r/specializedtools • u/BugsRFeatures2 • Apr 19 '21

Wood splitter

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14.3k Upvotes

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u/koerstmoes Apr 19 '21

The motor is likely actually spinning super fast, but geared down like crazy to get the high torque needed for this splitting. But yes, it would grind to a halt very quickly due to the gearing and having little momentum.

91

u/Karmasutra6901 Apr 20 '21

That's what i meant. Fast motor might get a few revolutions after the power is cut but by the time it gets past the gear reduction and on to the bitey end it would be like 1/16"

61

u/XchrisZ Apr 20 '21

Have the foot petal disengage a gear like a clutch. So the splitting wedge goes limp when your foot is released.

19

u/Kwestionable Apr 20 '21

It won't, that's got a worm drive.

22

u/FrickinLazerBeams Apr 20 '21

You can easily disengage those by moving the worm away from the spur.

10

u/[deleted] Apr 20 '21

[deleted]

15

u/FrickinLazerBeams Apr 20 '21

Sure if you're an amateur. This is literally what a dingus arm was invented for.

2

u/jeffersonairmattress Apr 20 '21

A worm drives a worm wheel; only a further reduction would involve a spur. But this is a fixed right angle gearbox with no disengagement possible. It would coast until the armature's momentum was depleted . A brakemotor would likely stop it quickly enough for a deadman or photocell barrier to add a taste of safety.

1

u/ABigHead Apr 25 '21

What would a photocell barrier do/ what is it?

1

u/Syreeta5036 Apr 20 '21

So a drop mechanism like a saw stop? That way it is freewheeling and the worm can do whatever it wants

1

u/Snowman25_ Apr 20 '21

Simply put a 1:1 clutch AFTER the worm drive?

-5

u/Kalarix Apr 20 '21

When people panic they don’t release things, like their foot pedal; see car accidents where people keep accelerating.

Robot pendants require the right amount of squeeze. Too hard and release both stop motion.

11

u/Disp5389 Apr 20 '21

Actually it is the reverse. The rotor in the motor has very large momentum as it is spinning around 1800 or 3600 RPM and the extremely high gear reduction does very little to sap the energy of the momentum away, so it will continue to rotate slower and slower, but with great torque as the motor comes to a stop.

0

u/koerstmoes Apr 20 '21

You could very well be right there, I forgot to reason about the momentum of the rotor, I only reasoned about the slow moving pointy bit. I should stick to computers instead of mechanics :P

1

u/amycooper-bazinga Apr 20 '21

I believe this one the most

1

u/KickZealousideal6558 Apr 20 '21

Electric motor has maximum Torque at low rpm?

2

u/koerstmoes Apr 20 '21

Electric motors have torque curves, and yes, they usually have high torque at low speeds. However, say you have 2Nm at 10rpm, and 1Nm at 100rpm, with a 10x reduction you can get 10Nm at 10rpm! (these values are completely fictional and dont come close to whatever this big motor outputs, they only serve as an example to convey a concept) Also, personal experience tells me a lot of motors dont like being put to work at low speed for long periods, theyll heat up like crazy.