Grapple Bucket.

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Well, from one of my more recent posts, it was brought up that one of our fellow members would like some high-resolution pictures of my biggest project to date.6011, 6013, and 7018AC were used, all 1/8" rods. material used is 3/8" plate and 2"x2"x1/4" square tube. all joints were beveled and pre-heated, except a couple. the few that were not beveled were still pre-heated and we welded with a nice hot arc. I do not think they will be going anywhere, any time soon.The farmer supplied me with his bucket (obviously pretty bad shape) and the piston. Other than that, he said he wanted a 3-armed grapple that he could remove later if he wanted to. he didn't care if it was bolted or welded. he just wanted it strong enough to move brush piles and a bale of hay or two if need be. He also wanted the entire back cleaned off so that he could attach a quick-attach plate to the back. here's what I have done:the original bucket was in pretty rough shape. the upper lip was completely bent over. the bucket is made from varying thicknesses of 3/16" and 1/4" steel, and the edges are all reinforced with a second layer of 1/4". the bottom leading edge is about 1/2" thick if I had to guess. it is obviously worn away pretty bad (as seen in other pictures) and was hard to measure accurately. I thought I had pictures of it, but I guess not. I'll see if I can find them later.The upper lip was 1/4", and all the stuff on the back was 1/4" as well. it all got torched off with the O/A torch.I added a new upper lip (3/8" x 2" x 73") and 15 gussets to the back. the gussets are 3/8" x 2" x 6". there were no gussets on the back of the oiginal bucket, do I think this should hold  up quite a bit better.here is the final product in the closed position. quick note: all the tubes are boxed in and the pivot points are sleeved. TIG welded on the outside to keep it flush, and sticker welded on the inside. I don't think the sleeves will be breaking.:Open:Here you can see just how badly the top was bowed in. thus, the need for a new, stronger, flat back to weld the pivot mounts to.as you can see, there is still a ways to go with the piston, so it should open up some more. This was as far as I could open it with the engine hoist without picking up the bucket, so this is obviously as far as I went with it.Still another 3" or so of travel in the piston. The farmer told me it was an 8" piston, but before I started anything, I measured 10" of total travel. maybe I measured wrong, maybe he thought wrong. I dunno. All I know is that it works.more on the next thread...
Reply:and some of the welds:these gussets help give some extra strength to the arm joints. I figured that these joints will probably see the more stress on the entire system, especially with the extra leverage from the arms. they are 3/8" x 6" x 6". one of the outter pivot brackets/mounts:the center mount for the pivot of the arms and the piston, along with some of the back gussets:This is just some of the stuff that I hacked off the back fo the bucket with the torch. It doesn;t look like alot since my wife dumped the vacuum canister all over the top, but that trash can probably weighs close to 120-130 lbs right now.and the baby that did all the work. I used my flux-core unit (or "spit gun" as sundown calls it) to help me tack a lot of the parts, but all of the welds are done with the tombstone.:as always, any questions, just ask.Later,Andy
Reply:Nice work Andy, I like the use of the old John Deere Cylinder too.  You don't see to many of those around in my parts anymore.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:that's a JD cylinder? huh... i never knew that. They guy just brought it to me and said "use this one", so I did. he said he had a pile of them laying around his barn, so he just grabbed a common one in case that one broke. If it were me, I'd at least try to replace the hoses. they are pretty beat up. I tried to take them off myself to bleed the cylinder,  but I was bending my wrenches before they ever came loose (Yes, I was turning them the correct way... i double checked the little bit of thread that was sticking out). Instead of busting them loose, I just held in the balls on the check valves on the ends of the hoses. that stuff came out like used motor oil. SUPER dark and thick.Later,Andy
Reply:FOUND 'EM!!! here's the pictures of the bucket before I started:Later,Andy
Reply:Looks good and I'm sure it will serve it's purpose Millermatic 210
Reply:OK,,,,,,,,   andy,,,,  You want some constructive criticism?  not just the "backslapping" "great job" you're getting elsewhere???   From somebody, both as a fabricator, and an operator????First.  The gussets underneath the flat on top.   You can space them however you want, but in any case they should line up directly with each hinge point, and the cylinder mounts.   As built, there is plenty of room for distortion and deflection between the gussets and the actual mounting tabs.Second.   Gussets on the tube 90*s.   You had the right idea, just applied it wrong.   It would've been FAR stronger, to put just two 1/4" gussets, on the OUTSIDE of the tube, at each 90*.  The middle one, where the cylinder is attached, I would've made the cylinder attachment/gusset all one piece, one on each side.Third.   Any cylinder, needs to have FULL extension, and FULL retraction.   2000+ PSI, times whatever the square inches of the barrel, produces HUGE amounts of pressure.   Most welded steel structures can't handle it, even if so,  costs too much to make it that strong.   If, by chance, you can't get full travel both ways, you either put a separate bypass in the lines, right off the cylinder, or you take the cylinder apart, and put spacers in to limit the travel to the extent the fabricated part can travel.  Otherwise, something is either gonna break, or distort, and then break.I would suggest, before this thing leaves your yard, put a two-way pressure relief between the two sides/ports of the cylinder.   Even with excavator thumbs.....   we generally lower the pressure,,,  not because of any engineering defects, just because otherwise, the bucket can rip the thumb mounts right out of the boom.  Set it low, 500 to 1000 psi, you may be ok. I'm not even gonna make any comments on the welds, or the choices of filler metal
Reply:If you notice in the picture with the close up of the excess travel of the cylinder, you will see a collar.  That collar is a "stop" collar designed just for those situations.   Mark8310 is right about the stress you will be inflicting on the parts.  All you need to do is loosen the collar slide it down until it comes in contact with the cylinder base JUST BEFORE it makes 100% movement so that  strain is transfered to the stop collar.  It doesn't look like much...but...boy oh do they work!  Additionally,  Before you deliver it,  The point where the pin goes through the square tubing,  I would have welded a bushing into the tubing for the pin to rotat on and inserted a Zerk fitting.  You can easily get a bushing from a tractor supply place.  Just find a tractor link bushing that fits your pin.  What is that pin? 5/8 or 3/4?  You should find either.Another issue that you will soon find out is the placement of the gussets will interfere with the optimal mounting of the quick attatch plate.  You need to mount a quick attatch plate near the top "brim" of the loader, especially with the rigging on the top, otherwise, it will destroy the bucket when pushing or using the "clam".  In fact,  you may not have enough room below the gussets to mount one correctly...Its hard to tell unless you had your space measurements under the gussets.Otherwise,  it looks like it should do the job.  Every one has a list of things they would do better the next time on the project.  I am sure you have your own...If you don't, you will after it is used a little.Last edited by lugweld; 03-12-2009 at 01:12 PM.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Well, let me address each of these points.#1, thanks for the constructive criticism. I appreciate it. No one gets better with nothing but "great job" and "way to go.#2, yes, the gussets should have been mounted directly under the mounting tabs. however, the outside tabs are going to be plenty strong for what he is using it for. he told me that he wants to just use it for moving downed, dead brush from his tree lines, and maybe (if it's big enough, and his skidloader is strong enough) to move some big round bales. I doubt that his loader is that strong, but I made the grapple open as wide as I could, just in case he wanted to try it. Also, if you look at the center gusstes, I could not get them in there tight enough, and still eave room for the D-Ring to easily move, as well as keep the gussets perpendicular to the lip. It is fairly common knowledge that a gusst is strongest in the perpendicular installation (as I have done), rather than also introducing a possible lateral stress. no it's not perfect, but it's better than cutting the gussets short. I did cut the center one short, but that was because there is no other way of doing it. the center one is fully welded.#3, yes, you are right about that. I never thought about doing that. thanks. I'll have to keep that in mind for next time.#4, this system has enough travel to allow it to fully extend, plus one extra inch, and fully compress, plus one extra inch. It does not bind or catch at all in this entire range of motion. The only reason that I did not show it any further in the up-right position was because my engine hoist could not open it any further without lifing the bucket. I could have probably tipped it back a little more to show the FULL open position, but the bucket would have probably fallen backwards from being top-heavy. if this thing binds, I'd love to see it happen. I drew it all up in 3D and never had a problem when I ran the motions in AutoCAD. I left plenty of room in the system in case it bounces around (we all know it will) so that it won't become damaged. I wanted to try and come up with a good stop system for the arms so that they do not use the piston as their only means of coming to a rest, but when it is on the ground, the arms rest on the dirt without putting stress on the piston, so there is no real issue with that.#5, as far as the hydaulics go, I had the guy sign a waiver and we came to the understanding that I was not responsible for the piston, hooking it up or anything of that nature. I would weld it and use the piston for dimensions only. Other than that, it's up to him and how he uses it.#6, I welcome any and all input on my welds. I know they are not perfect, but if you can get them to break under the conditions that they will see, be my guest. Like I said, as well as you and your buddies... no one gets better without negative input.Later,Andy
Reply:Lugweld. I never thought about the zerk fitting. dunno why either... we used to install them all the time in the tool & die factory that I used to work at. I'll have to remember that.I did however put in some 1.5" OD x 1/4" WT seamless tubes into the holes for the arms. they are welded from the inside of the tube, before I welded the ends on the tubes. that keeps the outside nice and smooth to minimize friction.The pins are 7/8" for the arms and the Piston pins are 1". when I lift it up with my hands, or with the engine hoist, everything is SUPER smooth. I'm sure that it will get pretty worn and rough as time passes, but from what this guy does with the rest of his equipment (all barn-kept, washed after just about every use, etc), I see no reason why it wouldn't last a while. he told me that the reason this one was in such bad shape is because he just bought it from some other guy who's skid steel busted for some reason.Later,Andy
Reply:Andy,,,,,   believe me,,,,   My "buddies" have nothing to do with this.   My previous post was my thoughts, and mine alone.   In fact,,,,,   if I happened to post up "crap",,,,,  I would expect, and not be surprised, to see my "buddies" dumping on me more than anybody else.The main thing I want to stress,,,,,,,   You NEVER build something based on what the customer says he's gonna do with it.   You build it based on the capabilities of the equipment, it will be attached to, or by stamped engineer drawings.   Either that, or you put the limitations (pressure bypasses) in before it leaves your shop.   Otherwise, I guarantee you,,,,,   the customer at some point will be conducting his or her own "destructive testing" on your build.   Just the nature of the business.One other thing.   I will, never, ever, ever, give a quote over the phone, without actually seeing the job or item beforehand.   Gonna be brutally honest here,,,,   that was STUPID!!!!!
Reply:Originally Posted by mark8310One other thing.   I will, never, ever, ever, give a quote over the phone, without actually seeing the job or item beforehand.   Gonna be brutally honest here,,,,   that was STUPID!!!!!
Reply:No skin off my back, just making comments based on observations of what you've previously posted,,,,,   and by the way, I can no longer see These comments are based on previous experience,,,,   25+ years of experience in the field, my own business, the buck stops here.   I know good customers, I know bad customers, I know customers you don't know till the **** hits the fan.  You can take my posts  for what it's worth, or ignore it, your choice.
Reply:Good lord.Proud to be self-employed and not have to rely on ANYONE but me to make my way in this world.Dynasty 350DXDynasty 200DX MM 350PMM 210MM Passport PlusSpectrum 375 Extreme08' Trailblazer 302
Reply:thanks for the input mud spaz.. it's always nice to see your bright and smiling face. how ya been buddy?Later,Andy
Reply:Lugweld----  I'm not sure the "collar" thing is an adjuster for travel stop.  I use special donuts that are spring loaded that snap over the shaft and rest against the cylinder to restrict closing.  They're for depth control on an implement.If a cyl. runs out of travel, it can put it in a "bind".  The machine it's attached to runs out of pivot room but the cyl. keeps on pushing.  It can snap stuff off in a heartbeat.Specially the piece of 2" tubing directly under the cyl. in the OP's post.  IF it comes into contact with the bottom side of the cyl. when it's in full retraction."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by aczellerthanks for the input mud spaz.. it's always nice to see your bright and smiling face. how ya been buddy?Later,Andy
Reply:Samm,That's exactly what it does.  The close up reveals that the cylinder has a built in relief valve that the collar contacts and pushes the valve in to stop the travel of the cylinder.  I have had experience with these type of cylinders for 25 years or so.  All he needs to do is adjust the collar down to it contacts the valve part. I would have said valve earlier, but I knew what it was when I saw it but didn't see the relieve valve sticking up...so I remained bland, or rather generic...If you would like, I can show you on a cylinder I have on a tractor of something simlar....In fact, wait a few minutes, I'll be back.Last edited by lugweld; 03-12-2009 at 03:09 PM.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Lugweld, and ac---------  These things.  They come in different thickness to limit cyl. travel safely.  They open up like a clamshell and slip over the shaft.  Might be a good idea here Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Samm,These are some hot off the press pictures.I just took them and posted little arrows on them so you can see...Now the blue arrow is the collar.   The lime green one is the contacting point that pushes in on the valve to "unload.  These cylinders aren't cheap as they have very specific applications.  But they are great for fixing a problem situation such as these.I know the clamp on type you are showing..Use them all the time on cylinders, particularly leaky harrow cylinders.But this is different. In fact, after rereading my original post, I gave the wrong impression.  I guess I was thinking about two different things and my thoughts melted together...But here is what I meant, not what I said. Attached ImagesLast edited by lugweld; 03-12-2009 at 03:16 PM.Reason: clarify.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Yeah,,,,  Samm,,,,,  those are good if you want to limit the travel of the cylinder,,,,,  for a purpose,,,   say, you only want an implement to go so far down.  IF, however,,,,   you have a mechanical restriction somewhere, or a binding issue,,,,   I would not EVER let something like that leave here.   The only CORRECT way to limit travel, when binding or restriction is an issue, is to take the cylinder apart, and put the spacers (properly cut and machined square) inside.  They can't fall off, pop off, or be replaced or used or lost somewhere else.
Reply:Those ARE the proper cylinder stops.  That's what the cylinder companies sell them for That IS the correct way.  Internal additions of spacers will cause other failures, particularly to the ends of the cylinders to which the come into contact.  These collars are correct for stroke limitations.  Having worked with and sold those cylinders for a long time, they are the only "approved" limiting devices for cylinders.  Internal additions woud immediately void any warranty.  I can "guarantee" you that.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Originally Posted by mark8310The main thing I want to stress,,,,,,,   You NEVER build something based on what the customer says he's gonna do with it.   You build it based on the capabilities of the equipment, it will be attached to, or by stamped engineer drawings.   Either that, or you put the limitations (pressure bypasses) in before it leaves your shop.   Otherwise, I guarantee you,,,,,   the customer at some point will be conducting his or her own "destructive testing" on your build.   Just the nature of the business.
Reply:Halfstep is absolutely right. That man is rough on his equipment. If you design it, you are responsible for its performance...or failure. If you don't limit the cylinder, it will rip that mount off pretty fast. The leverage it has with that plate in the air like that ...added to the force exerted by the bucket and the force exerted by the grapple under load, and you have a failure point. A 2" weld won't hold that very long.QamuIs Heg qaq law' lorvIs yInqaq puS
Reply:Andy - It's together and workable and hopefully proves adequate. Run it and see what happens.It must be nice to test run the grapple's cycle with CAD.I've spent days trying to match cylinder strokes to linkage travel, it can be a nightmare, any change, changes everything.The weak link here is definitely going to be the cylinder mount's  anchor to the bucket's top lip. The anchor point is probably not going to stand up to even light use, but it won't be a big deal to beef it up if the failure is caught early.For the next grapple build -When closed, grapple tines should contact the bucket near the cutting edge, so as to tighten-up with a pinch. Also the grapple should close making a round or ramp shape inside, so that ultimately if the grapple has to give up its grip on the load, it can do so damage-free.Ideally, with an open grapple, the bucket edges can be almost crowded flat against a wall, without touching the grapple.Good LuckOriginally Posted by mark8310Yeah,,,,  Samm,,,,,  those are good if you want to limit the travel of the cylinder,,,,,  for a purpose,,,   say, you only want an implement to go so far down.  IF, however,,,,   you have a mechanical restriction somewhere, or a binding issue,,,,   I would not EVER let something like that leave here.   The only CORRECT way to limit travel, when binding or restriction is an issue, is to take the cylinder apart, and put the spacers (properly cut and machined square) inside.  They can't fall off, pop off, or be replaced or used or lost somewhere else.
Reply:Keep that bag handy Samm.  Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Originally Posted by lugweldSamm,These are some hot off the press pictures.I just took them and posted little arrows on them so you can see...Now the blue arrow is the collar.   The lime green one is the contacting point that pushes in on the valve to "unload.  These cylinders aren't cheap as they have very specific applications.  But they are great for fixing a problem situation such as these.I know the clamp on type you are showing..Use them all the time on cylinders, particularly leaky harrow cylinders.But this is different. In fact, after rereading my original post, I gave the wrong impression.  I guess I was thinking about two different things and my thoughts melted together...But here is what I meant, not what I said.
Reply:I believe they call them self-limiting valves.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Originally Posted by lugweldKeep that bag handy Samm.
Reply:You can use it to give to members as an award for the most idiotic things said or done.  You could call it the "Okie" and present it to deserving people.  Denrep could give awards for the most outstanding with a "finger" of approval.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Originally Posted by darkknight19 years old as of June 2008, two college degree's and owns his own business.
Reply:Originally Posted by aczellerI'm 21, have one associates degree, and am working on another. what's your point?
Reply:When a person joins, the age never changes.  You must look at the birthdate if you want to see a true age.   If you would take the time to look.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:The cylinder collars and the limiting valve style are both designed to limit the retracted length of the cylinder not the extended length. The extend direction is the most powerful direction of any cylinder.Last edited by tnjind; 03-12-2009 at 06:01 PM.Reason: spellingTim Beeker.
Reply:A properly designed cylinder is equal in strength in both directions.  There is no difference.  There is no leverage.  Just fluid moving a piston back and forth.  The volume of fluid moved is exactly the same.  The only way a cylinder can exert a different force, is for there to be a restriction in the control valve of the cylinder, which in some instances is needed. But a simple spool valve provides equal pressures to both sides and equal volume.  An example of the strength of a retracted cylinder is on front end loader applications. The "break out" force is the retracted cylinder.Here's the formulas.Pressure (Psi) = Force (lbf) / Area (in2)Cylinder speed (ft/s) = 231 x GPM / (720 x net area (in2))Cylinder volume capacity (Gal.) = Pi x radius2 (inches) x stroke (inches) / 231Oil flow rate to cylinder = 720 x velocity (ft/s) x net area (square inches)Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Post #2 picture #4.  The gusset.  It should have about 3/4" cut out at a 45* angle.  I never weld the inside corner of a gusset.  The other thing I would do is cut the D ring off and lay a plate from the back of your new plate down to the bucket along the gussets you put there.  This will add a lot of support to the cylinder hanging out there in no mans land.   Maybe a few short plates so you can weld each one to the gussets.  This will make a triangle mount for the base of the cylinder.  Then add more support from the cylinder mount pin down to the newest plate.  It is going to need all the help it can get.  At least go from the true cylinder base pin back to the bucket.  Something heavy like 1/2X3.This machine prolly runs at 2350 PSI. I don't know what the bore of that cylinder is, but the force is in tons, tens of tons. David Last edited by David R; 03-16-2009 at 06:13 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Lugweld, I disagree.   The Rod end of the cylinder looses the square inches taken up by the rod, so unless it has rods coming out of both ends, it will always push more than pull.tnjind is correct.Andy, you should talk the customer into putting on a new cutting edge.  That one is shot.David  Last edited by David R; 03-12-2009 at 06:27 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by darkknightThe point is, it sounds like you both are doing well. I am curious as to which is correct, the age in his first post or the one in his profile.
Reply:Yes... I guess you are right.  I had been thinking of a power steering cylinder when I was originally thinking about the "push pull" action of  a cylinder on a Case tractor, completely oblivious to the obvious.  But I used another example of a front end loader, which would be wrong.  Sorry.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Originally Posted by David RAndy, you should talk the customer into putting on a new cutting edge.  That one is shot.David
Reply:Originally Posted by lugweldWhen a person joins, the age never changes.  You must look at the birthdate if you want to see a true age.   If you would take the time to look.
Reply:He may of changed it because it says something different than what you quoted....He also says he is a male prostitute....Why does age mattter to you ?  The only time I see age mattering is drinking, smoking and having sex with teachers (of which I don't approve).  And his join date that you quoted isn't what it says on my screen.  You can't change that.  What's the beef?  Speaking of...I don't see any info in yours or mine.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:FYI, the area the piston rod takes up is called the annulus.I have always found hydraulics fascinating. Trying to find the time to put a regeneration valve on my woodsplitter to decrease the retract time.Sorry for the hijack.Tim Beeker.
Reply:I thought the overtravel we were worried about was in the retracted position???I guess that's why there's been a focus on limiting the retraction of the piston.Now, here's one for y'all..............  The tons of pressure developed by a hyd. cyl. is meant to do work.  It pushes/pulls SOMETHING  All this talk of limiting is sorta funny in a way.  We want to build something that does work.  Has anyone considered the force generated by the work actually being done.  We don' t use 2500psi cylinders to just admireForgetting, for a moment, the discussion about cylinders in a bind.  The structure/machine that incorporates the cylinder has to be able to withstand the full force of that cylinder as it does the work that the machine was intended to do.My equipment has internal bypass pressure relief valves preset by the manufacturer at around 2000psi.  They're in the hydraulic system.  Anything hooked to the system has to be designed to withstand a cylinder operating at that pressure.  That includes implements.I've built things that end movement before the end of the travel of the cylinder piston.  I planned it.  My tree thing is designed to stop all movement 1/4 inch prior to full retraction of the cylinder.  It fully retracts, and holds the forks against the stop with full force.  The reason being, I don't want to push trees with the cylinder, and cylinder mounting brackets.  I want to push trees with the tractor and implement.  I want all force transferred to the steel structure instead of wallowing out the cylinder mounts or putting stress on the cylinder mounts beyond what they can withstand.  My structure is stronger than the force the cylinder can produce.I have a hay baler that uses cylinders to hold the rear door TIGHT.  Extended travel of the cylinder is arrested by the closing of the door.  It's designed that wayAll of the above restrictions(not binds) are relieved by the pressure relief valve.The key is to size the cylinder right for the work intended.  You can't put a 5" cylinder on a structure designed to withstand the force of a 3" cylinder."Any day above ground is a good day"http://www.farmersamm.com/
Reply:I been thinkin about that cylinder mount.  Maybe  your computer sez its strong enough, but I would have built it with tripple the steel and welds.  Only my opinion.  I am no engineer or computer design operator.  I know NOTHING about cad.David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by lugweldA properly designed cylinder is equal in strength in both directions.  There is no difference.  There is no leverage.  Just fluid moving a piston back and forth.  The volume of fluid moved is exactly the same.  The only way a cylinder can exert a different force, is for there to be a restriction in the control valve of the cylinder, which in some instances is needed. But a simple spool valve provides equal pressures to both sides and equal volume.  An example of the strength of a retracted cylinder is on front end loader applications. The "break out" force is the retracted cylinder.Here's the formulas.Pressure (Psi) = Force (lbf) / Area (in2)Cylinder speed (ft/s) = 231 x GPM / (720 x net area (in2))Cylinder volume capacity (Gal.) = Pi x radius2 (inches) x stroke (inches) / 231Oil flow rate to cylinder = 720 x velocity (ft/s) x net area (square inches)
Reply:That's where psi comes in"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Samm,David explained it in post 38 Tim Beeker.
Reply:Originally Posted by tnjindSamm,David explained it in post 38