KST CM509MG Micro Coreless Metal Gear 6.0Kgf.cm 0.08sec Digital Servo
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KST CM509MG Micro Coreless Metal Gear 6.0Kgf.cm 0.08sec Digital Servo
The KST CM509MG Micro Coreless Metal Gear Digital Servo is a compact servo for small-scale RC planes and cars. KST positions it for builds that need a lightweight micro servo with metal gears and programmable digital control.
Verified KST data lists a DC 4.8V-8.4V voltage range, up to 6.0Kgf.cm torque at 8.4V, and 0.08sec/60deg speed at 8.4V. It uses a coreless motor, metal gear construction, potentiometer feedback, and 2 ball bearings.
The 23 x 11 x 24mm case, 25T 5mm output spline, and 15g listed weight make CM509MG a small, fast option for compact PWM-controlled RC mechanisms.
Product Images



Features
- 6.0Kgf.cm peak torque - Listed torque reaches 6.0Kgf.cm at 8.4V.
- 0.08sec response - Listed speed reaches 0.08sec/60deg at 8.4V.
- Micro-size case - Listed dimensions are 23 x 11 x 24mm.
- Coreless motor - Supports smooth output in compact RC applications.
- Metal gear train - Adds durability compared with plastic gear micro servos.
- Aluminum alloy case - Rigid housing for small-scale models.
- 2BB construction - Dual ball bearings support the output shaft.
- 25T 5mm spline - Output shaft spline is listed in the technical PDF.
- Programmable soft start - KST lists soft start and programmability.
- Small-scale RC focus - KST positions CM509MG for small planes and cars.
Specifications
| Parameter | Value |
|---|---|
| Model | KST CM509MG |
| Shopify SKU | KST-CM509MG |
| Rated Voltage | DC7.4V |
| Voltage Range | DC4.8V-8.4V |
| Torque | 3.6Kgf.cm @ 4.8V; 4.8Kgf.cm @ 6.0V; 5.5Kgf.cm @ 7.4V; 6.0Kgf.cm @ 8.4V |
| Speed | 0.13sec/60deg @ 4.8V; 0.11sec/60deg @ 6.0V; 0.09sec/60deg @ 7.4V; 0.08sec/60deg @ 8.4V |
| Stalling Current | 0.95A @ 4.8V; 1.15A @ 6.0V; 1.35A @ 7.4V; 1.60A @ 8.4V |
| Working Frequency | 1520us / 333Hz |
| Default Travel Angle | +/-50deg = 100deg total |
| Output Shaft Spline | 25T, 5mm |
| Case Material | Aluminum alloy |
| Motor Type | Coreless motor |
| Gear Set Material | Metal gear |
| Position Sensor | Potentiometer |
| Ball Bearing | 2BB |
| Case Dimensions | 23 x 11 x 24mm +/-0.2mm |
| Weight | 15g +/-10% |
| Temperature Range | -10C to +65C |
| Programmable | Yes |
Reference Documents
Application
- Small-scale RC planes - KST positions CM509MG for compact aircraft applications.
- Small-scale RC cars - Suitable for compact steering or control mechanisms when size and torque match.
- Micro servo upgrades - Useful where the 23 x 11 x 24mm case fits the servo bay.
- HV micro mechanisms - Works across the listed DC4.8V-8.4V range with a compatible power system.
- Custom PWM prototypes - Can be used in compact mechanisms after checking load and thermal limits.
- Lightweight control surfaces - A fit for small control surfaces where the 15g listed weight is acceptable.
Packing List
| Description | Quantity |
|---|---|
| KST CM509MG micro servo | 1 |
| Plastic servo horn | 2 |
| Servo horn screw | 1 |
| Mounting screw | 4 |
FAQ
How does CM509MG compare with BLS88WP?
CM509MG is a 15g micro coreless servo rated up to 6.0Kgf.cm at 8.4V. BLS88WP is a brushless waterproof micro servo rated up to 8.5Kgf.cm at 8.4V and IP67.
Does OpenELAB list multiple Shopify variants for this product?
No. The current Shopify product is a single variant with SKU KST-CM509MG.
What is the maximum listed torque?
KST lists 6.0Kgf.cm at 8.4V.
What is the fastest listed speed?
The fastest listed speed is 0.08sec/60deg at 8.4V.
Is it waterproof?
The KST data used here does not list an IP waterproof rating for CM509MG, so it should not be treated as waterproof.
What spline does it use?
The technical PDF lists a 25T, 5mm output shaft spline.
What is included in the package?
KST lists one CM509MG micro servo, two plastic servo horns, one servo horn screw, and four mounting screws.
What should I check before installation?
Confirm the 23 x 11 x 24mm case, 25T 5mm spline, voltage range, and mechanical load before installation.
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| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
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|---|---|---|---|
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