SPEED RPM NEMA
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Hello I wanted to know the formula to calculate How many revolutions does the motor make if the printer moves at 100 mm according to the screw sfu1204 thanks
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@paolozampini1973 1204 means 4 mm for one rotation, so the motor needs 25 rotations for 100 mm. (formula: distance / mm for one rotation = number of rotations )
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@JoergS5 said in SPEED RPM NEMA:
@paolozampini1973 1204 means 4 mm for one rotation, so the motor needs 25 rotations for 100 mm. (formula: distance / mm for one rotation = number of rotations )
instead the calculation of the pulley motor pulley 20 mm shaft pulley 80 mm should be the same Thanks
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@paolozampini1973 said in SPEED RPM NEMA:
@JoergS5 said in SPEED RPM NEMA:
@paolozampini1973 1204 means 4 mm for one rotation, so the motor needs 25 rotations for 100 mm. (formula: distance / mm for one rotation = number of rotations )
instead the calculation of the pulley motor pulley 20 mm shaft pulley 80 mm should be the same Thanks
no, that's not right. If you mean a pulley with 20 teeth, it means one rotation moves a belt by 20 * 2 mm = 40 mm.
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@JoergS5 said in SPEED RPM NEMA:
@paolozampini1973 said in SPEED RPM NEMA:
@JoergS5 said in SPEED RPM NEMA:
@paolozampini1973 1204 means 4 mm for one rotation, so the motor needs 25 rotations for 100 mm. (formula: distance / mm for one rotation = number of rotations )
instead the calculation of the pulley motor pulley 20 mm shaft pulley 80 mm should be the same Thanks
no, that's not right. If you mean a pulley with 20 teeth, it means one rotation moves a belt by 20 * 2 mm = 40 mm.
practically I should calculate the same linear speed I wanted to have on the lathe spindle What is the ratio I should use
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@paolozampini1973 said in SPEED RPM NEMA:
@JoergS5 said in SPEED RPM NEMA:
@paolozampini1973 said in SPEED RPM NEMA:
@JoergS5 said in SPEED RPM NEMA:
@paolozampini1973 1204 means 4 mm for one rotation, so the motor needs 25 rotations for 100 mm. (formula: distance / mm for one rotation = number of rotations )
instead the calculation of the pulley motor pulley 20 mm shaft pulley 80 mm should be the same Thanks
no, that's not right. If you mean a pulley with 20 teeth, it means one rotation moves a belt by 20 * 2 mm = 40 mm.
practically I should calculate the same linear speed I wanted to have on the lathe spindle What is the ratio I should use
You need to calculate the ratio of the belt, then of the spindle. A always calcualte how much it linearly moves at the belt and at the spindle for one motor rotation.
Belt: teth * GT2 mm => one rotation for 20 teeth is 40 mm
Spindle: the slope/gradient eg 1204 => one rotation 4 mm
So you need an additional 10:1 gear at the spindle solution to get the same speed. (10:1 is 1 rotation translated to 10. The common gears are other round, translating down eg 1:5 etc).
The belts are faster, but lower torque than the spindle solution. So belt is often used for 3D printing, spindle for CNC. But of course you can use both for both by adding gears and knowing the dis/-advantages.
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@JoergS5 Ok more or less understood so yes with the 4 mm pitch worm I can get to 300 linear mm I would like the spindle to reach 3000 revolutions which pulleys should I mount
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@paolozampini1973 said in SPEED RPM NEMA:
@JoergS5 Ok more or less understood so yes with the 4 mm pitch worm I can get to 300 linear mm I would like the spindle to reach 3000 revolutions which pulleys should I mount
I cannot answer this in general because it depends on what torque you need and which motors you plan.
The steppers are limited to 1000 rpm and have relatively low torque. servos like iHSV series can reach 3000. But it depends what you want to achieve as torque.
Nema is a dimension factor, Nema 17 is a specific dimension, not the type of motor. But if you mean a stepper motor, then you can calculate with 1000 rpm, but with low torque (low Nm, like 60 Ncm for a Nema 17).
There is a calculator to play with:
https://www.reprapfirmware.org/emf.htmlYou can achieve 3000 with a stepper with a 3:1 gear, but then you'll have even lower torque (and lower accuracy/precision). A spindle has a mass to rotate which is higher than a belt solution, so you need some higher torque anyway.
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@JoergS5 Yes yes I know Ok come on Thank you unfortunately I had a mental apsus I don't remember something That's all Thanks
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@paolozampini1973 asking is never a problem, even problems you remember later that you knew it.
I myself thought about using spindle for 3D printing, that's the reason why I know the answers immediately.
