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Ali
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10K RPM is pushing it I think, but I’ve honestly started thinking in Hz and can’t remember on the machine I use. For lower speeds most of the spindles I’ve seen are belt driven (+ often gives you open spindle). What’s your maximum speed and tooling diameter?
Direct drive like the cnc router spindles.
Hood
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Even if torque was constant the power would be minimal at the low rpm.
Don't know the type of use you are intending but high rpm usually means smallish tooling requiring less power and lower speed means bigger tooling which requires higher power.
So lets say that the torque can be maintained over the full speed range, unlikely but could be fairly close depending on type of motor.
So a 1KW 10,000 rpm servo would have approx 0.95Nm of torque.
So if you then say torque remains constant then at 50 rpm you can work out the power, it would be 0.01Kw approx.
All assuming I am thinking straight at this time of night
Don't know the type of use you are intending but high rpm usually means smallish tooling requiring less power and lower speed means bigger tooling which requires higher power.
So lets say that the torque can be maintained over the full speed range, unlikely but could be fairly close depending on type of motor.
So a 1KW 10,000 rpm servo would have approx 0.95Nm of torque.
So if you then say torque remains constant then at 50 rpm you can work out the power, it would be 0.01Kw approx.
All assuming I am thinking straight at this time of night
Even if torque was constant the power would be minimal at the low rpm.
Don't know the type of use you are intending but high rpm usually means smallish tooling requiring less power and lower speed means bigger tooling which requires higher power.
So lets say that the torque can be maintained over the full speed range, unlikely but could be fairly close depending on type of motor.
So a 1KW 10,000 rpm servo would have approx 0.95Nm of torque.
So if you then say torque remains constant then at 50 rpm you can work out the power, it would be 0.01Kw approx.
All assuming I am thinking straight at this time of night
Yes that is my worry - hardly any power at low speeds.
And yet how do electric cars manage? Loads of low down power and huge acceleration - along with pretty good top end power.
MattH
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Most of the cheap Chinese router spindles will only go down to 60% of their rated frequency I.e. a 18KRpm at 200hz spindle will only go down to 120hz or 10800RPM.
They will not operate at 50RPM at all.
This is true of expensive spindles like Perske and HSD.
I have all these spindles so speak from first hand experience.
They will not operate at 50RPM at all.
This is true of expensive spindles like Perske and HSD.
I have all these spindles so speak from first hand experience.
It is doable, but it'll cost you.
Electric motors are typically constant torque sources. There are ways to boost torque at lower speeds, but not significantly without risking overheating.
It's why modern CNC mills have such high power spindles. It's not that you're ever likely to use the full power (which is only available at full speed), it's so they still have good torque at low speed. A big 20KW 10'000RPM mill, is still only likely to max out at a constant 2KW at 1000RPM, or 200W at 100RPM. Although they're likely to have a reasonable amount of overload at low speeds to help boost torque for a short period of time.
Electric motors are typically constant torque sources. There are ways to boost torque at lower speeds, but not significantly without risking overheating.
It's why modern CNC mills have such high power spindles. It's not that you're ever likely to use the full power (which is only available at full speed), it's so they still have good torque at low speed. A big 20KW 10'000RPM mill, is still only likely to max out at a constant 2KW at 1000RPM, or 200W at 100RPM. Although they're likely to have a reasonable amount of overload at low speeds to help boost torque for a short period of time.
but a car wheel doing 18000rpm would be quite fast I reckon
Hood
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Well I said I couldn't be ersed but things left up in the air bug me so..
Average car tyre would likely be more than 17" but we will use that to be on the safe side.
So dia would be (in metric) 431.8mm or 0.4318m
Circumference would be 1.356m
So at 18,000rpm that would be 24,405m/min or over 900mph.
I think
Average car tyre would likely be more than 17" but we will use that to be on the safe side.
So dia would be (in metric) 431.8mm or 0.4318m
Circumference would be 1.356m
So at 18,000rpm that would be 24,405m/min or over 900mph.
I think
