G3D driver

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A4988 G3D Stepper Drivers

Release status: working

G3d 1.jpg
Description
New generation stepper motor driver
License
CC (Noncommercial)
Author
Contributors
Based-on
[[]]
Categories
Electronics
CAD Models
External Link


Summary

This is the new innovative stepper motor driver for your 3D printer or any task involved stepper motors! It is a new generation as replacement for Pololu/StepStick.

Professional design ensure stable operation of this driver - it contain 2oz copper PCB for better heat dissipation.

Using standard A4988 drivers you face the problem of vibration / shaking stepper motors and frame when stepper motors are moving (most noticeable on Z stage). These drivers solves this problem by using an additional 30k trimpot to correctly select the off-time settings.


Is it complicated to use?

No, you only need to turn second trimpot (OSC) fully counterclokwise and that's all - you can enjoy smoother and quieter stepper motors operation and no more lost motor steps because of non-optimal off-time settings.


For what we need second trimpot ?

This is just 30k trimpot which turned fully counterclokwise pulling ROSC pin into ground and turning it clockwise let you to choose reference.


Quotet from A4988 datasheet:

"By pulling the ROSC pin to ground (second trimpot turned fully counter clockwise in our driver), mixed decay is set to be active 100% of the time, for both rising and falling currents, and prevents missed steps. If this is not an issue, it is recommended that automatically-selected mixed decay be used, because it will produce reduced ripple currents. Refer to the Fixed Off-Time section for details."

You can check A4988 datasheet for more informations.

Where to get it?

4pcs or 5pcs G3D Drivers fully soldered and assembled and ready to use:

4pcs GADGETS3D.com
5pcs GADGETS3D.com
Fabster3D Ebay

You can also build it by yourself design files you can find at bottom of page.

VREF Calculation Formula

REF = I_TripMax * 8 * 0.1 I_TripMax - Trip current of your motor (A)

Example: 0.4A * 8 * 0.1 = 0.32V

Pictures

G3d 11.jpg

G3d 22.jpg

G3d 33.jpg

Design Files

Schematic Gerber files

Licences

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