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.
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Shipping address should be input in English without any special symbols to help the courier company recognize your address in the system. We will ship according to the shipping address you provided. Please notify us of any address change before your order is marked "Shipped" to avoid parcel loss.
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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.
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We can ship all in-stock orders within 1 business day as your order has been confirmed.
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All items are inspected before dispatch and are carefully hand-packed.
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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.
2. Shipping Options for Germany, EU* countries and US
(For Products in Munich Warehouse, Long Beach Warehouse)
2.1 Orders with a value not exceeding €5:
Shipping Options:
| Shipping Options |
Germany |
EU* |
Deutsche Post
|
€6
Arrive in 3-4 Business Days |
€15
Arrive in 5-9 Business Days |
|
| Shipping Options |
Continental U.S. |
Non-Continental U.S. |
USPS Ground Advantage
|
€7.95
Arrive in 3-7 Business Days |
€8.95
Arrive in 5-9 Business Days |
UPS Express
|
€13.95
Arrive in 2-4 Business Days |
€17.95
Arrive in 3-7 Business Days |
2.2 Shipping options for an order value between €5 and €30 inside Germany, €5 and €50 inside the EU, or €5 and €45 in the U.S.:*
Shipping Options:
| Shipping Options |
Germany |
EU* |
Deutsche Post
|
€3.5
Arrive in 3-4 Business Days |
€6
Arrive in 5-9 Business Days |
DHL Paket
|
€6
Arrive in 2-3 Business Days |
€15
Arrive in 3-7 Business Days |
DHL Express
|
€14
Arrive in 1-2 Business Day |
€65
Arrive in 2-3 Business Days |
| Shipping Options |
Continental U.S. |
Non-Continental U.S. |
USPS Ground Advantage
|
€4.95
Arrive in 3-7 Business Days |
€6.95
Arrive in 5-9 Business Days |
UPS Express
|
€11.95
Arrive in 2-4 Business Days |
€13.95
Arrive in 3-7 Business Days |
2.3 Free shipping options for an order value of above €30 inside Germany, €50 inside the EU* or €45 in US :
| Free Shipping Options |
Germany |
EU* |
Deutsche Post
|
Free Above €30 |
Free Above €50 |
DHL Paket
|
+ €2 for Above €30 / Free Above €60 |
+ €8 for Above €50 / Free Above €80 |
DHL Express
|
+ €10 for Above €30 |
+ €60 for Above €50 |
| Free Shipping Options |
Continental U.S. |
Non-Continental U.S. |
USPS Ground Advantage
|
Free above €45 |
Free above €60 |
UPS Express
|
+ € 8.95 for Above €45 |
+ € 11.95 for Above €45 |
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Certain EU Countries are not included in our EU Zone definition: United Kingdom (excluding Ireland), Switzerland, Liechtenstein, Vatican City, Albania, Belarus, Norway, Ukraine, and Iceland. For the above countries, the International Shipping Rule applies.
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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, the Armed Forces of America, the Armed Forces in Europe, the Armed Forces in the Pacific, and the U.S. outlying islands. The shipping and delivery to these areas are subject to the Non-Continental U.S. shipping rules.
2.4 Shipping Options for International Countries:
(via Deutsche Post or YunExpress)
| Order Amount |
International |
| €0 - €15 |
€8 |
| €15 - €30 |
€7 |
| €30 - €50 |
€6 |
| €50 and above |
€4 |
Important Notice:
- Please verify the inventory location on the product page before placing your order to confirm delivery timeframes.
- For products in the Shenzhen warehouse, we will typically first ship the products from the Shenzhen warehouse to our Munich warehouse or Long Beach warehouse, which will take around 1.5 weeks. After we receive the shipment in Munich/ Long Beach, we will send the items to you. We will only arrange YunExpress shipping from Shenzhen for orders with products in the Shenzhen warehouse worth more than €50.
- If you place an order with products from both Munich and Shenzhen warehouses, we will first ship the products in the Munich warehouse, and then send the remaining products to you when we receive them from Shenzhen.
3. International Warehouse
Our products are stored in both our Munich 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
We will only arrange YunExpressexpress shipping from Shenzhen for orders with products in the Shenzhen warehouse worth more than €50. Orders directly shipped from our Shenzhen warehouse are handled by YunExpress. 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, the products will first be shipped from China to our Munich warehouse and then shipped to the final destination.
To ensure that your order is delivered within your desired timeframe, we recommend reviewing the warehouse information provided on the product pages before placing your order and selecting the appropriate shipping option. If you have any questions or need further assistance, please don't hesitate to contact our customer support team—we are here to help you!
4. Customs and Taxes
4.1 How are customs handled by OpenELAB for import or export?
Whether shipped from Germany or China, we cover all import duties and taxes, ensuring that you receive your package without any additional costs or hassle with customs.
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. The standard rate of actual VAT applied is subject to the European government's freedom to set the number and level. Such an amount of VAT will be charged when you place an order from OpenELAB. Please contact OpenELAB if you have any questions when you pay such VAT.
4.3 What kind of fee will be charged except VAT?
Except for the VAT, OpenELAB will charge any handling fee when you are placing any purchase orders, which includes but is not limited to customs duty, import VAT, freight costs, etc. Customs duty and import VAT will be paid on the importation of goods from outside the EU into an EU country, and such amount is calculated as a percentage of the customs value of goods. Please note that it may take 1-2 working days for Deutsche Post/DHL/FEDEX or 3-4 working days for YunExpress for the status to update.
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:
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Warranty Period: OpenELAB provides a 12-month warranty from the date of delivery.
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Coverage: This warranty covers defects in material and workmanship under normal use.
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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.
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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.
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Physical Damage: Drops, moisture/water damage, or electrical surges (lightning).
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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%)
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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:
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Signs of Use: Visible scratches, mounting marks on screw holes, or fingerprints.
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Damaged Packaging: Original box is torn, written on, or missing.
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Technical Modification: The device has been powered on, programmed/flashed, or soldered.
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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
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Defective / Wrong Item: OpenELAB covers the return shipping cost.
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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:
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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.
