{"product_id":"flexible-shaft-coupling-coupler-cnc-3d-printer-stepper-motor","title":"Flexible Shaft Coupling Coupler CNC 3D Printer Stepper Motor 12\/14\/15\/16\/19\/20mm","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eFlexible Shaft Coupling Coupler — Precision Motion Control for CNC \u0026amp; 3D Printer Builds\u003c\/h2\u003e\n\u003cp\u003eWhen misalignment between a stepper motor shaft and a lead screw causes binding, vibration, or lost steps, the coupling is almost always the culprit. Engineers, makers, and machine builders who demand repeatable, low-backlash motion need a coupler that absorbs angular and parallel offset without transmitting shock loads back to the motor bearings. These flexible shaft couplings are designed for exactly that application.\u003c\/p\u003e\n\u003cp\u003eEach coupler is machined from aluminum alloy with a helical-cut flexible body that accommodates angular misalignment of typically 1–3° and parallel offset of typically 0.2–0.5 mm. Available in two outer-diameter families — D40 mm (≈1.57 in) and D55 mm (≈2.17 in) — with lengths ranging from 55 mm to 80 mm (≈2.17–3.15 in). Shaft bore options span 12 mm to 28 mm (≈0.47–1.10 in), covering the most common stepper motor and servo shaft standards.\u003c\/p\u003e\n\u003cp\u003eTypical use cases include CNC router Z-axis lead screw connections, FDM 3D printer Z-axis couplers replacing rigid spider couplings, and light-duty servo motor test rigs where flexible shaft coupling for stepper motor misalignment compensation is critical to print quality and machining 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 \u0026amp; NEMA 23 stepper motors · T8 \/ T12 lead screws · 5 mm, 6.35 mm, 8 mm, 10 mm, 12 mm–20 mm motor shafts · CNC routers, laser engravers, 3D printers (Ender, Voron, RatRig, and similar platforms)\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These Flexible 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\u003eHelical-Cut Flexible Body\u003c\/strong\u003e\n\u003cp\u003eThe spiral cut pattern allows the coupler to flex under angular and parallel misalignment, reducing vibration transmission to motor bearings and extending motor service life.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n\u003cstrong\u003eWide Shaft Bore Range\u003c\/strong\u003e\n\u003cp\u003eBore options from 12 mm to 28 mm (≈0.47–1.10 in) cover NEMA 17, NEMA 23, and many servo motor shaft standards — same-diameter and stepped-bore configurations available.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\n\u003cstrong\u003eDual Set-Screw Clamping\u003c\/strong\u003e\n\u003cp\u003eEach shaft end is secured by set screws that grip the shaft directly, providing positive torque transmission without relying solely on friction — suitable for both smooth and D-cut shafts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🏗️\u003c\/span\u003e\n\u003cstrong\u003eTwo Coupler Size Families\u003c\/strong\u003e\n\u003cp\u003eD40 mm body suits compact NEMA 17 builds; D55 mm body handles higher-torque NEMA 23 applications. Select the coupler dimension that matches your motor frame and available clearance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\n\u003cstrong\u003eMulti-Pack Value Options\u003c\/strong\u003e\n\u003cp\u003eAvailable in quantities of 1, 2, 3, or 5 per order — ideal for stocking spares for multi-axis machines or ordering for a full printer farm build.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\n\u003cstrong\u003eDrop-In Replacement Fit\u003c\/strong\u003e\n\u003cp\u003eStandard OD and length dimensions match common aftermarket coupler footprints, making these a direct swap for worn or rigid couplings on most CNC and 3D printer frames.\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 Shaft Coupling Coupler\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eCoupler Body Material\u003c\/th\u003e\n\u003ctd\u003eAluminum alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCoupler Type\u003c\/th\u003e\n\u003ctd\u003eHelical-cut flexible jaw coupler\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter (OD)\u003c\/th\u003e\n\u003ctd\u003eD40 mm (≈1.57 in) \/ D55 mm (≈2.17 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOverall Length\u003c\/th\u003e\n\u003ctd\u003e55 mm \/ 65 mm \/ 78 mm \/ 80 mm (≈2.17–3.15 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eShaft Bore Diameter\u003c\/th\u003e\n\u003ctd\u003eSee variant options (12 mm–28 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Configuration\u003c\/th\u003e\n\u003ctd\u003eSame-diameter or stepped (see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eAngular Misalignment Tolerance\u003c\/th\u003e\n\u003ctd\u003eTypically 1–3°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eParallel Offset Tolerance\u003c\/th\u003e\n\u003ctd\u003eTypically 0.2–0.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eClamping Method\u003c\/th\u003e\n\u003ctd\u003eSet screw (both shaft ends)\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\u003eQuantity per Order\u003c\/th\u003e\n\u003ctd\u003eSee variant options (1 \/ 2 \/ 3 \/ 5 pcs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight (per unit)\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 coupler dimension for my stepper motor?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMatch the shaft bore to your motor shaft diameter and lead screw diameter. For NEMA 17 motors (typically 5 mm shaft) paired with T8 lead screws (8 mm), select the 5 mm-to-8 mm bore variant. For same-shaft connections, choose a same-diameter bore. The coupler OD (D40 or D55) should fit within the clearance of your motor mount and frame.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan this coupler handle the torque output of a NEMA 23 stepper motor?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe D55 mm × L78 mm and D55 mm × L80 mm variants are sized for NEMA 23 applications. The larger body diameter and longer clamping zone provide greater torque capacity than the D40 mm family. For high-duty-cycle or high-torque applications, confirm your motor's rated torque against the coupler's bore and set-screw clamping capacity.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill this coupler work with a D-cut (flat-sided) motor shaft?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. The set-screw clamping design works with both round and D-cut shafts. For D-cut shafts, orient one set screw to bear against the flat for maximum grip and to prevent shaft rotation under load.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow much misalignment can this flexible shaft coupling absorb?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe helical-cut body typically accommodates angular misalignment of 1–3° and parallel (radial) offset of 0.2–0.5 mm. These values are conservative estimates for standard helical aluminum couplers of this size. Minimizing misalignment at installation will extend coupler life and reduce vibration.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs this coupler corrosion-resistant for use in humid or outdoor environments?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe aluminum alloy body with anodized finish provides moderate corrosion resistance suitable for indoor workshop and enclosed machine environments. For prolonged exposure to moisture, salt air, or chemical vapors, consider applying a light protective coating or selecting a stainless-steel coupler variant.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhy buy a multi-pack instead of a single coupler?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMulti-axis CNC machines and 3D printers often require 2–3 couplers per build (X, Y, Z axes). Ordering a 2-, 3-, or 5-pack reduces per-unit cost and ensures you have spares on hand for maintenance. The 5-pack is particularly cost-effective for printer farm operators or workshop stock.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I install and tighten the set screws correctly?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eInsert each shaft fully into its respective bore end until it reaches the center stop. Tighten the set screws with an appropriate hex key (typically 2–3 mm) to the manufacturer's recommended torque — usually finger-tight plus a quarter turn for aluminum shafts, slightly firmer for steel shafts. Do not overtighten, as this can deform the bore or strip the set-screw thread.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-cta\"\u003e\n🛒 Select your Coupler Dimension, Shaft Diameter, and Amount 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 coupler dimension for my stepper motor?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Match the shaft bore to your motor shaft diameter and lead screw diameter. For NEMA 17 motors paired with T8 lead screws, select the matching bore variant. The coupler OD (D40 or D55) should fit within the clearance of your motor mount and frame.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can this coupler handle the torque output of a NEMA 23 stepper motor?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The D55 mm variants are sized for NEMA 23 applications. The larger body diameter and longer clamping zone provide greater torque capacity than the D40 mm family.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will this coupler work with a D-cut (flat-sided) motor shaft?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. The set-screw clamping design works with both round and D-cut shafts. Orient one set screw to bear against the flat for maximum grip.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How much misalignment can this flexible shaft coupling absorb?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The helical-cut body typically accommodates angular misalignment of 1–3° and parallel offset of 0.2–0.5 mm.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this coupler corrosion-resistant for use in humid or outdoor environments?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The aluminum alloy body with anodized finish provides moderate corrosion resistance suitable for indoor workshop and enclosed machine environments.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why buy a multi-pack instead of a single coupler?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Multi-axis CNC machines and 3D printers often require 2–3 couplers per build. Ordering a multi-pack reduces per-unit cost and ensures spares on hand for maintenance.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I install and tighten the set screws correctly?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Insert each shaft fully into its bore end until it reaches the center stop. Tighten the set screws with an appropriate hex key — finger-tight plus a quarter turn for aluminum shafts. Do not overtighten.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"D40mm x L55mm \/ 20mm to 20mm \/ 1","offer_id":52421852463378,"sku":"GY$$$BJT02199x1","price":15.15,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 14mm to 14mm \/ 1","offer_id":52421852496146,"sku":"GY$$$BJT02200x1","price":14.91,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 15mm to 15mm \/ 1","offer_id":52421852528914,"sku":"GY$$$BJT02202x1","price":17.3,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 16mm to 16mm \/ 1","offer_id":52421852561682,"sku":"GY$$$BJT02204x1","price":17.14,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 17mm to 17mm \/ 1","offer_id":52421852594450,"sku":"GY$$$BJT02205x1","price":16.95,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 19mm to 19mm \/ 1","offer_id":52421852627218,"sku":"GY$$$BJT02206x1","price":16.62,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 20mm to 20mm \/ 1","offer_id":52421852659986,"sku":"GY$$$BJT02207x1","price":16.4,"currency_code":"USD","in_stock":true},{"title":"D55mm x L78mm \/ 14mm to 28mm \/ 1","offer_id":52421852692754,"sku":"GY$$$BJT02203x1","price":32.25,"currency_code":"USD","in_stock":true},{"title":"D55mm x L80mm \/ 12mm to 28mm \/ 1","offer_id":52421852725522,"sku":"GY$$$BJT02201x1","price":29.31,"currency_code":"USD","in_stock":true},{"title":"D40mm x L55mm \/ 20mm to 20mm \/ 2","offer_id":52421852758290,"sku":"GY$$$BJT02199x2","price":29.31,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 14mm to 14mm \/ 2","offer_id":52421852791058,"sku":"GY$$$BJT02200x2","price":28.85,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 15mm to 15mm \/ 2","offer_id":52421852823826,"sku":"GY$$$BJT02202x2","price":33.65,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 16mm to 16mm \/ 2","offer_id":52421852856594,"sku":"GY$$$BJT02204x2","price":33.35,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 17mm to 17mm \/ 2","offer_id":52421852889362,"sku":"GY$$$BJT02205x2","price":33.01,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 19mm to 19mm \/ 2","offer_id":52421852922130,"sku":"GY$$$BJT02206x2","price":32.27,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 20mm to 20mm \/ 2","offer_id":52421852954898,"sku":"GY$$$BJT02207x2","price":31.89,"currency_code":"USD","in_stock":true},{"title":"D55mm x L78mm \/ 14mm to 28mm \/ 2","offer_id":52421852987666,"sku":"GY$$$BJT02203x2","price":63.54,"currency_code":"USD","in_stock":true},{"title":"D55mm x L80mm \/ 12mm to 28mm \/ 2","offer_id":52421853020434,"sku":"GY$$$BJT02201x2","price":57.7,"currency_code":"USD","in_stock":true},{"title":"D40mm x L55mm \/ 20mm to 20mm \/ 3","offer_id":52421853053202,"sku":"GY$$$BJT02199x3","price":43.51,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 14mm to 14mm \/ 3","offer_id":52421853085970,"sku":"GY$$$BJT02200x3","price":42.79,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 15mm to 15mm \/ 3","offer_id":52421853118738,"sku":"GY$$$BJT02202x3","price":49.99,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 16mm to 16mm \/ 3","offer_id":52421853151506,"sku":"GY$$$BJT02204x3","price":49.53,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 17mm to 17mm \/ 3","offer_id":52421853184274,"sku":"GY$$$BJT02205x3","price":49.04,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 19mm to 19mm \/ 3","offer_id":52421853217042,"sku":"GY$$$BJT02206x3","price":47.97,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 20mm to 20mm \/ 3","offer_id":52421853249810,"sku":"GY$$$BJT02207x3","price":47.36,"currency_code":"USD","in_stock":true},{"title":"D55mm x L78mm \/ 14mm to 28mm \/ 3","offer_id":52421853282578,"sku":"GY$$$BJT02203x3","price":94.86,"currency_code":"USD","in_stock":true},{"title":"D55mm x L80mm \/ 12mm to 28mm \/ 3","offer_id":52421853315346,"sku":"GY$$$BJT02201x3","price":86.05,"currency_code":"USD","in_stock":true},{"title":"D40mm x L55mm \/ 20mm to 20mm \/ 5","offer_id":52421853348114,"sku":"GY$$$BJT02199x5","price":71.86,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 14mm to 14mm \/ 5","offer_id":52421853380882,"sku":"GY$$$BJT02200x5","price":70.69,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 15mm to 15mm \/ 5","offer_id":52421853413650,"sku":"GY$$$BJT02202x5","price":82.69,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 16mm to 16mm \/ 5","offer_id":52421853446418,"sku":"GY$$$BJT02204x5","price":81.91,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 17mm to 17mm \/ 5","offer_id":52421853479186,"sku":"GY$$$BJT02205x5","price":81.1,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 19mm to 19mm \/ 5","offer_id":52421853511954,"sku":"GY$$$BJT02206x5","price":79.29,"currency_code":"USD","in_stock":true},{"title":"D40mm x L65mm \/ 20mm to 20mm \/ 5","offer_id":52421853544722,"sku":"GY$$$BJT02207x5","price":78.3,"currency_code":"USD","in_stock":true},{"title":"D55mm x L78mm \/ 14mm to 28mm \/ 5","offer_id":52421853577490,"sku":"GY$$$BJT02203x5","price":157.47,"currency_code":"USD","in_stock":true},{"title":"D55mm x L80mm \/ 12mm to 28mm \/ 5","offer_id":52421853610258,"sku":"GY$$$BJT02201x5","price":142.84,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture2of8_31569cb2-f16c-4793-81e8-6c17d82318a6.jpg?v=1783335123","url":"https:\/\/homediyer.com\/products\/flexible-shaft-coupling-coupler-cnc-3d-printer-stepper-motor","provider":"HomeDIYer","version":"1.0","type":"link"}