Hydraulic Question

WH_Conley · January 26, 2007, 09:01:08 PM

Looks like I am back to sawing by myself again. Main gripe I have is the speed of the hydraulics in my LT40HD, didn't make it in the house before the people at WM left for the weekend. The question or questions are

(1) what would a person have to do to increase hudraulic speed?

(2) Is there another pump that will fit on the standard electric for this mill?

(3) What is the gallons per minute on the standard pump?

Thought about an external pump like Bibby's but I want the option of still being portable. Already thought of upgrading to a super but I would be right back to needing help that won't show up to use it to anywhere it's potential. Also I am pretty sure a new Super comes with a payment book as standard equiptment, mine is paid for. 8)

Dan_Shade · January 26, 2007, 09:25:58 PM

my understanding is the super has 2 pumps (i'm assuming in parallel, but I have no clue), and larger diameter hoses to pump more fluid, making the hydraulics faster.

I have another wierd thing going on with my hydraulics, sometimes after some use, they'll slow down and will stop working right.

pineywoods · January 26, 2007, 09:41:59 PM

The super has 2 pumps running in parallel AND a much bigger alternator to provide electrical power for them.

You can have your cake and eat it too. Put quick disconnects in your existing lines and run them out to your log splitter. Leave the original pump in place for use when you go portable.

derhntr · January 26, 2007, 10:00:01 PM

What part do you want to make faster? The log lift?

Gary_C · January 26, 2007, 10:00:55 PM

Yes, you can go to two pumps, but like the others have said, you also need a lot more alternator capacity to keep the batteries charged. If you just have problems when it's cold, make sure you are using the WM hydraulic fluid as it is the best multi viscosity hydraulic fluid available.

I have the same LT40HD and what bothers me more on the speed of sawing is the up-down speed. It seems like I am always waiting on the head to either go up to clear or to drop where it needs to be. The supers have a bigger, faster up-down motor, and to me, that is the first thing that needs to be faster on the non supers.

WH_Conley · January 26, 2007, 10:14:31 PM

I cut a lot crossties, cut, turn, cut, turn and so on. The speed of the turner is what really gets me. I have ran the battery dead while sawing hard down. Normally, while sawing at the house I have an external battery hooked to the hydraulics with a seperate charger hooked to it. If I want to go portable I just unhook that battery and rehook it up to the mill battery, just the way it was as new. I don't think the extra juice draw would be too bad because when sawing portable there would be less turning. Even mobile I take my skids with me, as long as there is a loader available, lot faster than using the loading arms. No problem cold over hot as far as speed, cold seems to bother me more than the mill :D

As far as head speed, I know what you are saying, real slow, but on ties you don't have that travel distance, on most logs. If I can figure out the hydraulics first maybe address that problem next.

Gary_C · January 26, 2007, 11:04:31 PM

You could have some other issues causing that much battery draw. High current on the pump motor, corroded connections, and/or poor alternator performance. Even the battery could be suspect.

I have a hydraulic dump trailer that is powered by a 12V Hydraulic pump system. I have a lot of trouble with connections and solenoids. If I have to use a battery charger, usually something else is wrong. On those systems, everything has to work perfectly or the whole system fails to work correctly.

Also on large cants, it's usually faster to flip with the clamp.

WH_Conley · January 26, 2007, 11:32:37 PM

Can't do it with the clamp. Old style, not two plane.

Gary_C · January 27, 2007, 12:45:57 AM

LT40 Super HD + payment book = priceless ? 8)

Bibbyman · January 27, 2007, 02:57:57 AM

Question 1.

More GPM would increase your hydraulic function speed but you need to check with WM to see what the upper limit would be. The valve body, lines, etc. can take only so much.

Question 2.

I don't know. Never explored that possibility.

Question 3.

If the pump on your mill is the same as what was on our Super, it would be a max of about 3 GPM. (Again, check with WM because you're mill may be different.)

With a Super you get two pumps in parallel for a theoretical max of about 6 GPM. I called and talked to the people who supply the pumps to WM and they told me that the max GPM on the pumps were when they were not under load. When under load, they may drop down to as little as 1 GPM.

Other consideration.... You can't just add a second (or third) pump or necessarily a bigger pump without adding a lot of other stuff. Alternator has been noted but also all the cables are larger and the Super uses three big honking solenoids in the connections to the motors that I don't think the standard hydraulic uses. I think the battery is much bigger too. I think you're talking 500 amps or more maximum draw when both motors are pumping.

Splicing in a remote pump system would not be hard as noted. But when you're mobile, you'd be back where you were before and that would be very painful. I've stepped up to standard HD mills at shows and such and tried to run them. At first I'm thinking, "What's wrong with this mill?" and the answer is nothing. It's just going as fast as it's designed and built to do. ................ Remember when the speed limit was 55? Now think about how slow that would feel if you were running on the interstate today?

Now an external HD source with a gas engine (like a firewood splitter) would work as you could take it along to the job site. You would still have to be concerned with max PSI and GPM. But you could get flow reducers to regulate that. You'd also want to make sure the oil used in the external pump was OK for the mill. I don't know why it wouldn't but it'd be something to check.

My best suggestion is... If you're standard HD is paid for and you feel the need (and can use) the speed, put that mill on the market and buy a new Super or even LT70.

There is a lot more to a Super than just faster hydraulics. The up/down motors are a lot larger and faster for one. Board drag back and a lot of other features are standard with these models.

Besides, you're old mill is probably depreciated out and you need some more deductions on your taxes. ;)

Quartlow · January 27, 2007, 07:57:35 AM

What Bibby said :D except I wouldn't worry about the flow part. excessive pressure is what will kill your system.
Flow equals speed
pressure equals power

I changed my garden tractor around so it had a 2 spool valve so I could get 1 remote without messing with the deck lift I discovered it was slow lifting the dump cart. I was all for changing out the pump for a bigger one. Wifes cousin works with hydraulics, He suggested just changing the drive pulley. Which is what we ended up doing. The bad part was now the deck/and the rototiller lifted too fast. The deck wasn't much of an issue but sometimes you only want to lift the tiller a little bit and it was real touchy. Ended up putting a flow control on the line that ran the lift cylinder on the tractor. It's been that way 4 years now and nothing has failed

Bibbyman · January 27, 2007, 08:53:11 AM

Quote from: Quartlow on January 27, 2007, 07:57:35 AM
What Bibby said :D except I wouldn't worry about the flow part. excessive pressure is what will kill your system.
Flow equals speed
pressure equals power

Our new pump is designed to put out 6 GPM. But it should be doing that at max PSI and it appears to be doing so. THAT IS PLENTY FAST! Any faster and you may risk pitching a log over the back supports, etc. And often times things like the back supports, toe boars, etc. SNAP at the end of their travel with pretty smart authority. Its pressure that will overstrain the design but the speed the things work and come to the end of there travel is also hard on the parts that the hydraulics is working.

One good thing about the old DC pumps was ...they worked more slowly under pressure and thus cushioned a lot of the slamming around. You don't have that with the pump system we now have and I end up feathering the valves most of the time. I have to feather them when I'm trying to get the back supports at just the right level, when I'm adjusting a toe board, or when I'm trying to camp a small, soft log like cedar.

A second good thing about the two DC pump system on the Super and LT70 is ... if one pump goes out, you can run with just the other one pumping until you can fix the down one.

The new hydraulic pump made such a change that our neighbors noticed it. When then next dropped in, they mentioned they thought I must have gotten a different mill because they could hear the louder bang of the cants rolling over and the linkages coming to the end of their travel. I gave them a quick demo and they got the picture.

Brian_Rhoad · January 27, 2007, 12:14:49 PM

If I understand hydraulics correctly, I think speed is controled by the hydraulic pump volume and power is the pressure. A larger pump with the same pressure but more volume should raise the speed but keep the power the same. Also if your hydraulic lines are small, bigger lines could speed up the equipment if they are restricting the flow.

Tom · January 27, 2007, 12:35:03 PM

I don't care how fast your mill is when you buy it, when you gain experience, it slows down. It's not the mills fault, it's that you have outgrown its speed. Things that used to befuddle you were being thought about as you loaded the next log. Now, as you load the next log, you are probably looking at the next two or three and maybe eyeballing the real long one on the back of the log deck, thinking it might might that special beam the customer wanted.

I've walked beside an LT40HD for a lot of passes and the best way I found to increase production was consistency. The next log needs to be ready. The loader might be slow but it needs to be moving. The log needs to be dumped and the loader gotten out of the way. Playing with it wastes time.

Think about what needs to be done next so that it can be done in the least amount of time. Sorting flitches to be edged instead of trying to do it on the mill is a great time saver. Having some small blocks for dunnage when the toeboards aren't enough instead of having to look for a block each time saves time.

A good off-bearer is worth his wait in gold if he is clearing the mill before you have to wait on him

It's a great technique to know that you can cut an entire cant without taking a board off of the mill. But, it isn't always the best way to do it. If raising and lowering the head of the mill is a slow thing, don't do it. Have the off-bearer take the board you just cut so that you don't have to raise the head but 1/8 of an inch to return. Instead of pulling the board off of the top of the cant, you push it onto the deck on the loader side and let the off-bearer take it from there. Have the off-bearer move the board out of the way before he pulls it.

Make the other operations wait on the mill. Don't make the mill wait on the other operations.
An off-bearer can stop you dead in your tracks if he wants to by standing in a place that is in the way of you or the head return, playing with the board and picking splinters off of its edge while you wait for him to get it out of the way.

When I got my Baker 3638 I was awful happy to have that 38 horse kubota and fast hydraulics. It was no time at all before I was looking for some way to make it faster. You will always be faster than some part of your mill. To much speed on the mechanical stuff can be dangerous though. Having the opportunity to think is as important as getting the blade in the cut.

One of the important things is to remember that your help is human, not machines. That goes for you as well. When you start doing too many things by rote, your mind becomes detached from your hands and that is a dangerous situation around dangerous equipment. Even God gave us a tomorrow so that we don't have to do it all today.

Bibbyman · January 27, 2007, 03:03:43 PM

Quote from: Brian_Rhoad on January 27, 2007, 12:14:49 PM
Also if your hydraulic lines are small, bigger lines could speed up the equipment if they are restricting the flow.

I've heard that said but I think the valve body is more the limiting factor on the flow rate. When I had our unit designed and built I brought that up with the builder. He said the hose size wasn't a problem. He wanted to know the flow max on the valve body, design type, and max PSI.

woodbowl · January 27, 2007, 03:22:31 PM

WH, this was posted last year and I saved it. It is a very good source to understanding hydraulics.

http://64.78.42.182/free-ed/MechTech/hydraulics01/default.asp

If your handy, you can also make your own double pump system.

WH_Conley · January 27, 2007, 05:46:07 PM

Woodbowl, thanks for the link.

Tom, I know what you are saying about getting in a routine seems to make everything seem slow, problem is by the time the claw turner goes through a cycle to turn the log if I get the lead out I can walk around and turn the log by hand and be back at the controls, only problem is, I'm lazy, hate to make the extra trip.

Bibby, If I understand hydraulics correctly the flow will be no greater than the smallest fitting.

big_sid · January 27, 2007, 08:49:22 PM

Heck Bill, just go with the super :D payment book is nothing ;).No kidding every thang does work twice as fast. maybe this would be a good time for you to come over to my place to visit, I'll let ya run my mill all you want, until you get this thing figured out. :