DaVinci’s notebook — the real one, not the band — was full of wonderous inventions, though many were not actually built and probably weren’t even practical with the materials available at the time (or even now). [How To Make Everything] took one of the Master’s drawings from 1478 of a sawmill and tried to replicate it. How did he do? You can see for yourself in the video below.
There are five different pieces involved. A support structure holds a water wheel and a saw. There’s a crank mechanism to drive the saw and a sled to move the wood through the machine. It sounds simple enough, although we were impressed and amused that he made his own nails to be authentic. No Home Depot back in the 1470s, after all.
Watching him produce, for example, castle joints, makes us think, “Hey, we could do that!” But, of course, we probably can’t, at least not by hand. We must admit we are pretty dependent on CNC tools and 3D printing, but we admire the woodwork, nevertheless. There’s some pretty cool metal working, too.
We thought the waterwheel would be the easy part, but it turned out to be a bit of a problem. Things worked, but it was slower than you would think. We’ve seen sawmills put together before. Da Vinci worked for money, and there was always money in weapons so he did design a lot of them, too.
Glad I clicked about 14 minutes into the video. Tl;dr machine doesn’t work.
It was more that the pump he was using to simulate a water source overheated and died halfway through testing. If I had to guess though, if run for awhile it might have had problems as the cutting and log pushing mechanisms are not independently adjustable so unless it cuts faster than it pushes there could be binding.
It seems the ratchet springs back under the tension of the rope if it can’t push forwards easily enough.
I was just thinking about how he could adjust the speed of the log pushing. First, he could adjust the diameter of the rope take-up spool. Next, he could use additional pulleys to trade off the force/distance ratio for the pulling rope. If he wanted to get really fancy, I suppose he could make a gearbox.
A thought:
Why bother with any complicated log-advance mechanism at all? Simply attach a rope to the log carriage, guide the rope with a couple of pulleys to the top of a mast, and then tie the free end of the rope to a stone or iron weight. (The “mast” need only be as long as the longest log that you’re set up to cut.) As the log advances, the weight falls.
This approach eliminates ratchets and any other complex parts than can break or wear out, the force applied to the cutting edge is uniform from start to finish, and basically, it’s infinitely adjustable.
Because you don’t want the log to push against the saw on the upstroke when it’s not cutting, unless you have the teeth sharpened on both sides. Still, that would end up lifting the log off the car.
That said, in this design, the ratchet is exactly on the wrong side – it advances on the upstroke.
The ratchet mechanism can be used to make a simple variable gearbox. If you move the pivot point of the lever that pushes the ratchet pawl down, you change the stroke length and the advance of the wheel. It just needs smaller teeth on the wheel to catch the shorter strokes.
If I understood you correctly then what you are describing is basically really similar to an infeed mechanism used on really old shapers to advance the table (or knife) into a cut on each stroke of the knife (or table).
Post drills also use a pawl/ratchet mechanism to feed the drill bit while while it is spinning.
Given the build quality, it’s not that surprising. Those joints that are admired in the article are, for the most part, awful. Some of them got patched up with a suspiciously-modern-looking glue but actually the old-fashioned solution would probably have worked better; hammer a wooden wedge into the gap.
Good ol’ Leonard of Quirm…
I see what you did there.
This is possibly one of DaVinci’s less impressive inventions, as the Romans had water powered mills (including various types of sawmills) over 1000 years earlier.
https://en.wikipedia.org/wiki/List_of_ancient_watermills
(Note that I am “dissing” DaVinci here, not the YouTubalist)
Well that’s the essence of the Renaissance era in Europe: reinventing/rediscovering, and then gradually improving on, stuff that the Romans, ancient Greek, Arabs, Chinese etc already had a looooong time earlier. Still a big deal.
I don’t know that everything in his notebooks are claimed to be inventions. He was a very commercial engineer and I think he built or thought about building things he thought he could make money on. So I don’t think he invented everything he built or proposed. Although he often brought interesting innovation to things he did build and he did certainly invent many real and imagined things.
If you had lived 120 you’d be saying the Wright Brothers were no big deal because birds already knew how to fly.
This is the evolved version with multiple saws, called a sash gang–
https://www.youtube.com/watch?v=Kq20TErRLuU
They were notorious for requiring massive foundations and still vibrating everything around. To their credit, horsepower demands were modest.
Nobody has time for that pace anymore and this would be a typically paced modern gang saw with rotary saws (and lots more horsepower)-
https://www.youtube.com/watch?v=jQ3dMOZLdc8
Visit Germany. Germanys past was full of different Waterpowered Mills. And Here are still many museums which still maintaining them for the visitors. Some Put a Giants Dynamo to Produce their own Energy.
Sorry for some mistakes Googles autocorrections doesnt understand If you use severall languages per day and want correct everthing.
+1 Absolutely. I spent a decade in the sawmill industry trying to talk someone into installing a sash gang, but the only one I’ve seen in the wild was a small mill in Bavaria. Not active at the time, but logs were floated down the dammed stream to the mill where they were retrieved from the water and sawn by the water-powered saw. Very elegant.
https://www.youtube.com/watch?v=wwZttgIjGBQ
This saw type was used a lot in Norway from the middle ages up to quite reason.
Norway has a lot of small rivers and water falls so it was hundreds, if not thousands of these saws all over. Exporting lumber and planks was a big business
Thanks for sharing!
Just wish peeps would waste their time, making something to benefit Mankind.
Oppenheimer made the A-bomb. No world wide hot wars sense.
What more do you want?
“….. But, of course, we probably can’t, at least not by hand. We must admit we are pretty dependent on CNC tools and 3D printing,”
That is why this is a great article and build attempt even if it didn’t work. Nice to see hand crafted projects. Another project site I go to has a lot of great projects but when it comes to diy… the instructions include CNC this or 3D print that… Which leaves a good portion of the readers out….
I thought it was surprising just how bad a lot of the joinery in the video is. He’s making mortise and tenon joints, but there are 1/4 inch gaps around the mortise. He then makes his own nails and bangs one in to hold it in place.
An accurately-made joint would have been a massive improvement in the stability of the frame, but even if you don’t have the ability to make it accurately, a wooden wedge hammered into it will be nearly as good. In a few places they used wooden dowels to hold a joint in place, but again didn’t bother to wedge the joint. The nails they ended up using are going to come loose pretty quickly.
Looks somewhat similar to saw mill creek in Michigan. It had water wheel to move the saw and turn another wheel that moves the wood block. That one worked.
https://youtu.be/m7LB7fGIjCg?si=-TKZA9Mg6MBX4PYd&t=658
Interesting video!
Thanks!
Try a hamster wheel in place of the water wheel. You might also consider gearing to output from the wheel to the crank, and a larger crank would also be good to increase torc and the length of movement on the blade.
I don’t understand the sentiment of “I can’t do that by hand”. Woodworking isn’t rocket science. The reason you can’t do it is simply because you haven’t tried.
I have wanted to like this channel for a long time. It’s cool to see someone trying these old designs out and to see them working. It just gets a little cringey though with their executions.
For this one in particular: With a tiny bit of care/effort and no redesigns, this would have worked a lot better and more efficiently. None of the areas where 2 moving parts touched were greased (something like beef or pork tallow or even just wax would have been historically accurate) and (much closer to) round wheels could be made with a little more care and/or a jig using historically accurate tools.
As a woodworker and mechanic: I love what they are trying to do, I wish they would put a little more thought and effort into it.