Alternative engines for homemade sawmill designs

[Murf]

Olen, a hydrostatic drive system is not 100% efficient, just like a propeller there is power losses.

In the case of a hydrostatic system though, most of the loss is because there is heat generated by the pump and motor, some of the energy that should produce work, instead produces heat, between 2% & 5% generally.

There are however some big benefits sometimes. Like being able to have nothing more than a couple of hoses between the power source (pump) and the motor.

Another is, as I mentioned earlier, being able to have a single source (pump) making enough power (pressure & flow rate) to run several things simultaneously.

The other consideration is weight, or in this case, the lack of it. A relatively small, light hydraulic motor is capable of producing some pretty impressive horsepower.

If a substantial engine-driven pump and remote reservoir were used to power a small mill, the head would be very light and the construction would be greatly simplified.

As an example, you could generate 20-25hp using a hydraulic motor that weighed less than 30 pounds given an adequate supply of hydraulic power to that motor.

Then a few smaller (read cheaper) motors could give you a live log deck, a hyd. slab conveyor to the off-bearer, a hyd. de-barker, a hyd. log turner, a loader, maybe even a hyd. edger blade or two.

Hydraulics are also very easy to automate or set to do repetitive cycles, and are very weather (and sawdust) resistant.

[robotguy]

who knows about or has seen  hyd, drives for circle saws, 16 inch??
i am headed in that direction for the contraption sitting in my garage as i did not want go with pullys & belts  and direct drive wont work out for my application. as it is mobile elect is not an option.

some thoughts on hyd.

weight of total oil volume vrs pullys belts bearings shafts ??

wear-tear / lifespan on hyd vrs mech /  belts pullys bearings ??

fire hazard ??

water based hyd  fluid ????

appears this is a newer water based  hyd  fluid replacement  that works with additives for rust , ect.  any one seen / hear any thing about this ???

with hyd, my concern was that the hyd pump will bog down during the cut & the log feed will continue to feed the log & break all kinds of stuff !!!
this probably could be solved but i have not got that problem worked out so far.

my powerplant has 136 h.p. & is governed/ controlled by the cruise control system that was in the vehicle as it is *matched* to it and i did not have to fab, make, invent, a governer system.

blade speed is constant  with & without load on the blades

again thanks  for all help & workd of wisdom on this

robotguy.

[iain]

I have no experiance with circles, peter has a 52" circle with a pump sitting in the woods
for the life of me i cant remember if the drive is direct, through belts. or hydralic pump as all the afore mentioned gubbings are there
i know the pump is rated at about 78hp

if i can find my little dig ill go and take a pic or two ( i dont think Linda will let me have her big shinie new nikon )


iain

[Dan_Shade]

one thing to be aware of using automotive cruise controls, is the hysteresis of the controls is very large (hysteresis is the difference from turning off and on, or on and off, it's the term for your heating thermostats on/off difference)

case in point, jack your car up, put it in gear, and try to set the cruise control for whatever speed, the engine will surge and go crazy with no load against it. at least my Mustang does this, I tried it once!

It may work, but it may prove worthwhile to test it first, and then come up with plan B

[Opiki]

why not look around for a bus air conditioning unit that has been removed to make way for a motorhome conversion.
I have just purchase and installed a toyota 2c diesel engine into my Mahoe sawmill the engine has the govenor of course and so far my only problem is the engine strains a bit and cutting is abit slow when cutting 12x6 cuts. Although in tinkering with the fuel flow settings I am getting more torque from the motor. I think the engine was "depowered" when it was put into the bus.
I have also just purchased a turbo which bolts stright on and soon I will be installing this.
I know here in New Zealand pop 4 million there are quite a few of these units floating around( different buses use different designs) So where you are there should be a few.
Worth looking at.