When designing a custom mechanical keyboard, weight is more than a way to make the keyboard feel heavier. This guide explains how to choose the right material, calculate the required mass, and design a custom keyboard weight around your available space and overall keyboard structure.
What Is a Custom Keyboard Weight?
A custom keyboard weight is a metal component designed to add mass to a mechanical CNC keyboard case. You can install it inside the keyboard case, mount it externally on the bottom, or integrate it into a dedicated weight cavity.
Why Add a Weight to a Custom Keyboard?
When designing a keyboard, you usually add a custom CNC-machined keyboard weight to achieve the following purposes:
Stability on Desktop
More overall weight helps the keyboard move less on the desktop, especially with a heavier metal case.
Acoustic Behavior & Sound Tuning
The weight may alter the overall quality and structural response of the keyboard, but a heavier keyboard does not automatically produce better sound. Ultimately, the sound is also influenced by factors such as case geometry, mounting system, plate, PCB, switches, keycaps, and foam/damping materials. Therefore, if you are adjusting the keyboard sound, it is not recommended to solve the problem simply by increasing the weight.
Balance and Center of Gravity
The position of the CNC keyboard weight will affect the center of gravity of the whole keyboard. If the weight is concentrated at the bottom or on one side, you need to consider whether the entire keyboard still maintains a reasonable weight distribution. This is especially important.
Product Feel and Perceived Quality
For high-end custom CNC keyboards, the weight adjustment not only serves a functional purpose but also often plays a role in visual design. For instance, you can use brass, copper, or stainless steel to create different metallic textures, or you can incorporate the weight adjustment into a part of the overall design through surface finish and logo engraving.
How Heavy Should a Custom Keyboard Weight Be?
There is no “optimal keyboard weight” that applies to all keyboards. You need to determine the target weight based on the following factors:
- Overall size of the keyboard
- Case material
- Current weight of the keyboard
- Available space for keyboard weights
- Installation position of the weights
- The desired center of gravity and stability
- Overall design style of the product
If you have a larger weight space, you will have more freedom in geometric design; if the internal cavity is small, you need to pay more attention to the material density.
Choosing the Right Material for Custom Keyboard Weights
The choice of keyboard weight materials will directly affect the weight, volume, machining difficulty, surface effect, and cost.
Aluminum Keyboard Weight
Aluminum alloy has a lower density, so if you want to reduce the overall weight or if the balance needs to match the aluminum case, aluminum alloy is a common choice. It is also relatively easy to machine by CNC, and different colors can be obtained through anodizing.
Brass/Copper Keyboard Weight
Brass/copper has a higher density, allowing for a greater mass to be achieved within a limited space. If you want a custom keyboard weight with a distinct metallic texture and a high visual weight, brass/copper are very common choices in custom keyboards. However, the surface of brass/copper may oxidize or develop patina over time, so you need to consider the final surface effect in advance. Usually, sandblasting with a clear coating is a better option if you need a smooth finish.
Stainless Steel Keyboard Weight
Stainless steel has a high density and also possesses excellent corrosion resistance and durability. But it is harder for machining compare with aluminum and brass/copper. If you value a long-term stable appearance and durability, stainless steel is a worthy choice to consider.
Titanium Keyboard Weight
The density of titanium is lower than that of brass, copper, and stainless steel, but it has higher strength and a unique metallic luster. However, its machining cost is very high.
Brass vs Copper vs Stainless Steel vs Aluminum Keyboard Weight
Density isn’t the only consideration. If you are choosing between brass, copper, and stainless steel, don’t just compare their densities. Although brass and copper are denser than stainless steel, material selection should also consider machining, surface finish, corrosion/oxidation, appearance, cost, and available space.
| Material | Density | Weight Potential | Corrosion / Aging | Cost |
| Brass | 8.5 | High | Patina | $$ |
| Copper | 8.9 | Very High | Strong patina | $$$ |
| Stainless Steel | 7.9 | High | Excellent | $$ |
| Aluminum | 2.7 | Low | Excellent | $ |
If your weight is external, you also need to consider whether the surface treatment is in harmony with the keyboard case, badge, logo, and other visual elements.
- If your focus is on achieving a large weight within a limited space, copper or brass would be the preferred choice.
- If you are more concerned about durability and corrosion resistance, stainless steel might be a better option.
- If you want to control the weight and have the flexibility to customize the color, aluminum alloy would be more suitable.
How to Calculate Keyboard Weight Mass
The mass of a keyboard weight can be estimated from the material density and its volume: Mass = Density × Volume. For a simple rectangular weight: Weight = Length × Width × Thickness × Material Density.
For example, if a brass weight measures 100 mm × 30 mm × 5 mm,
- its volume is 15 cm³
- Its density is approximately 8.5 g/cm³
- Estimated weight: 15 × 8.5 = 127.5 g
In addition, some design software can also automatically calculate the weight based on your weight structure and the material.
Step-by-Step Guide to Designing a Custom Keyboard Weight
After determining the target weight and materials, you can proceed with the custom keyboard weight design in the following steps.
- Check available space inside the keyboard case.
- Select the materials based on the target weight and the available space.
- Calculate required volume according to the material density.
- Determine weight geometry based on the structure of the entire keyboard case.
- Determine weight location
- Select mounting methods – rubber pins, top mount, o-ring, gasket, or others.
- Check clearance and case integration with PCBs, daughterboard, screws, or others.
- Prepare CAD and drawing requirements
Surface Finishes for Custom Keyboard Weights
Surface treatment not only affects the appearance, but also influences the final style of your product and maintenance requirements. Common options include:
- Brushed
- Polished
- Sandblasted
- PVD
- Anodizing
- Clear coating
See tables below for common different finishes for different materials.
| Material | Common Finishes |
| Aluminum | Anodizing, Sandblasting, Brushing |
| Brass/Copper | Brushing, Patina, Sandblasting + clear coating |
| Stainless Steel | Brushing, Polishing, Mirror polishing, PVD |
| Titanium | Brushing, PVD, Anodizing |
FAQ
Is brass heavier than stainless steel for a keyboard weight?
Under the same volume, the density of brass is slightly higher than that of stainless steel. Therefore, the brass counterweight of the same size will be heavier.
Where should a keyboard weight be placed?
Both internal weight and external weight are common to see in keyboard designs. Its position usually needs to be determined based on the case geometry and the overall center of gravity. However, you still need to check the clearance of the PCB, mounting structure, and other internal components.
Can keyboard weights be engraved?
Sure, we can do keyboard weight engraving by CNC engraving for simple logos and laser engraving for complex patterns.
What should be included in a keyboard weight drawing?
Usually, it includes 2d drawings and 3d drawings.
2D drawings: you should mark all the tolerances, size, material, and the surface finish.
3D drawings: in STEP, STP, X_T, STL format.
Why is CNC machining suitable for custom keyboard weights?
Because for normal group buy orders, the total quantity cannot be in the thousands. Compared to the time and cost invested in the mold, we can use CNC milling without being limited by the material or surface treatment, and achieve a more perfect texture.
Final Thoughts
Shanghai Yecheng is a high-end CNC keyboard manufacturer with an in-house anodizing line and over 5 years of experience in keyboard machining. We have worked with keyboard designers and brands to turn their designs into production-ready products and successfully support group buys from prototype to production.
Send your keyboard case drawings today for a free weight calculation & DFM check.
