> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt # FEETECH Sub-Micro Servo FS0403-FB with Position Feedback **Type:** Product page · **SKU:** POLOLU-3438 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia) **Page:** https://core-electronics.com.au/feetech-sub-micro-servo-fs0403-fb-with-position-feedback.html ([markdown](https://core-electronics.com.au/feetech-sub-micro-servo-fs0403-fb-with-position-feedback.html.md)) This version of the FS0403 sub-micro servo from FEETECH is specially modified to provide access to the feedback potentiometer through a fourth (green)... ## Pricing - **Price:** $25.75 (inc GST) — $23.41 AUD, exc GST - **Quantity discounts:** 10+ $22.47 (exc GST) · 25+ $21.77 (exc GST) ## Availability & dispatch - Available with a lead time — expect dispatch between Aug 21 and Aug 24. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=POLOLU-3438:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart. - **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/POLOLU-3438:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.) - **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## Description The FS0403-FB is a specially modified version of FEETECH’s [FS0403 sub-micro analog servo](https://core-electronics.com.au/feetech-sub-micro-servo-fs0403.html) that provides access to the feedback potentiometer through a fourth (green) wire, which makes it possible to directly measure the output angle. With this extra information, you can determine when the servo has reached its target position (or detect if something is interfering with its ability to get there). This feedback also enables more complex closed-loop control of the servo from your main controller. Like the FS0403, the FS0403-FB works with standard RC servo pulses, providing an operating angle of approximately 120° over a servo pulse range of 900 µs to 2100 µs. The feedback voltage varies linearly over this range by a couple of volts. As with most servos, the pulse range can be expanded to achieve an expanded operating angle, but the limits of this are not specified by FEETECH. (In Pololu's tests, Pololu were able to get an expanded range of approximately 180° over a pulse range of 650 µs to 2500 µs, but as this is not part of FEETECH’s official specifications, it is possible different units will behave differently in this regard.) The servo signal, power, and ground are provided through a 3-wire servo cable that is terminated with a standard [JR-style connector](https://core-electronics.com.au/jr-connector-pack-female.html), which is Futaba-compatible. The feedback is accessible through a separate green wire that is terminated like Pololu's female [premium jumper wires](https://core-electronics.com.au/prototyping/prototyping-wire.html) and works with standard [0.1" male header pins](https://core-electronics.com.au/connectors-sockets/headers.html). These cables are approximately 6" (15 cm) long. | [![](https://core-electronics.com.au/attachments/localcontent/0J9680_16286638003.jpg)](https://core-electronics.com.au/attachments/localcontent/0J9680_11055dd3100.jpg) | |---| | Servo and feedback connectors on the FEETECH servos with position feedback. | For more information about this servo, see the [FS0403 datasheet](https://core-electronics.com.au/attachments/localcontent/FS0403-specs_970243717f8.pdf) (97k pdf) (please note that this is the datasheet for the standard FS0403 sub-micro servo, so it does not include any information about the special feedback modification). | [![](https://core-electronics.com.au/attachments/localcontent/0J8283_15534afd6a2.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8283_62654ff53ba.jpg) | |---| | An example of hardware included with the FEETECH FS0403 sub-micro servo. Actual hardware might vary. | Note that, as with most hobby servos, stalling or back-driving this servo can damage it. **People often buy this product together with:** | [![Power HD Sub-Micro Servo HD-1440A](https://core-electronics.com.au/attachments/localcontent/0J2014_4637a98b25.jpg)](https://core-electronics.com.au/power-hd-sub-micro-servo-hd-1440a.html) | [Power HD Sub-Micro Servo HD-1440A](https://core-electronics.com.au/power-hd-sub-micro-servo-hd-1440a.html) | |---|---| | [![Sub-Micro Servo 3.7g](https://core-electronics.com.au/attachments/localcontent/0J4128_4341e5cf36.jpg)](https://core-electronics.com.au/sub-micro-servo-3-7g-generic.html) | [Sub-Micro Servo 3.7g](https://core-electronics.com.au/sub-micro-servo-3-7g-generic.html) | |---|---| | [![FEETECH Sub-Micro Servo FS0307](https://core-electronics.com.au/attachments/localcontent/0J8278_54645930bf.jpg)](https://core-electronics.com.au/feetech-sub-micro-servo-fs0307.html) | [FEETECH Sub-Micro Servo FS0307](https://core-electronics.com.au/feetech-sub-micro-servo-fs0307.html) | |---|---| **Dimensions** | Size: | 20.0 × 8.3 × 19.3 mm | |---|---| | Weight: | 6 g | **General specifications** | Digital?: | N | |---|---| | Speed @ 6V: | 0.08 sec/60° | | Stall torque @ 6V: | 0.7 kg·cm | | Speed @ 4.8V: | 0.09 sec/60° | | Stall torque @ 4.8V: | 0.6 kg·cm | | Hardware included?: | Y | | Lead length: | 6 in | **File downloads** - **[Datasheet for the FEETECH Sub-Micro Servo FS0403](https://core-electronics.com.au/attachments/localcontent/FS0403-specs_970243717f8.pdf) (97k pdf)** ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/i/m/image_11687.jpg)