Advanced Keyboard Guide: How to Lubricate Switches

Keyboard Switch Modding 00 Cover Image

Lubricating keyboard switches isn’t rocket science. However, this isn’t something you can get right on your first try, either. Most end up ruining hundreds of expensive switches while mastering the craft. And that still doesn’t guarantee you’ll achieve consistency. In fact, an inconsistently lubricated keyboard feels objectively worse than an unlubricated one.

Fortunately, this isn’t an average switch lubrication tutorial. You won’t be blindly following instructions without understanding the process. In this lubing switch guide, you will learn how keyboard switches work; figure out the different tools, lubricants, accessories, and why you need them; and lastly, how to lube switches.

Tools of the Trade

Let’s take a stock of all the tools and consumables required. At around three minutes per switch, hand-lubing switches takes a couple of hours per keyboard. Spending a bit extra on tools that make the job easier as well as quicker is worth every penny.

Keyboard Switch Modding 01

Nevertheless, you will find such optional (and relatively more expensive) tools listed alongside their cheaper counterparts. It’s your call whether you want to spend more time or more money to achieve the same goal.

  1. Switches
  2. Switch lubricant
  3. Switch films (optional)
  4. Switch opener (optional) or fine-tip angled tweezers (type-15)
  5. Jeweler’s claw pick-up tool (optional)
  6. Paintbrush (size-00)
  7. At least four containers with lids (optional)

The Anatomy of MX-Style Switches

Let’s take a closer look at the workings of MX-style switches. A vast majority of popular switches in this hobby are based on the original Cherry MX design. Learning how these switches work is critical to identifying the points of friction. That is critical to formulate a good lubrication strategy.

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The Cherry MX design is fairly simple and is comprised of three main components: the upper housing, lower housing, and slider assembly.

Keyboard Switch Modding 08a

The image below should give a better idea of the individual components. The upper housing is a single piece of injection-molded plastic. It is nothing complicated, since it only exists to prevent the slider from popping out of the housing.

The slider assembly is a bit more complicated. It consists of a plastic slider that interfaces with a coil spring. The coil spring is what gives every switch its unique weight. Making heavy, medium, and light switch variants is a simple matter of using lighter or stiffer springs.

Keyboard Switch Modding 08b

The lower housing is the most complicated part of the switch and includes three separate components – that is, the plastic housing and copper contact leaves. The plastic housing contains a central hollow shaft that allows the slider to move up and down. This is a major source of plastic-on-plastic friction.

The central shaft is flanked by two rails designed to reduce slider wobble. These rails prevent wobble by providing a straight path for the corresponding guide tabs on the slider to move along. This is another significant source of friction.

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The contact leaves are comprised of a two-part assembly consisting of a leaf spring and static contact leaf. The latter is the smaller copper plate isolated on the right side of the image above.

The contact leaf spring has a natural tendency to push against the smaller contact leaf at all times. However, the two contact leaves are held apart by the slider when the switch is at rest. Actuating the switch causes the slider to move down, which in turn allows the contact leaves to connect and complete the electrical circuit. This is registered as a key input.

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The image above explains how two tiny prongs (right side, marked in green) on the slider keep the contact leaf spring away from the static contact leaf when the switch is at rest. The prongs or slider cams act like plastic fingers pushing against the corresponding protrusions on the contact leaf spring (left side, also marked in green).

Pressing the switch causes the slider to move down and the slider cams to move out of the way, which in turn allows the contact leaf spring to fall onto the static contact leaf and complete the circuit. The points where the slider cams and the contact leaf spring meet are also substantial sources of plastic-on-metal friction.

Keyboard Switch Modding 01a

Switch Films Are Indispensable

Switch films are optional. However, they are the cheapest way to significantly improve stock linear and tactile switches at $5 for 110 switches. The source of improvement here is the wobble (video demonstration) that exists between the two halves of switch housings. Virtually all switches exhibit some degree of wobble by design. Switch films eliminate wobble by filling the gap between the upper and lower switch housings.

Is it worth spending $5 to eliminate the gap between switch housings?

The gap between two housings not only generates wobble, but it also makes the switches act like miniature hi-hat cymbals. (Watch this video to understand how hi-hat cymbals work.) The upper and the lower halves of the switch housing generate a percussive note just like hi-hat cymbals in a drum set. Taking the slack away with switch films eliminates this problem, thereby making the switches sound consistent and quieter. This video demonstrates how films make switches sound better.

This won’t be a problem if, for some reason, you actually enjoy the percussive note. However, the gap between the two halves of the housings isn’t consistent between the switches. This leads to the switches generating inconsistent-sounding acoustic notes. Not to mention, linear and tactile switches aren’t supposed to produce these rather loud and annoying sounds to begin with.

Jeweler’s Claw Pick-Up Tool

The jeweler’s claw is a pick-up tool that makes the job of holding the slider easier during the process of lubrication.

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Choosing the Right Paintbrush

A good paintbrush is a bare necessity. Higher-quality brushes made of fine, natural-hair bristles will hold lube better and more consistently than cheaper ones with coarse, artificial bristles. The quality of lubrication further hinges on choosing the right brush size.

I absolutely recommend a size-00 paintbrush. Achieving consistent lubrication depends singularly on the quantity of lubricant loaded onto the brush. Using a larger brush will load an excessive amount of lube per application, which will lead to over-lubrication. Nothing ruins switches quicker than using excessive lubrication.

Switch Lube Considerations

The bog-standard switch lubricant used by keyboard enthusiasts across the world happens to be Krytox brand lube. It’s plastic-safe and durable and available in the form of oil or grease. The higher viscosity of greases guarantees better adhesion and makes switches feel buttery smooth compared to oils. But they are difficult to apply correctly and not recommended for beginners. Higher viscosity lubes such as greases are ideal for linear switches where the primary goal is smoothness. However, greases can reduce the tactility of tactile switches and completely eliminate clickyness of clicky variants.

Keyboard Switch Modding 02

That makes oils more suitable for tactile and clicky switches, which deliver a fair degree of smoothness without overly reducing the tactile feedback or clickyness. Krytox oils are available in viscosity grades ranging from 103 through 107, with the viscosity increasing with higher numbers. Krytox greases are generally only found in the 205 grade in the keyboard world, which makes it ideal for use with linear switches.

Switch Opener Recommended

Opening switches quickly and safely with a $9 set of electronics tweezers is cheaper but take longer and adds the risk of inadvertently ruining switches. If you are adamant about avoiding switch openers, this video demonstrates how to open switches with type-15 angled tweezers. For those who wish to take our advice, the following shows how to use a switch opener.

1. Buy a switch opener.

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2. Locate the switch’s south face. That’s the one with the sloping edge and through-holes for socketing an LED. Place it on either of the alignment posts on the switch opener. Refer to the image below for clarification.

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3. Press the switch downwards. Release. That’s it, you’re done.

Keyboard Switch Modding 04c

How to Lube Different Switch Types

Cherry MX style switches, or any switch for that matter, come in three primary variants: linear, tactile, and clicky. The audible click, as well as the tactile feedback produced by clicky switches, makes them the most complicated of the lot in mechanical terms. Tactile switches, on the other hand, can largely be felt but not heard as much. These produce no audible click but only tactile bump. Linear switches are the simplest of the lot and do not provide tactile feedback nor generate an audible click.

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Fortunately, the simplicity of Cherry MX switch design is centered around keeping manufacturing costs low. In other words, every single switch component (except the slider) is interchangeable between all three switch types. This makes our job easier and less complicated.

Keyboard Switch Modding 09b

That also means our lubing strategy must adapt to the different slider variations for each switch type. Thankfully, the diversity in slider design is further restricted solely to the slider cam profiles between linear and tactile switches.

One look at these profiles shows how linear switches incorporate a simple slope, whereas the cam on the tactile switch slider has a pronounced bump. This protrusion generates tactile feedback as it slides against the contact leaf spring.

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Heavily lubricating the slider cams of a tactile switch will cause a significant loss in tactile feedback. You are better off not lubricating the slider cam and contact leaf spring if you want to maximize tactile feedback. Light application of thin lube on this part, however, will ensure smoother actuation without excessively attenuating the tactile feedback.

Clicky switches divide the slider further into a new discrete part known as the click jacket. The new component (click jacket, in white above) incorporates the slider cams and is free to move about the slider along a pair of integrated guide rails. The click jacket also produces the distinctive clicky note by smacking against the lower housing during actuation.

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As a clicky switch is being depressed, slider cams are held in place by the contact leaf assembly, even as the contact leaf spring compresses progressively. As the slider moves down further, the cams pushing against the leaf spring generate compressive energy.

This pent-up energy eventually launches the click jacket rapidly onto the lower housing. That’s how you get a click, which sounds more like a horrible rattle in reality. No wonder custom keyboard folks hate this switch type with a vengeance.

Lubing the top and bottom surfaces of the click jacket must therefore be avoided, or you will lose the click altogether. You can, however, lube the contact leaf spring and slider cam if you don’t care about losing tactility.

Zoning Sliders to Control Switch Behavior

Now that the basic concepts have been drilled in, let’s take a close look at the most critical component of the lubing process – the slider. Achieving consistent lubing is easy, provided the process is streamlined. Doing that is a matter of dividing the slider surfaces into separate zones.

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The idea with that is that each time you load the brush with a consistent amount of lube, the very first application is the heaviest, with the subsequent ones transferring progressively lower amounts of lube to the component surfaces.

This way, the parts/zones that need light lubrication can be pushed further down the lubing order and others can be omitted altogether. Because we now know exactly what each part/zone does, you can choose the correct lubrication strategy for either a specific switch type or further customize it to your own personal typing preference.

The following example demonstrates the slider of a tactile switch being lubed in a specific manner to achieve specific results – that is, to ensure the smoothest actuation, slight reduction in tactility, and greatest reduction of bottom-out as well as upstroke noise.

Keyboard Switch Modding 10a

1. The guide tabs (highlighted in green) on either side of the slider must be lubed first after loading the paintbrush with lube. This is one of the most significant sources of friction, so you’ll need a relatively generous application of lube here.

2. Because we have prioritized buttery smooth switch actuation over tactility, we can lube the slider cams (highlighted in red) next. This will reduce tactility by some extent, but the cam-to-contact leaf spring friction will be eliminated.

3. The third and final application of this lube load is reserved for the north face of the slider (highlighted in grey). This part has the least contact area and hence experiences the lowest amount of friction as well. There’s no real need to add a lot of lube here.

1. With the paintbrush reloaded with the same amount of lube, the slider guide rod (highlighted in grey at the bottom) gets the first lube application since it is the largest source of friction among these zones.

Keyboard Switch Modding 10b

2. The subsequent application focuses on the parts of the slider (highlighted in red) responsible for the bottom-out and upstroke sounds. This is how you take the edge out of a harsh sounding switch.

3. Like the north face, the south face of the slider is also lubricated last for the same reason.

Lubing Switches

We start off by opening the switch as illustrated earlier. The specific lube used in this example is a 1:5 ratio blend of Krytox 205 grease with 104 oil. This is a ratio I have settled upon after exhaustive trial and error. With time and experience, you will find your own ideal lube viscosity and/or blend. We will be lubricating a Zealios V2 tactile switch with the intention of making it as smooth as possible while sacrificing some of the tactility to reduce slider-on-contact leaf friction. Softening the bottom-out and upstroke notes is also an important consideration.

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Loading the Brush: This may seem elementary, but the very success of this endeavor hinges on getting this seemingly simple step right. Dip the size-00 paintbrush into the lubricant container until it is saturated. Now remove excess lubricant from the brush by wiping it on the neck of the container. Don’t forget to wipe the other side of the brush.

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Note: your brush should look like the one depicted in the bottom half after wiping. Please don’t lube your switches with the overloaded paintbrush evident in the top half.

Our goal is to achieve consistency. We do that by dipping the brush once to the same depth to pick up a consistent amount of lube. If you removed excess lube by wiping it on the container three times per side, make sure you repeat the exact same process each time you reload the brush. Consistency isn’t achieved by chance; you need to be deliberate while making and counting every move.

Warning: The examples in the photos have been lubed excessively for visibility. Greases should be applied in a thin layer that barely shines when held under a bright light. Less is more here. If you apply thick coats of viscous lubricant on the switch components, the assembly will gum up and feel horribly mushy and slow during operation.

Lower Housing

1. Load the paintbrush with lube.

The two rails maintaining the alignment of the slider are large sources of friction. That’s why we lube them first to transfer most of the lubricant. Lube the first rail with one side of the brush but use the opposite side to paint the remaining rail. Whether you use one or two strokes per rail, keep the number consistent between switches.

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While lubing the entire width of the rail seems obvious, don’t forget to paint the narrow orthogonal edges that also interface with the slider. I prefer lubing each rail in two passes. Touching the right and left-hand corners in separate passes makes sense because the size-00 brush is too narrow to lube the entire width of the slider.

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2. Next up is the hollow central shaft that interfaces with the slider. Skip the hollow of the shaft because we will instead lubricate the male end of the slider (guide rod) that goes into it.

Lubing both these complementary parts is a recipe for disaster. Excessive lube can cause the gap between the shaft and the slider guide rod to become airtight. This causes the switch to feel like someone has slipped an extra pneumatic spring inside.

We only lube the outside of the switch in a clean circular motion. This prevents the spring from grating harshly against the shaft and making an annoying crunchy sound. Once again, count your strokes and maintain consistency between switches.

Keyboard Switch Modding 12c
Keyboard Switch Modding 08d

3. By now the brush is running pretty low on lube. That makes it a perfect time to apply a thin coat onto the two actuation points on the contact leaf spring. Use the highlighted part in the second image above to give you a better idea.

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4. If you plan on using switch films, now is the time to add one. The larger hole of the switch film corresponds with the part of the lower housing containing the contact leaf assembly. Just slip it on the lower housing.

You’re done with the lower housing of the switch. Set it aside for the time being inside a clean container. However, I find it easier to cover it by placing a clean, inverted drinking glass on top of it. That way, you’re less likely to accidentally drop the housing or touch the lubricated internal surfaces. Glass is also a great barrier against dust ingress.

Spring

1. Load the paintbrush with lube.

Squeezing the tweezer prongs together, slipping them inside the hollow of the spring, and releasing pressure is the best way to transform a pair of regular tweezers into improvised reverse clamp tweezers. This makes it nearly impossible to drop the spring.

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Use only one side of the brush to lubricate the outer surface of the spring lengthwise.

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2. Use the other side of the brush to lube the inside of the spring with a clean circular motion. Apply a consistent amount of lube (count your brush strokes) to the bottom of the spring as well.

Paint the remaining half of the spring occluded by the tweezers. You will have to hold the spring by the opposite end for that. Transferring the spring to another pair of tweezers while removing the first one is the quickest and easiest way to go about that business.

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You’re done with the springs as well. Remove the drinking glass covering the lubed lower housing and place the spring onto the shaft. Pinch the tweezers to release the grip on the spring so that it is transferred onto the shaft. Cover the lubed parts again using the inverted drinking glass.

Slider A

1. Load the paintbrush with lube.

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The alignment tabs on either side of the slider ride in the corresponding vertical rails in the lower housing. That’s a large source of friction, so we will be lubing this zone first. Apply a thin coat of lube to one side and flip the brush around to paint the tab on the other side.

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2. Because we value smoothness over tactility, lube both slider cam legs with either side of the paintbrush as depicted above.

Keyboard Switch Modding 14c
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3. The north and south faces of the slider aren’t subjected to much friction. Therefore, we save these for last while our paintbrush is running nearly on empty. Apply a thin, even coat and count your brush strokes as always.

Slider B

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Keyboard Switch Modding 15b

1. Load the paintbrush with lube.

Let’s focus at the bottom of the slider. Remember the hollow central shaft in the lower housing that we didn’t lube? We are going to lube its male counterpart found at the bottom of the slider. Apply a consistent amount of lube all around the guide rod as depicted in the image above.

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2. Lube the bottom edges of the slider. This is the part that hits the floor of the lower housing and produces the bottom-out sound. Lubing this part softens the sound of the bottom-out and gives it a nice low-pitch note.

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3. Repeat the process for the top of the alignment tab. This part smacks against the upper housing to produce the upstroke sound. Lubing it also makes the switch sound much better.

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The slider is done. Remove the drinking glass and drop the slider through the spring and into the central shaft using the jeweler’s claw pick-up tool. Place the drinking glass back into position.

Upper Housing

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1. Load the paintbrush with lube.

The left and right sides of the upper housing have internal channels cut out for accommodating the corresponding pair of guide tabs on the slider. Follow the same lubing strategy used in the first step of the Lower Housing for this part.

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2. Rotate the upper housing quarter turn to reveal two strips of plastic designed to reduce friction. This is achieved by hollowing out the strips in the middle, such that the point of contact with the slider is reduced to a pair of thin vertical lines. There’s no point applying lube in the hollowed middle part. Apply a thin coat of lube to both the vertical edges of the pair of strips.

Keyboard Switch Modding 17b

3. Remove the drinking glass and retrieve the lubed assembly consisting of the lower housing, replete with switch film, spring, and slider. Align the upper housing so that the sloped side (south face) containing the LED socket is aligned with the side on the lower housing that doesn’t house the contact leaf assembly. The image above should give you a fair idea.

Don’t mix these up, as you will crush the delicate contact leaf assembly upon closing the switch. With the alignment verified, press the upper and lower housings together until the four retention latches on the upper housing snap into the corresponding indents in the lower housing. Verify that the retention latches are secure and press the switch to ensure smooth actuation.

Congratulations. You have lubed a grand total of one switch. Now you only have anywhere between 60 to 95 more to go depending on the size of your custom mechanical keyboard.

Nachiket Mhatre Nachiket Mhatre

Growing up, Nachiket had a penchant for disassembling household electronics and appliances; most of which couldn’t be reassembled successfully. His parents didn’t approve. These days, he leverages his lifelong pursuit of dissecting gadgets to write about technology. His parents still don’t approve.

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