New product: FEETECH FS90R Micro Continuous Rotation Servo

Posted by Ben on 2 June 2014
Tags: new products

Continuing with our recent theme of tiny new actuators, we are now carrying FS90R micro continuous rotation servos from FEETECH. Continuous rotation servos are standard hobby RC servos that have been modified for open-loop speed control instead of their usual closed-loop position control, and they make convenient drive systems for robots because they are effectively a motor, gearbox, and motor controller/electronic speed control (ESC) in a single compact package. They are also very easy to use as they can be connected directly to an RC receiver or controlled by a single microcontroller I/O line programmed to output RC servo pulses.

With a weight of just 9 g, the FS90R is the smallest servo we have come across that is manufactured specifically for continuous rotation. It has great speed and torque for its size (up to 130 RPM and 1.5 kg-cm at 6 V), and at only $5 per servo, it is a very simple and affordable way to add some motion to your next project. For comparison (or if you are looking for an alternative servo that offers position control), it is very similar in size, weight, speed, and torque to the Power HD Micro Servo HD-1900A.

For more information on the FS90R micro continuous rotation servo, see the product page. For other options, you can check out our full selection of continuous rotation servos or our entire RC servo category.

Continuous rotation servo size comparison. From left to right: SpringRC SM-S4303R, Power HD AR-3606HB, FEETECH FS5106R, Parallax Feedback 360°, Parallax (Futaba S148), and FEETECH FS90R.

Related post: Understanding continuous-rotation servos and multi-turn servos


Hi, I'd like to buy this product but I need the datasheet, Please, if it was possible, thanks.

We do not have a datasheet for that servo. If you need additional information, you might try contacting the manufacturer, Feetech.

- Grant
These servos are junk. I had high hopes and ordered ten and I just tested two. They bind in spots (slow down) and they have very poor low speed control. It's a shame, as they are the only 9g CR servo I've found. I'm returning all ten and suggest Pololu stops selling these before they sully their fine name. Modifying an HXT900 yields an infinitely better 9g CR servo.

I am sorry you were not happy with these servos. As I said in my reply to your email, you might just be expecting too much from these. Sure, it would be nicer if these were smoother, but like you, we do not know of any other continuous micro servos, and for a few bucks, many people might still prefer these to having to modify regular servos themselves. This speculation is based on our having sold thousands of these without complaints (yours is the first negative feedback that I recall).

By the way, does our new wheel for this servo work with that HXT900 servo?

- Ben
Ben: Your wheels fit the HXT900 perfectly. They are very nice and I will be buying more! Thanks for your numerous and patient emails. I should not have been so harsh in my review of the Fitec servos, they could be fine in some non-mission critical applications. I had unusually high expectations going in.
Hi, I have couple simple questions.

- The datasheet for FS90R shows motor specs for 4.8 and 6V. Is the servo operating voltage range between 4.8 to 6 V? What would be the best operating voltage to be used with these servos?

- There is an RC servo FS90-FB with an additional wire from potentiometer on the website. Would the continuous servo FS90R also have a version with a potentiometer feedback wire?

4.8V to 6V is the normal voltage range for standard RC servos including the FS90R. We do not carry a version of the FS90R servo with feedback. The only continuous rotation servo we carry with feedback is the Parallax Feedback 360° High-Speed Servo. Note that Parallax servo has an operating voltage range of 5.8V to 8.4V.

Depending on your application, you might also consider a brushed DC motor with an encoder. Some of our micro metal gearmotors are similar in torque and speed to the FS90R.


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FEETECH FS90R Micro Continuous Rotation Servo
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