Question The problem is with the 150kg servo.

Hello friends. I decided to make active seat belts on a servo drive and ran into this problem. Everything is working on the sg90 servo and I decided to install one 150 kg servo at 12 volts.(power is supplied separately from the power supply). and he twitches, then gets up and freezes. Please tell me what could be the problem?

Well, it seems the problem is that it's too small. The 150 kg would be in the central part of the shaft, not on the outer part of the arm. I hope you understand.

i have made G-seat using 150KG servos and it works great. i have two servos on my back belt and two on my lap belt. they pull really nice. i will try and get you some pictures.

i also use the 150KG that have the metal bracket these:




I have made holders and brackets in 3D printer to mount these on chair. i'll send pictures or files for that too.
i then run these on a Arduino Uno board. i've created a 3d box that hold that.

i take 24V and use a DC-Dc converter so these run at 12V. this give the maximum torque which is more like 170kg.

The Ardunio runs some firmware i found here on the forum and linked to SimTools

I had purchased a pro G-seat belts but go rid of them... these do the job the same or better at a fraction of the cost.

Are you grounding the negative wire from the power source back to the Arduino? Without grounding, the servos will twitch uncontrollably. You can use an electric bus bar.

Basically, you wire the negative terminal from the power source to the bus bar, and then wire the bus bar to the Arduino GND pin and the negative pin for the servo.

Here's an example of a bus bar. You can pick up one from Amazon for like $10:

I should add that I use 65 KG servos for my g-seat so 150 KG should work fine.

Couple answers to the above questions.
1. Yes i would use the 150KG servo, otherwise it all depends on the total force you are trying to pull. The 150KG work very well as i have 4 on my machine. 2 shoulder and 2 lap belts. I can then control them each by themself as they map to an Axis each. Amazon has these for right now for a $52 for 2 of them
amazon.com/dp/B0DZ71YDT1

2. Yes, you must connect all the grounds to a common ground.
i will provide a full write up with images and stl files for people to make a low cost g-belt soon.

for now, my set up is using the Arduino Duo board with 4 PWM outputs. i removed the power connector and am using a 24V supply that i am using with my Motion Actuators. The 24V connects to a 12V regulator i found on Amazon. this converts the 24V to 12V which you need for the servos to run.

The 12V i connect to all the positive leads of the Servos at what i call my "motion belt box" which is just the Arduino and regulators with connectors. The 12V l output from the regulator i then solder back onto the V+ input of the Arduino DUO board. now ALL GND servo lines, are tied together and soldered to the DUO GND.

PM me if you want the STL files early for the servos. i will post a quick picture tonoght so you guys can see this.
but full write up to make a low cost G-belt will be coming

here are some quick pics i found on my phone for now.
here you see 3d parts for belt with servo inside. just bolts to chair. you can see control box in middle.
the orange servos are DOCKYE Servos i use for G-SEAT.





This image shows bottom Seat how i mounted servos on seat. Notice no housing.
however the roller bar is not installed on this picture yet.

Again Green DOCKYE servos are for the Butt G_SEAT which work find.
i did change DOCKYE top covers with 3d printed cover that has built in Fan so they stay cool





i'll provide all 3d stl's soon, if you can't wait PM me.