Centroid Community CNC Support Forum

Hello all from Canary Islands

I'm designing a router mill with 4 axis with this configuration.

X axis: 2 servo motors
Y axis: 1 servo motor
Z axis: 1 servo motor
A axis(rotary): 1 servo motor

This kind of configuration is it possible with the Acorn board?

Thanks in advance
Tenesor

The Acorn handles four Axis, however, a slaved x-axis counts as two of the axis.

THANKS

Tenesor…
You can build a system with the configuration you desire using the Acorn but you will have to
"sister" the step and direction signal for your X axis. A number of US OEMs do this. The only thing you may give up would be independant axis squaring, which depending on your machine drive system and size, may or may not be required.

Gary Campbell wrote: ↑Sun May 20, 2018 4:19 pm Tenesor…
You can build a system with the configuration you desire using the Acorn but you will have to
"sister" the step and direction signal for your X axis. A number of US OEMs do this. The only thing you may give up would be independant axis squaring, which depending on your machine drive system and size, may or may not be required.

Gary, Can you elaborate on just how to "sister" the step and direction signals? Is it as simple as hooking both drives up to the same step and direction signals? Won't one of the motors have to spin in the opposite direction?

Thanks in advance.

[/quote]
Gary, Can you elaborate on just how to "sister" the step and direction signals? Is it as simple as hooking both drives up to the same step and direction signals? Won't one of the motors have to spin in the opposite direction?

Thanks in advance.
[/quote]


Yes, just as simple as using the same step and direction signals. In most cases one motor will be required to turn the opposite direction. This can be done with the motor wires at the drive. Simply reverse one of the pairs

Gary Campbell wrote: ↑Sun May 20, 2018 4:19 pm Tenesor…
You can build a system with the configuration you desire using the Acorn but you will have to
"sister" the step and direction signal for your X axis. A number of US OEMs do this. The only thing you may give up would be independent axis squaring, which depending on your machine drive system and size, may or may not be required.

Gary, I setting up an Acorn to control my router, which slaves the Y axis. I plan on using the 4th axis for a rotary, and to set the X and Y work offsets by probing the stock or a fixed reference on the table. Have you had any issues caused by the loss of gantry squaring? Does it get way out of square over time? For now, I am using open-loop steppers.

WaJo…
In most cases a physical reference (hard stops) are used to ensure gantry squareness.

The only time this would cause an issue would be when steps are lost on the dual motor axis.

Assuming no overload or loss of steps, I have seen no issues. If it were common, the internet would be full of horror stories.

Acorn Axis Pairing Guide
http://www.centroidcnc.com/centroid_diy ... _guide.pdf