[dwalsh62]

Wrong.

Torque is a measure of force, not power. Power is a measure of work done per unit time.

If you have more power then youve put in then you have a perpetual motion machine. I guess I should alert you to the fact that that is an impossibility.

Its pretty obvious that a reduction gear train reduces the rpm and increases the torque. And since the power is the product of those two, the power remains the same, ignoring frictional losses, which reduce it in the real world.

I see so because of the gear box, my 100W power rated motor has the strength/force of a 7.2KW power rated motor.

It would be better if you spent your energy clarifying what I have been saying instead of trying to prove what I am saying is wrong.

[daniellyall]

boys question
why can a hobby servo have a lot of Torque when its got a tiny motor (gear reduction) and yes they can move fast too.

[keebler303]

I see so because of the gear box, my 100W power rated motor has the strength/force of a 7.2KW power rated motor.

It would be better if you spent your energy clarifying what I have been saying instead of trying to prove what I am saying is wrong.

With a gearbox it does have the same torque as a 7.2KW motor but it does NOT have the same power!

Everyone is trying to prove you are wrong because you are. Just relax.

[acannell]

boys question
why can a hobby servo have a lot of Torque when its got a tiny motor (gear reduction) and yes they can move fast too.

define your question in quantitative terms and the answer follows the same rules

[daniellyall]

its called being sarcastic

[acannell]

its called being sarcastic

my bad sorry

but back on topic..I do have to at some point design the drivetrain for this thing..I'm not sure how much torque I'll need.

Seem like 3rpm is about as fast I can turn the table by hand..and I dont think I'll need anything faster than that.

3rpm = 270rpm at the handwheel.

As far as cutting forces..that gets a little interesting.

If I only do 4th axis pre-positioning and no simultaneous 4 axis cutting, then I can probably just clamp it and not worry about cutting forces, but I'd still have to deal with the force required to turn the table with a big object on it if its vertical. I'm guessing that is still a pretty small force.

But if I'm not going to be doing any clamping of the table, then the question is, what is the deflection of the table vs radial force relationship?

And how much cutting force is it likely to see?

Drilling a big hole at the outer rim of the table with the table vertical could probably put alot of torque on it. I'm not sure if I can count on the worm gear to resist that through friction or not.

HMM



But as far as torque.

[Garageguy]

Acannell I just got mine 2 days ago and I am up to the same. Does it feel to you that the tilt moves to fast? Or is it just me?

[Windscreen]

I have the same table and agree, the tilt does move too fast. So fast, it makes the handwheel stiff. When I get around to putting steppers or servos on mine, the tilting axis will definitely get a bunch of belt ratio reduction.

[asuratman]

Hello dwalsh62,
Where do you get your harmonic drives? How much do they cost you? I plan to make rotary 8" 4th axis, what kind of harmonic drive for plasma tube cutter do you suggest?

[keebler303]

Hello dwalsh62,
Where do you get your harmonic drives? How much do they cost you? I plan to make rotary 8" 4th axis, what kind of harmonic drive for plasma tube cutter do you suggest?

I don't think plasma cutting big dirty pipes needs the accuracy or rigidity of a harmonic drive. I'd probably suggest a timing belt drive with a big pulley on the spindle giving you a big through hole to accommodate big pipe.