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

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:

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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.

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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:

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The OEM stepper motor will handle it fine.

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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)

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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:

Keep in mind you have a max 10A power budget for the stepper motors, the OEM stepper motors are rated at 2.8A max where as the 425oz in are rated at 4.2A…

Also the controller runs at 12-36v, to consider higher voltage would lead to a 3rd party controller solution.

Noted, which is why I’ve been looking at the Masso G3 controller in conjunction with stronger drivers as a viable alternative.

For now, though, I’m leaving things as they are and moving into “testing phase”. The machine will let me know what it requires as it’s presented with various scenarios.

I’ve thrown a heck of a lot at it and stalling the stepper motors hasn’t been an issue, it’s been more than happy snap off or bend bits before stalling.

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Hey Carrianne,

I don’t think that stronger steppers will bring the Onefinity CNC, which is decidedly sold as hobbyist machine, into the direction of a machine reliable enough to attempt to start a production and a business. And I say this as someone who bought the Onefinity CNC for professional use, but very aware that it’s not in the stock state that you can expect that reliablity. Before thinking of this, I would first replace the whole cabling and these plugs unsuitable for CNCs, and the money you think to spend for bigger steppers would better be saved to replace the ‘step-and-pray’ motors (aka open-loop) by something reliable, not forcibly closed-loop steppers, linear encoders on glass scales are something very reliable too. Also I would make sure there is a reliable cable routing concept with of course strain relief on moving cables (the lack of such there on stock machine is very unserious) and finally, at least for milling wood, add convoluted rubber gaiters to the axes since oiled mechanics like ballscrews are absolutely incompatible with wood dust.

I don’t want to spill water into your wine, you express a lot of joy over your acquisition of this CNC machine that I don’t want to stop you, and I think in matters of hobbyist CNC machines, Onefinity has advantages over competitors. But starting a business requires to really be sure to be able to rely on your equipment. Hobbyists usually have the time to stand beside the machine, but that does not apply to a professional user. I would try to eliminate sources of possible (inevitable?) disappointment before starting a production.

PS: For the 3D model of the machine above, did you measure the machine yourself?

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I’ve got a tendency to overdrive the small stuff so I’ve had to learn to ease up on doc and feeds for >= 1/8" bits. I’ve achieved some promising results from 1/4" and larger end mills at acceptable doc / feeds, though. I’ve only stalled the XY a few times with surfacing bits by trying to hog more material in a single pass than I reasonably should. That’s on me. Upgrading the steppers means more risk to the tooling so, either way, I’ve got to stop treating this like a Bridgeport and let it work at its own pace.

It’s just adding torque which, in turn, affords higher ipm at greater cutting depths, which is pretty much asking for a Bridgeport. The compromise is Nema 23 425 oz/in for a 400 pound machine vs the 8,000 pound machine’s Nema 42’s at baseline ~3600 oz/in per axis. I’m unstable… but not insane. :wink:

No worries on that. If it turns out that the higher carbon steels prove too much for the system, the contingency is stepping down to fully supporting the other side of the business exclusively. I set my wife (the Carrianne in this scenario) up with a ceramics business alongside my metal fab endeavors and there’s always developing new products and cnc’ing models used to subsequently create plaster molds for slip casting.

FYI, she owns the machine. She made the purchase in her name, received it and helped with its setup. The purpose for this was to pull her into my world, to inspire an interest in the seemingly pointless, expensive equipment I was striving to obtain and to punctuate the point that the machine can definitely be used to support her ceramics endeavors. At this point, I think she gets it. It’s about having the flexibility to create just about anything (Joey’s a wood carver, a metal mill, a plotter, a glorified vinyl cutter, an engraver and, if I have more to say about it, a laser cutter / engraver and a plasma cutter and maybe even a ginormous 3d printer if I get find the motivation to experiment). This onefinity grants the flexibility to adapt. But no flag signs and no coasters. The market’s already flooded to the point that I’m personally sick of seeing flag signs and coasters. :smiley:

It’s pretty much the same with the heavy industrial stuff. I recall when I became a machinist apprentice many moons ago, I inquired if I could just test on scraps of hardwood instead of wasting steel. That went over like a lead balloon and I was told that under no circumstances will I subject a milling machine to the destructive nature of sawdust. I lol’d because, at the time, I thought, “How can something far softer than steel cause damage when the steel, itself, doesn’t?”. “Can I turn wood on a metal lathe?” “You can, but not for long!”

You’re just speaking my language now. I wasn’t excited about the Molex connectors to begin with. They’re a little flimsy… and I’ve abused them terribly already. On the other hand, if it wasn’t for a Molex connector on the gantry when that cable caught up on the shelving, we’d be having a slightly different conversation right now, not regarding upgrades to the cnc but how destructive and dangerous a the cnc can be and how a workstation crashed to the floor. Fortunately, the X-axis connector just simply unplugged and there was nothing but a cable management lesson to endure.

A few aspects of it initially, yes, but that was before I discovered that others here had already invented that particular wheel. What I ended up doing was combining bits of a couple different models to have a general reference for designing accessories. It’s been an enormous benefit in mocking up the table on which it lives and creating its spoilboard.

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@Moggy, I am in Aus too and looking at the 2.2kw Spindle. Could I please ask which one you bought, with what VFD and accessories? I have found what I think is the right one on Amazon.com.au, except that it is spec’d for 220V rather than 240.

Did you come to any conclusions as to whether the OOTB stepper is powerful enough?

Same as you I think I will start with the Makita, but don’t want to fork out heaps for bits/cutters for it, then have to rebuy them for 1/2” for the Spindle. It seems here in Aus the Makita cost is closer to that of the Spindle as well (looks about 1/2 the cost rather than 1/3 to 1/4 in the US/Canada) so less financial incentive to go the Makita route.

Tas :slight_smile: