Acorn Build-bench testing complete!

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Bill, hey Larry, hey Tom,

@Machinist

Doubtful, as the Onefinity controller will not support a 4th axis.

I doubt Onefinity will make one available, but the accessory market is full of them.

Regarding the ability of the Onefinity or the Buildbotics Controller to use the fourth stepper driver for driving a stepper in a rotary Axis, see this:

https://forum.onefinitycnc.com/t/4th-axis-option/495/12
https://forum.onefinitycnc.com/t/worth-the-price/4525/15 ← Roger’s Rotary Setup for Onefinity
https://forum.onefinitycnc.com/t/worth-the-price/4525/11
https://forum.onefinitycnc.com/t/masso-g3-build-tangential-knife-success-with-sheetcam/7730/40

The Onefinity CNC machine has three axes, but the Onefinity Controller has four drivers. By default, the two Y Axis steppers of the Onefinity are controlled by separate drivers. But since they’re supposed to always do the same, there exists the possibility to drive them with a single driver (see below). This allows to free the fourth motor driver and to do what Roger @rblur01 has done.

It mainly depends on your CAM software to define the fourth axis as a rotary one.

3.8. Motors

[…]

A single output port can drive two motors with certain limitations. It is recommended that the motors be wired in parallel when driving two motors from a single motor output. The limitations are:

• Since the two motors are wired in parallel, the current supplied by the motor output will be doubled. For instance, if each motor has a current rating of 2.8 amps, then the current on the motor output must be set to 5.6 amps. The maximum output current from a motor port on the Buldbotics Controller is 6 amps, so you cannot connect two motors that require more than 3 amps each to a single port.
• When motors are wired in parallel on a single output port, they tend to resonate with one another. When the resonance occurs, the motors will stall. As a result, the motors must run at a speed below this resonance to avoid stalls. Unfortunately, it is not possible to predict the speed at which this resonance will occur without wiring them up and connecting them to the machine.

Source: Buildbotics Manual, #motors

@TMToronto made a Y Axis splitter board:

@TMToronto

As an aside. Once my Masso and CNC are reconnected, I plan test the Y axis splitter board I made. It may help those wanting to keep the 1F controller and adding a rotary axis (without having to switch cables etc…) - would require homing sensors which I assume the 1F controller can accept vs stall homing. Will post that adventure’s result once completed and tested.