🔬 [Review] “Silent” SR6 From AliExpress: How Quiet Can It Be?

I read about FunOSR and their AI-H200 “silent” servos earlier and was intrigued.

Since I’m desperately in need of a T-Code device that is powerful and doesn’t require an Internet connection, I bought a pre-built SR6 from them.

After a lengthy wait I got my unit and get it running. Here’s a review of their craft.

:framed_picture: Overview

Weighs ~1.5kg with receiver and mount

(yes that’s a coffee scale)

:mechanical_arm: Metal Bearing Arms

Full metal bearing arm with rose joints. I’m not sure if they helped at reducing noise but they look damn good.

:gear: Servos

AI-H200 25KG Metal Servo. The main selling point is it being very quiet.

Specs as provided by FunOSR:

Their demonstration of the servo noise:

The “maximum noise” is stated to be 45 decibels. They didn’t state how far they took the measurement.

Wouldn’t that be a little too quiet for something packed with 6 servos? 840979552129515600

:studio_microphone: Sound Test

The best I can do at the moment is to compare it with a standardized stroker (a well-lubed Handy) and other household appliances. I will be able to compare with other servos in the upcoming month. Feel free to do the same test with your device and share your result.

:bookmark_tabs: speedtest.funscript (7.5 KB)

Triangular wave that varies between 41 unit/s and to 507 unit/s.
The script is played in MFP, full range. Twist is tested by linking R0 to L0.

Placed the SR6 and the Handy 1ft (30cm) away from the recorder. Also placed my phone next to the recorder and measured with app DecibelX.

:page_facing_up: Handy.txt (7.3 KB)
:page_facing_up: SR6-OpenReceiver-NoLoad.txt (7.3 KB)
:page_facing_up: SR6-OpenReceiver-420g.txt (7.3 KB)
:page_facing_up: SR6-OpenReceiver-630g.txt (7.2 KB)
:page_facing_up: SR6_T-Twist_Receiver.txt (7.3 KB)

Device Avg dB Max dB Video Timestamp
The Handy 50.8 60.7 00:00
SR6 w/ Open Receiver 57.9 67.1 00:52
SR6 Load 420g 59.4 68.3 01:46
SR6 Load 630 59.9 68.8 02:36
SR6 w/ T-Twist Receiver 59.7 69.3 03:21
SR6 w/ T-Twist Working 63.9 73.3 04:13
Coffee Grinder - 78 05:15
Hairdryer - 84 05:23

Sound Sample

Click here if the video doesn’t load

Still loud to the ears, though quite impressive for an SR6.

  • Approximately 7 decibels louder than the Handy.
  • The T-twist receiver makes a lot of noise, and is very loud spinning at full speed.
  • Adding weight increases the noise by a slight amount.

In practise I was able to hear it coming through the door (11ft away). I can hardly hear it through the wall in an adjacent room. Noise-cancelling earbuds filter out most of the noise for me and it become inaudible if the video has intense music. I really want to test these on my OSR2+ and see how much noise they’d make with half the servo amount.

Listen to it again I’m hearing some collision noises at slow speed. I checked the joints and found one of the ball swivel being a little loose. This can be easily sourced and replaced, but I do hope the seller could pay more attention to these little details.

:rocket: Speed Test

One of the reason I bought it is because I’m fed up with the speed limitation popular strokers imposes.

Let’s see how this SR6 holds up against speed.

The onahole used in this test is PxPxP’s JUST RIGHT MOTTO which weighs 420 gram.

Fast Strokes

Slow Strokes

Looks like actions below 600 unit/s are safe to use. As for slow strokes… Be as slow as you want! yukkuri

:movie_camera: See It in Action

:red_circle: LIVE SR6 REACTION

Click here if video doesn’t load

Script Link

:nut_and_bolt: Accessories

Desk Mount

Tempest’s desk mount modified to work with a C-clamp. Simple and effective. I believe it can be made better though. I’m not a fan of the two protruding bolts for example.

Twist Receiver

The classic T-Twist receiver. Onaholes can be mounted by using a adapter designed by Vamrobot.

It also uses the AI-h200 servo. The servo is 180° which kind of limits the rotation range. I would replace it with a 270° servo even if that’s louder (T-Twist is never quiet).

Open Receiver

An receiver designed to fit other toys such as onaholes. This is a much more improved design that snuggly holds the toy in place. It has slots for two velcros and an additional plate that sandwiches the toy. I’ve also found this to work without the plate.

If you’ve used the original open receiver by Tempest, you’ll notice it allows room for the toy to wiggle, resulting in less movement on the pitch and roll axis. This remix aptly addresses that issue.

Twist is fun, but I think I like this receiver better.

Fleshlight holder + TValve

Plug-and-play vacuum cup for Fleshlights.
I unfortunately do not have a Fleshlight sleeve to test these out.

USB A to C Cable

A fancy white-label cable. The USB-C end has a blue LED and a hinge that can be rotated. The wire is thick but very soft.
Would make a premium cable if it doesn’t disconnect the ESP32 when the hinge rotates… I’ve been using my own cable since then.

Power Adapter

Unless you live in China, bring your own C7 plug.

:black_square_button: Buttons

There are four buttons on the unit. According to seller these are supposed to generate random motions with adjustable speed, so that the device can be used without a script. Good as fillers.

Unfortunately the ones on my unit never worked. Possibly because I’ve chosen to flash jcfain’s TCodeESP32 firmware instead. I tried to use these buttons for Tempest’s Button Box but they don’t seem to be compatible at the moment. The button module is directly plugged into the pins on the ESP32, with each button occupying one.

Personally I’m not a huge fan of these buttons but I do appreciate the innovative attempt. FunOSR told me this is an experimental feature and there won’t be these buttons in their next batch until it’s more polished. Sounds like a wise decision to me.

:screwdriver: “Unboxing”

Content warning: Machine gore

:memo: The Experience

This is too much power packed in a sex toy. I’m not being stroked, I am being seriously violated. And that’s just great…

  • Summons an earthquake on my IKEA desk. I need to consider better mounting solutions.

  • It strokes down with force so you could feel the onahole bashing against your lower abdomen, producing kinky noises.

  • Carries up to 1200 grams. My entire toy collection is now interactive!

  • The twist module is fun and adds an extra level of stimulation, at the cost of being very loud and a little fiddly to set up.

  • The surge and sway axis definitely enables more realistic and interesting movements. Here is a demonstration on how the addition of the sway axis may be better for your cock:
    osr2 sr6
    (This is not to say the SR6 is plainly superior. OSR2 is still loved for good reasons.)

  • There are many other benefits that are universal to T-code devices, such as offline connectivity and a much wider speed range. I plan to dedicate a topic to this in the future

The Build by FunOSR

What’s good:

  • USB-C for the win
  • Quiet and powerful servos
  • Metal bearing arm
  • Improved open receiver (best onahole solution I’ve seen)
  • It just works! Good value for money.

What can be improved:

  • The USB cable isn’t practical and I’d rather not have it.
  • Mounting solution could be better. I’m considering the Springy Desk Mount designed by TBD.
  • T-twist could have been 180°.
  • More tinker-friendly upgrades. Something like heat press inserts would be very welcomed.

Shopping & Communication
Took 12 days to arrive. Got held at custom and I paid additional charge for VAT and clearance fee. Gotta deal with all the bureaucracy buying from abroad. copium

When I got the device it had problem booting up. It was the Lunar New Year when I reached out to them so that doesn’t help me get a quick response. They offered replacement but I was desperate enough to take it apart. They helped troubleshooting and it was quick to bring it back to work.
I think myself deserved more credit on that lol.

Communication felt a little sluggish due to language barrier and timezone differences. I can tell these guys are trying very hard to communicate with AI translation. It wasn’t that bad though. Despite all the awkwardness the meaning does come through. I’m glad that they try.

Nonetheless, it was a delight to see more open-source toys are being built and enjoyed around the world, and that someone is dedicating their time and money to improve its design. Hope this will eventually spark some changes in the industry of teledildonics.

:label: Links

This isn’t a paid review, but I was reached by the FunOSR guys for affiliation as I’m writing it.
As a result I now have a referral link you can use for a $10 discount.
I did ask if I can get a free unit or something, they declined saying they can’t afford it lol

:point_down: Click the image below for a $10 coupon:
(Bet I do better graphic design than them, eh?)

FunOSR’s AliExpress Store: Interactive Future Store - Small Orders Online Store on Aliexpress.com

FunOSR’s Official Site: https://www.funosr.com/product-category/all/

Some multi-axis scripts coming soon!
Looking forward to bring your OSRs to life…


Thank you for vetting this product for the rest of us. I’m sure this will be great for buyers wanting to know the real details of this thing.

Though I have a suspicions a certain individual is going to make a post/update of some sort with suspicious timing again.

Competitive pricing and innovation ftw!


I got mine a few weeks ago and I’ve been very happy with it. Initially, I had an issue where the twist servo would start twitching a few seconds after boot up and it was unable to turn clockwise much beyond the center position without vibrating. I ended up swapping out the board for another I had flashed with SR Control firmware, and that solved the problem. This is my second SR6 with a twist and I feel like the FunOSR Twist is a lot quieter than my older one with a 360 servo. The rest of the servos are also much quieter than my old one, plus they are faster and more powerful. It seems like the servos have such precise gears with so little slop in them that they can deliver more nuanced slow moves, too. The Twist is thrilling because it can keep up with the BJ scenes I play in VAM. Paired with an onahold that has a tongue, there is no way I can keep from cumming.


:+1: Very detailed test report. I think funosr should give you an SR6 as a gift.


It can be confirmed that the AI-H200 is indeed relatively quiet. How does the smoothness compare to other servos?

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Thank you very much for the review you’ve made, we will continue to improve our product.

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Thank you for your recognition of our product. We are working hard to develop a 270° servo motor.

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fwiw I tried out the same test–same script, same app, same 1ft distance, same 5v power, sr6 under load with flashhobby 37kg bls3837med servos. i saw 66.2db avg and 72.3db max.

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Hey! When I go to your Aliexpress account it doesn’t seem to have the SR6 it only displays a OSR2 and a replenishment order. and when I try to get to it threw the site it tells me page not found.

Seems to be a bug with AliExpress. Check if these link works:
FunSR6: https://a.aliexpress.com/_EHyoqyl
FunSR6 + Twist: https://a.aliexpress.com/_EuVKokd

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An amazing in-depth review!

Ive been on the fence about getting an sr6 with the understanding that some of the shared research here will undoubtedly blossom into something even more magnificent probably soon, With this company, tempest, g90ak, and I believe a few others doing some interesting things. I am no mechanical engineer or computer engineer by far and sometimes the sr6 and osr sound daunting to fabricate and maybe even actively use as far as day-to-day troubleshooting. But reviews like this make it easier to get into the product, increase understanding, and I’m sure help out community as a whole!

Thank you Falafel! You’re awesome!

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this related item though… lmao!


Man, finally a proper review, thank you very much.
I’m just amazed that I (hoping for the best) put +/- 45 degree angles into the scripts math, and judging by the video it doesn’t even handle 20…
Equally amazed by the volume, somehow there were few real examples…
You have turned my world upside down in my head…


Great review! I’m always so appreciative of how detailed and thorough both your posts and responses/comment always are. You really went the extra mile with your videos and measurements. If I had the chance, I would 100% go back and tell myself to invest in the the SR6/OSR ecosystem over the Syncbot; this all just looks so much more immersive. I have been waiting on ordering an OSR2/SR6 as I wanted better servos at purchase without needing to message anyone or buy them and replace them myself; this might be the year I do so!


Made a quick enhancement to the desk mount. Stick two piece of rubber strip next to the C clamp. This prevents the protruding nuts from digging into your tabletop, also makes the unit more stable during operation.


Notice the gears being lubricated in their photo. Most servos are bone dry, but you can open them up and add the same silicone grease you’d use on the screw drive of a 3d printer and it quiets them noticeably.

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What is the maximum stroke length?

Just took a measure and it’s approximately 12cm.

And I quote Tempest:

On stroke lengths, for reference the stroke length of the OSR2 is actually 112mm, although it is possible to make it longer with minimal changes to the firmware. The SR6 is designed to a stroke length of 120mm.

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The STLs of this receiver is now available in Tempest’s server: Discord
I also designed one for the OSR2 with a similar concept. Not yet test printed. Will share later.


Maybe post it here too?

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