Hydraulic ?s

The Toolman · Jan 7, 2010

My bobcat has fluid tanks on both sides an they both have vents on'em

Caseguytoo · Jan 7, 2010

Tencubed said:
I've been following this thread since it started and found it to be thoughtful and chuck full of good information.

I have one question/comment I'd like to clear up.

As I understand it both uprights will be used for fluid storage. This being the case should not both be vented at their tops or tied together above the fluid level to keep the one from air-locking? Or has that been covered and I missed it?

Mike

You are correct. Either install a tube/brace between the two towers and vent one side or forget the brace and vent both sides. Of course, you need a balancing line that runs from one tower to the other at the bottom of each.

02dmaxx · Jan 7, 2010

Well,picked up my pump today.This thing is going to be a booger to mount.I'm not sure how familiar you all are with narrow fram cubs,but I think my best bet is to mount the pump on the starter/generator side and drive it with the pulley at the back of the engine.Would have to remove the drive shaft to replace the belt,but I don't see any other options.I wonder if that particular pulley can be replaced? It's shy of the recommended 4" suggested by Bob.
Thanks,Bill

TUDOR · Jan 7, 2010

Tencubed said:
I've been following this thread since it started and found it to be thoughtful and chuck full of good information.

I have one question/comment I'd like to clear up.

As I understand it both uprights will be used for fluid storage. This being the case should not both be vented at their tops or tied together above the fluid level to keep the one from air-locking? Or has that been covered and I missed it?

Mike

I only vented the tank supplying the pump. Since the pump is positive displacement, it will move oil as soon as it starts turning and the return goes into the other tank thereby pressurizing it slightly and forcing the cooler oil at the bottom of that post to crossover to the supply tank. I fabbed up baffles in the bottom of both tanks to direct this crossover flow to gain maximum cooling. The crossover hose is 3/4" pressure hose for strength, since it droops below the tractor.

The only issue in 25 years has come from over filling slightly, then oil comes out the vent on the supply tank the next time I use it. Usually about a half a cup, but it does make a mess. My concern with venting both tanks was oil taking longer to transfer than space was available on the return tank to deal with pump output, thus making a mess at startup or throttle increase every time until the oil level was reduced enough to cause a concern about overheating. With small reservoirs that have a capacity of less than half the flow capability of the pump, heat is a real issue and must be addressed in some fashion. This is an inexpensive way of accomplishing that task and causes no other problems. The other way of cooling is the large surface area of tall, small cross section tanks. Every little bit helps, and I didn't know how warm the system would get when I built it. At -25* F, there is no ice or snow on any part of my system by the time I've done the driveway. It's not overheated by any stretch, but it does make heat in two hours of use.

My pump capacity is 8 GPM at full throttle and system capacity is about 11 or 12 quarts, a little light for what I prefer, but acceptable.

Bob :rauch10:

Caseguytoo · Jan 8, 2010

02dmaxx said:
Well,picked up my pump today.This thing is going to be a booger to mount.I'm not sure how familiar you all are with narrow fram cubs,but I think my best bet is to mount the pump on the starter/generator side and drive it with the pulley at the back of the engine.Would have to remove the drive shaft to replace the belt,but I don't see any other options.I wonder if that particular pulley can be replaced? It's shy of the recommended 4" suggested by Bob.
Thanks,Bill

My guess is that pump is directional so take care as to how you mount it or you'll have it spinning in the wrong direction. The drive belt should last for many years if it's correctly aligned and tensioned so taking off the driveshaft to change it isn't much of an issue.

As for the pulley size, both pulleys matter. I hope you understand that the volume of oil you get from a pump is proportional to the speed it rotates. If I were you, I'd want to know the size of the pulley on the crankshaft of the engine this pump came from. At least that would be a starting point. I'd also want to know if it was a gas or diesel engine because max rpm of those engines would also be important. Your Kohler should be governed to run at 3600 RPM max. The rest is math.

Maybe changing the pulley on the rear of the engine would be easier.

02dmaxx · Jan 8, 2010

Caseguytoo said:
My guess is that pump is directional so take care as to how you mount it or you'll have it spinning in the wrong direction. The drive belt should last for many years if it's correctly aligned and tensioned so taking off the driveshaft to change it isn't much of an issue.

As for the pulley size, both pulleys matter. I hope you understand that the volume of oil you get from a pump is proportional to the speed it rotates. If I were you, I'd want to know the size of the pulley on the crankshaft of the engine this pump came from. At least that would be a starting point. I'd also want to know if it was a gas or diesel engine because max rpm of those engines would also be important. Your Kohler should be governed to run at 3600 RPM max. The rest is math.

Maybe changing the pulley on the rear of the engine would be easier.

I'm hoping I can change the engine pulley.I'm not sure if there's anything compatible to the the pulley thats on it now,only bigger.The pump is off an older GM diesel,so RPM shouldn't be a problem.I was hoping someone familiar with a Cub,or kohler for that matter,would chime in.
Bill

Tractor-Holic · Jan 8, 2010

I learned the hard way to be sure the pump can be used with a belt drive,not all can withstand the side loads a belt induces..I had the pump start leaking only an hour or so after using it that way..

I had to make a angle iron bracket "foot" to put a 4 bolt pillow block bearing in front of the pump shaft so that would take the side load and not the bushings in the pump I was using on a log splitter we made..

02dmaxx · Jan 8, 2010

Tractor-Holic said:
I learned the hard way to be sure the pump can be used with a belt drive,not all can withstand the side loads a belt induces..I had the pump start leaking only an hour or so after using it that way..

I had to make a angle iron bracket "foot" to put a 4 bolt pillow block bearing in front of the pump shaft so that would take the side load and not the bushings in the pump I was using on a log splitter we made..

Fortunately,this is a belt drive. Believe me,I'm trying to cover every single detail of this build. To me,It's like a child learning to ride a bike,only I don't want the "band aids and stitches" :i_praying .
Bill

TUDOR · Jan 8, 2010

02dmaxx said:
Well,picked up my pump today.This thing is going to be a booger to mount.I'm not sure how familiar you all are with narrow fram cubs,but I think my best bet is to mount the pump on the starter/generator side and drive it with the pulley at the back of the engine.Would have to remove the drive shaft to replace the belt,but I don't see any other options.I wonder if that particular pulley can be replaced? It's shy of the recommended 4" suggested by Bob.
Thanks,Bill

Bill

Underdriving (smaller drive pulley on the engine) the pump is not a problem. As previously mentioned, this will be a good training pump while you figure out what flow rate you want to end with. Low pump flow can be compensated with more throttle, to its flow control max. This will give you a little more time to find the right size pulley.

As Caseguytoo mentioned, those pumps are directional and pulley size on the engine would be real nice to know for calculating ratios. If you check at the auto recyclers you may be able to find a smaller pulley for that pump off the pump in a car or gas powered truck. Failing that, get another pulley with the same hub and make a new pulley with the second hub. Weld on pulleys are available at TSC, I believe. You will need access to a lathe for this second option.

These pumps flow their max controlled rate by approximately 1500-2000 engine RPM in their original home, which is why you need to know the truck engine's crankshaft pulley diameter. Further increases in flow can be achieved with skyrydr2's modifications and assistance.

Bob :rauch10:

TUDOR · Jan 8, 2010

Caseguytoo said:
Bob,
Suction line filters are a notoriously bad idea..... if that's what you are suggesting here. Perhaps I misread you. A better place for a filter is on the return line just before the oil reaches the reservior.

Caseguytoo

While this may be true with tanks built by experienced welders using migs and tigs or robotic welding machines, this is a home built unit, and as such, there is a remote possibility that welding slag or even bits of weld may have entered the interior through a small crack before that crack was sealed or maybe a blowthrough on that last fitting. There is a 100% chance that scale formed on the interior from the welding process. These small tanks have all kinds of little nooks and crannies for small particles to hide, unlike large square bent or round formed tanks with a minimum of weld that have been acid bathed and steam cleaned to a fair-thee-well.

Metallic particle contamination is not healthy for hydraulic pumps, bearings and seals, and the system must receive clean oil at the pump intake. This can only be guarranteed with a suction filter on a home built unit.

Fortunately, the hydraulic filters most easily obtained have a flow capacity well in excess of the flow rate on most home built systems, like this one. A filter change at 50 hours will take care of most of the contamination and eliminate the potential problem of a collapsed filter. 25 hours would probably be better, and every 200 hours thereafter. Some particles could take several hundred hours of use to dislodge.

Even though my pump is 2' above the reservoir bottom and there is little chance that heavy metal particles would be drawn up the 3/4" intake hose, I chose to be certain that none would make it to the pump. My filter outlet is less than 3" from the pump inlet and never had a problem.

With a factory built and cleaned tank, I agree with you completely.

Bob :rauch10:

TUDOR · Jan 8, 2010

skyrydr2 said:
I can elaborate just a bit more, on your bucket, use 1/8 sheet for the shell, 3/16 is too much, Use "cutting edge material for your front edge ! What is this ? When you go to the steel guy ask him for 1045 steel or x-1050 or T1 this is what the edges are made of in a construction bucket. Also when making your bucket you want to keep your mold board a single piece if possible. You need access to a press break and roll, roll is optional. you can use 3/16 for your mounting brackets with bushings for the pins,and 1/2 or 3/8" for the edge, paying attention to the grain of the steel for this part, and for your mold board you want it the opposite(so when bending it it doesn't stress the joints and crack,
you want it going the long way or the width for the edge .You can put "Side cutting" edges made of x-10 or T-1 3/16 steel (this is what BeBeau uses for their dumpdody floors and sides, lighter and very wear resistant.
I peronally would also add 2 wear strips on the bottom tieing the cutting edge to the mounting brackets and reinforcing the bucket floor. Thesed can be strips of 1/4" plate 2" wide only need 2 but if you want more feel free to add.
When bending the top front lip fold it to a 90 and add a strip to "box" this part in ,and weld it all sides. I don't think you will ever hurt this bucket then, and you can use this part for lifting with out worry of bending it.
Look at the bucket on say a JCB backhoe or any front end loader ,they will give you a better idea than just building a box, and they work much better too.

Keith

Cutting edge material is an unnecessary expense on a 10 hp. tractor that when all is said and done will weigh considerably less than a ton and can put less than 1000 lb. downforce on the cutting edge with a full bucket of wet sand. That's less than 6 PSI on a 44"x4" cutting edge flat on the ground. If I pivot on the ball of my foot while wearing my boots, I exert over 13 PSI on the sole of my boot in contact with the ground with my 215 lb. weight.

If I can't wear out a 4" wide 1/2" thick mild steel cutting edge while moving several hundred yards of granular material over 25 years with my 1655, I don't think Bill will have a problem.

Commercial tractors operate more hours in a month than most GTs operate in a year. The concepts are the same but the design rules are radically different. GTs do not have the weight, the speed or the lift capability to utilize the parameters used to design a bucket for an industrial TLB.

General bucket shape, and lift and tilt geometry are a different story. I followed your advice 25 years ago when I designed my buckets and I definitely agree about reinforcing the top edge. The method of that reinforcement will be governed by the shape of the bucket. The same will hold true for the extra weight of the skids on the bucket bottom. The 47" bucket on my GC2310 doesn't have them and neither does the 54" bucket on my 1655. Two totally different designs.

I guess we should let him get his pump running before we mess with his mind anymore on the bucket. :ROF

Bob :rauch10:

TUDOR · Jan 8, 2010

Caseguytoo said:
It will work even though it's a tad large for the task. You can dial down the relief setting to something more appropriate. To do so, you need to buy a glycerin-filled gauge that reads up to 3000 PSI. Those can be had for less than twenty bucks at many on-line stores such as Northern Tool. If you use the power beyond port for the backhoe, then you must make provision in your loader tower for another return line coming from the backhoe control valve.

However, you have chosen a pump that has low pressure compared to most hydraulic systems used in this application. The second way to increase breakout force is to increase the diameter of the cylinders used for the backhoe's boom, stick and bucket. The problem with going to larger cylinders means the cylinders cost more to buy and they take longer to extend and retract because more fluid is needed due to the increased internal volume of the cylinders. In other words, larger cylinders will slow the speed of your hoe down but make it more powerful.

Like everything else in life, there are trade-offs. Designing a good-working hoe isn't as simple as it sounds. There's a lot of math involved along with a good working knowledge of hydraulics. So, you need to go slow and careful here because everything that you select component-wise will have an effect on the system as a whole. Some people say that copying someone else's design is the most sincere form of flattery but I say that it's just plain smart. If someone else has already designed a backhoe that really performs, then studying what they did can save you a ton of grief and expense down the road.

I second the motion on the guage.

Caseguytoo, MF GC2310 backhoe relief pressures are 2000 +/- 100 PSI, depending on the circuit.

Last paragraph = words to live by.

Bob :rauch10:

skyrydr2 · Jan 8, 2010

Bob, your probably correct on the cutting edge ,but the materials I suggested are for strength as well as wear , we don't want any smiley faces looking at the bucket a few years later. And a 4" wide piece for this little bucket is pretty excessive , 3" wide of 1045 1/2 " material with 3/16 side cutters, this bucket would be a lifer.

In my many years at Wain-Roy I tested and tortured many many a bucket ,as this was my job to do, kinda like that show "Smash Lab" just utter total fun Trying to ruin things to see what they can take and what this little weld does and that little gusset.... I loved and miss that job...
So as for strength and design, they go hand and hand. We built some really nice stuff and ruined even more, the most fun was taking the competitions' buckets and attachments and trashing them for the sake of science :sidelaugh
Did you know that there is fluid dynamics in the design of a bucket! Who would have thought this?? :fing32:

Caseguytoo · Jan 8, 2010

TUDOR said:
Caseguytoo

While this may be true with tanks built by experienced welders using migs and tigs or robotic welding machines, this is a home built unit, and as such, there is a remote possibility that welding slag or even bits of weld may have entered the interior through a small crack before that crack was sealed or maybe a blowthrough on that last fitting. There is a 100% chance that scale formed on the interior from the welding process. These small tanks have all kinds of little nooks and crannies for small particles to hide, unlike large square bent or round formed tanks with a minimum of weld that have been acid bathed and steam cleaned to a fair-thee-well.

Metallic particle contamination is not healthy for hydraulic pumps, bearings and seals, and the system must receive clean oil at the pump intake. This can only be guarranteed with a suction filter on a home built unit.

Fortunately, the hydraulic filters most easily obtained have a flow capacity well in excess of the flow rate on most home built systems, like this one. A filter change at 50 hours will take care of most of the contamination and eliminate the potential problem of a collapsed filter. 25 hours would probably be better, and every 200 hours thereafter. Some particles could take several hundred hours of use to dislodge.

Even though my pump is 2' above the reservoir bottom and there is little chance that heavy metal particles would be drawn up the 3/4" intake hose, I chose to be certain that none would make it to the pump. My filter outlet is less than 3" from the pump inlet and never had a problem.

With a factory built and cleaned tank, I agree with you completely.

Bob :rauch10:

I see your point and agree with it in principle. As you and I both know, the issue here is potential oil starvation for the pump. Anyone putting a filter on the suction side of the pump, must be diligent in their maintenance program to prevent oil starvation from happening. If the filter element ceases to flow the GPM rate that the pump is calling for, cavitation can occur which is deadly for most pumps. I don't know how forgiving vane pumps are to this issue but I suspect that increased wear would result.

Just so the OP understands, there are intake filters or screens available with a much, much higher micron rating than a true filter. Those units are less prone to plugging up and are designed to keep the larger, nasty stuff from ever getting close to reaching the pump. A low micron filter can be installed on the return line to remove the fine particulate that has a tendency to do a slow grind on all other components.

I toss all of this out there because I can see that there is a fair bit of interest in this thread and those who want to learn more about hydraulics should be made aware as to what the options are and the "why" behind them.

skyrydr2 · Jan 8, 2010

I totally agree CGToo and Bob as well. One thing with vein pumps is they don't like to run dry and they have rather poor draw, due to the veins. They like a little "head" pressure(or weight of the oil) on them. This is why they work so well on a car ,they allow you to start the engine and get some rpms up before they go to work.
So try and keep this pump close to the bottom if possible? You at least want some oil above this pump when it is off ,it will always keep it primed.

This is why Fords whine like a little girl when cold or have been starved for oil during their life, poor vein/feed design, you would have thought they would fix this issue ? Well GM pumps work much better so your rig should be fine, does the pump dody have only hose fittings on it ? Or does it have a cap ?

02dmaxx · Jan 8, 2010

skyrydr2 said:
I totally agree CGToo and Bob as well. One thing with vein pumps is they don't like to run dry and they have rather poor draw, due to the veins. They like a little "head" pressure(or weight of the oil) on them. This is why they work so well on a car ,they allow you to start the engine and get some rpms up before they go to work.
So try and keep this pump close to the bottom if possible? You at least want some oil above this pump when it is off ,it will always keep it primed.

This is why Fords whine like a little girl when cold or have been starved for oil during their life, poor vein/feed design, you would have thought they would fix this issue ? Well GM pumps work much better so your rig should be fine, does the pump dody have only hose fittings on it ? Or does it have a cap ?

It has a remote reservoir if thats what your asking.

skyrydr2 · Jan 8, 2010

More or less , that's great ! It will work pefectly.

Caseguytoo · Jan 8, 2010

OK. The pump you bought came with a remote reservoir that I think that you are going to abandon that one. It is fine for a power steering application but not for your FEL/BH plan. What skyrydr2 is suggesting is this.

Use both loader towers as your new reservoir because they will hold much more oil. The towers will also act as a radiator to get rid of excessive heat from the oil and that's important. When building the towers, put the bung that is going to feed the pump a few inches higher than the bottom of the tower. The bung does not have to be higher than the pump inlet because as long as the oil in the tower is substantially higher than the pump inlet, that oil will flow via gravity to the pump.

Pursuant to my previous discussion with tudor, here is what I mean by a suction line filter.

http://tinyurl.com/yc4yhnc

And here is what I mean by a return line filter.

http://tinyurl.com/d2xd3d

If you read the specs, you will see that the suction line filter will take out all contaminants down to 148 microns but the return line filter will only leave particles in the oil that are smaller than 10 microns. The suction filter will protect the pump from junk that will destroy it instantly. The return filter will remove the rest of the junk that will destroy the pump over a much longer timeframe.

02dmaxx · Jan 8, 2010

Would a little vent like the ones used on car/truck rears be sufficient?I figure I could drill and tap one or both of my uprights,and add one or two of those vents.I have enough room under my lift arms to mount them/it up right.
Or,I could attach the remote reservoir to one of the uprights and have a vented fill cap.

02dmaxx · Jan 8, 2010

Caseguytoo said:
OK. The pump you bought came with a remote reservoir that I think that you are going to abandon that one. It is fine for a power steering application but not for your FEL/BH plan. What skyrydr2 is suggesting is this.

Use both loader towers as your new reservoir because they will hold much more oil. The towers will also act as a radiator to get rid of excessive heat from the oil and that's important. When building the towers, put the bung that is going to feed the pump a few inches higher than the bottom of the tower. The bung does not have to be higher than the pump inlet because as long as the oil in the tower is substantially higher than the pump inlet, that oil will flow via gravity to the pump.

Pursuant to my previous discussion with tudor, here is what I mean by a suction line filter.

http://tinyurl.com/yc4yhnc

And here is what I mean by a return line filter.

http://tinyurl.com/d2xd3d

If you read the specs, you will see that the suction line filter will take out all contaminants down to 148 microns but the return line filter will only leave particles in the oil that are smaller than 10 microns. The suction filter will protect the pump from junk that will destroy it instantly. The return filter will remove the rest of the junk that will destroy the pump over a much longer timeframe.

So you suggest using both filters? Can never be too cautious,that I do know.

Hydraulic ?s

The Toolman

Caseguytoo

02dmaxx

TUDOR

Caseguytoo

02dmaxx

Tractor-Holic

02dmaxx

TUDOR

TUDOR

TUDOR

TUDOR

skyrydr2

Caseguytoo

skyrydr2

02dmaxx

skyrydr2

Caseguytoo

02dmaxx

02dmaxx

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