What I Learned While Upgrading To 2.2kw Water-Cooled Spindle

Hello, Team Onefinity. I know that there’s already a lot of information out here about upgrading to a Huanyang 2.2kw spindle but I’d like to offer a perspective from a machinist’s point-of-view.

As a machinist, not an electrician, I discovered right away that there’s things about plugging in upgrades that I didn’t even know that I didn’t know, things like EMI (electromagnetic interference) and how that can dramatically, negatively affect the signals being sent to the axes steppers. Blatantly put, a machine experiencing EMI can freak out, destroying tooling, work pieces and, at worst, cause serious physical harm to the operator. As a machinist, I had to learn to have a little more respect for the electrical side of things.

The first thing I did in anticipation of receiving the spindle / vfd delivery was hit youtube for reference on how to effectively install it all. The most popular how-to video on the subject was a very concise tutorial aimed directly at adding a 2.2kw spindle to the onefinity so I soaked up as much info as I could from that.

Fortunately, however, I also ran across a related how-not-to video that inspired me to dig a little deeper into why I can’t just cut a standard drop cord and use it as the spindle / vfd cabling. EMI. If I had stuck with the initial video, I would have invited some potential hazards into the mix that I wasn’t even aware of at the time, hazards that I don’t think the video creator was even aware of.

This isn’t to trash-talk Ben, either. I believe that good people share what they know with the best of intentions and I think that’s exactly what Ben did. However, considering the machine moves on 3 axes and is about to have a 24k rpm spindle on steroids going along for the ride, we’re better off knowing what we’re dealing with than just diving right in.

For starters, a drop cord of whatever flavor is not going to be good enough for you. You deserve better. They’re not shielded so they’re just introducing EMI to your system. Will they work? Sure but function doesn’t necessarily mean safe by itself. For example, that cord could be spewing so much EMI that you lose signal on the Z stepper, crash the axis into your work or, worse, have a busted end mill thrown at you or someone else in your shop. These are legitimate scenarios, ones that you can totally mitigate by not cutting machinist corners. We tend to want to get the job done and only concern ourselves with if we can hit our tolerance marks but let EMI become a consideration, something else you need to mill right down to a very tight tolerance.

To punctuate the point, I ran a dry test of the upgrade with basic cabling (the aforementioned hacked-up drop cable) and my X-axis let me know something was wrong when it lost signal. The proximity to the unshielded drop cable was apparently enough to dirty the signal and cause the axis to stop receiving data. My configuration had the axis cable zip-tied to the spindle cable near the X-axis plug which likely contributed to the increased signal degradation. It’s what we do without thinking about it that can affect outcomes.

So, if we’re going to make stupid choices for cable management, let’s at least do so with shielded cabling so that stupidity doesn’t have to arrive at tragedy.

Now that my safety speech is out of the way, let’s talk about how the machinist went ahead to accommodate for a couple of things that needed attention: the stock Z-axis stepper not being able to hold the increased weight of the spindle upgrade and the spindle cooling system.

So, the first thing I noticed after installation of the spindle was that the Z-axis crashed in idle. The 178in/oz stepper didn’t have enough holding torque to keep the axis from bottoming out so I did what any decent machinist would do and tossed on a 425in/oz stepper in its place. Let me be completely frank here: it’s probably overkill but it’s definitely got the torque required to do its job. End of discussion on that.

On to the cooling system, some guys were content to run out of a bucket. I didn’t like that idea, mostly because I have dogs roaming about and I don’t want there to ever be a chance that I leave the lid off and expose them to coolant. What I did was modify a popular kitchen container by installing a couple brass bulkhead fittings for the tubing into the lid. An entire gallon of 50/50 automotive coolant fit snugly within with the Huanyang pond pump and the container sits on a shelf (to which I plan to attach the container to further secure it against accidental spillage).

I have the VFD, onefinity controller and coolant pump on a single power block to facilitate emergency shutdown of “all things CNC” at a moment’s notice and to effectively power-up and power-down everything at once just for simplicity’s sake (I’d totally forget to power-up the cooling system if it didn’t already start with the VFD / controller). Aside from the obvious gain in safety, having the spindle’s cooling system operational whenever the spindle is capable of running was the priority.

I’m also fully intending on turning an old gaming computer tower case into a control box to hold the onefinity controller, VFD, power block with remote switch and various other relevant switches / controls. The thing’s been collecting dust for a couple years and it seems just the right size to become home to some rogue electronics.

I found that setting up the VFD and breakout board adapter was pretty straight forward so I do, indeed, have control of the spindle from the controller / software. One thing to note is that the spindle does take some time to get up to speed so you’ll want to add a GO4 command at the beginning of all your programs to facilitate an appropriate start delay or you’ll totally end up starting the job / cutting into material several seconds before the spindle is actually ready to do so.

I also highly recommend the exact spindle / VFD combination Onefinity has linked in the description for the 80mm spindle mount accessory. I also highly recommend not going with air-cooled. Those tend to be much louder and also tend to heat up far sooner than water-cooled. Some of our jobs can run upwards of 24 hours or more. I really wouldn’t advise putting an air-cooled spindle through that level of torture. I can say with experience that this particular spindle is disgustingly quieter than a trim router. I can hear it above the VFD’s fan at 24k rpms but, at around 18k, I don’t even notice it’s spinning. Granted, that’s not to say that it’s not loud when actually milling… because it is, at least the tooling is. There’s no getting around that without a decent enclosure (also on the list of things to get done).

To sum, the spindle upgrade did add a lot of extra weight to the gantry but, aside from the stock stepper not holding idle torque due to the 3x weight load, the rest of the system hasn’t batted a lash. The upgrade was fairly straight forward and fairly simple. There is some soldering involved if you want to ensure the safety of your 3-phase upgrade but, all-in-all, I wouldn’t say that this qualifies as something requiring excessive mastery of various industries to effectively pull off.

As an aside, I’m even further convinced that I made the correct choice in desktop CNC after this upgrade. Any deviation from stock, with regards to torque, is a risk to the integrity of the system. I effectively tripled the weight on the gantry and the torque specs on the Z-axis and noted absolutely no affect on rigidity. This is a Woodworker X-35 (Original) with Stiffy that continues to prove itself capable of much more than wood carving. I’ll also say that I wouldn’t dare try any of this with comparable desktop brands because they look like they’d just fold right up under the pressure… while this Onefinity just keeps asking for more.

If you have any questions on component sourcing, assembly or whether or not I think I’ve pretty much lost my mind in general over the years, hit me up in the comments.


All those reasons and more are likely why Onefinity recommends and supports the use of the Makita style router as the spindle :slight_smile:

The VFD to spindle wiring is the part of most concern when people DIY their own cable, there are a few companies out there that will sell you the proper cable with a connector on one end - for people unfamiliar with this type of wiring it makes sense to pay the premium for the proper kit. As you said, using 3 wire extension cord is not the right way to go, the ground is required and if you have a spindle without the internal ground connection you need to add it. It would be nice to get a manufacturer supported spindle/vfd kit in the future.

That is interesting, I have the base stepper motor and haven’t experienced an issue with the heavier spindle. Have you adjusted any of the controller settings? I run everything stock with respect to the motor settings.

You can look into “RV Antifreeze” as well which is propylene glycol and is “non-toxic” (before I get reeee, anything is toxic in large enough amounts :wink: ) I use a aluminum fuel cell for my tank to allows it to conduct heat better than plastic and also has a spot where I can put ice in… never had to thus far. Some people use ‘chillers’ which have a radiator and a fan to remove heat (better ones will use refrigerant and operate like a refrigerator and can reduce the water temp below ambient temp)

If you intend drill at low RPM or mill metals I would avoid air cooled, one metal chip in a air cooled unit can ruin your day.

Agreed, the X50 journeyman I have holds better tolerances than the almost $8,000 (without the spindle cost) 4x8 setup they have at a nearby maker space. Having never owned a hobby CNC before this one I knew I didn’t want to deal with belts and v wheels although everyone who owned one that had belts assured me they’re not an issue. Interesting to see some of the other vendors are now adopting ball screws in their designs for over 2x the cost of their belt driven models.

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Not even a little.

Indeed. I noted Sierra’s version but inevitably just used what I already had in abundant stock. I usually carry about 4 gallons in the toolbox of the C60. Ancient truck basically carries half its gvwr in spare parts “just in case”. :smiley:

+1 on that. That was one of the big reasons I went with water-cooled over air-cooled. If I’m not mistaken, I think the air-cooled spindle is recommended to be operated between 8k and 24k rpms whereas the water-cooled variant can safely operate between 0 and 24k rpms.

Ya know, truth be told is that I went into this thoroughly committed to buying the Journeyman maxed out but, due to wanting a few other pieces of equipment in the new shop, I kind of settled for the barebones Woodworker. I’m still not disappointed. In a past life as a machinist II in the workforce, I operated a lot of milling and CNC machines. Aside from the obvious drawbacks, like significantly scaled-back production capabilities and being far more delicate with the speeds and feeds than I otherwise would be if this wasn’t my own equipment (haha everyone abuses the boss’s CNCs lol), I really couldn’t ask for more bang for my buck.

It does what I ask it to. It may not do it as quickly or as accurately as I’d like but it does it. I mean, I’m not building jet engines so who needs ±0.001. :wink:

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How much filtering do we need? Is 47db enough?

This would be above my pay-grade. What I do know is that the individual from whom I purchased the double-shielded 16/4 stated that this cable would “eliminate” all noise. I don’t know what that actually translates into as far as decibel reduction, though, and the formulas for calculating that sort of thing remind of the recurring algebraic nightmares I experienced throughout high school. :smiley:

Me either just saw DB in a description for a power strip. The Noise filter shows in DB, but that’s not the the type of noise I’m worried about. doesn’t sound correct.

DB appears to be a proper measurement of em interference but I wouldn’t have the faintest clue as to what that translates into in a practical sense. We think of noise as something we can hear, also measured in decibels, but, also like our laughably limited perception of the light spectrum, a far greater percentage of that noise flies under our biological radars for being at frequencies that we’re incapable of perceiving [without technological means].

I suppose there’s a ton of ways to reduce or eliminate em/rf interference, some as simple as employing ferrite beads and some as complicated as ensuring that all equipment in the CNC system are sharing a common ground. Some of us might even be rather adept at crafting tinfoil hats, also would apparently work to mitigate interference with the added bonus of CNC sporting stepper motors that look like elves on shelves. :woman_shrugging:

Apparently line-in filters do help, though our cheap Chinese VFDs are apparently really awesome at spewing EMI so I’m not sure how effective a line-in filter will be at calming those storms.

Thanks for this.

I haven’t heard of anyone having an issue with the z axis stepper? Is that a thing? How hard is it to change out the z axis stepper?

It doesn’t make a lot of sense to me because the the forces on the z axis from machining would seem to dwarf the load from simply holding it in the air?

Mine could definitely be a one-off issue. Basically, as soon as I added the new spindle to the newly-mounted 80mm spindle mount to the Z, the entire axis bottomed out. I, then, could move the axis back up by hand to zero and it would bottom out again. I don’t even recall if I tested it under power, though. This was just a decision made on the fly based solely on an observation made during the spindle upgrade.

I actually did take the advice of another forum member on which stepper to upgrade to (a recommended 425in/oz from Steppers Online / Amazon). I also can’t recall but, since that’s an actual thread as well, I think there may have been some reasoning behind the recommendation.

You’re definitely right, though. Since the stepper was holding during operation, I think I may have actually replaced it prior to giving it a chance under actual power. I’d like to say “oops” on that but I also grew up watching Home Improvement so I’m not really feeling any remorse for installing the largest nema 23 I could find. :smiley:

Hey Paul,

there was the thread Upgrading stepper motor for 80mm Spindle in the forum some longer time ago, where most people did not really see the need to upgrade the Z stepper.

Not difficult, you have to replace four screws by longer ones and loosen and tighten the screws of the coupler. But you got to attach the wires.

What Aiph5u said with the addition that, depending on what you upgrade to, you may have to change the shaft coupler as well. I think the stock 178in/oz steppers is 6.5mm while the ballscrew is 8mm. For the 425in/oz stepper, I had to source a 10mm-to-8mm shaft couple to accommodate the larger 10mm shaft of the new stepper.

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Hey Cesar,

thanks for showing, what you have found here seems to be one of these nice power strips with surge protection for 8 outlets and additionally for 1 HF cable/antenna and 1 phone line, with built-in EMI filter and two USB ports as well as a resettable circuit breaker.

What is given in dB here is the signal-to-noise ratio of the built-in EMI filter.

The value of 47 dB is nothing special, but it’s good to have a EMI filter there. However this will not prevent the heavy EMI that the VFD and the spindle cable typically emit. For this, besides ferrite chokes, the most effective way is to enclose them both into faraday cages, which means an earthed control cabinet for the VFD and an earthed shielding in the spindle cable.

Image: Control cabinet suitable for a VFD.

Images: Countermeasures around a VFD for preventing EMI

As for EMI filters, some manufacturers of VFDs (like mine) offer so-called “footprint” EMI filters for their VFDs (e.g. this one for my VFD), which means you can screw the VFD onto them, they have the same “footprint” (width and height dimensions).This makes a very effective earth connection. The VFD/EMC filter assembly is then attached to the (earthed) mounting plate of the control cabinet. Will provide a photo (when my work allows it :slight_smile:).

dB” is the unit decibel, which is a tenth of a bel (B). A bel, named after Alexander Graham Bell, is a relative unit, which means it doesn’t measure a physical quantity, but expresses a ratio between two values.

The exact definition is:

A bel expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 (approximately 1.26) or root-power ratio of 101⁄20 (approximately 1.12)."

– Source: Decibel – Wikipedia


Update on “CNC freakout”:

During a light machine inspection this morning, I noticed that the X axis plug wasn’t seated. It would literally fall out with the slightest pressure. At this point, I’m concluding that all of my X axis-related issues experienced during this upgrade were caused by an axis cable that was not making a solid connection.

Some background on that: awhile ago during a job, the X axis cable snagged up on a leg of the shelving I have over the workstation next to the CNC (see post #1 image). Long story short, Joey tried to drag that shelf and all its contents down the length of the Y axis until the X axis plug disconnected. I apparently did not reconnect that plug sufficiently enough. This morning, however, it clicked into its home and isn’t pulling out.

I’m concluding “operator error”, beginning at worktable design phase. In theory, the 3 inches afforded as a gap between the shelving on the left and the machine on the right is sufficient enough to allow Y-travel without cables getting snagged. In practice, I’ve had to hold back the cables I can with zip ties and give lots of open space to the cables I can’t… like the X-axis cable that needs freedom to roam.


That would better explain the behavior you described over EMI from the spindle cable. I’ve had the same thing happen when I first had my machine with the X axis cable between the controller and the X axis end connection getting hooked around the e-stop button on the controller that was mounted to the side of my table, it quickly located the weakest point in the cable and showed me where it was :slight_smile: Cable management on the default machine setup could use some improvement.


A few things I forgot to mention when upgrading to the Huanyang spindle / VFD:

  • I replaced the opaque, rigid polyurethane tubing that came with the setup with some super flexible, fairly clear silicone tubing. I was concerned that the rigidity of the poly tubing was going to become an issue over time / repeated bending and I really want to visually see the coolant flowing.

  • I used a lot of heatshrink tubing on the electrical side of things. Should my shoddy soldering ever arrive at failure within the spindle connector, my backup for avoid arcs is that I slid heatshrink tubing over the leads and cups. That should leave enough of an insulator to fully encompass the lead should any pull out.

  • This is an ER20 setup, meaning that it can accommodate up to 1/2" (12.7mm) shanks. No noticeable runout.

  • Operator Error (again): prior to the upgrade, I was adding tools to databases with arbitrary spindle speeds because, as you’re aware, that bit of information was irrelevant to operating a trim router. HOWEVER, all of my programs are now having to be gone through to correct that discrepancy because that bit of information is now totally relevant. Do yourself the favor of adding tools to databases right the first time so you don’t end up having to rework programs later… because, haha, a 2" surfacing bit running at 1k rpms may seem hilarious but the material being surfaced got the last laugh.


I dont want to jump in too early, as i haven’t even received my 1F yet, however i did order the 2.2kw spindle in anticipation of doing heaps of shit with it.
My spindle turned up today & i can say as i already have a Makita router, this spindle is shitloads heavier, so do have some concern whether the OEM stepper motor will handle the extra weight.
I will weigh each spindle/router tomorrow & post the actual physical weights & perhaps some of the learned folk can comment as to weather the OEM stepper should be able to cope.
I do plan on using the Makita initially but do plan to install spindle once i have mastered the dark art of 1F CNC

Edit: OK i need to read more & type less, after clicking links… ok i’m an aussie & new at this :slight_smile:

The OEM stepper motor will handle it fine.

Hey Carrianne,

Perhaps you better should have :slight_smile: When power is cut off from stepper motors they loose their Electromagnetic Detent so they can hold their position only by the remaining Magnetic moment, which is usually not enough to prevent massive moving parts in the kinetic chain from moving them by gravity.

The remedy for this is not buying a beefier stepper but to switch the power on on the CNC Controller :wink:. But you already know.

However this becomes a known issue in matters of safety when power is cut to the controller unintentionally. As explained above, parts with a certain weight move freely then, which can damage your workpiece and be dangerous to humans (which is one of the many reasons why CNC machines are usually in an enclosure with a safety switch on the doors which stop the machine’s operation and hold the steppers with idle holding current in their position as soon as the door is opened). On power outage, the holding current is absent, which can cause danger,

A remedy for this is to retrofit an electromagnetic brake. It lets the stepper axis move freely when there is power, but when the power fails it clamps the stepper motor axis and prevents it from turning, preventing damage to the workpiece or the equipment or harm to humans. This has recently been discussed here and here, as well as other possible solutions against parts moving freely.

As for the performance of the stock stepper, I don’t think the Onefinity CNC manufacturer would have released the 80 mm mount without thoroughly testing the machine with a 80 mm spindle, there was too much demand for it to deceive buyers with a underdimensioned stepper. They stated repeatedly that they see no reason for a stronger Z stepper.

However if the monster stepper you put on the machine has a magnetic detent so high that it is enough to hold the spindle when power is off, I understand you will leave it there :slight_smile: (although in terms of safety, it’s not the right solution. But stepper stock configuration isn’t either)

Are people experiencing their spindles sliding down the Z axis when they turn off their machine? Mine requires in excess of 10lbs of force in addition to the spindle weight to overcome the stepper motor and other sources of friction holding it in place.

I definitely should have done that. Honestly, after reading about the 425in/oz stepper, I think I already had my mind made up that it was going to happen and anything would have justified it happening.

I hadn’t actually considered it in that context. I looked it as being “you asked for it, we delivered, you were going to do it with or without us making a spindle mount available anyway and you were going to do it whether or not we approved so here, live your life, make your mistakes, don’t cry about it when you crash your machine into a wall for being a moron!”

I could live with that but I definitely didn’t see it as any sort of attempt at deception. Another thing to know is that it’s not like I haven’t thoroughly abused the machine already. I’ve crashed it a few times and have put it through some pretty scary scenarios (almost pulled metal shelving down on which my “can-only-afford-once-in-a-decade” custom workstation lives). I attributed the Z-stepper’s lack of grip to all of torture I’ve put all of the steppers through since this machine arrived.

One thing to note is that I didn’t go into this purchase to ever engage with warranty issues. I know who I am and what I’m capable of (compulsive and prone to breaking things). If something breaks, I broke it and I’ll fix it. Having said that, I went into this with the full intent to achieve production-scale manufacturing with it by the first quarter of 2023. It will become stronger and faster because it needs to in order to achieve that objective. All joking aside, these 425in/oz steppers will be finding themselves attached to every ballscrew on the chassis by the time I’m done because I want all the torque I can get out of this chassis. It can definitely be advised against doing but I figure nobody ever gets anywhere by playing things safe all the time.

By the start of next year, I want to legitimately be able to say that Onefinity, alone, has facilitated the successful launch of this poor guy’s first small business. No flag signs. No coasters. No toying around with all the things hobby cnc’s can do. I want this thing roided-up and ready to take on actual machining jobs. And, at the end of the day, Onefinity’s got to get the credit for it for engineering a design that redefined the value and capability of a desktop CNC.

LOL at it taking 6 months of scraping funds just to do a spindle upgrade one measly component at a time, though. Everything hinges on this one machine. This family has existed for generations at poverty level / blue collar servitude to a system that doesn’t provide many opportunities for escape. This machine is all my economic eggs, hopes and dreams in a single basket. It cannot and will not fail me. :slight_smile: