Just bought the 4th axis. Need advice on connection

I have made the purchase for the 4th axis with tail stock.
I bought the 4th axis off of ebay from an LA source. Here is the stats on it:
CNC Router Rotational Rotary Axi A-axis 4th-axis 3-Jaw and Tail stock

Features:

  • Chuck type: 80mm self-centering 3 Claw Chuck
  • Chuck center height?49MM
  • Transmission ratio 1:6 (1200 pulses / revolution) synchronization gear reducer
  • 3.5A 4 lead 57 stepper motor(1.8 Degree Step Angle)
  • Stainless steel dust cover
  • Processing load 30KG
  • Anodized rust treatment
  • 4-pin connector 1 = A +, 2 = A-, 3 = B +, 4 = B-
  • Dimensions 17020090
  • MACH3 setup instructions: 1 degree required Pulse
  • The formula is: 360 / subdivision stepping angle * Drive * Transmission ratio / 360 = MACH3 Pulse

I am using Ethernet SmoothStepper Control Board for the interface with my laptop
and connected to it now is the Gecko G540

The Gecko G540 has 4 axis outputs. The A output is being used for the 2nd Y motor.
For those who have experience with this I have a question about hooking up the 4th axis.
If I use the G540’s A port then how do I drive the other Y motor? Is it possible to use a TB6600? Or do I need to get a BOB (Break Out Board) to hook up the 4th axis to it instead?
Any suggestions by those who are already doing this?

2 Likes

I use B-Axis for my rotary I added an additional Gecko G251 board to run it.

I do not have the cash to get another Gecko board. I do have 4 TB6600

The smoothstepper gives you a total of 3 parallel ports, I use one to drive the laser driver…I would assume you could drive the TB6600 with outputs on port 2 or port 3 of the smoothstepper.

I’d use the TB6600 on the rotary and use the same Drivers for all your main axis.

How do I hook up the TB6600 to the smooth stepper?

Show me the connections on your driver…stepper and power and the signals from the smoothstepper…I used a small breakout board to make wiring easy to port 3 of my smoothstepper.

It should be similar to the Gecko 251…

It should be the exact same. You should have the Smooth Stepper pinout in its manual.

Your B axis STEP, EN, and DIR would go to the respective TB6600 inputs. A breakout board would make things cleaner but it’s not required.

https://warp9td.com/index.php/documentation/doc-ess#EssDriveMotorsDirectly

Thats the manual for the board (Smooth Steppper)
I just want to know if I need a special board that has drivers on it or do you hook it directly up?

The TB6600 is the stepper driver, it will be hooked up between the motor and the smoothstepper…pick port 2 or port 3…then configure it in mach3.

I am not in my shop so I can’t tell you which pins I used for my rotary axis.

Output pins on ports 2 and 3 are pin 1, 14, 16 and 17, but you can also set pins 2-9 as outputs in the smoothstepper plugin within mach 3.

I could buy this:

then use port 3 for the G540
Then for the 4th axis I can use that BOB to connect up the pins to the TB6600.
Whould this work?

I have finished all the necessary connections and all is working.
If anyone is interested in my setup let me know.

1 Like

I have ran into a snag :confused:
Mach3 and Vcarve Pro
When I run a rotary job the rotary axis moves 1mm incriments instead of smaller degree incriments.
The job I setup is 50mm in the X and 71mm is in the Y based on the 22.27mm diameter for the A
When I save and use the PP Mach3 wrap y mm, I get the problems no matter what I set up.
The rotary axis has the follow specifications:

  • Chuck type: 80mm self-centering 3 Claw Chuck
  • Chuck center height?49MM
  • Transmission ratio 1:6 (1200 pulses / revolution) synchronization gear reducer
  • 3.5A 4 lead 57 stepper motor(1.8 Degree Step Angle)
  • Stainless steel dust cover
  • Processing load 30KG
  • Anodized rust treatment
  • 4-pin connector 1 = A +, 2 = A-, 3 = B +, 4 = B-
  • Dimensions 17020090
  • MACH3 setup instructions: 1 degree required Pulse
  • The formula is: 360 / subdivision stepping angle * Drive * Transmission ratio / 360 = MACH3 Pulse

I do not know what value the Drive is and I do not understand how to divide the transmission ration (6:1) with 360.

has your 4th axis been properly calibrated for steps/deg?

I did my best to do that.

I finally have my 4th axis working.

3 Likes

So what was the issue? Looks great! I’ve love to see your whole setup.

The issue was initial settings and in the motor tuning I had to set different values than what was calculated.
When I discovered that the rotation was turning 5 times when it should have been one. It would land perfectly on the start after 5 turns. I then divided the value by 5 to get a smaller value and placed that in the tuning dialog of Mach3.
After that all worked fine.
Here is my test setup. I plan on making a rail and better mount.
Did you want to see the electronics set up too?

Looks great. Now you have to do some four axis milling!

1 Like