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Any mods for faster hydraulics of portable woodmizer

Started by MikeH, February 24, 2008, 06:48:12 PM

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MikeH

 Anybody do this or is it out of the question? I would not mind real fast hydraulics. smiley_smash smiley_smash smiley_smash <---- Maybe the loading arms going about that fast.

rbhunter

How are you going to figure the distance for the mill to catch the log as it flies throught the air?
"Said the robin to the sparrow, I wonder why it must be, these anxious human beings rush around and worry so?"
"Said the sparrow to the robin, Friend I think it must be, they have no heavenly father, such as cares for you and me."
author unknown. Used to hang above parents fireplace.

MartyParsons

Safety First!  :o I think Bibbyman has 6 gpm vs 4 gpm. Bibbyman it any faster? Bibby's hydraulics is powered by AC Volts and is stationary.
M
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

Bibbyman

 

6 GPM is way fast for the hydraulic system on the Super HD.  (Ever see a demo of the LT300?) 

We're sawing small logs right now and even with a year or more of practice, it's easy to over run something.  The biggest danger is lowering the back supports too fast and further than you wanted. The second biggest danger is pushing a log over the back supports if you're not watching what you're doing.

The 12 v DC pump system had a bit of a variable speed to them.  They were a lot faster when not under load.  When under load they slowed down – maybe as much as 1/3 as fast as when there was no resistance.  Thus, you kind of move fast up to something and then slowed down as the pressure increased.   Not so with the 6 GPM pump powered by 7.5 hp 3ph motor.  Things slam around quite a bit more and come to the end of their travel with a snap.  Something to consider.

I end up cracking the valves for most of the functions to slow their movement speeds.  The speed comes in handy when you're running the clamp back all the way and down,  putting the back supports up, etc.  But you don't want to go full speed when pushing a log towards the back supports – easy does it.  Or when lowering the back supports part way down.

We do not have the loading arms as we have a live deck so I don't know how more GPM will affect that function but I'd think you'd want to feather the speed back as the log is about ready to roll onto the mill.

One way to achieve more GPM on a mobile mill would be to drag along something like a firewood splitter.  Splice in some quick couplings so you can bypass your 12v DC pump and plug in the lines from the wood splitter.  I think this would be a lot of trouble and expense for the little return. 

Now if you're doing a lot of stationary sawing where electricity is available, then a power pack like we have would work.  Just keep all the 12v pumps stuff intact and put quick compliers in the lines to switch back and forth between HD sources. You'd have to switch out or remove one wire to the solenoids that start the 12 DC pumps to keep them from running when you didn't need them.   

Before going overboard on the GPM, better check and see how fast you can go with the valves and hoses, etc. on your model mill.  I've got the impression that 6 GPM @ 2000 psi is the limit on the newer LT40 Super and probably LT70.  I don't know what it would be on older LT40 Supers or standard LT40 hydraulic mills. 

Another thing...  getting HD power from an external source will allow you to use the hydraulic functions any time the pump is pumping as you're not dependant on the head being on the contact strip.  That is very handy many times but you need to be aware as you could move something while the head is "down range" and do some damage.
Wood-Mizer LT40HDE25 Super 25hp 3ph with Command Control and Accuset.
Sawing since '94

MikeH

 Sounds like you have a nice set-up Bibbyman but I go mobile quite often and dont think I want to drag a log splitter around.  ;D

Dave Shepard

You might be able to rig up your own power pack fairly easily. Many smaller log splitters use a two stage pump. This would allow you to use a smaller HP gas engine, and still have some speed. Then when the power unit was under load, it would drop the gpms exactly when you need it to be a little more delicate.  ;)


Dave
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

MartyParsons

[quote One way to achieve more GPM on a mobile mill would be to drag along something like a firewood splitter.  Splice in some quick couplings so you can bypass your 12v DC pump and plug in the lines from the wood splitter.  I think this would be a lot of trouble and expense for the little return.  ]

Wow! you would realy want to have faster hyd bad to go through all that trouble. the 4 gpm is not that slow. You would have more maintenance with other power source + hoses + dirt. IMO.
M
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

MikeH

 Marty, 4 gpm is not that slow I admit but neither is a 42 horse diesel and you guys came up with a 62 horse and I am just looking for a simple mod. to compliment the hydro's. Like on your 300.  Is there anything possible without using seperate power souce? 

LeeB

'98 LT40HDD/Lombardini, Case 580L, Cat D4C, JD 3032 tractor, JD 5410 tractor, Husky 346, 372 and 562XP's. Stihl MS180 and MS361, 1998 and 2006 3/4 Ton 5.9 Cummins 4x4's, 1989 Dodge D100 w/ 318, and a 1966 Chevy C60 w/ dump bed.

Bibbyman

Mike,

Are you sure both pumps are pumping?  Sometimes a solenoid will go out or a motor will go out and you'll not really notice it.   
Wood-Mizer LT40HDE25 Super 25hp 3ph with Command Control and Accuset.
Sawing since '94

MartyParsons

Change the hydraulic oil to the J13 winter grade oil. Clean the motor burshes every 850 - 925 hours. Hydraulic filter change at 500 hours. The electrical system can not handle any more amp draw, so adding more pump or more motors are out of the question. Some customers change to the winter grade oils to speed up the pumps. If you are in a realy warm climate I am not sure what the effects of wear to the pumps may be? If you do this make sure you get all of the original oil out.
M
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

bandmiller2

M ike,you could go to synthetic hydraulic oil and gain some speed in cooler weather.Are all functions slow or just one, possible kinked hose or restriction.Watch anouther mill of the same type and compare speed.You may have to just slow down and smell the roses.Frank C.
A man armed with common sense is packing a big piece

beav39

i agree with bandmiller the lt40 hydros only go so fast the only thing i would like to see a little more faster would be the loading arms   like band miller says smell the roses     or trade up.
sawdust in the blood

MikeH


MartyParsons

It looks like you have a LT70 walk mill. Have you ever changed the hydraulic oil? How many hours on the meter? If MN is Minnesota you should try the Winter grade oil. If any WM hydraulic owner has installed any other oils in the hydraulic system it will s l o w the system way down. I see this from time to time. We drain the pumps and purge as much oil out of the system and add the J13 oil and it speeds things way up.
Glad to try and help!
Marty
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

logwalker

Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

Bibbyman

One thing that would speed up the loading arms function would be to replace the lift cylinders with ones with a smaller diameter.  But smaller means speed, larger means power.  You can't have both (with the same GPM and PSI). If you saw only small, light logs, this would work. I'd think?  ::)
Wood-Mizer LT40HDE25 Super 25hp 3ph with Command Control and Accuset.
Sawing since '94

beav39

sawdust in the blood

MartyParsons

Part # P12822 Exxon Univis HVI 13   Recommended for:
Cold-weather applications
Here are the temp ranges for recomended oil.
1. Dextron III  30 degree - 120 degree F
2. Exxon Univis HVI 26  minus 20 -- 100 degree F
3. Exxon Univis HVI 13   minus 30 degree --   60 degree F

I can not answer your question if it is over 60 degree F will it protect your pump at 100 degree F ?  I am also not sure about the syntethic.  :-\

Maybe Sparks would know.

Marty

"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

Brucer

Quote from: Bibbyman on February 26, 2008, 02:20:10 AM
One thing that would speed up the loading arms function would be to replace the lift cylinders with ones with a smaller diameter.  But smaller means speed, larger means power.  You can't have both (with the same GPM and PSI). If you saw only small, light logs, this would work. I'd think?  ::)

Actually, you can have both. Here's an old-timer's trick. All you need is a 2-position, 3-way valve, a T connector, and three short hoses.

Arrange the valve so that in one position it connects the regular control valve to the lift cylinders in the normal manner. You'll use this position to retract (lower) the cylinders and to extend (raise) the cylinders at the normal, slow speed (with full lifting force).

In the other position the valve will connect both ports of the lift cylinder to the pressure line from the control valve. The return line to the control valve will be isolated.

"What? Connect both cylinder ports to the pressure line? It'll never move!", says a friend of mine. Oh yes it will, and very fast, too. It will extend at the same speed as a cylinder with the same diameter as the cylinder rod in your lift cylinders. That's about 6 times faster on my mill. Naturally you'll have only one-sixth the lifting force.

You just gotta remember that the cylinder will only extend with the new valve in the high-speed position. To retract you have to switch the new valve back to the low speed position. Mind you, cylinders always retract faster than they extend (under the same load).
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

logwalker

That is pretty clever Brucer, if I see it correctly you are using the oil from the return side to boost the extend side. The larger piston surface on the extend side overcomes the retract side and uses the extra oil to boost speed. Who thought of that one? I think you can do anything with hydraulics if you are smart enough. Joe
Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

Brucer

Yep, that's it exactly, Joe.

It certainly wasn't me that thought of it. First heard it mentioned by a mechanical draftsman who'd been trained in Holland. He knew more about practical hydraulics than any of the millwrights or machinists in our company.

Many years later I found it discussed in "Industrial Fluid Power - Volume 2". It's called a regenerative circuit.
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

Dan_Shade

do you have a picture for this hydraulically challenged guy?

Woodmizer LT40HDG25 / Stihl 066 alaskan
lots of dull bands and chains

There's a fine line between turning firewood into beautiful things and beautiful things into firewood.

logwalker

Think of it this way: the extend side of a cylinder is empty in that there is no rod extending thru it. That makes the piston surface larger on that side then on the retract side. Apply the same pressure on both sides at the same time as Brucer's valving circuit does and the larger surface area of the extend side will overcome the retract side. Because he has connected both sides together the fluid on the retract side is forced into the extend side and extends the piston about 6 times faster. Clear as mud, eh?
Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

Dan_Shade

Woodmizer LT40HDG25 / Stihl 066 alaskan
lots of dull bands and chains

There's a fine line between turning firewood into beautiful things and beautiful things into firewood.

Bibbyman

Would there be any added danger in this mod? 

As the WM loading arms are powered, there is a "fuse" that would prevent the loading arms from falling should pressure be lost - as in a broken line.
Wood-Mizer LT40HDE25 Super 25hp 3ph with Command Control and Accuset.
Sawing since '94

logwalker

Quote from: Dan_Shade on February 28, 2008, 12:52:40 PM
what about the other direction?


That is the rub, with this configuration there is no other way. Have to throw the selector valve back to normal.
Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

logwalker

Quote from: Bibbyman on February 28, 2008, 01:25:06 PM
Would there be any added danger in this mod? 

As the WM loading arms are powered, there is a "fuse" that would prevent the loading arms from falling should pressure be lost - as in a broken line.

I think it would depend on where the fuse is located in the circuit. If I remember right they are at the cylinder where the extend line goes in. They would probably still function correctly. Maybe...
Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

Dan_Shade

so you'd have to have a selector valve at the cylinder, or other hoses running back to the control box?
Woodmizer LT40HDG25 / Stihl 066 alaskan
lots of dull bands and chains

There's a fine line between turning firewood into beautiful things and beautiful things into firewood.

MikeH

 Six times faster loading arms? better get offbearer a nut cup. :o

Dave Shepard

My Kubota L48 uses a regen circuit on the dump side, it's really fast. I thought something was wrong with the loader when I got it because you could not lift the tractor when the bucket was flat on the ground. The loader on my tractor takes care of all functions in a number of hydraulic blocks, it also has automatic leveling. Lot's of hoses.


Dave
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

Dave Shepard

Doing a little late night insomnia inspired engineering here. If you were to use electric solenoid valves, you could easily set up your regen circuit. Bibbyman, what is this "fuse" you are talking about? Does the system pressure have to excede a certain amount before the cylinder will move, like on a man lift? I wouldn't think that would come into play for what we want to do, unless it won't flow the added volume. The available pressure to overcome it would be the same. I would think some care would be in order, don't want the log to hop over the backstops. :D


Dave
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

MartyParsons

OK,
The velocity fuse is located on the bottom of the loading arm clyinder. It is rated at 5 gpm on the LT40 and the 6 gpm on the LT70. Its function is to keep the loader from falling if there was a failure of the hose. It is a small fitting that has holes rated at a rated gpm if there is more oil passing through these holes it pushes a check ball on a seat and keeps oil from passing. So if you and a friend are doing a sawing job and you are loading a log and your friend is helping with a BIG Log Rite Cant hook trying to help the log on the mill and the hose failes your friend and you will be away and then you will repair the hose and go on with life. If you remove the safety fuse you or you good friend will be under the log or loader and you will be saying o ----- how do I get my buddy out from under the log!  :'(
Be safe out there!  :)
Marty
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

freddycougar

 :P... forget the regen circuit.. u lose power.. add an accumulator

Brucer

You don't need to do any "plumbing" at the cylinders. You've got 2 hoses connected to the 2 cylinder ports, so you can do everything in the hydraulic control box.

I believe (could be wrong) that the velocity fuses work one way -- they kick in if fluid is leaving the "extend" side of the lift cylinder too fast. Regeneration will cause extra high velocity only when the fluid is entering the cylinder. This is certainly something to check out before getting too far into this mod. I would most definitely not remove or bypass the velocity fuses. It's the biggest and heaviest logs that fall the fastest (and are more likely to cause a hose to fail).

The point of the mod is to allow a faster lift with lighter logs. Yes, regen sacrifices lifting force for speed. The downside of accumulators is that you have to run the hydraulic pump for a while to charge them up. That's fine on a conventional hydraulic circuit where the pump is running constantly. It's not so great on a mill that only runs the pump when a control lever is activated.

I'll dry to come up with a circuit diagram sometime this week (but don't hold your breath).
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

Dave Shepard

If you had a diverter valve setup, you could select between standard and regen. If the velocity valves are truely one way, then it is a simple matter of gettin' some parts and git'n'r'done. :)


Dave
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

Brucer

Been thinking about his some more. Theory is all very well, but looking at it from the practical side raises some safety issues.

What the regen circuit does, in effect, is allow you to switch from the normal size cylinder (3" on the WM lifting arms) to a cylinder the size of your cylinder rod (1-1/4" on the WM). That's about a 6-1 ratio. Just throw a selector valve and you've effectively got a different sized cylinder. Six times the speed and one-sixth the force.

Here's the problem. Suppose you were to lift a heavy log (say 3000 lb). You'd have to use the "normal" mode to do it, and you'd be running about 1000 PSI in your hydraulic circuit (relief valve setting is just over 2000 PSI). Now suppose for some reason, you stopped lifting when the log was still on the loader arms, and then switched over your regen selector valve. That would be exactly the same as replacing the 3" cylinders with 1-1/4" cylinders, and the weight of the log would push the system pressure up by a factor of 6 -- in other words, about 6000 PSI. With the control valve not in use the system's relief valve would be separated from the extra load, making it useless.

In this situation, you'd for sure blow a hose. That would immediately disable the regen effect, but meanwhile you'd have a falling log to deal with. If you were smart enough not to remove the velocity fuses, they would hopefully stop the fall. But now you've got a suspended log and a ruptured hose to deal with. No way to shift the log with the hydraulics until you fix them, so you've got a real mess on your hands.

To make this a safe(r) circuit, you must add a relief valve between the regular control valve and the cylinder. It goes in the hose that connects to the bottom of the cylinder (the "extend" side). This relief valve will have to be set higher than the system's regular relief valve but lower than the safe operating pressure of the hoses and components in the system. And no, you can't rely on the sawmills existing relief valve. Remember, it's on wrong side of the control valve.

This little addition complicates the plumbing a lot, because now you have to vent the new relief valve back to the reservoir.

Realistically, a 6-1 regen ratio is not ideal. You'd be better off with a 3" cylinder with a 1-3/4" rod. That would give you a 3-1 regen ratio, which is a little more useful and also keeps the potential system overload down to a more manageable level.

Hydraulics packs a lot of energy into a very small package, and you've got to be careful when you mess around with it.
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

Dave Shepard

I may be wrong, but I think we are only changing the volume of oil, not pressure. The pressure on the rod is not going to change, only the speed that it is lifting. Another question: what happens when the valve is in regen, and we aren't putting pressure into the system, isn't the oil going to try and go to the other side of the circuit and lower the arms?


Dave
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

Brucer

You aren't changing the pressure on the cylinder when you're sending oil to it. The arms lift faster and with proportionately less force. However, when a dead load is applied to the arms, it generates pressure. With regen active, the pressure is much higher.

When you have the system in regen and the main control valve is closed, the oil might "try" to flow through the system to the other side of the piston, but there's no room for it! Don't forget, the cylinder rod is there, taking up some of the space the recirculation oil would occupy.
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

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