Servo Motors to replace steppers

While I recognize that it is entirely overkill for a hobby CNC machine and the cost is kind of ridiculous, I can’t help but be intrigued by the idea of changing from stepper motors to servos. Has anyone else had the same thought?

No. Xxxxxxxxxxxxxxxxxx post must be 20 characters. :joy:

@Battlefield I work with both in my line of work. Without making it overly complicated and to put it in to simple terms, in our applications with hobby cnc machines, stepper motors are easier to work with and cost is low. Servo electronics can be very tricky to maintain for the average guy at home, they are best left to be used in an industrial setting.


Now I gotta get some!!

@charleyntexas Servos are awesome. the only real down side is cost. For one that is about the same physical size of a NEMA 23 stepper motor they are about 250.00 each. The stepper motors we have are about 17.00 each. High speed and constant torque are the prize you win though.

Don’t forget that servos don’t have the annoying noise. Well, the ones I have on my laser engraver and vinyl cutter are quiet anyways. The steppers on my Sherline CNC setup sing like crazy.

Just as the development developes :slight_smile: -> there is also a cheap way for servos i.e. change your stepper into servo. MKS SERVO57A or B costa 15$ per motor. But the problem is that in order to get them working, you would need the closed loop drivers to be connected using DIR,STEP,Enable and some other signals which maybe arent provided directly from the Onefinity controller box ?

I would love to see the the option to be able to connect these cheap close loop drivers to a stepper motor :sunglasses:

Basic concepts -> A pcb is mounted on the stepper motor. the pcb has a hall or other magnetic sensor which senses the stepper motor shaft movement and if the motor misses a step the closed loop will sense that and privide +1 step for the missed steps.
I have these closed loop drivers on my dust shelf. I havent had time to hook them up to my current setup but i will do it and test how they work, when i have time, i have the problem that i have through shafts on my motors so the SERVO57B cannot be connected that easy. i need to print some adapter on the bottom of the stepper to get the pcb leveled with the shaft.

I found this video comparison interesting:


actually the low noise of steppers would be neat eg when laser engraving.
I know 3d printers with 32 bit controllers as eg. Ender 3 V2 the steppers are quite quiet.

Yes, it is very clear that the stepper motors are quiet as compared to the servo motor. But servo motors can be repaired easily. For more details visit servo drive repair.

:thinking: I just watched the video, and the Clearpath Servo seems to be a superior product to the comparable stepper motors being used by the Onefinity CNC, and at lower cost. It appears to me that the superior value of the 1F CNC has been achieved in general by keeping production costs low by finding existing (superior in class) components and modifying them only as required. These servos would seem to be a natural next step in the 1F evolution (other than offering an 80MM spindle bracket), unless there’s something that I’m missing given my non-engineer background. I’d be really interested to hear what a 1F technical person thinks of this option, unless we are going to see upgrading to servos as one of the May 21, 2021 anniversary product offerings!

I am not sure what you are using as your source, but Clearpath products, and comparable servos in general, are much more expensive than the steppers used on the 1F. Most users with experience who joined earlier servo vs stepper conversations believed the motor choice was appropriate for the 1F hardware and operation.

Thanks for the reality check. I see the replacement stepper motors on the 1F website are about $21 while the Clearpath products start at about $260 – a factor of 10 greater! I was mislead by the comment at the end of the video where they say the Clearpath products are “less money than a comparably powered stepper motor”. In listening more carefully, I notice that they said earlier in the video that “if you don’t need [the amount of power that the Clearpath servos have], a stepper motor is going to be more economical”. Just a thought on my part, and a question for you: with the possible upgrade to the 80mm brackets for the significantly heavier 80mm spindles, do you think that the existing stepper motors will be able to handle the increased mass over time without failing prematurely?

Unfortunately this is out of my area of expertise, as I have no real-life machining experience - yet (I should have my 1F in about a month). I am sure other forum members may have an interest to share their thoughts. I will say that I do plan on eventually getting a 80 mm spindle, and have decided to go a different route with a new controller and components - this included getting new stepper motors and driver.

Dredging up an old topic because I just recently became interested in ClearPath servos. Seems like the next logical upgrade after my recent controller upgrade. Loaded up my cart with all the requisite components and it came out to $1519, plus a $48 adapter board for the Acorn controller. I think this would truly push my Onefinity to the “Pro” level. I have no real compelling reason to do it, other than the fact that I’m obsessed with making it the best and I’m trying to launch/grow my business.


I looked into them as well if I going to go with an aftermarket controller, they’re a little out of my budget for now. Are you planning to use them in SD mode or are you updating your controllers as well? I’m very curious to see the results if you go this route.

Derek, I just upgraded my controller so I wouldn’t be doing anything different with that other than to set it up for the ClearPath servos (running SD mode). From the very little I’ve read and know about servos, the ClearPath seem to be the most user-friendly to set up.

I used the wrong word when I said controllers, I intended to ask about the stepper drivers. From what I have read the ClearPath is the closest thing to a drop in replacement for a stepper motor. My primary goal would be to get closed loop feedback operation, I’ve looked at other solutions where a replacement driver is involved and the cost is equal to or more than the ClearPath solution, although at this point I haven’t invested in different stepper motor drivers changing to a closed loop style driver is not out of the question.

Currently I’m running a Gecko G540 stepper driver, which is not closed-loop capable. If I were to move forward with this, I’d be looking at using this interface board which is plug & play between the Acorn CNC board and the ClearPath motors. As far as power to the motors, that would be handled by the Teknik IPC-5 power supply, distributed thru their 4-port power distribution hub that plugs into the IPC-5 and feeds power to the 4 motors. This would really be a nice setup, but definitely at the very top-end of the price range. I’m sure a DIY home-brew servo motor system could be done cheaper but would not be as cleanly integrated as the ClearPath.

Through my research I ended up with that same plan if I went with the Acorn. If I go through all the steps to implement and aftermarket controller I really want that 5th axis… only thing that has held me back from pulling the trigger on the acorn :wink: