Hydraulic Sawmill

[charles mann]

Hello folks, just found this site, and so far, it seems there is a lot of experience and wealth of knowledge here. Lets get started shall we?

So, I will be buying my metal and some start off stuff ( 26" wheels, 2" blade guides, carriage wheels from cooks sawmill) to build roughly, a 65"-68" cut width mill. 
I want to go full hydraulic, from powering the drive wheel via direct coupling, to the raise/lower and carriage feed system. I have an 18hp v-twin engine horizontal shaft, and a 23hp vertical shaft. I went to the local hydraulic shop to inquire about motors/pumps and evidently, the 18 and 23 is to small. Any recommendations as to pony motor size? i was thinking running between a 20 and 30 GPM pump, which should give enough flow to drive wheels and carriage, with enough left over to raise/lower the head. I want to go diesel, but diesel is heavy, but yet it has plenty of torque, which is what is needed to drive enough fluid or pull through a cut. But finding a used diesel, is pricey, so i was thinking of going to a 22R gas engine out of an old toyota p/u or car. 

The motor seems to be the starting point of where i need to start my build, even though i can layout and weld the frame, carriage and saw head, without a way to power the head and wheels, it seems kinda moot to even buy the metal and parts.
Any suggestions? 
So far, Im into this build at nearly $5,000 in metal and parts, and thats before a power source or a raise/lower mechanism, which the raise/lower will be my next inquiry.

Thanks in advance

[ronwood]

Welcome to the forum.
Ron

[charles mann]

Welcome to the forum.
Ron

Thank you Sir.

[ladylake]

 With a hydraulic motor powering the band (I'd go with a 50+ diesel with a belt drive triple pulley) cutting 65" wide you'd need a 75hp diesel unless you want to cut REAL slow.  For up - down a worm gearbox hooked to roller chains  powered by a hyd motor with a high enough ratio to hold the head weight when off .   If using a hyd cylinder for up - down it might want to drift down unless there was a check valve to prevent that. Steve

[Chuck White]

Welcome to the Forestry Forum, charles mann!

[Southside]

Welcome to the Forum. You are going to have parasitic loss by powering the band via a hydraulic motor, and you will need a lot of cooling capacity for the oil. Even with a motor driven band you are probably talking at least a 75 HP turbo diesel. I would put a bit more study into the proven designs out there before going the route you are suggesting. 

[Ianab]

The effiency of driving a big high speed load like a sawblade with hydraulics is the killer.

I'd suggest using one of you motors to drive the sawhead directly with a 99% efficient belt drive.

Then the other motor can be set up on the frame with hydraulics / big alternator and that drives the log loader, rollers, toe boards, carriage drive and head lift (electric?). Those loads are either intermittent, slower or smaller , and are best suited to hydraulics.

Pity the larger motor is vertical shaft, not really practical with a band saw. But it would cut, and leave space to upgrade it later if needed.

[ladylake]

 With hydraulics you don't need a big alternator, also a deck mounted motor running a hydraulic pump is the way to go for the deck hydraulics .  You could raise the head with a electric motor but I'd put a small hydraulic pump on the main motor to raise the head, if you made that remotely controlled no need for a energy chain or cord reel.  Steve

[charles mann]

The effiency of driving a big high speed load like a sawblade with hydraulics is the killer.

I'd suggest using one of you motors to drive the sawhead directly with a 99% efficient belt drive.

Then the other motor can be set up on the frame with hydraulics / big alternator and that drives the log loader, rollers, toe boards, carriage drive and head lift (electric?). Those loads are either intermittent, slower or smaller , and are best suited to hydraulics.

Pity the larger motor is vertical shaft, not really practical with a band saw. But it would cut, and leave space to upgrade it later if needed.

Would using the vertical still work, but rigging up a series of deep groove pulleys to change the angle from vertical, to horizontal? I can see it my head, but putting it to paper in a manner suitable for others to understand, is out of my wheel house. 
Iv seen old stem piwered engines do that, but those flat belts were LONG. 

[Ljohnsaw]

I have an 18hp opposed (not V) twin B&S running a 158" x 1¼" blade (.042), belted drive on electric clutch.  I can cut a 30" pine log with some difficulty.  My mill can cut up to 42".  It does really well at 24" and below so 18hp (or 23hp) is not going to cut it for you.  If your cut is twice my "ok" cut I'd say you'd need at least 35hp!  You are going to need a big blade (1½ x .050) and a lot of tension to keep your cuts straight.  How about an old VW air cooled engine?  Light with tons of power.

[charles mann]

I have an 18hp opposed (not V) twin B&S running a 158" x 1¼" blade (.042), belted drive on electric clutch.  I can cut a 30" pine log with some difficulty.  My mill can cut up to 42".  It does really well at 24" and below so 18hp (or 23hp) is not going to cut it for you.  If your cut is twice my "ok" cut I'd say you'd need at least 35hp!  You are going to need a big blade (1½ x .050) and a lot of tension to keep your cuts straight.  How about an old VW air cooled engine?  Light with tons of power.

I was looking at using either engine to drive a hydraulic pump, not drive the mill, then put a low rpm (700 rpm max) for the drive wheel and maybe same rpm for raise/lower and carriage motor. 

[charles mann]

Welcome to the Forum. You are going to have parasitic loss by powering the band via a hydraulic motor, and you will need a lot of cooling capacity for the oil. Even with a motor driven band you are probably talking at least a 75 HP turbo diesel. I would put a bit more study into the proven designs out there before going the route you are suggesting.

But would the parasitic loss be there even on a divorced drive motor and pulley system? As soon as the wheels are put in motion, drag is being placed on the engine (gas or diesel), and when the saw enters the material, more drag is added to the engine. Maybe im not understanding your definition of parasitic drag, im going off my knowledge of parasitic drag when it comes to flying. I know this isnt flying, which is why im asking what you are referring to as parasite drag in terms of turning the band cia hydraulic. 
As for cooling, i figure a 50-55 gal reservoir with a cooling fan pulling/pushing air across a cooler. 
Are you saying 75hp if i want to run everything via hydraulics, or some hydraulics and powering the band too? 
Cooks sawmill has a 62" wide mill, powered by, i think, a 38hp kohler engine, it may be a 37hp. 
You think 5" more of cut width will require double the hp? 
If so, i may go all electric then.
I was wanting to be mobile, use hydro cylinders to lift the bed, bolt my axles in place and retract and stow the cylinders till i get where im going, the deploy them again, take axles out and level the bed, then go to work. But mobility is mostly for my property, so i can move around to get it out of my way, which is why i wanted to go internal combustion, bc i dont have the room thats not water logged at times, close enough to my power pole, and i dont have 3ph, just single, which can be overcome by getting a phase converter. 

[charles mann]

With a hydraulic motor powering the band (I'd go with a 50+ diesel with a belt drive triple pulley) cutting 65" wide you'd need a 75hp diesel unless you want to cut REAL slow.  For up - down a worm gearbox hooked to roller chains  powered by a hyd motor with a high enough ratio to hold the head weight when off .   If using a hyd cylinder for up - down it might want to drift down unless there was a check valve to prevent that. Steve

Im not looking at any production pace speed, just need to get these big pecans, walnuts, live and red oaks milled. Once these big logs are milled, i really wont have a need for a saw of my size. So fast speed isnt a factor and this is mostly for a hobby, and to eventually build my house. 
What type of clutches are out there to hold up to that much power off of these 50-75hp diesels? 
I was thinking of using maybe an old carburated 22R engine out of an yota, or similar out of datsun, but a clutch is the thing that is holding me up. I thought about using a regular clutch with plate and throw out bearing and the input shaft from a manual xmsn for that type gas engine. But i dont know. 

[mike_belben]

A brand new high quality hydraulic pump and motor is only about 80% efficient at best, much energy being given off as heat.  Worn out, youre down in the 60% range.  Pump leakage through the gear housing to gear clearance is a major issue in both the pump and motor. 

Right angle drive is the device one fellow was looking for.  Boston gear and many others make them in many ratios, face patterns and mounting patters.  Surplus center is likely cheapest place to shop for one.   

[Southside]

Mike beat me to explaining what I was referring to.  As far as your comparison to Cooks - look at it this way the 38 hp Cooks is not driving a hydraulic pump as well, depending on your PSI and GPM that could be a significant amount of HP draw just to run fluid in a circle.  

For a real world comparison my feller buncher has a 175 hp Cummins 6BT mated to a couple giant hydraulic pumps. I think the saw pump is 80 GPM @ 4000 PSI - serious oil.  Now obviously a sawmill is not cross cutting like a feller buncher is, and the feller buncher has  a 2.25" kerf - but the buncher also has a 1000+ lb saw disc that gives it significant inertia.  That being said if I cut a 24" tree and go into it too fast I will stall the disc out.  In part because the relief does it's job and protects the circuit and in part because I have exceeded what that much oil can push steel through.  So everything has a limit - and my machine has a 75 gallon dedicated hydraulic tank for the saw pump and a dedicated cooler with a 20" or so fan.  

Now you say that you are not interested in production speed sawing - well there is a catch there too.  If you saw below the ideal speed of your bands then you will generate excess heat on your band which will impact band tension, band life, and cut quality.  You will also have excess sawdust remaining on your boards which will lead to additional work for you all the while it is shortening overall band life and economy.  So just like flying there are ideal parameters that you really want to remain within.  Not saying you can't be successful outside of those parameters, the question is at what cost.  

[Ljohnsaw]

I have an 18hp opposed (not V) twin B&S running a 158" x 1¼" blade (.042), belted drive on electric clutch.  I can cut a 30" pine log with some difficulty.  My mill can cut up to 42".  It does really well at 24" and below so 18hp (or 23hp) is not going to cut it for you.  If your cut is twice my "ok" cut I'd say you'd need at least 35hp!  You are going to need a big blade (1½ x .050) and a lot of tension to keep your cuts straight.  How about an old VW air cooled engine?  Light with tons of power.

I was looking at using either engine to drive a hydraulic pump, not drive the mill, then put a low rpm (700 rpm max) for the drive wheel and maybe same rpm for raise/lower and carriage motor.

Others got to what I was hinting at.  To cut the width with a decent finish, you would need double the power I have with direct drive.  Going the hydraulic route, add another 30 to 50% more hp due to system losses.

[Ianab]

Thought about just going with a chainsaw slabber for the oversize stuff instead?

The 23 hp vertical shaft would be ideal for driving a wide bar with super skip chain. Look at the commercial Peterson / Turbosaw / Lucas machines to get the idea. Lucas make a completely portable machine that can cut 9ft wide. You loose a bit on the wider kerf, but may gain that back on the more accurate cuts, simpler maintenance and engineering. 

[charles mann]

Thought about just going with a chainsaw slabber for the oversize stuff instead?

The 23 hp vertical shaft would be ideal for driving a wide bar with super skip chain. Look at the commercial Peterson / Turbosaw / Lucas machines to get the idea. Lucas make a completely portable machine that can cut 9ft wide. You loose a bit on the wider kerf, but may gain that back on the more accurate cuts, simpler maintenance and engineering.

i had thought of that, but didn't think about using the pony motor/s to drive the chain, i was thinking of my 661, or upgrading to the 880, or even trying to find an old 090, but the bars is where it got difficult. i couldn't find many bars in the 60"-72" range, other than processor bars and the prices were a bit on the steep side, and as rare as 60"-65" pecans, or 46" black walnuts, i wanted to limit the waste in saw chips. in 8 cuts, that equals a 2" slab, wasted in chips. in addition, i would have to buy the granberg 72" milling kit. i have a 36", but never could find a method, that i built at least, that would provide a "true" cut. the 2 different rails i built, would flex under the weight of my jonsered 2166 and definitely under the weight of that 661, which left me with uneven thickness slabs. my next attempt was to use a fiberglass ladder, which might work well on logs, but not for some of the other stuff i wanted to mill. 
1 of the pecans i have to mill, was stuck by lightening, where the canopy section starts. it blew out, and burned a section out that, when filled with bar top epoxy, will make a nice bench, and using the curved limbs from the black walnut, doing a 2 side live edge, for the legs. it would be literally, 1 of a kind. looking at the lucas mill, it might just work for my needs, then i don't need to build anything. 
thanks for the info sir. 

[charles mann]

Mike beat me to explaining what I was referring to.  As far as your comparison to Cooks - look at it this way the 38 hp Cooks is not driving a hydraulic pump as well, depending on your PSI and GPM that could be a significant amount of HP draw just to run fluid in a circle.  

For a real world comparison my feller buncher has a 175 hp Cummins 6BT mated to a couple giant hydraulic pumps. I think the saw pump is 80 GPM @ 4000 PSI - serious oil.  Now obviously a sawmill is not cross cutting like a feller buncher is, and the feller buncher has  a 2.25" kerf - but the buncher also has a 1000+ lb saw disc that gives it significant inertia.  That being said if I cut a 24" tree and go into it too fast I will stall the disc out.  In part because the relief does it's job and protects the circuit and in part because I have exceeded what that much oil can push steel through.  So everything has a limit - and my machine has a 75 gallon dedicated hydraulic tank for the saw pump and a dedicated cooler with a 20" or so fan.  

Now you say that you are not interested in production speed sawing - well there is a catch there too.  If you saw below the ideal speed of your bands then you will generate excess heat on your band which will impact band tension, band life, and cut quality.  You will also have excess sawdust remaining on your boards which will lead to additional work for you all the while it is shortening overall band life and economy.  So just like flying there are ideal parameters that you really want to remain within.  Not saying you can't be successful outside of those parameters, the question is at what cost.  

actually, you explained your reference pretty good here. i don't know much on the hydraulic side of things, beyond wrenching on my acft, which has hydraulics for the flight control system and some of the utility systems, but we are running 3000 psi normal, 3300 for engine start up, but those are very LOW gpm. since we added an internal water tank for wildfire fighting, we have a pump that drives a motor that sucks roughly 45 gal a sec, which takes a LOT of power, especially when the tank has 1000 gal in it and now the motor has to push through 8000 lbs of water head pressure, through a 10" diameter corrugated poly hose. 
you all have given me a lot to think about and some great advise, and since this kind of thing is out of my wheel house, its wise to heed the advise and recommendations of those with more experience. 
what about running a 4 cylinder gas engine out of a car/pick up, it would be lighter than a diesel, with probably double the hp yaw are saying i may need, but the trade off, i loose about half the torque the diesels produce. and I'm not talking staying with the hydraulic system, but in general, and iv seen small gas burners running 1/4-1/2 the price of a new 37-38hp air cooled gasser. 
i may just scrap this whole plan, pay a guy in austin that has the woodmizer wm1000 and can mill everything i currently need milling, for around $1000, and maybe less by doing some bartering, and building a mill with a cut size of 40".
i want to get my ducks in a row before dumping money into a project, that may fail after 6 months, mostly bc big trees are becoming more scarce every year. 
again, thank you, and the rest of the folks who have commented and left their advise and recommendations. I'm glad i found this site and asked, before dumping 1000s of $ into a possible titanic failure. 

[Ianab]

Long bars cost $$, this is true. This is why large slabs also cost $$. No matter what you use to cut them, it costs. 

Woodmizer makes a great slabbing bandsaw, but it costs ~50k. It's a beast of a machine, and you can see why it costs that. 

The portable chainsaw slabbers start around $10k, Need to recover a LOT more slabs to make up the extra investment, AND it's not exactly portable. 

If you have the budget to build a working ~48" band mill, then a chainsaw mill on a similar carriage should be relatively simple. Not talking about a chainsaw powerhead. Think BIG bar, powered by a vertical 4 stroke, via an idler shaft to get the chain speed right. 

[Southside]

In a sawmill application torque is your friend, thus why electric is the answer with industrial sized equipment. I am not convinced a 22r would perform the way you are hoping it will. My guess is they produce their top HP at an RPM that is a long way out of the torque curve, so when she needs that extra to get through twisted grain or big knots it just might not have the ability to muscle through without dropping off on RPM's to a point where it's too slow for the band.

Not trying to discourage your project, but if you have access to an experienced sawyer with a WM1000 and $1K will do the job you need then unless you are building this beast for the challenge then that is a much more economical solution.

[charles mann]

Southside, 
The low tq at rpm speed is what i thinking too, there wouldnt be enough. I think ill go with a 40-50hm diesel, belt drive for the band and put a pump/motor for the rasie/lower and carriage trolley. 

[charles mann]

well, iv located several engines, a 44hp kubota diesel, a 67hp perkins, already attached to a hydraulic power unit (not going hydraulic band wheel drive though) and a cummins 4bt. the cummins is $1000 per cylinder, but local for me, but still the last choice if possible, the others are either in northern idaho, or just across the border in washington and they are closer to my price range.

I am sorry if I'm asking a lot of questions, but i have been given a LOT of GREAT advise, i will follow/learn from those who have been down that road before. Iv gotten to where i look at things in the perspective of "you get what you pay for" and skimping on things can and most often DO lead to negative consequences. So following yaws advise, I'm dropping the hydraulic drive option and going conventional. "Why reinvent the wheel?" as the saying goes.

I still may run hydraulics for the carriage drive and maybe for the raise/lower, unless 12 vdc would be better. Which is where the question of chain/sprocket or pulley/belt comes to play.  
Now that I'm not going hydraulic drive for the band, which would be recommended, chain and sprocket drive or belt and pulley drive?
 
I'm sure, after reading a few replies, that more than 1 belt, and assuming more than 1 sprocket will be required on the drive wheel. Going chain, if something happens, i could go to tractor supply for the weekend break downs, or the john deere dealer during the week days and get chain and possibly sprocket. Which is why I'm leaning to chain/sprocket. 
Belts, i fear will have to be custom ordered, unless i build to what i can get locally at napa or john deere, or even the big rig service/parts centers locally, IF they even carry in stock the size (diameter/thickness, not length so much) belt. Im assuming and probably correct in my assumption, that normal automotive belts wont hold up to the stresses that will be encountered. But iv been wrong many times before on things. That is how we learn, form our mistakes. 

Again, Thank You all for your help and advice. 
 

[Southside]

Hopefully some others will chime in on the engines here as I seem to recall some issues have been around the Perkins when used in a sawmill application - I want to say it's a side loading issue on the crank but never having owned one I could be off on that.  Baker uses a 4BT on their mills, and Woodmizer has plenty of Kubota engines running out there.

As far as the up / down, forward / reverse, the chain system on the Woodmizers works very well.  Up / down is a climbing motor on a fixed roller chain and the forward / reverse is off the hanging chain on the side of the frame with a gear pulling through the chain.  I know of a couple guys who had mills where the chain was mounted on top of the frame rail and sawdust / sticks / debris can be an issue getting jammed in there.  With both motors I would think that hydraulic will give you longer life and better vertical hold as your head won't be light when you are done.    

[mike_belben]

A hanging vertical chain is sort of a poor mans gear rack and pinion, not a bad design at all.  12vdc winch and cables  is another cheap and straightforward means.



However you choose to raise and lower, hold capacity is very important.  If you dont want to be setting a clamp brake with every height change, then you need a lot of gear reduction to hold.  Either worm drive gear box, winch motor planetary, or a positive lock such as a boat winch.  


Winch motors themselves are not terribly impressive without the planetary.  I am inclined to say v8 starter motors put out considerably more torque for a lot less money in direct drive and are a lot more available on sunday afternoon.  You can modify starter to run a pulley or sprocket pretty easy.  Delco 10MT is a real good platform to fool with imo.  Cheap and super easy to rebuild or mod.

A 12vdc reversing contactor is the name of the part you will want to make dc motors run two ways.