{"product_id":"flexible-shaft-coupling-d16-d25-stepper-servo-motor-encoder-coupler-aluminum","title":"Flexible shaft Coupling D16 D18 D25 Step Servo Motor Encoder Coupler Joint Alu","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eFlexible Shaft Coupling for Stepper \u0026amp; Servo Motors — Reliable Torque Transmission\u003c\/h2\u003e\n\u003cp\u003eMisaligned motor shafts and encoder connections are a common frustration for CNC builders, robotics engineers, and 3D printer enthusiasts. When your coupling can't absorb angular or parallel offset, vibration transfers directly to your mechanics — causing positioning errors, premature bearing wear, and noisy operation. This flexible shaft coupling is engineered for DIYers and automation professionals who need a dependable, low-backlash connection between their stepper or servo motor and lead screw, encoder, or driven shaft.\u003c\/p\u003e\n\u003cp\u003eEach coupling is machined from aluminum alloy with a helical-cut flexible body that accommodates angular misalignment (typically ±1°–3°) and parallel offset (typically 0.2–0.5 mm). Available in outer diameters of D16, D18, and D25 mm (approximately 0.63\", 0.71\", and 0.98\"), with a range of bore combinations to suit common motor shaft and lead screw diameters. The clamping collar design ensures a secure, tool-accessible connection without permanent modification to your shafts.\u003c\/p\u003e\n\u003cp\u003eIdeal for CNC router Z-axis and X\/Y-axis lead screw connections, stepper motor to encoder shaft coupling in closed-loop systems, and 3D printer Z-axis flexible coupling upgrades where rigid couplers cause layer shifting. The helical slot design makes these couplings a go-to solution for flexible motor shaft coupler replacements in desktop CNC machines and DIY automation rigs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e🔧\u003c\/span\u003e \u003cstrong\u003eCompatible with:\u003c\/strong\u003e NEMA 17 \u0026amp; NEMA 23 stepper motors, servo motors with standard shaft diameters, lead screws, encoders, and rotary shafts. Select your bore (φd1 × φd2) and outer diameter × length (D × L) from the variant options above.\u003c\/div\u003e\n\u003ch2\u003e✅ Key Features of These Flexible Shaft Couplings\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚙️\u003c\/span\u003e \u003cstrong\u003eHelical-Cut Flexible Body\u003c\/strong\u003e\n\u003cp\u003eThe precision helical slot allows the coupling to flex under angular and parallel misalignment, absorbing vibration before it reaches your mechanics and protecting bearings and encoders from shock loads.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e \u003cstrong\u003eDual Clamping Collar Design\u003c\/strong\u003e\n\u003cp\u003eEach end features a split-clamp collar secured by set screws, providing a firm grip on both shafts without requiring adhesive or permanent modification — easy to install and re-adjust.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🏗️\u003c\/span\u003e \u003cstrong\u003eAluminum Alloy Construction\u003c\/strong\u003e\n\u003cp\u003eMachined from lightweight aluminum alloy, these couplings offer a strong strength-to-weight ratio suitable for moderate-torque applications in CNC, 3D printing, and light automation systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e \u003cstrong\u003eMultiple Size Options\u003c\/strong\u003e\n\u003cp\u003eAvailable in outer diameters D16, D18, and D25 with a variety of bore combinations (φd1 × φd2), covering the most common stepper motor shaft and lead screw diameter pairings used in DIY CNC and robotics builds.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e \u003cstrong\u003eLow Backlash for Precision Motion\u003c\/strong\u003e\n\u003cp\u003eThe one-piece helical design minimizes rotational backlash compared to jaw-type or Oldham couplings, making these suitable for positioning applications where accuracy matters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🛠️\u003c\/span\u003e \u003cstrong\u003eTool-Accessible Installation\u003c\/strong\u003e\n\u003cp\u003eSet screws are accessible with a standard hex key (Allen wrench). No special tooling required — slide onto shaft, align, and tighten. Suitable for workshop and field installation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch2\u003e📐 Technical Specifications — Flexible Shaft Coupling\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eProduct Type\u003c\/th\u003e\n\u003ctd\u003eFlexible Helical Shaft Coupling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eAluminum Alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter (D)\u003c\/th\u003e\n\u003ctd\u003eD16 \/ D18 \/ D25 mm (see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLength (L)\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter (φd1 × φd2)\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMisalignment Tolerance (Angular)\u003c\/th\u003e\n\u003ctd\u003eTypically ±1°–3°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMisalignment Tolerance (Parallel)\u003c\/th\u003e\n\u003ctd\u003eTypically 0.2–0.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFastening Method\u003c\/th\u003e\n\u003ctd\u003eDual clamping collar with set screws\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eNatural anodized aluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTypical Application\u003c\/th\u003e\n\u003ctd\u003eCNC, 3D printer, stepper\/servo motor, encoder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I choose the right bore size (φd1 × φd2) for my motor and lead screw?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eMeasure the diameter of your motor shaft (φd1) and the shaft or lead screw you are connecting to (φd2) using a caliper. Common stepper motor shaft diameters are 5 mm and 6.35 mm; common lead screw diameters are 8 mm and 10 mm. Select the bore combination that matches both shafts exactly — a loose bore will cause slippage under load.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between D16, D18, and D25 outer diameters?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe outer diameter (D) affects the coupling's torque capacity and physical clearance in your build. D16 (≈0.63\") suits compact NEMA 17 setups with limited space. D18 (≈0.71\") offers a balance of torque and size. D25 (≈0.98\") is suited for NEMA 23 motors or higher-torque applications. Choose based on your motor frame size and available clearance around the coupling.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan this coupling handle both angular and parallel shaft misalignment?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes. The helical-cut flexible body accommodates angular misalignment of typically ±1°–3° and parallel (radial) offset of approximately 0.2–0.5 mm. However, for best performance and longevity, align your shafts as closely as possible before tightening — the coupling is designed to absorb residual misalignment, not to compensate for large installation errors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs this coupling suitable for high-speed or high-torque applications?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThese aluminum helical couplings are well-suited for moderate-torque, moderate-speed applications typical of CNC routers, 3D printers, and light automation. For very high torque or high-RPM industrial applications, please contact us to confirm suitability, as the helical slot design has inherent torque limits compared to solid rigid couplings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill this coupling corrode or degrade over time?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe aluminum alloy construction provides good resistance to oxidation in typical indoor workshop environments. The natural anodized finish adds a layer of surface protection. These couplings are not recommended for prolonged exposure to salt spray, strong acids, or highly humid outdoor environments without additional protective measures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I install and secure the coupling on my motor shaft?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eSlide each end of the coupling onto the respective shaft, ensuring the shaft reaches fully into the bore. Align the shafts as closely as possible. Tighten the set screws on each clamping collar using a hex key (Allen wrench) to the appropriate torque — do not overtighten, as this can deform the bore. Check alignment once more after tightening and re-adjust if needed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use this coupling to connect two shafts of different diameters?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes — that is one of the key advantages of the dual-bore design. Each end of the coupling can accept a different shaft diameter (φd1 ≠ φd2), making it straightforward to connect a motor shaft to a lead screw or encoder shaft of a different size. Simply select the variant with the bore combination that matches your two shaft diameters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your Bore (φd1 × φd2) and Diameter × Length above, then add to cart.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"HomeDIYer","offers":[{"title":"2 x 2 \/ D16 L23","offer_id":52421795119378,"sku":"FASDGZCWJ1016x1","price":12.97,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of6_d43facb1-7ee7-4829-9728-028c4d38db72.jpg?v=1783325698","url":"https:\/\/homediyer.com\/products\/flexible-shaft-coupling-d16-d25-stepper-servo-motor-encoder-coupler-aluminum","provider":"HomeDIYer","version":"1.0","type":"link"}