Thread: Sawstop Slo-mo incl dado

Only skimmed through it but Not a cheap exercise if he just sacrificed a dado stack and a couple of blades for the video.

He's not paying for it but he sacrificed 3x dado stacks and 6x regular blades and of course 9x Sawstop cartridges. I was surprised by the shattering of the carbide and welds on the teeth not in contact with the cartridge. Thats a huge amount of force. At 3000 rpm thats 146 km/h to 0 km/h in a fraction of a second.(I think my calcs are close)

Originally Posted by NCArcher

I was surprised by the shattering of the carbide and welds on the teeth not in contact with the cartridge.

I don't think it's the carbide cutter letting go due to the deceleration, but rather the far plate slipping and the cutter smashing into another cutter on the centre plate.

Look at the 6:02 mark.

Annotation 2020-07-14 152740.jpg

Originally Posted by LanceC

I don't think it's the carbide cutter letting go due to the deceleration, but rather the far plate slipping and the cutter smashing into another cutter on the centre plate.

Look at the 6:02 mark.

Annotation 2020-07-14 152740.jpg

I agree with your observation.

Yeah you're right, I didn't look at it that closely. It looks like the closest blade was grabbed by the cartridge and the others kept rotating till they also hit the cartridge.

Originally Posted by NCArcher

Yeah you're right, I didn't look at it that closely. It looks like the closest blade was grabbed by the cartridge and the others kept rotating till they also hit the cartridge.

The relative rotations of outer and chipper blades only occurs because of the difference in teeth numbers and the spacing of the teeth on each blade in the dado stack.

The outer blades will most likely stop first as they have the most teeth, so they will always be one of the first blades to make contact with the cartridge. A chipper blade may also make simultaneous contact however with the blade orientations in the stack the chipper teeth are far fewer and offset so there is a much lower probability of that occurring and highly dependent on the chipper blades orientation at the instant of deployment.

Once the outer blades teeth contact the cartridge the huge G forces appear to overcome friction between blades / spacers permitting the other blades in the stack to rotate until their teeth also make contact the cartridge. As he mentions in the clip the G forces are incredible so I would not be surprised if welds or carbides do indeed fail even if they do not clash.

If all blades in the stack were identical, and in alignment, then they should all stop at the same instant that the cartridge deploys.

Due to the design of blades and the recommended method of stacking the internal chipper blades with offsetting to balance the stack and to avoid teeth clashing it is inevitable that the chippers will rotate relative to each other once the cartridge deploys. I'm not sure that I would like to be hit with carbide shrapnel at that speed.

The Saw Stop technology is good, however I have reservations about the integrity of the saw arbor after one or multiple deployments of the cartridge. Does it induce micro cracks in the arbor shaft? Not sure I would ever purchase a S/H Saw Stop machine no matter how convincing the seller was about "the cartridge has never deployed!"

I have this concern as we have a Caravagi garden mulcher powered by a Honda 4 hp horizontal shaft motor coupled to a "flywheel" which houses one 100 mm "planer blade" cutter. The shaft on the original motor sheared off near the seal on the crank case, so at its thickest diameter. It would not have been experiencing the same G forces as the Saw Stop example, though it would have experienced high repetition lower G forces.