Hydraulic conversion of circular sawmill

[Jim1934]

 Greetings,
Am powering an old Knight 54 " circular mill from the PTO
of A JD 870 tractor. Original 100 HP IH diesel is no longer available.
JD can only handle 6" logs; not acceptable.

Saw arbor also powers carriage thru a complicated worn out series of clutches and belts.
Considered isolating carriage drive from main arbor and driving it with separate hydraulics
but that will do little to increase the size of log that can be sawn.

Would like to correspond with anyone who has experience (or not) converting a circular mill to hydraulics in part or in whole.

Thanks, Jim  

Please see my later reply on April 29

[mike_belben]

id set it up for a stationary truck engine that can be maintained via napa and has modern parts available everywhere for cheap.  chevy 350, ford 351w etc.  

[Mooseherder]

I have a few pictures of my hydraulic deck in my gallery under Sawmill. 



 

 

 

 

 

[dgdrls]

Greetings,
Am powering an old Knight 54 " circular mill from the PTO
of A JD 870 tractor. Original 100 HP IH diesel is no longer available.
JD can only handle 6" logs; not acceptable.

Saw arbor also powers carriage thru a complicated worn out series of clutches and belts.
Considered isolating carriage drive from main arbor and driving it with separate hydraulics
but that will do little to increase the size of log that can be sawn.

Would like to correspond with anyone who has experience (or not) converting a circular mill to hydraulics in part or in whole.

Thanks, Jim  jladd52@comcast.net.

Hi,  Jim
lots to consider,
first to my mind is how large an arbor are you driving?
Any chance you have electric power (3 phase) available?
If not I'd be looking for diesel power.
Other members with a ton more experience than I
have, and will weight-in
FWIW, I would take your email off the post,
best
D

[moodnacreek]

There are more diesel engines out there than ever before. A cheap rusted out ford/ih 6.9 or 7.3 stick cut like Mike says would be good power. Hardest part is putting the truck rear end drive shaft yoke on your mandrel and putting a belt drive governor on the engine. It would be well worth the effort.

[Ron Wenrich]

We always ran an industrial diesel straight to the arbor.  There was no need for the rear axle.  The saw speed was done through pulley sizes.  Most hand mills would be run with a Detroit 3-71 or better or a Cummins.  We did change our hand mill over to a hydraulic feed by running a hydraulic pump off of the arbor.  We used a valve for our control to a motor that was hooked to the cable spool.  There was a gearing difference through sprockets that adjusted our feed speed so that it was controllable, and fast enough to be efficient.

Are you planning to put other hydraulics to the mill? We ran a Detroit 6-71.  In addition to running our automatic Jackson mill, we ran a huge hydraulic pump off the motor.  We used that hydraulics to run our edger.  I did see an Amish mill that had a long jack shaft that had 25 belts running off of it to power their mill.  Engineering genius, but I didn't see it running, so I don't know how efficient it was.

[moodnacreek]

What I was saying is that to run a sawmill, a r/h sawmill] with an old truck is that you take the drive shaft yoke off the truck rear and have it machined to fit a shaft or the mandrel.

[mike_belben]

the early ford 7.3 idi is an overbored 6.9 block with thin parent metal bores that eventually will cavitate through from the coolant jacket into the bores and is then junk for most people.  also they had very tight valve seals that starved the stems and tended to drop valve heads in.  if buying an engine i would want to pressure test the radiator to see that it isnt already pin holed.  theyll hydrolock once it happens.  and pull the rockets to wobble the valves.   if youve already got one that runs, hey run it.  but i wouldnt part with too much money for a idi 7.3 personally.  i really really disliked the one that i owned briefly and was constantly working on. ive stayed away from 7.3 thereafter.   


dont discount little foreign 4cylinder econocar engines either IMO.  they are super cheap, start in artic temps, sip fuel, quiet, market saturated with parts, compact footprint and all make about 110hp or more. you can weld up the spider gears in a manual transaxle pretty easy and use just one CV axle for your driveshaft.  this gives you a variety of speeds in either direction since you just swap the custom CV and stub shaft to the other hole to reverse rotation.  and you can take it out of gear to run the hydraulics without the saw.  hydraulic takeoff power can come from the vee belts or weld a vbelt to a steel serpent pulley for takeoff power.  if you start with a whole wrecked car that runs youve got everything you need right there to plop on a skid. 


man ive just talked myself into building a sawmill out of the yaris.  what the heck.  why do i keep logging in here!?  :D ;D 

[moodnacreek]

 7 .3 idi's are a dime a dozen and I have had good luck so far with diesel antifreeze in them. The glow plugs are a pain but there is a way around that , same with the lift pump. I recomend them because there are so many that have out lasted the truck or van. The other cheap diesel is the ford 6.6 [401] and of course the 5.9 come apart or the actual power units. A few years back you would see the Mercedes truck fronts direct connected to small sawmills like I have mentioned.  I get the feeling the work needed to do these cheap power hook ups is not on the menu for most today , I mean who needs dirt under their fingernails with free money coming in.

[dgdrls]

Well.. I vote Detroit power,

More Detroit Diesel Power! - YouTube

[mike_belben]

Tow behind ingersoll compressors tend to have the air end die before the engines.  Deutz, cummins, deere etc often in them.  

Reefers have 3 cyl isuzu and kubota or thermo king power. 

[moodnacreek]

Today's 'car' engines will not run a 54" saw in anything except small pine and cedar.  The straight 8 Buick is long gone. You need about 80 hp at  say 2000 rpm. The 7.3 I mention is around 180 hp in the pick up and probably would be 100 + on a sawmill.

[welderskelter]

I thought Jim said he was under powered already. Now isnt hydraulics the most inefficient form of power there is? Dont know but seems he will need a bigger engine yet. Just my 2 cents worth.

[Ron Wenrich]

For those cold periods, we always had a block heater and didn't need glow plugs.  But, we always had some electric in the mill.

[mike_belben]

Today's 'car' engines will not run a 54" saw in anything except small pine and cedar.  The straight 8 Buick is long gone. You need about 80 hp at  say 2000 rpm. The 7.3 I mention is around 180 hp in the pick up and probably would be 100 + on a sawmill.

choose a different gear, get your 80hp at 4000rpm.  sheave to correct sfpm at the saw rim either way.

these little 4 bangers can simply live at WOT for very long periods of time.  theyre fairly amazing and overlooked. 

[mike_belben]

I thought Jim said he was under powered already. Now isnt hydraulics the most inefficient form of power there is? Dont know but seems he will need a bigger engine yet. Just my 2 cents worth.

yes.  new hydraulic components of high quality have around a 15-20% thermal loss rate from input to output power.  if not on day one, they will soon after being put into service and itll get worse from there.  
however in a sawmill, much hydraulic power is generally only used when the saw is not in the wood. a carriage feed being the exception.  you dont HAVE to be running a livedeck while the carriage is going.  

[mike_belben]

 The straight 8 Buick is long gone. 

..and thank god for that! 
;D

[moodnacreek]

Today's 'car' engines will not run a 54" saw in anything except small pine and cedar.  The straight 8 Buick is long gone. You need about 80 hp at  say 2000 rpm. The 7.3 I mention is around 180 hp in the pick up and probably would be 100 + on a sawmill.

choose a different gear, get your 80hp at 4000rpm.  sheave to correct sfpm at the saw rim either way.

these little 4 bangers can simply live at WOT for very long periods of time.  theyre fairly amazing and overlooked.

'At 4000rpm' Yeah sure, that is on paper. It will take a pile of junk to bring 4 grand down to 600. I tried alot of such things when I was a kid and really broke. The big pulley on the mill would have to be on a separate shaft due to the overhung load and another 'jack' shaft for another set of pullies to keep the driver big enough so the belts don't slip. Been there and done that.

[mike_belben]

'At' 4000 rpm Yeah sure, that is on paper. It will take a pile of junk to bring 4 grand down to 600. I tried alot of such things when I was a kid and really broke. The big pulley on the mill would have to be on a separate shaft due to the overhung load and another 'jack' shaft for another set of pullies to keep the driver big enough so the belts don't slip. Been there and done that.

The junk you need is already under the hood.

Dime a dozen 1990s accord 2.2L (F22A_ engine series) with 5speed manual trans, the H2A5.

Makes 100hp AT THE TIRE by around 4,250 rpm.   Flat out theyll make 150ish hp and live a very long life at that power level.  They can make 400hp quite reliably and up into the low 1,000hp one pass at a time.


4250 rpm ÷  1.809 (2nd gear) ÷ 4.062 (final drive ratio) = 578.37 at the arbor shaft.  


For over 20 years now its been possible to socket the ECMs in various OBD-0 and OBD1 cars, burn your own Eproms and use any number of softwares to set rev limiters and fuel/ignition timing maps. Ive done it and somewhere still have the gear.
Honestly you could put a junkyard turbo on a hacked up cast iron oem manifold and have that saw running spot on at your target speed by ignition governing and have power to spare.


I know thats outside the scope of the OPs likely intentions but ya kinda called me out a bit doug so im backing it up.  Google mike_belben honda if you think im blowing smoke  ;)

[luap]

I converted the friction drive on an American#1 to a simple hydraulic carriage drive, similar to what Mooseherder showed. The drive pulley was mounted on the outboard side of the arbor bearing using a 2 belt pulley. The valve is a single open center valve. The open center allows you to physically move the carriage with the motor off. A low speed ,high torque motor was directly coupled to the shaft that moved the carriage. I used a high pressure needle valve  in return line to fine tune the speed on wide open to allow a faster return. They make a device for this but can't recall what it's called. One advantage to driving off the arbor is if you over feed and your arbor slows,so does the carriage speed. Don't compromise your safety by using pipe fittings rather than hydraulic fittings. Everything can be sourced from Surplus Center.

[moodnacreek]

Mike I'm with you 99 percent of the time and the small high speed engine would cut the wood but it is not the practical way to power a mill.

[moodnacreek]

I converted the friction drive on an American#1 to a simple hydraulic carriage drive, similar to what Mooseherder showed. The drive pulley was mounted on the outboard side of the arbor bearing using a 2 belt pulley. The valve is a single open center valve. The open center allows you to physically move the carriage with the motor off. A low speed ,high torque motor was directly coupled to the shaft that moved the carriage. I used a high pressure needle valve  in return line to fine tune the speed on wide open to allow a faster return. They make a device for this but can't recall what it's called. One advantage to driving off the arbor is if you over feed and your arbor slows,so does the carriage speed. Don't compromise your safety by using pipe fittings rather than hydraulic fittings. Everything can be sourced from Surplus Center.

This description is something I need to do. I always thought you set it up for the gig back speed and needle valve the feed to what it can handle. Am I right?

[mike_belben]

Doug i been called a lot of dirty names but practical is not one of them. 

;D

[moodnacreek]

Doug i been called a lot of dirty names but practical is not one of them.

;D

It's a long pull coming up out of Port with a little 466 :D. Your turn.

[mike_belben]

Yeah those 466s dont handle the boost, fuel or rpms like a honda does ill tell ya that.  

[luap]

"This description is something I need to do. I always thought you set it up for the gig back speed and needle valve the feed to what it can handle. Am I right?" short answer, Yes.
     It will depend on  the gpm of the pump and the motor and the valve. Some valves are very good at feathering the volume to control the flow. I am using the control valve for feed rate and my focus is on the cut. The gig back I can full stroke the valve and focus on advancing the set works or where to stop the carriage to load the next log. So the needle valve restricts max return speed with control valve held all the way back.   I had to downsize my pump as my first attempt,the carriage speed was too fast. I just used what I had laying around as I have collected many hydraulic components over the years. Hydraulics is an expensive hobby.

[Jim1934]

Thanks to all for responding!
Someone asked about arbor size - 2 5/8.
Electricity only available from portable generator.
I agree that building a speed reduction unit from parts is difficult
especially to power entire saw.
Desire to have separate power source  for carriage so it can be moved  when saw stalls in a cut.
So I won't power hyd. for carriage from main saw arbor.

Yes- I  need more power than JD can deliver. The original IH 6Cyl. 100 hp Diesel is on site
but needs work. It probably can do 50 HP at 1500 RPM and its 8 inch
wood pulley drives a 24 " pulley on saw arbor via an 8 inch twisted flat belt.
Pulleys separated by about 18 feet. I believe 50 Hp would be adequate from what I have observed.
Belt stays on pulleys until we start the cut and then it throws belt.
We are not smart enough to solve that problem and we have tried.
Those two considerations make me look for a new power source.
I am 86 and want to leave my son something better.

The Accord engine solution is especially appealing.
Any "throw the belt" solutions?

Very appreciative. Jim

[moodnacreek]

Luap, thanks for the reply here. So you restricted the gig and control your feed speed with the hand valve. Not the way I thought after looking a the kit Lanetec once offered. But if your valve gives comfortable control of the feed that all that is needed. I can't help wonder what valve is best. I think prince makes a rotary [motor] valve that might be better than a spool.    Doug

[fluidpowerpro]

Ive got a bit of experience with Hydraulics so if you have any questions along the way, feel free to ask.

[dogone]

   Jim 1934
The people to ask about belts are threshermen /steam guys.They deal with long flat belt drives all the time. They will have an answer. Start by googling steam engine forums.