will this 18NM servo motor work for 6DOF?

Hi, i am looking at the following motors to build a 6DOF small rig.
while these motors are smaller than the larger one, i'm hoping they are ok for a 6DOF and will fit well.

the Servo motors are rated at 18NM with a peak of 55NM
based on my research at 18NM these motors should lift a combined weight with a 3in arm of 318lb,
at peak 55NM which is 486.9 lb

if i reduce my lever arm to 2.5 in for a full motion 5 in, my calculations are at 55NM/1168LB or 18NM/832lb

will this work for a home 6DOF, i don't want to throw you around to much, just have some feel to my flight sims along with the G-seat i already have installed.

this is what i know right now:

- the motor is a servo based motor that runs on PWM so it connects to a arduino or something similar.
- Servo speed is .16s/60 deg
- servo angle is 0-360 deg
- Rated torque 18NM
-Max Torque 55NM
- Max current 22A
- voltage range max 24V
-Precision .32 deg

Could you please post a photo of the motor or a link to the data sheet? From your specs I can guess it should be a servo meant for model remote controls, right?

If you use all metric units (Nm, m) the formula for calculating force is easy:
Force = Torque / Arm length

So for 3in and 55Nm it's
55Nm / 0.076 = 724N or ~163lbf

unfortunately the spec parameters i posted above are the only data i have on the motor.
i appreciate the formula but i used ChatGPT to figure out the weight and configuration LOL.
if you plug in the numbers for force like you said and ask about 6DOF, it will tell you the overall calculations .
From there i realized that i could not effectively build a 3DOF as the output was to weak, but a 6DOF was acceptable with these motors since they all share the weight.

here is a link to the chat:
https://chatgpt.com/share/66fac81a-e010-8001-8063-dd67013748d1
https://chatgpt.com/share/66fd618c-90bc-8001-ad74-e3260a4b44e1

Now do i relay solely on AI, nope that is why I'm here asking for real experience feedback before i go spending money on these servos.

Are these motors more of a servo, Yes i think. They are Docyke high torque 550kg/cm servos. I am using 4 of them currently for a G-seat which is working very well. For the G-seat i have two servos pushing up on the seat. one for the right side and one for the left side with a arm length of 2 in. while playing DCS in heavy G's (heave) both servos are lifting me up and held for long duration. So far they lift my fat A@# at 190lbs no problem.

You will notice from my picture of them that i 3d printed a new cover with a fan that blows air over the driver and after playing for hours, i tested the motor/servo temp and they were at 80deg ish.

i'm sure the servos in a 6DOF configuration will be pushed a lot harder than my two butt checks so again i'm looking for real feedback.

Note, in my build i am wanting just a small 6DOF that connect to the bottom of my chair, nothing to wild.
ChatGPT says that i would need at least 4-6 inch of movement in the platform. in my calculations i chose a 3in lever arms to produce a full 6in travel. yes i could use a 2in lever arm and increase my lifting capacity but i'm not sure how much loss of feel i'll get from the chair.

maybe one of my questions should be is 4in travel good enough?

What i liked about the servos i picked for the g-seat was the ease of just mapping them to an arduino and setup in Simtools was easy. i'll post later more about the g-seat with images and cad files for people if anyone is interested.

thank guys for jumping on my thread and providing feedback.

Be careful. The share the weight only if you are at the exact center position and are not moving. Here is a spreadsheet to calculate the forces. At high yaw/pitch/roll angles the forces of half of the actuators can even go negative and over twice the average force for the other half.

Servos for remote control are usually not built to withstand the full rated force/torque for longer periods of time. They get very hot as you already found out. For theese reasons I'd calculate with an average force of weight/3 instead of weight/6 per servo for a 6DOF rig.

this is why my original question was about 18N which is the average force, instead of the 55N peak.

• For 18 Nm (183.55 kg·cm):
  
  • Force at the end of a 3-inch arm: 183.55 kg·cm ÷ 7.62 cm ≈ 24.1 kg (or 53.1 lbs).
  • Total for 6 motors (6DOF): 53.1 lbs × 6 = 318.6 lbs.
  • Total for 3 motors (3DOF): 53.1 lbs × 3 = 159.3 lbs.

I'll look at the spreadsheet, thanks

any idea or thoughts on 4in , 5in of 6in travel? from experience?