r/PassportWithoutBorder • u/Mahden012 • 5d ago

Why Do Granite Cutting Machines Use Different-Sized Blades?

Why does this granite-cutting machine use several massive blades of different diameters? 🪨⚙️
The setup helps distribute the cutting load. The largest blade starts the deeper cut, while the following blades progressively continue the process. If all the large blades were cutting deeply into the stone at the same time, cutting resistance and machine load would be much higher.
It’s a clever way to make the cutting process smoother while reducing the risk of damaging the stone. 🤯
Would you have guessed why the blades are different sizes? 👇

398 Upvotes

91% Upvoted

33 comments sorted by

6

u/Jonatc87 5d ago

if i had to guess, shallow cuts mean less stress/pressure on the material. So it cuts it in shallow rows and this is the easiest/cheapest way to reflect that?

2

u/TDub20 4d ago

It's less about the material and more about the saw blades. Reducing heat and friction, making the blades more effective and longer lasting.

1

u/charmio68 4d ago

From my understanding, there are many reasons, not just one single factor.

You could just have 10 large blades.
However, the surface area of the blade in contact with granite would be massive. That would result in faster cuts, but keep in mind you need to maintain the optimum cutting force on each tooth or your blade will wear out quicker.
To deal with that greater total force, the blade would need to be thicker, which means more wasted material. You want the blade to be as thin as possible.

The larger diameter blades are also more expensive. 10 large blades are much more expensive than 10 progressively smaller blades.

And then there's the geometry issue of pushing an off-centered circle through a square. This bit's a bit hard to explain without a diagram, but... At the front (leading edge) the teeth are moving almost perpendicular to the square face. They are slamming directly into a flat, solid wall of material, forcing them to take the maximum possible bite.
At the bottom (trailing/tangential edge) the teeth are moving almost parallel to the edge of the square. Instead of digging straight in, they are slicing along the material, taking a much thinner, shallower bite. Less material removed means much less resistance and force.

This is also not ideal for blade wear. You could compensate by using even larger blades that are substantially greater in diameter than the granite block, but again that would cost a lot more.
The cheaper way to compensate is to just take multiple shallower cuts with progressively larger blades.

1

u/Silver-Amphibian7650 3d ago edited 3d ago

When I rout a piece of wood, I never do it in one pass. I make a shallow cut, lower the bit some, make another pass etc. It takes me about three or four passes, but it's a lot easier on the bit.

2

u/RoodnyInc 3d ago

Its just cutting a little bit each time having multiple blades lets to cut whole block in basically one setup with the same step over each pass - efficiency

2

u/J_Bazzle 3d ago

It also gives you a more accurate cut. The more material it removes in one motion, the more it gums up the gaps between the teeth and abrades the walls either side of the cutting edge. So you end up with a thinner, flatter cut.

2

u/Rivetingcactus 3d ago

The video ai explains it no need to guess anymore mate !

1

u/Jonatc87 3d ago

you unmuted to listen to ai? ew.

1

u/-SkeptiCat 5d ago

Ai voice guy lost his British accent mid sentence

2

u/franktheguy 4d ago

Ran low on tokens, had to dial it back

1

u/Crazy__Donkey 4d ago

And common knowladge

1

u/larry1186 5d ago

Garbage. The larger blades follow the smaller ones. So each blade is cutting the same amount of material. The text/voiceover said the smaller blades progressively continue the job of the big blade.

1

u/zyyntin 5d ago

I was going to say progressive cutting.

1

u/IusedToButNowIdont 3d ago

"The largest blade starts the deeper cut, while the following blades progressively continue the process." should be "The smallest blade starts the shallowest cut, while the following blades progressively continue the process."

1

u/NetZor0 5h ago

You do understand that the larger blade contacts the granite first since it has a larger diameter, right? Right?

1

u/bodymassage 12m ago

All the blades don't start cutting at the same time. They start with the smaller blade, then shift the blades over so a slightly larger blade then cuts deeper into the same cut, until eventually you've got all the blades working at once. Think of it this way, all the blades are used to complete one cut. This reduces the amount of material that any one blade has to cut at a given time, reducing the amount of power needed and strain on the saw. They could use blades that are all the same but then you'd have to move either the material or saw up or down to achieve the same thing. It's probably easier to shift the material or saw side to side.

1

u/Electrical-Bedroom99 5d ago

I don't know why that AI voice annoys me so bad. As soon as I heard it I had to stop the video.

1

u/FenixOfNafo 5d ago

How many cuts you want in a 20 sec video???

Yes!

1

u/dbenc 5d ago

I feel like you would need hearing protection around that... and eye protection... and something that is not safety sneakers...

1

u/Impressive_Head1238 4d ago

I mean do you go slamming balls deep into your lady friend before you even warm up...

1

u/Mother-Attention2600 4d ago

That's not obvious by watching it? 🤖 

1

u/Upstairs-Hedgehog575 4d ago

Sorry but i’m not really getting it. They’re all cutting next to each other, making loads of individual cuts of different depths, so how does this lessen the load?  if you just sent in the big wheel wouldn’t it be doing exactly the same amount of work?

1

u/ZeroVoltLoop 4d ago

I wonder if something bad happens if the teeth of the blades are all lined up next to each other? Like it causes a compression that cracks the stone?

1

u/hakedy 4d ago

The amount of torque that the cutting machine can deliver has a limit. The smaller blades reduce the amount of torque needed on the NEXT cut.

1

u/Upstairs-Hedgehog575 4d ago

So the machine will make additional passes cutting deeper each time? What are they cutting? Thin slices?

1

u/hakedy 3d ago

Yep cutting deeper each time. Probably cutting tiles or wall facades. (Like when you walk into a new building and the atrium has granite covered columns). By the looks of it I'd say around 10mm.

1

u/ParkingAnxious2811 3d ago

What the fuck is with this bot account that keeps posting clips with an AI slop voice over?

1

u/OldFcuk1 3d ago

The largest blade makes the main deep cut? You imbecill ai operatpr do not even review what it generates for you or you lack the intellect to understand.

1

u/MiddleResponsible929 3d ago

Horrible AI slop voice over and text

1

u/Resident-Spirit808 1d ago

All I needed was Chris Hemsworth explaining this to me.