I have a project where I need to lift about 2 kg about 15 cm above the ground with a stepper motor. I understand the holding torque can be calculated force times distance. So that would give me holding torque of:
2kg x 10N x 0.15 = 3 Nm
Is this correct?
These kind of steppers are however pretty expensive and since I need around 15 pcs of them I need to look for some cheaper options. Are there any other way increasing the torque? Ive read about worm gear but havnt find any that suits my project. Any recommendation would be apreciated.
Another option would be to lasercut some gears out if wood for making my own gearbox, not sure how to do it properly though. Is it enough to have a small cogwheel rotating a bigger for generate lower speed but higher torque and in that case how can I calculate how much?
Any tips of good approaches of increasing the torque?
Also look into your power supply and motor controller. Increased torque is obtained by increasing the voltage to the controller, but limiting the current to the motor coils to their maximum values. I have 4 volt stepper motor used with a 42 volt supply and all in a device REQUIRING high torque for pumping drywall mud.
Maybe, depending on the configuration. If you have a 15cm wheel or arm that the 2kg is attached to the end of, it is correct. If the weight is hanging on a string wound around a 5mm shaft, then it is:
Right, I think. The bigger the wheel is that you are winding up around, the more torque you need to do the winding. The smaller the wheel/drum, the less torque you need.
The vertical distance you lift isn't as important as the radius of the winch-like drum.
A pic/drawing of your setup would go a long way towards clarifying your question.
Proper gear ROTATE around the tooth surface, as they mesh together and move apart, no sliding. Sliding is friction and is what caused noise from gear trains.
Exactly what I was going to say. Why did you want to use a stepper motor in the first place? They are good only for precise positioning; if you don't need that, then a normal motor is almost always better - wider speed range, wider torque range, cheaper, etc.
If you need to switch off the motor when the 2kg weight has been lifted a certain distance, then use a limit switch.
Many ways. You drill a hole in the wheel or arm and press it on. You can file the shaft so it has a flat spot and use a thick enough arm that allows you to put a set screw in the arm so it locks to the flat spot. I guess you could rough up the shaft and use epoxy.
Really time for you to learn some shop work skills.
Here is one I built that uses a 12 volt motor with a worm gear that drives a chain to a second gear that drives a drum with a 90lb rated steel cable. The control fob runs relays, but they could be just as easily be controller by an Arduino.
Ok so it wont be able to hold the weight when it is not running?
The gearbox that cant be backdriven wont work in my case because it shall be possible for the motor to run in two directions. So how can I arrange a brake? Do I always need a brake on a dc motor to hold some load?
Are you using a brake as well in your construction?
