Forum » Smoothie Firmware / General » External Drivers Do Nothing
Started by: aswegeaswege
Date: 3 May 2016, 00:36
Number of posts: 5
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Summary:
Using cheap external stepper drivers, nothing seems to get the motors turning
External Drivers Do Nothing
aswegeaswege 3 May 2016, 00:36

I'm in need of some help with my external drivers.

I am using the ST-7128 stepper drivers from stepperonline. I just switched to Smoothie from RAMPS, and on RAMPS they worked quite nicely. On Smoothie they seem to be doing nothing.

So far I have tried wiring them in the two modes suggested by the wiki (common cathode and common anode). Neither of these seemed to work so I searched the internet for others with a similar problem. The main suggestion I found was changing the timing - so in the config file i changed microseconds_per_step_pulse from 1 to 10 and several higher values. Still no success.

Recently, for a project in a class, I had to wire this stepper driver up to a National Instruments Data Acquisition device (DAQ), and I had some trouble there too. with that I was using a 5V power supply that outputted 5.07 V. I was using the DAQ to control three transistors that would in turn control the inputs on the driver. I found that using 2n3904 transistors didn't work, but tip120 transistors did. This leads me to believe my problem lies in some quirk of electronics that I don't understand.

I'm open to any suggestion. Whatever gets my printer running again will satisfy me.

Unfold External Drivers Do Nothing by aswegeaswege, 3 May 2016, 00:36
Re: External Drivers Do Nothing
arthurwolfarthurwolf 3 May 2016, 10:38

Maybe the smoothie's 3.3v is not enough ? And you'd need a level shifter to bring it up to 5v ?

Re: External Drivers Do Nothing
ElectritechElectritech 3 May 2016, 14:49

I ran into some issues this past weekend hooking up ST-6600 drivers to my smoothie. In addition to the configuration in the wiki (I used the common anode setup), I also had to invert (place a ! after the pin) both the step and the enable pins. After that my smoothie controlled the steppers perfectly.

Re: External Drivers Do Nothing
LoftonharrisLoftonharris 3 May 2016, 20:15

Yet again, I've fried another stepper driver, this time on my smoothieboard. Don't ask how. I'm planning to replace the stepper with an external driver and have a couple of questions:
1. The stepper driver that failed is on M3. MY board is a 4XC. Can I connect the new stepper to connectors on M3? I understand that the config needs to be changed to indicate it is an external driver (insert "o" after the pin designators).
2. I ordered this from Amazon: by AMX3d: 20KHZ CNC Single Axis 32 Segment Upgraded TB6600 Micro Step Stepper Motor Driver Controller. Will this work, do you think? Here are the specs:
20KHZ CNC Single Axis TB6600 2/4 Phase Hybrid Stepper Motor Driver Controller
Features:
9V-40V DC power supply
H-bridge bipolar constant phase flow driver
Up to 32 segments of six kinds of sub-modes available
High Speed optically isolated input signal
Standard common anode single pulse interface
Built-in thermal protection and over-current protection
Note:
This driver is the upgraded version TB6600, heightening segment to 32 subdivision, suitable for high segmentation applications.
For step motor: 42, 57, 86 type 2 phase 4 phase (4 / 6 / 8 line)
Thanks for any advice!

Re: External Drivers Do Nothing
aswegeaswege 6 May 2016, 23:26

I did some playing around with it and the one thing I found that seemed to work was using Ethernet instead of USB to connect to the Smoothieboard. After this I had to change the timing (microseconds per step pulse) to prevent skipped steps. A value of 7 seems to work best for my drivers.

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