{"product_id":"shaft-coupling-flexible-plum-spider-jaw-coupler-stepper-motor-connector-o20-mm","title":"Shaft Coupling Flexible Plum Spider Jaw Coupler Stepper Motor Connector Ø20 mm","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eFlexible Plum Spider Jaw Shaft Coupling — Reliable Motion Transfer for Stepper Motors\u003c\/h2\u003e\n\u003cp\u003eWhen shaft misalignment, vibration, or torque shock threatens the precision of your CNC router, 3D printer, or automation rig, a rigid coupling simply isn't enough. Engineers and DIY builders who demand consistent, low-backlash motion transfer rely on flexible jaw couplings to protect their motors and lead screws from the stresses of real-world operation.\u003c\/p\u003e\n\u003cp\u003eThis flexible plum spider jaw shaft coupling features an outer diameter of Ø20 mm (~0.79 in) and a length of 25 mm (~0.98 in). The two-piece aluminum alloy hubs grip each shaft independently, while a polyurethane spider insert sits between them to absorb shock and dampen vibration. Bore sizes range from 4 mm to 10 mm (d1 and d2), covering a wide range of motor shaft and lead screw combinations.\u003c\/p\u003e\n\u003cp\u003eTypical applications include stepper motor to lead screw connections on CNC milling machines, flexible coupling for 3D printer Z-axis drives, and servo motor shaft connectors in light industrial automation — all scenarios where angular and parallel misalignment compensation is critical for long-term accuracy.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e⚙️\u003c\/span\u003e\n\u003cstrong\u003eCompatible with:\u003c\/strong\u003e NEMA 17 \/ NEMA 23 stepper motors, standard lead screws (T8, T12), servo motor shafts, and encoder shafts with 4–10 mm diameter. Verify bore size (d1 × d2) before ordering.\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These Flexible Plum Spider Jaw Shaft Couplings\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-list\"\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\n\u003cstrong\u003eTwo-Piece Aluminum Hub Design\u003c\/strong\u003e\n\u003cp\u003eEach hub clamps independently onto its shaft via set screws, allowing different bore sizes on each end (d1 ≠ d2) — ideal for mixed motor and lead screw shaft diameters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🌟\u003c\/span\u003e\n\u003cstrong\u003ePolyurethane Spider Insert\u003c\/strong\u003e\n\u003cp\u003eThe star-shaped elastomer spider absorbs torque shock, reduces vibration transmission, and compensates for angular, parallel, and axial misalignment between connected shafts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n\u003cstrong\u003eØ20 mm Outer Diameter, 25 mm Length\u003c\/strong\u003e\n\u003cp\u003eCompact form factor fits within tight motor mounts and gantry assemblies. Outer diameter of 20 mm (~0.79 in) and length of 25 mm (~0.98 in) suit most desktop CNC and 3D printer builds.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\n\u003cstrong\u003eLow Backlash for Positioning Accuracy\u003c\/strong\u003e\n\u003cp\u003eThe interference-fit spider insert minimizes rotational play, maintaining positioning repeatability in open-loop stepper motor systems where backlash directly affects part accuracy.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🛡️\u003c\/span\u003e\n\u003cstrong\u003eCorrosion-Resistant Aluminum Alloy Hubs\u003c\/strong\u003e\n\u003cp\u003eLightweight aluminum alloy construction resists oxidation in workshop environments. Anodized finish (where applicable) adds surface hardness and extends service life.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\n\u003cstrong\u003eWide Bore Size Selection (4–10 mm)\u003c\/strong\u003e\n\u003cp\u003eAvailable in 28 bore size combinations from 4×4 mm up to 9×10 mm, covering the most common stepper motor shaft and lead screw diameter pairings used in DIY CNC and automation projects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — Flexible Jaw Shaft Coupling\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter (Ø)\u003c\/th\u003e\n\u003ctd\u003e20 mm (0.79 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCoupling Length\u003c\/th\u003e\n\u003ctd\u003e25 mm (0.98 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Size d1 Range\u003c\/th\u003e\n\u003ctd\u003e4 mm – 9 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Size d2 Range\u003c\/th\u003e\n\u003ctd\u003e4 mm – 10 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHub Material\u003c\/th\u003e\n\u003ctd\u003eAluminum Alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSpider Insert Material\u003c\/th\u003e\n\u003ctd\u003ePolyurethane (PU)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCoupling Type\u003c\/th\u003e\n\u003ctd\u003eFlexible Jaw \/ Plum Spider\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMisalignment Compensation\u003c\/th\u003e\n\u003ctd\u003eAngular, Parallel, Axial\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFastening Method\u003c\/th\u003e\n\u003ctd\u003eSet Screw (grub screw)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMax Recommended RPM\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMax Torque\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\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 (d1 × d2)?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMeasure the shaft diameter of your motor (d1) and the shaft or lead screw it connects to (d2) using a caliper. Select the variant where d1 matches your motor shaft and d2 matches your lead screw or driven shaft. Both bores are clamped independently, so d1 and d2 do not need to be equal.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan this coupling handle angular and parallel misalignment?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. The polyurethane spider insert flexes to accommodate angular misalignment (typically up to 1°–3°) and small amounts of parallel offset. For best results, align shafts as closely as possible — the spider compensates for residual misalignment rather than replacing proper alignment practice.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill the aluminum hubs corrode in a humid workshop environment?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eAluminum alloy naturally forms a thin oxide layer that resists further corrosion in typical indoor workshop conditions. For environments with exposure to cutting fluids or high humidity, periodic inspection of the set screws is recommended to prevent galvanic corrosion at the fastener contact points.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs this coupling suitable for NEMA 17 and NEMA 23 stepper motors?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. NEMA 17 motors typically have 5 mm shafts and NEMA 23 motors commonly use 6.35 mm or 8 mm shafts — all within the 4–10 mm bore range of this coupling. Select the bore size that matches your specific motor shaft diameter.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow does the spider insert affect backlash?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe polyurethane spider is designed to fit snugly between the hub jaws, minimizing rotational play. In open-loop stepper motor systems, low backlash is essential for repeatable positioning. The interference fit of the spider insert keeps backlash to a minimum under normal operating loads.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I replace the spider insert separately if it wears out?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe spider insert is a separate component from the aluminum hubs. In many cases, replacement spiders of the same jaw count and outer diameter can be sourced independently, extending the service life of the aluminum hubs. Contact us to confirm compatibility with your specific coupling size.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between a plum spider jaw coupling and a rigid coupling?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eA rigid coupling transmits torque without any flex, requiring near-perfect shaft alignment. A plum spider jaw coupling uses an elastomer insert to absorb vibration, compensate for minor misalignment, and protect motor bearings from shock loads — making it the preferred choice for CNC and 3D printer applications where some shaft runout is unavoidable.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-cta\"\u003e\n🛒 Select your Ø-(mm) x Length and Bore Size (d1–d2) above, then add to cart.\n\u003c\/div\u003e\n\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I choose the right bore size (d1 × d2)?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Measure the shaft diameter of your motor (d1) and the shaft or lead screw it connects to (d2) using a caliper. Select the variant where d1 matches your motor shaft and d2 matches your lead screw or driven shaft. Both bores are clamped independently, so d1 and d2 do not need to be equal.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can this coupling handle angular and parallel misalignment?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. The polyurethane spider insert flexes to accommodate angular misalignment (typically up to 1°–3°) and small amounts of parallel offset. For best results, align shafts as closely as possible.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will the aluminum hubs corrode in a humid workshop environment?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Aluminum alloy naturally forms a thin oxide layer that resists further corrosion in typical indoor workshop conditions. Periodic inspection of set screws is recommended in high-humidity or cutting-fluid environments.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this coupling suitable for NEMA 17 and NEMA 23 stepper motors?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. NEMA 17 motors typically have 5 mm shafts and NEMA 23 motors commonly use 6.35 mm or 8 mm shafts — all within the 4–10 mm bore range of this coupling.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How does the spider insert affect backlash?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The polyurethane spider is designed to fit snugly between the hub jaws, minimizing rotational play. The interference fit keeps backlash to a minimum under normal operating loads.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I replace the spider insert separately if it wears out?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The spider insert is a separate component from the aluminum hubs. Replacement spiders of the same jaw count and outer diameter can often be sourced independently. Contact us to confirm compatibility.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the difference between a plum spider jaw coupling and a rigid coupling?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A rigid coupling transmits torque without any flex, requiring near-perfect shaft alignment. A plum spider jaw coupling uses an elastomer insert to absorb vibration, compensate for minor misalignment, and protect motor bearings from shock loads.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"Ø 20 x L25 mm \/ 4 x  10 mm","offer_id":52421890244882,"sku":"FOB08303x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 4 x  4 mm","offer_id":52421890277650,"sku":"FOB08304x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 5 x  5 mm","offer_id":52421890310418,"sku":"FOB08305x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 6 x  6 mm","offer_id":52421890343186,"sku":"FOB08306x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 7 x  7 mm","offer_id":52421890375954,"sku":"FOB08307x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 8 x  8 mm","offer_id":52421890408722,"sku":"FOB08308x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 9 x  9 mm","offer_id":52421890441490,"sku":"FOB08309x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 10 x  10 mm","offer_id":52421890474258,"sku":"FOB08310x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 4 x  5 mm","offer_id":52421890507026,"sku":"FOB09616x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 4 x  6 mm","offer_id":52421890539794,"sku":"FOB09617x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 4 x  7 mm","offer_id":52421890572562,"sku":"FOB09618x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 4 x  8 mm","offer_id":52421890605330,"sku":"FOB09619x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 4 x  9 mm","offer_id":52421890638098,"sku":"FOB09620x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 5 x  6 mm","offer_id":52421890670866,"sku":"FOB09621x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 5 x  7 mm","offer_id":52421890703634,"sku":"FOB09622x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 5 x  8 mm","offer_id":52421890736402,"sku":"FOB09623x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 5 x  9 mm","offer_id":52421890769170,"sku":"FOB09624x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 5 x  10 mm","offer_id":52421890801938,"sku":"FOB09625x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 6 x  7 mm","offer_id":52421890834706,"sku":"FOB09626x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 6 x  8 mm","offer_id":52421890867474,"sku":"FOB09627x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 6 x  9 mm","offer_id":52421890900242,"sku":"FOB09628x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 6 x  10 mm","offer_id":52421890933010,"sku":"FOB09629x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 7 x  8 mm","offer_id":52421890965778,"sku":"FOB09630x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 7 x  9 mm","offer_id":52421890998546,"sku":"FOB09631x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 7 x  10 mm","offer_id":52421891031314,"sku":"FOB09632x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 8 x  9 mm","offer_id":52421891064082,"sku":"FOB09633x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 8 x  10 mm","offer_id":52421891096850,"sku":"FOB09634x1","price":9.55,"currency_code":"USD","in_stock":true},{"title":"Ø 20 x L25 mm \/ 9 x  10 mm","offer_id":52421891129618,"sku":"FOB09635x1","price":9.55,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of7_0b160325-413a-4141-8c49-50e3f961d409.jpg?v=1783338573","url":"https:\/\/homediyer.com\/products\/shaft-coupling-flexible-plum-spider-jaw-coupler-stepper-motor-connector-o20-mm","provider":"HomeDIYer","version":"1.0","type":"link"}