Water wheel or wind powered firewood saw

DMcCoy · September 19, 2021, 09:06:03 AM

Someday project(s)- Just thought I would put this out there.
There are plenty of old lumber saw mills run by both water and wind but no firewood cutting mills that I have been able to find.
Without doing the math I would think one could run a small overshot water wheel in a "river run" kind of set up using flexible drain pipe to deliver the water at elevation. Using a pitman arm to run a reciprocating saw seems like a real possibility. It would be very slow to the point it would be ideal to have a "shut off" or ledge for the arm to slide on once the cut was complete so you don't have babysit the thing. Some sort of cow bell alarm when the cut was complete.
I have taken this project as far as buying 100' of drain pipe. :

Wind powered could be crude and simple.
Someday...

mike_belben · September 19, 2021, 09:56:55 AM

If the grid went dry at the same time fossil fuels were banned, id do a steam drive stationary circle mill and hide it before they ban that too.

At that point id also make my stoves out of layed down water tanks in a rocket configuration so i can feed in spindly 4 foot long limbs sawed with a one man crosscut instead. Theres enough thinnings to keep me heated for eternity.

Don P · September 19, 2021, 10:57:55 AM

I've been playing down by the creek and having similar mind wanders :D.
There's a very crude waterwheel hp calc in my corner of the toolbox but I'd like to know more about sizing them.

We were working on a gristmill that had originally had 2 big stands of old time slow stones and a wooden overshot wheel. Shortly after the Great War it was refitted with a 20' steel overshot wheel and a 3 stand high speed roller mill with big sifter elevators, etc. A university professor/expert on old mills who knows the mill well was out walking through it showing me how it all worked. As we walked up the old raceway and were surveying the breached dam I was asking if one set of the old stones could be turned "run of the creek". He made the comment that with the current flow of the creek maybe. Then he said with the flow and the size of the millpond that when they installed the "modern" equipment he didn't see how they could run continuously, there isn't enough water to be running that machinery, it must have run in "pulses" then recharged the pond, then run for another hour or two.

DMcCoy · September 20, 2021, 08:46:56 AM

Don, you took this the direction I was thinking. I have a small pond which I could also use. I added an adjustable drain (the sluice gate) to it because of beavers, it's about 18" below the overflow.
Either way, river run or using the pond as a battery my thoughts were to make a metal frame with a wooden 4' wheel with maple wood bearings - lacking east coast hard maple I have set aside some vine maple.
I cannot remember how I determined the following but somehow I estimated 35lbs of force would move the saw. Cutting up to a 12" dia. log would be adequate for my use so a 6" pitman x2 would deliver @ 12" stroke. If the wheel buckets were 6" deep and I did the easy way and went with 3' dia. or 18" radius I would get 3x power. If 35lbs is adequate then I need @ 12 lbs of water at the horizontal spot. This is where I stopped doing the math as far as sizing, with all buckets adding to the force and wheel speed needed to determine the flow required. This seems relatively easy to get the required force but I would like my math to back me up, so my project sits.
Below is a very inclusive document on overshot water wheels.

Joe Hillmann · September 21, 2021, 11:19:01 AM

I see no reason that design wouldn't work. Powered hacksaws used to be quite common before metal cutting bandsaw blades became cheap. They are pretty much the same idea.

Assuming your math on how much power you need and how much power your wheel will produce the next issue will be, do you have enough water? A small pond could be drained in a few minutes, a big pond with an inlet stream would never drain.

There were also antique drag saws that used the same idea but coupled to some type of engine or tractor. There is no reason they couldn't be powered by anything spinning that had enough torque.

I also like the idea of cutting the firewood to longer lengths, two times the firewood and half the cuts. When you have a chain saw that will make the cuts in a few seconds there are more benefits to having shorter wood. If you don't have the power to make cuts quick the cons of shorter wood may outweigh the pros.

Having a waterwheel could also give you power via shafts or belts for other tool/experiments as well.

Here is a video on a similar project
Constructing a Bushcraft Waterwheel / Harnessing Hydropower Energy for My Log Cabin Camp - YouTube
He uses it to grind wheat, sharpen tools, generate electricity and wash clothes.

I started building a waterwheel for a similar project last year but building the cabin has pushed everything else aside so it has been sitting in the basement ever since waiting for me to get back to it.

mike_belben · September 21, 2021, 12:44:42 PM

our first metal cutting bandsaw was a ww2 model hacksaw off a ship. it beat pushing the blade by hand.

WV Sawmiller · September 23, 2021, 09:29:35 PM

I would think speed could be improved by just gearing it down further. Starting with big going to small gears/cogs makes for increased speed. I keep thinking of the size difference between the gears on my honey extractor.

DMcCoy · September 24, 2021, 08:09:08 AM

My concern with trying to go faster is I would loose an equal amount of torque.
4x faster but 1/4 the torque. I agree it would be very, very slow. One fear I have is it will cut just fast enough that you can't walk away from it. That would be very irritating.
If I attach the saw directly to the pitman so it would swing up and down slightly maybe my calculation of 35lbs would be so much more than needed that I could increase the speed, I simply don't have anything to reference to other than pushing on a floor scale, which isn't very scientific.
I have an old drag saw hanging in my shop, the saw blade is held on a frame so it slides back and forth. Often there is a lot of wisdom built into old, lightly powered equipment, so the swinging saw blade might have an issue I don't see yet.
Also I have concerns over the pitman and the force it will exert through it's entire circle being uneven. The water wheel itself would act as a flywheel to help overcome this but by how much.
I'm going to have to build one and find out.
Joe Hillmann - Thanks for the video. I have another reason to save my old dead battery powered drills, the original reason escapes me at the moment...
Wife - 'Why are you saving all these old drills'?
Me - 'Well, Joe Hillmann posted this utube link....' ;D

mike_belben · September 24, 2021, 08:18:29 AM

This is just a fun tinker time project, right?

DMcCoy · September 24, 2021, 09:18:10 AM

Quote from: mike_belben on September 24, 2021, 08:18:29 AM
This is just a fun tinker time project, right?

Totally!

Don P · September 24, 2021, 06:39:44 PM

A green firewood processor. Jed move away from here :D

upnut · December 19, 2021, 04:13:49 PM

We visited this mill a few years back with the kids, pretty interesting.....Water Power - The Sawmill at Historic Mill Creek Discovery Park - YouTube

Scott B.

DMcCoy · December 20, 2021, 07:34:18 AM

Thanks for posting!
I have watched a few water and wind sash saws but this one was unique in it's overall simplicity.
I had not considered a paddle wheel which is easier to construct.

Joe Hillmann · December 20, 2021, 01:21:48 PM

Quote from: upnut on December 19, 2021, 04:13:49 PM
We visited this mill a few years back with the kids, pretty interesting.....Water Power - The Sawmill at Historic Mill Creek Discovery Park - YouTube

Scott B.

I learned where the term "pitman arm" comes from. I have used the term many times but never put two and two together to an actual pit man.

trimguy · December 20, 2021, 01:43:33 PM

I stopped in there one time when I lived up there ( 1986 ? ) The saw was not in operation when I was there. We will have to go check it out when I go back up there in the spring. Thanks for posting.

Magicman · December 21, 2021, 08:23:32 PM

Thank You @upnut. That is the sawmill that we visited a few years ago:

IMG 1084 - YouTube

IMG 1085 - YouTube

IMG 1083 - YouTube

Don P · December 22, 2021, 05:29:22 AM

I'll save those vids till I have the speed to watch but from the comments and the pic of MM's that looks like what we call a flutter wheel which is often what powered sash saws.

moodnacreek · December 31, 2021, 07:21:15 PM

I once visited a grist mill on a fair sized river. They ran it with a diesel tractor pto. The maintenance of these water power structures is too much for a small operation. It may seem that they run for nothing, far from it, same deal with steam.

DMcCoy · July 26, 2022, 07:54:29 AM

I found one, well a picture of one. Not sure the copyright so here is the link.
Windmill powered firewood saw!
The Homemade Windmills of Nebraska

Don P · July 26, 2022, 10:54:51 PM

That's cool. I think you probably need a better fan on a taller tower for most places. I came across several pages on old windmills last night, the old Aeromotors and similar. Most were in the 8-12' diameter range and produced from 3/4 to 1-1/2 hp. Several had wooden towers with a tilting upper half that brought the fan to the ground for service.

moodnacreek · July 28, 2022, 09:49:12 PM

If I needed to saw firewood without buying fuel I would use an old indirect injection diesel engine and burn used vegetable or motor oil. I did this for several years on a sawmill with an old Cat 318 diesel, pony start. The settling and filtering of the dirty oil is the thing plus having easy access to the injectors and the old Cat was just right. I also have a 1 cyl. 7 1/2 hp that will do this. Water power is a beautiful thing but way too much up keep.

Ianab · July 29, 2022, 01:01:35 AM

Hydro would be my choice, assuming a suitable location.

This is a historic hydro generator that's in the local National Park. The unit was built in 1896, and has been operating continuously at it's current site since 1935, It was moved there at that time because there was no mains power at the guest house. It's actually rated for 75 kw, assuming enough water flow and pressure.

https://www.doc.govt.nz/documents/conservation/historic/by-region/dawson-falls-power-station-fact-sheet.pdf

Now that technology is over 100 years old and would run a decent sized sawmill. On a smaller scale a micro-hydro could charge an old EV battery pack. Even if it was only producing ~1kw, it's doing that 24/7, and storing it for later. I guess the same goes for solar and wind too, where a battery would overcome their intermittent nature.

DMcCoy · July 29, 2022, 08:14:58 AM

Don P. - I have decided to build something, though my current project list is overflowing. I already have the hub on the the lathe, bored to 1". I will broach a keyway.
Using my junk pile, it will have 4 spokes of 1 3/8" galvanized greenhouse tubing and cedar blades. If I can make the blades swivel on the spoke it might be useful for over speed protection. Thinking 8' blades at the moment, which could get real exciting in a bad way. Either spring loaded or counter weights to reef the blades, not sure yet.
Our winds are light when it is windy 5-8 mph. Max out at 13-15
I really want a jack shaft and pitman arm down near the ground to move the saw. The see-saw motion would be useful to overcome the starting inertia and help with overall low power. I have an abundance of #55 ag chain and sprockets so it is doable. Perhaps a V belt pulley and a portion of belt for a brake. The tower thing I have no ideas, lots of 1/2" galvanized pipe and of course lumber.
Reading about Dutch windmill operators who might put in a 36 hr shift while the wind blows I will never get rid of my chainsaw. ;D

DMcCoy · July 29, 2022, 08:38:36 AM

I have become increasingly concerned with anything in the alternative energy realm that requires fuel or batteries. There is a girl in FL who bought an $11,000 used EV only to need a new battery $14,000...BUT...the battery is not even available.
Jim Kunsler's home solar system needs new batteries and the new code requires lithium ion. He isn't sure it economically viable anymore.
Supply chain issues are still there. Anything I can fix with common and readily available parts, big plus. Imho our interconnected, just in time inventory, has been shown to be fragile.
I believe fuel and oils will be available for years into the future, but the price will make the economics of old systems look better.
The intermittency was something our predecessors just accepted. This is a just a for fun project.
I did find a modern and radical design for windmills. Interesting to say the least- they store the energy created by compressing 'air' into a liquid and transporting it like you would LNG.
Technology - Keuka Energy