{"product_id":"gt2-pulley-ratio-set-16-20-30-36-40t-5mm","title":"GT2 Timing Pulley Ratio Set: 16T, 20T, 30T, 36T and 40T, 5 mm Bore, 6 mm Belt, Aluminium (16 Pulleys)","description":"\u003cp\u003e\u003cstrong\u003eA GT2 pulley ratio set is a spread of 2 mm-pitch timing pulleys in different tooth counts on one bore size, bought together so that a belt-driven axis can be geared, tested and re-geared without ordering a new pulley for every attempt.\u003c\/strong\u003e\u003c\/p\u003e\u003cp style=\"border-left:4px solid #5c6ac4;background:#f6f6f7;padding:0.8em 1em;margin:1.2em 0\"\u003e\u003cstrong\u003eFunctionally equivalent to:\u003c\/strong\u003e \u003cstrong\u003eGates\u003c\/strong\u003e PowerGrip GT2 and \u003cstrong\u003eSDP\/SI\u003c\/strong\u003e 2 mm-pitch timing pulleys (USD 12–30 each) · \u003cstrong\u003eMisumi\u003c\/strong\u003e GT2 series. Same 2 mm pitch, 6 mm belt width and grub-screw bore.\u003cbr\u003e\u003cem\u003eCompatible replacement part. We are not affiliated with, authorised by or endorsed by these manufacturers, and this is not an OEM part — check the specification below against your application before ordering.\u003c\/em\u003e\u003c\/p\u003e\u003cp\u003eBelt-drive design is mostly guessing the ratio, then waiting a fortnight for the pulley you should have ordered. This set covers the five tooth counts a small machine actually uses — 16, 20, 30, 36 and 40 — all on a 5 mm bore, so you can try every sensible ratio on the bench in an afternoon instead of one per order.\u003c\/p\u003e\u003ch2\u003eWhat can you use it for?\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eChoosing the reduction on a belt-driven 3D printer or CNC axis by testing, not calculating\u003c\/li\u003e\n\u003cli\u003eGearing down a NEMA 17 for more torque or up for more speed on the same motor\u003c\/li\u003e\n\u003cli\u003eClosed-loop and camera-gantry builds where the ratio is not known until it runs\u003c\/li\u003e\n\u003cli\u003eRebuilding a printer's X\/Y drive with matched 20T idlers and drive pulleys\u003c\/li\u003e\n\u003cli\u003eTeaching belt-drive ratios with real hardware rather than a diagram\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWho is it for?\u003c\/h2\u003e\u003cp\u003ePrinter and CNC builders, robotics teams and makerspaces who iterate on mechanics and would rather own every common ratio than wait two weeks for the right one.\u003c\/p\u003e\u003ch2\u003eCompatibility\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eBelt: GT2 \/ 2GT, 2 mm pitch, 6 mm wide — the standard on Ender, Prusa, Voron and most desktop machines\u003c\/li\u003e\n\u003cli\u003eShaft: 5 mm, the NEMA 17 standard; two M4 grub screws per pulley\u003c\/li\u003e\n\u003cli\u003eMixes with GT2 idlers and open-ended GT2 belt\u003c\/li\u003e\n\u003cli\u003eNot compatible with 3M, 5M or HTD belts — the tooth profile differs\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eContents\u003c\/th\u003e\n\u003ctd\u003e5 × 16T, 5 × 20T, 2 × 30T, 2 × 36T, 2 × 40T — 16 pulleys in total, all 5 mm bore\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRatios available\u003c\/th\u003e\n\u003ctd\u003eAny pairing of 16 \/ 20 \/ 30 \/ 36 \/ 40 teeth — 1:1 up to 2.5:1 reduction without ordering again\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBelt\u003c\/th\u003e\n\u003ctd\u003eGT2 (2 mm pitch), 6 mm wide\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore\u003c\/th\u003e\n\u003ctd\u003e5 mm, with two M4 grub screws per pulley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eAluminium alloy, silver anodised\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eShipping weight\u003c\/th\u003e\n\u003ctd\u003e185 g — inside the 250 g tracked-shipping band\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBought separately\u003c\/th\u003e\n\u003ctd\u003e$49.95 as five line items; this set is $42.99\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCountry of origin\u003c\/th\u003e\n\u003ctd\u003eChina; packed and shipped from Singapore\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2\u003eWhat's in the box\u003c\/h2\u003e\u003cul\u003e\u003cli\u003e\n\u003cstrong\u003eGT2 Pulley Ratio Set (5 mm bore):\u003c\/strong\u003e 5 × 16T, 5 × 20T, 2 × 30T, 2 × 36T, 2 × 40T — 16 aluminium pulleys with grub screws\u003c\/li\u003e\u003c\/ul\u003e\u003ch2\u003eShipping and returns\u003c\/h2\u003e\u003cp\u003eShips from our warehouse in Singapore with tracking. Parts and accessories: free standard shipping on orders over $25 ($4.99 below) to Canada, the UK, EU, Japan, Korea, Australia and most other countries, 5–15 days; to the United States at carrier cost from $27.99 (SingPost) or $109.99 (DHL Express). Assembled robot-arm kits over 2 kg are built and calibrated to order in Singapore (dispatch in 7–10 business days) and ship worldwide at carrier cost: SingPost Speedpost Priority from $124.99 (10–14 business days) or DHL Express from $229.99 (3–5 business days), shown at checkout. 7-day returns; defective items are replaced or refunded with shipping covered. Import duties, where charged by your country, are paid by the recipient.\u003c\/p\u003e\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\u003ch3\u003eWhat ratios can I actually make?\u003c\/h3\u003e\u003cp\u003eAny pair from 16 \/ 20 \/ 30 \/ 36 \/ 40 teeth. Common ones: 20:40 gives 2:1 reduction, 16:40 gives 2.5:1, 20:20 gives 1:1 for a simple belt transfer, 16:20 gives a light 1.25:1.\u003c\/p\u003e\u003ch3\u003eWhy are there five of the small pulleys and only two of the large?\u003c\/h3\u003e\u003cp\u003eSmall pulleys get used in pairs and as idlers, so you run out of them first; the large ones are usually one per axis.\u003c\/p\u003e\u003ch3\u003eIs 5 mm bore right for my motor?\u003c\/h3\u003e\u003cp\u003eYes if you are driving a NEMA 17 — that is the standard shaft. NEMA 23 and many spindles use 8 mm; we list the 8 mm bore pulleys separately.\u003c\/p\u003e\u003ch3\u003eDo the grub screws hold on a flatted shaft?\u003c\/h3\u003e\u003cp\u003eBetter than on a round one. Align one grub screw with the flat on the motor shaft; on a fully round shaft, use both screws and a drop of threadlocker.\u003c\/p\u003e\u003ch3\u003eAre these Gates pulleys?\u003c\/h3\u003e\u003cp\u003eNo. They are aluminium GT2-profile pulleys sold under our own ArmDojo brand, dimensionally compatible with Gates PowerGrip GT2 and Misumi GT2 belts and pulleys. We are not affiliated with those manufacturers.\u003c\/p\u003e","brand":"ArmDojo","offers":[{"title":"Default Title","offer_id":50864403775727,"sku":"GT2-RATIO-SET-5MM","price":55.0,"currency_code":"SGD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0821\/5406\/2063\/files\/01_collage_7eebf670-afbe-4f8d-a772-035f44e5a822.jpg?v=1789970689","url":"https:\/\/armdojo.com\/products\/gt2-pulley-ratio-set-16-20-30-36-40t-5mm","provider":"ArmDojo","version":"1.0","type":"link"}