http://www.simplicityva.com/winter/hydraulic.html If I go to the time and expense of adding hydraulics to a non-hydro tractor, I'll use a pump that is capable of powering more than a couple of small cylinders (like a log splitter, dump trailer, or auger).

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HubbardRA
Kent, Dutch, You guy seem to be referring to my comments. The bigger the pump is, the more horsepower required to drive it. The larger the cylinders are, the less power to drive them, but the slower the response. The only point I am trying to make when people talk about pumps is that you have to start the design with the engine that is on the tractor. A B-1 will not drive the same pump that a 9020 will. It is just engineering, no magic. I don't care what type of pump someone uses. There is no single answer to any of these questions. It all depends on the application and usage. Rod H.

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Kent
Rod, I wasn't referring to your comments specifically -- the whole discussion started with the idea of using power steering pumps to power loaders. My point was that the cost of the pump is small in comparison to the cost of all the other hydraulic components required -- plus I recommended that they look at two stage pumps specifically designed for small engines and lower RPM than an automotive power steering pumps.... You could spend almost as much for a power steering pump (new or used) as you'd spend for a new hydraulic pump made for the purposes in mind... Bottom Line: I wasn't shooting at anyone -- only offering my opinion.... The foot-draggin' Clubhouse Custodian...

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PatRarick
I would have to agree that the best way to go is with a gear type hydraulic pump. As to whether a power steering pump can handle the load, I would also say yes. Several years ago, there was an aritcle in Popular Mechanics magazine on constructing a hoist for the box on 1/2 ton through 1 ton pickups. The hoist was powered by the existing power steering pump. A two gallon resorvoir was built and mounted on the fender well above the level of the pump. A 1" steel hose barb was brazed to the top of the pump in place of the cap, and the reservoir was connected with a hose. A flow divider was installed in the output line of the pump to divide the flow between the steering and the hoist. The thing is, that the pump was already there. Pat

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HubbardRA
Kent, Everyone seems to be missing the point that I was trying to make. A power steering pump is already set up for belt drive, and it is pretty close to optimum for garden tractor size engines. Most of the American cars usep pumps set for a bypass at 1500 psi, which can easily be changed to increase the pressure. With bypass modifications, a power steering pump will pump a sufficient amount to kill an 18 Hp engine. I've seen it. My points: 1. They're everywhere! (I've got three laying in my garage) 2. They are the right volume for small garden tractor engines. 3. They are already set up for mounting and belt drive. 4. They will do the job. Everyone seems to be worrying about pump volume and speed of operation. You can get hydraulics too fast. My father-in-law used a pump from a piece of mining equipment to build hydraulics for an Economy tractor. The system was so fast that it was uncontrollable. The instant that you touched the lever, the mower deck would slam into the bottom of the tractor or be driven into the ground. It broke numerous parts and eventually blew the valve body apart. Also one needs to know whether he is going to be using a closed center or open center valving system. Closed center units are quick responding and multiple cydinders can be activated simultaneously. Closed center requires a large pump and a larger engine to drive it, since it operates at full volume and full pressure all of the time. This is what large construction equipment uses. These closed center systems require cooling of the fluids due to the friction from the high flow volumes. They also require large fluid tanks to allow air to escape and prevent bubbles from being cycled back through the pump. Open center systems pump fluid, but build no pressure until a valve is opened, and the pressure only builds to the amount necessary to move the load. they run cooler, and require less engine horsepower to drive the pumps. Only drawback is that they do not effectively drive multiple hydraulic circuits at the same time. Open center is plumbed in series where if you open the first valve, none will be able to flow to the secone, etc. Closed center is plumbed in parallel and all circuits can be active at the same time. Most small equipment uses open center hydraulics. Rod H.

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powermax_paul
Rod, I guess I misunderstood your reply. I thought that you were saying that a high pressure pump would take more HP than a low pressure pump to do the same job in the same amount of time. That is wrong. HP requirement is a function of both flow and pressure. I think we're talking similar pressures cuz I think 1200 to 1800 psi is probably about the right pressure for GT hydraulics. (I thought PS pumps ran much lower like 500 - 600 PSI) Anyway, with the compact design of something like a Barnes gear pump is quite suitable and easy to mount on a GT. They're also pretty cheap, say $85.00. Unless there's a very special application, I think any hydraulic system on a Garden Tractor should be Open Center. To choose a pump/cylinder combination, you first have to look at the force required to move the load. Then you have to choose a pressure and a cylinder diameter that will give that force. For Example: 2" cyl = PI x 1" SQD = 3.14 square inches. 1500psi x 3.14 sq in. = 4712 Pounds of force from the cylinder. If you have to move that load 4 inches in 10 seconds, then you need a volume of oil: 3.14 sq in x 4 in = 12.6 cubic inches in 10 seconds or 75.6 cu-in per minute. 75.6 divided by 231 = .33 gallons per minute. So you need a pump that puts out .33 GPM at 1500 psi. .33GPM x 1500psi divided by 1714 = .29 HP or roughly 1/3 HP. The smallest Barnes pump puts out .5 GPM at 1800 rpm so you want to run it at (.33 divided by .5) X 1800 = 1188 RPM So you'll have to get pulleys that will run the pump at about 1200 rpm at normal engine speed. The moral is that the load that needs to be moved and the amount of time you want that load moved in determines the HP.

Paul Kjorlie, The Norwegian

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