Inexpensive controler for B axis

Does anyone know of an inexpensive controller that can be set to read in degrees?

The plan is to run an indexer off a separate controller doing cut, turn, cut, turn…

I wonder how Onefinity is doing with the 4th axis upgrade. They stated end of this year or early next. @OnefinityCNC any update?

1 Like

The fourth Axis from Of would be GREAT but I have learned that if I want something that is not currently available, make it.
After several nights of research if @OnefinityCNC doesn’t have encouraging news I think I am looking at an Arduino, a power supply, a motor driver, and an unknown amount of time programming.

Nothing at this time


I needed a better solution to operate my laser. It isn’t a jtech and has weird wiring in comparison. I had used it before with Mach3 and that didn’t work well at all so I threw together a makeshift machine and built a standard grbl controller and tried it with PicSender. Bingo!

Then came the OneFininity and my patchwork Laser machine got evicted. I was able to connect my L-Cheapo laser to the onefinity but it just didn’t work right due to the max voltage in the pwm signal. I could only get the laser to fire at about 75% max power. I needed to build a new controller for the OneFinity. Problem is, I didn’t want to just discard the original controller and wanted to keep it as original as possible if for no other reason than being able to create tutorial videos. Still, I just couldn’t help myself, I had to build a new controller. Good news is now I have the best of both worlds for controlling the OneFinity. I can very easily switch from the native OneFinity Controller to my new GRBL controller in less time than it takes to power one off and the other one on. The GRBL Controller is built using a Arduino Uno with a Demon Shield from Designs By Phill.

Both controllers are powered independently and isolated from one another. When one is on the other is powered off and do not share any wiring that might send an unwanted power surge to the other. It is simply a matter of being able to switch the source of controlling the stepper motors from one controller to the other. This is done in the power off state of both controllers by moving the aviation plugs in the picture below. The movable part of the connectors go straight to the motors while the fixed connection goes to each controller separately.


vFWCJOBdllKMusdVFQ1SiJ.jpeg) 870B562DC6704666B64E5F65EB4F4B0C



I do believe you are the winner of the first major mod/hack of the onefinity…

I don’t know if that is a good thing or not. I certainly don’t mean to insinuate that the OneFinity controller is bad. The only real modification to the machine was in wiring the stepper motor motor outputs to allow a independent controller to provide motion. I didn’t hack the OneFinity Controller itself in any way. I prefer to think of it as Innovative achievement rather than a mod/hack.

Wow, nicely done! Overkill for me but still. Anyway, can one or more of the axis on the grbl be configured specifically as a rotary axis? If so I’d sure appreciate some sources. All I’m needing is to be able to type in and angle and have it go there. If buying this is not that much more than an Arduino and a stepper shield it would be worth it to me to save hours and hours of programming.

I don’t see why it wouldn’t work that way. I haven’t used the rotary function (yet) but PicSender has multi mode capabilities for GRBL. You can switch between Spindle, Laser Raster, Laser Vector, and Rotary modes.

Here are the parts you will need to build the Demon controller. It works very well and they pause / resume functionality is instant.

Demon Shield $36.00 incl. Shipping

Arduino Uno R3 $18.40 Amazon

Stepper Motor Drivers

TB6600 Stepper Drivers 4 pack $32.99 Amazon

Stepper Motor Driver Power Supply

24 volt Power Supply $24.96 Amazon

Controller Cooling

24vdc Cooling Fan 2 pack $6.99 Amazon

Controller wiring

20 AWG Ribbon Cable 6 leads $12.99 Amazon

5 Pin Plugs. 4 pins for Stepper Motor and 1 for Shielding drain

Aviation Plugs 5 pin 10 Pk $11.90 Amazon

18awg 4 conductor shielded w/drain stepper motor cable to extend stepper motor wiring to desired length.

500 feet box $72.95 Amazon


Sold by the foot at Triquetra CNC for 0.25 per foot. Contact me for availability.

Buttons for E Stop, Pause and Resume

Momentary Push Buttons 3 pcs @ $7.99 each Amazon

USB Cable for Arduino to PC connection.

USB A to B 2.0 6 feet $3.43 Amazon


Wow @charleyntexas that list will be handy no matter what I do. Thank you.

Well crap. So I bought a 30w NEJE laser module to use with the Onefinity, but essentially I’m not going to get full power due to the pwm output voltage only being 3.2-3.3v?

I could be wrong there.

I measured voltage from one of the outputs and it was 3.2. However I did not measure the PWM voltage because I couldn’t find the power supply for my PWM meter which will measure the wave pulses and peak voltage. I made the assumption that it was 3.2 volts like the rest of the board.

With that said, when I added the Demon Controller which does put out 5 volt peak signal on the PWM output, my laser was noticeably brighter and performed way better.

1 Like

That is great, have you tried a rotary carve yet, also my friend if you will can we do this with a Mach controller, just for rotary purposes?

It would be just as easy to add a Mach3 controller to control the OneFinity as it is to add the Demon controller. The exception is the cost of components. A Mach3 license will cost you $175 on their website but I am an authorized distributor for them and I have them available for $150.00. Aside from the components being a little different for roughly the same cost, you will also need to add a UC100 or something similar to provide the interface between a computer and the Mach3 controller. That is an additional $120 or so.

If you already have a Mach3 controller available then it is a simple matter of wiring. You could wire it in and completely replace the OneFinity controller or set it up so that you could use either controller just by moving the motor plugs from one controller to the other the way I did with the Demon controller. Adding a Demon Controller is by far less expensive than adding a Mach3 controller built from scratch. However there are some significant benefits to a Mach3 controller in that it does have a profile for rotary carvings that is hard to beat as well as other functionalities that allow you to adjust your carving feeds and speeds on the fly while carving.

1 Like

Would you also need - at least - homing sensors and associated cables/connectors?

Charlie you know I appreciate you
What my interest is is to be able to rotary carve

Can you walk through what to purchase, and set up

Technically No. Your OneFinity will run normally without limit switches or homing., However, it is always a good idea to have them. The stock OneFinity controller doesn’t use physical switches, but relies on detecting the amount of current being drawn to detect a crash or for homing. Switching to a different controller will likely not have that functionality.

What type of controller do you want to build?

One that’ll run the rotary attachment add a true rotary
To make like bats etc.?

PicSender has a rotary configuration as does Mach3. There is a significant gap in pricing though. To use PicSender you would need a easy to build GRBL controller. To use Mach3 you would need a more expensive Mach3 controller at double the cost. You would also need design software to create your projects such as VCarve Desktop or higher Versions.