The CubeMars RO100 KV55 Lite is a high-performance frameless brushless DC outrunner motor, engineered specifically for robotics, cobot joints, exoskeletons, and medical and aviation devices. As part of the advanced RO Series, this motor stands out with its enhanced torque, ultra-low cogging, and innovative hollow through-hole design—offering superior integration within tight and demanding spaces.
Building on the robust foundation of the R Series, the RO100 KV55 Lite incorporates a larger hollow shaft for maximum flexibility, lightweight aluminum alloy construction for impact and corrosion resistance, and integrated Hall and temperature sensors for real-time feedback and protection. Its ultra-low cogging torque and high efficiency (up to 92.6%) make it ideal for precision applications where smooth and reliable motion is critical.
Highlights
• Rated voltage 48V - KV55
• Ultra-low cogging torque
• Increased large hollow through-hole design
• High adaptability, switch the shaft for versatile usage
• Rated torque 4Nm
• Equipped with Hall and temperature sensors
• Mainly used in exoskeleton robots, collaborative robotic arms, as well as in medical and aerospace fields.
Features
Ultra-Low Cogging Torque
The RO series motor exhibits 50% lower tooth count torque compared to the R series, ensuring smoother operation at low speeds.
Large Hollow Through-Hole
In comparison to the GL series, the RO series motor boasts a larger hollow diameter, adapting flexibly to various diameter requirements, allowing for versatile applications with a simple shaft replacement.
Integrated Temperature and Hall Sensors
Real-time monitoring of motor temperature prevents damage due to abnormal temperatures, and precise positioning control is provided through Hall sensors.
Aluminum Alloy Housing
The rotor of the RO series adopts an aluminum alloy housing, enhancing impact resistance, corrosion resistance, and providing various customization possibilities for appearance. This also improves transparency in controlling raw material costs.
Easy Installation
Stator features pin holes for easy assembly, and the product is equipped with magnetic pins and screws, greatly simplifying the installation process.
UNVEILING A NEW ICON
the entirely redesigned RO Series
High Adaptability & Large Hollow
ULTRA-LOW COGGING TORQUE
A 50% reduction in cogging torque compared to products of the same level offering a silky-smooth new experience
LARGE HOLLOW THROUGH-HOLE DESIGN
Featuring a reserved large-diameter hollow through-hole, providing flexible and versatile usage;
Simply replace the shaft to meet different hollow requirements, achieving a one-motor-multiple-uses scenario
HIGH EFFICIENCY STABLE & RELIABLE
The RO series utilizes high-grade magnets for peak motor efficiency, reaching up to 92.6%
Enhanced temperature adaptability, improved operational stability, and extended lifespan
RO Lite
Streamlined Engineering for Lightweight Performance
BUILT-IN TEMPERATURE HALL SENSORS
Real-time monitoring of motor temperature providing precise rotor position and speed information, ensuring precise motor control
Technical Drawing
RO100 KV55 Standard Version
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RO100 KV55 Lite Version
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Specification
RO100 KV55 Standard Version
|
| Application |
Cobot Arm |
Insulation Class |
F |
| Driving Way |
FOC |
Insulation High-Voltage |
500V |
| Operation Ambient Temperature |
-20℃~50℃ |
Insulation Resistance |
10MΩ |
| Winding Type |
star |
Cogging Torque |
55N.mm |
| Pole Pairs |
21 |
Inertia |
8700gcm² |
| Maximum Torque Weight Ratio |
16.9Nm/kg |
Weight |
710g |
| Rotor Weight |
324g |
Stator Weight |
356g |
| Hall Temperature SensorWire |
30#AWSilicone Wire100±5mm Tinning5±2mm |
Lead-Out |
Three-Phase Motor Lead-Out: Enameled Wire StraightOut 100±5mm Tinned 5±2mm |
| Three-Phasewire |
4.5mm |
|
|
RO100 KV55 Lite Version
|
| Application |
Cobot Arm |
Insulation Class |
F |
| Driving Way |
FOC |
Insulation High-Voltage |
500V |
| Operation Ambient Temperature |
-20℃~50℃ |
Insulation Resistance |
10MΩ |
| WindingType |
star |
Cogging Torque |
55N.mm |
| Pole Pairs |
21 |
Inertia |
5290gcm² |
| Rotor Weight |
190g |
Weight |
525g |
Maximum Height of Enameled WireBulge |
7mm |
Stator Weight |
335g |
| Three-Phasewire |
4.5mm |
Lead-Out |
Three-Phase Motor Lead-Out: Enameled Wire Straight Out 100±5mm Tinned5±2mm |
| Electric Parameters |
| Rated Voltage |
48V |
Ke |
18.67V/krpm |
| No-Load Speed |
2550rpm |
Phase To Phase Resistance |
143mΩ |
| Rated Torque |
4Nm |
Phase To Phase Inductance |
137μH |
| Rated Speed |
2000rpm |
Km |
0.53Nm/√W |
| Rated Current |
20ADC |
Mechanical Time Constant |
1.73ms |
| Peak Torque |
12Nm |
Electrical Time Constant |
0.96ms |
| Peak Current |
62ADC |
Kt |
0.2Nm/A |
| Kv |
55rpm/V |
|
|
Links
Resource
RO100 drawing.pdf
RO100_KV55.zip
RO100-KV55-lite.pdf
RO100-KV55-lite.zip
RO100 Test Fixture.zip
1. General Shipping Information
- We provide premium shipping methods with a tracking number for each order.
-
Shipping addresses must be entered in English without special symbols to help the courier company recognize your address in the system. We will ship strictly according to the shipping address you provided. Please notify us of any address change before your order is marked "Shipped" to avoid parcel loss.
- Please contact our customer service staff immediately if you need to cancel or change an order. Once your order has reached "Shipped" status, it can no longer be canceled or changed in any way. To avoid complications, please recheck your shopping cart before checkout.
- We can ship all in-stock orders within 1 business day after your order has been confirmed.
- All items are inspected before dispatch and are carefully hand-packed.
- With standard courier practice, you need to check the contents of the parcel before signing for your goods. Otherwise, we will not be held responsible for any damage that may have occurred in transit.
🚀 Need Faster Shipping?
If you require expedited shipping (Express), please contact our customer support team at info@openelab.io for a customized quote tailored to your location.
2. Shipping Rates & Options
Our shipping rates are calculated based on the order value and destination. Please refer to the tables below for details.
2.1 Germany (Domestic)
| Shipping Method |
Order Value |
Cost |
Est. Delivery |
| Deutsche Post |
€0 - €50.00 |
€4.95 |
2-4 Business Days |
| Deutsche Post |
Over €50.00 |
Free |
2-4 Business Days |
DHL Paket (Faster Delivery) |
€0 - €50.00 |
€6.95 |
1-3 Business Days |
DHL Paket (Faster Delivery) |
€50.00 - €100.00 |
€2.00 |
1-3 Business Days |
DHL Paket (Faster Delivery) |
Over €100.00 |
Free |
1-3 Business Days |
2.2 European Union (EU)*
*Including:
Åland Islands, Andorra, Austria, Belgium, Bosnia & Herzegovina, Bulgaria, Croatia, Czechia, Denmark, Estonia, Faroe Islands, Finland, France, Gibraltar, Greece, Guernsey, Hungary, Ireland, Isle of Man, Italy, Jersey, Latvia, Lithuania, Luxembourg, Malta, Moldova, Monaco, Montenegro, Netherlands, North Macedonia, Poland, Portugal, Romania, San Marino, Serbia, Slovakia, Slovenia, Spain, Svalbard & Jan Mayen, Sweden.*
| Shipping Method |
Order Value |
Cost |
Est. Delivery |
| Deutsche Post |
€0 - €100.00 |
€7.95 |
5-9 Business Days |
| Deutsche Post |
Over €100.00 |
Free |
5-9 Business Days |
DHL Paket (Faster Delivery) |
€0 - €100.00 |
€15.95 |
3-7 Business Days |
DHL Paket (Faster Delivery) |
€100.00 - €250.00 |
€7.95 |
3-7 Business Days |
DHL Paket (Faster Delivery) |
Over €250.00 |
Free |
3-7 Business Days |
2.3 United States
| Region |
Shipping Method |
Order Value |
Cost |
Est. Delivery |
Continental U.S. (50 States) |
USPS Ground Advantage |
€0 - €45.00 |
€4.95 |
3-7 Business Days |
| USPS Ground Advantage |
Over €45.00 |
Free |
3-7 Business Days |
| USPS Priority Mail |
€0 - €45.00 |
€16.95 |
1-4 Business Days |
| USPS Priority Mail |
Over €45.00 |
€14.95 |
1-4 Business Days |
Non-Continental U.S. (AK, HI, PR, etc.) |
USPS Ground Advantage |
€0 - €60.00 |
€6.95 |
5-9 Business Days |
| USPS Ground Advantage |
Over €60.00 |
Free |
5-9 Business Days |
* The regions in the Non-Continental U.S. include: Alaska, American Samoa, Guam, Hawaii, the Marshall Islands, the Northern Mariana Islands, Palau, Puerto Rico, the U.S. Virgin Islands, and all U.S. Armed Forces addresses. The shipping and delivery to these areas are subject to the Non-Continental U.S. shipping rules.
2.4 International (Outside EU)
For specific international destinations, including Switzerland, United Kingdom, and Norway.
| Order Amount |
Shipping Cost |
| €0 - €300.00 |
€19.95 |
| Over €300.00 |
Free |
Important Notice:
-
Inventory Status: Please check the inventory status on the product page. Our system displays real-time stock for our Munich and Long Beach warehouses. If an item is out of stock in these locations, it will be marked as "Pre-order". You can still place an order for these items.
-
Pre-order Fulfillment: For "Pre-order" items, we arrange the most efficient logistics solution to ensure you receive your goods as quickly as possible. Your package may be shipped directly from our Shenzhen warehouse. Alternatively, as part of our standard restocking process, we may transport the goods to our Munich or Long Beach warehouse first (typically taking 5-10 business days) before dispatching them to you.
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Split Shipments: If your order contains both in-stock and Pre-order items, we will prioritize shipping the in-stock items from the local warehouse immediately. The remaining Pre-order items will be sent to you in a separate shipment once they are ready.
3. International Warehouse
Our products are stored in our Munich, Long Beach, and Shenzhen warehouses to provide more flexible logistics solutions tailored to different regions and customer needs. On each product's description page, we indicate the specific warehouse location to help you better plan your purchase and delivery schedule.
3.1 German Warehouse
For products stored in our warehouse in Munich, we use either Deutsche Post or DHL for shipping, depending on the size of the package. Logistics within Germany are very efficient, with an estimated delivery time of 2-4 business days, ensuring you receive your order quickly and conveniently. For Western EU countries, the estimated delivery time is 4-6 business days. For Eastern EU countries, the estimated delivery time is 6-8 business days.
3.2 US Warehouse
For products stored in our warehouse in Long Beach, we use either USPS or UPS for shipping, depending on the size of the package. Logistics within U.S. are very efficient, with an estimated delivery time of 3-7 business days, ensuring you receive your order quickly and conveniently.
3.3 Chinese Warehouse
For Pre-order items or orders fulfilled directly from our Shenzhen warehouse, we utilize YunExpress for reliable international shipping. Given the complexities of international shipping, the estimated delivery time for these packages is around 10 business days, though this may vary slightly due to customs processes or other uncontrollable factors. Otherwise, products will be restocked to our Munich or US warehouses before final delivery, as detailed in the "Important Notice" above.
4. Customs and Taxes
4.1 How are customs handled by OpenELAB for import or export?
For EU Member States: Whether shipped from Germany or China, we cover all import duties and taxes (DDP), ensuring that you receive your package without any additional costs or hassle with customs.
Important Exception for Non-EU Countries (e.g., Switzerland, Norway):
For countries outside of the European Union, such as Switzerland and Norway, you may be subject to import duties, taxes, and/or customs fees charged upon delivery. These fees vary from country to country and are the sole responsibility of the recipient.
⚠️ Refusal of Delivery: If you refuse to pay these fees upon delivery and the package is returned to us, the refund amount will be calculated after deducting the original shipping costs, return shipping costs, and any applicable customs or storage fees.
4.2 How is VAT charged when the Customer places an order from OpenELAB?
In accordance with the newest VAT e-commerce rules in the EU, OpenELAB shall have the right to charge the amount of VAT at checkout. The standard rate of actual VAT applied is subject to the destination country's regulations. No additional VAT will be charged upon delivery for these orders.
Effective Date: December 10, 2025
At OpenELAB, we are committed to providing accurate product descriptions and high-quality electronics. The following policy outlines your rights and obligations, designed to be fair to both our customers and our business operations globally.
1. Warranty Policy
A. Standard Limited Warranty (Global & US)
For customers in the United States, Asia, and other non-EU regions:
-
Warranty Period: OpenELAB provides a 12-month warranty from the date of delivery.
-
Coverage: This warranty covers defects in material and workmanship under normal use.
-
Resolution: We will repair or replace defective units at no charge.
B. Statutory Rights for EU/UK Customers (EU Compliance)
If you are a consumer residing in the European Union or the UK purchasing from our global site:
-
Statutory Guarantee: You are entitled to a 24-month statutory guarantee for conformity defects present at the time of delivery, in accordance with EU consumer protection laws.
-
Relation: The Standard Limited Warranty (Section 1.A) applies in addition to, and does not replace, your statutory rights.
C. Warranty Exclusions (Applies to ALL Regions)
Warranty coverage is VOID if the damage is caused by:
-
Misuse: Incorrect installation, reverse polarity, or exceeding voltage limits.
-
Unauthorized Modification: This explicitly includes soldering, cutting pins, modifying the PCB, or flashing unauthorized/beta firmware that "bricks" the device.
-
Physical Damage: Drops, moisture/water damage, or electrical surges (lightning).
-
Normal Wear & Tear: Consumable parts (e.g., batteries), unless defective upon arrival.
Note: For non-warranty repairs (e.g., customer-induced damage), we may offer repair services for a fee. Shipping and diagnostic costs will be borne by the customer.
2. Return & Refund Policy
A. Return Window
B. Refund Conditions & Restocking Fees
To protect against policy abuse, the refund amount is strictly determined by the condition of the returned item.
1. Full Refund (100%)
-
The item is Brand New, Unopened, and Unused.
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The original packaging is intact and sealed.
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All accessories are present.
2. Partial Refund (Restocking Fee / Value Depreciation)
If the item is returned in a condition that prevents it from being sold as new, OpenELAB reserves the right to deduct a Restocking Fee (or "Compensation for Loss of Value" for EU customers) from the refund.
Deductions apply if:
-
Signs of Use: Visible scratches, mounting marks on screw holes, or fingerprints.
-
Damaged Packaging: Original box is torn, written on, or missing.
-
Technical Modification: The device has been powered on, programmed/flashed, or soldered.
-
Broken Seals: Anti-static bags or security seals have been opened.
Depending on the severity of the usage/damage, the deduction may range from 15% to 50% of the product price. Items damaged beyond repair due to misuse will not be refunded.
C. Shipping Costs
-
Defective / Wrong Item: OpenELAB covers the return shipping cost.
-
Customer Remorse (Changed Mind / Ordered Wrong Item): The customer is responsible for all return shipping costs to our designated return center (located in the US, Germany, or China, depending on your region). Original shipping fees are non-refundable unless required by local law.
3. Return Process (RMA)
To ensure a smooth return process, please follow these steps:
-
Authorization: Contact us at info@openelab.io before returning any item. Returns without prior authorization will not be accepted.
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RMA Number: We will provide you with a Return Merchandise Authorization (RMA) number and the correct return address.
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Packing: Ship the item back in its original packaging with the RMA number clearly marked on the shipping label (not on the product box).
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Tracking: We strongly recommend using a trackable shipping method. OpenELAB is not responsible for returns lost in transit.