With Instructables you can share what you make with the world, and tap into an ever-growing community of creative experts.
We have a be nice comment policy. Please be positive and constructive.
We noticed you attached photosto your comment.
Never mentioned variable but did say gear ( speed implied ) down of a motor to a lower speed and increase the torque.
Cheap printers use regular motors plugged to disks with black stripes and then use optical switches to make them work as stepper motors at a fraccion of the price, so you could try to make a similar system.
They do gear motor down though.
The L293d is a simple 2wire motor H-bridge see pics
Your best bet would be to use Pulse_Width_Modulation that gives you the low speed and high torque just as a stepper.
If you are good with programming you can do better then delay by momentarily reversing your brush machine to halt spin using the H-bridge.
This wont work for CNC without very good feedback, and certainly not at all a possibility of successfully running a 3D printer.
Yes and no. You can turn the motor on and off after a brief period of time giving a partial rotation. How fast the motor stops will depend on the load on the motor or any active braking system you put on there. However there isn't any force to prevent the motor from being turned by the load when it is off and it may free wheel further round, or get pushed backwards by the load.
Your best bet is to put a worm drive on the end of the motor which will prevent the load from turning the motor when no voltage is applied and also slow down the output of the drive.
This isn't however very accurate. Lots of variables will make the amount turned different every time.
You could however make a type of servo system. Putting a slotted disc on the motor shaft and shine a light through and you have a positive feedback system that your micro can count to see how far the motor has turned.
As an alternative you could make a linear actuator. coupled with the slotted disc this can give very accurate and repeatable positioning.
How to Make Arduino Based CNC Machine at Home
Arduino cheap cnc, 3d printer, router ,laser engraver
CNC Machine from Inkjet Printer
Compact CNC/3D Printer
Homemade X Y Z Axis Slide by Aluminium for DIY Laser 3D Printer CNC Router Mill Machine
Diy X-carve milling project | reusing old mobile phone
3 Custom Arduino Cases - 3D Printing & CNC Milling
How to Wire a Arduino Nano Cnc
How to wire a arduino cnc easy diy
T8 mini CNC Complete Guide
Posted:Feb 24, 2014
Let your inbox help you discover our best projects, classes, and contests. Instructables will help you learn how to make anything!
© 2016 Autodesk, Inc.