Hydrolic motor and pump question

[lesswork]

New boy on the block looking for some help ,guess most of us join to gleem eachothers knowledge, I hope when this project is up and running I can share what I've learnt. So my project is a firewood processer , the main of which has been built.  48'' circ saw blade,20 ton wood splitter below, built as a king size chopsaw .  Cummins 12 valve to run the pump.  Sure you get the picture !  My question is ,does anyone have an idea of what size pump and motor I will need to drive the blade plus the splitter plus clamp plus conveyer belt.  I'm thinking I will have to have two pumps piggy backed so the blade can run constant ??  Blade was from a pto driven mill ,rated at 600 rpm.Max log dia would be 20'' Any help would be great.   Thanks

[Magicman]

I am of no help with your questions, but Welcome to the Forestry Forum lesswork.  Adding your location to your profile always helps.   

[Ljohnsaw]

Wow, now that sounds awesome, and scary!  Not an expert on hydraulics but I would think what motor you choose for the blade, etc, will determine what size pump you need to run it.  You probably will need a lot of HP delivered on that blade.  Will the blade cut cross grain?  I'm assuming it was from a sawmill made to rip wood.  Got any pictures of your build so far?  We like pictures

[North River Energy]

As ljohnsaw suggests, your saw pump capacity is determined by your hydraulic motor demand. That, in turn, depends on saw diameter, speed, tooth count/type, and probably a few other variables.
As to the rest, the pump you use for the splitter depends on cylinder size, desired cycle time, and hydraulic valve configuration.  For instance, most common splitter valves top out around 25gpm.  You can shove more fluid through them, but it makes more heat and that consumes more fuel.

For the clamps and conveyor, again it depends on what size cylinders/motors, and how fast you want the stuff to move around.
Based on my own experience, I would use three pumps, rather than just two.  As a guess, I'd say 25-30 on the splitter, and 11 to 18 for the 'accessories'.

[Chuck White]

Welcome to the Forestry Forum, lesswork.

[lesswork]

Thanks for the welcomes. Is anyone driving a 48'' blade directly off a tractor PTO. If so what PTO  Hp are you using.  I'm thinking the blade I have ,as it was used for ripping will cut easier cross grain than ripping,plus for only about 2 seconds.  I have a little experience with hydrolics as all the farm implements have them. Just not sure how many horses needed to drive this blade,  replaceable teeth ....38...3/8''  wide   hammered at 600 rpm.

[beenthere]

lesswork
Click your forum name and it will take you to where you can update your profile with at least your location. Having your location helps a lot in answering your questions.. and am sure if you read other posts on the forum, that knowing the posters location helps a lot in understanding that forum member.

If you are talking about using an inserted tooth sawmill blade for cross cutting, you might not be happy with it.. has to do with the grain direction and is a reason that crosscut saws have a different design in the teeth.

[Kbeitz]

Putting a flywheel on the blade shaft will help a lot.

[Gearbox]

From what I read you are trying to use a circle blade from a sawmill . If this is what you plan DON'T USE THAT BLADE EVEN FOR ONE CUT . YOU MAY NOT LIVE TO FINISH THE CUT . The rip blade will grab the log and throw it tearing up all your hard work bulding the machine .    Gearbox

[beenthere]

Well said Gearbox.

[lesswork]

Thanks for your input , but a 9000 Lbs clamp , I think should hold it solid, check out...charlies home made wood processer...which I am baseing mine on. and see what you think.

[beenthere]

lesswork
Think you are missing the point.

Think back to the basics of just using a sharp chisel to make a dado groove in wood. You get all manner of splinters if you just start out gouging the wood across the grain without cutting off the wood fibers first along the edge of the dado.

With the grain, a chisel is much easier and less fiber cutting is needed along those edges.

Don't know if this helps any, but hope so.

Or consider the design of the chainsaw teeth, that are curved with side cutting to sever the fibers as well as the top of the tooth to remove the chip. Without the side cutting, couldn't make a chainsaw cut wood across the grain.

[schmism]

Its my understanding that most circle mills are generally powered in the 50-90hp range.   (depending on blade size, tooth count etc)

You probably want to be north of the 23 cubic inch/rev motors.
http://www.surpluscenter.com/Hydraulics/Hydraulic-Motors/Low-Speed-High-Torque-Hydraulic-Motors/23-87-CU-IN-DYNAMIC-BMK6-HYD-MOTOR-9-8665-400.axd

something like that puts you at 60 gal/min @ 3000 psi would take roughly 70hp to run

now for the pump side.   Figure your diesel wants to pure along at 2200 rpm  your looking at pump to drive (just) the saw at 6.5 CU. IN/rev

There are various hydraulic calculators floating around. 
http://www.baumhydraulics.com/pages.php?pageid=4

For instance the hydraulic cylinder speed calculator you can play with to get an idea of what kind of flow you'll need for the cylinders you want to use on the splitter and mill.  You can plug in known numbers from existing splitters to get an idea of the speeds you might shoot for.

As for the conveyor,  perhaps run some math from existing youtube vids of other circle mills.
https://www.youtube.com/watch?v=UPrFb4jNBis
3 sec to clear a 8' log gives a belt speed of 480 ft/min   Useing that linear speed you can figure an rpm for your hydualic motor based on the size of the drum you want to use to drive the belt.  (so like an 8" drum has to run at 230rpm)

[lesswork]

Thank you ''beenthere'' I have a better understanding of your point,I'm more a metal worker for the past 50 yrs than a wood sawyer so its a learning curve. Also a big thanks to ''schmism'' that was a lot of usefull info.I much appreciate your time.   ''lesswork''.