Servo List


I have finally got around to updating the servo list. I have now added details of servos such as 360 degree modding, speed modding, 7.4v capable and various recommendations. Scroll down to the old list.

New Servo list

Old Servo list


At Reading Robots 9 the move was towards geared micro motors and small speed controllers. It appears as if using servos for drive is on the way out. At the moment all my ants still use servos, I guess I will go with the flow sometime.


New Servo list

The following was made with input from multiple antweight builders from Robotwars 101 Forum

Recommended servos



Speed s/60

Torque kg/cm 360 degree mod Speed mod ok at 7.4V Notes
SD200 16g 0.14s 2.5 @ 4.8v very easy semi easy yes 1BB
GWS Park HPX F 19g 0.07 3 @ 4.8v yes easy, fast as standard yes faster, less torque
GWS Park HPX 19g 0.10 4.2 @ 4.8v yes easy, fast as standard yes still fast but more torque than above
S136L 34g slow 8 @ 4.8v yes yes yes  
Supertec Naro Max 14g 0.15 1.8@4.8v yes easy   1BB
Naro +F HP BB 10g 0.10 2.2@4.8v unsure unsure ok at 6 1BB
GWS Pico BB+, Graupner C141, Multiplex Pico 6.2g 0.12 0.79@4.8v yes yes yes 1BB
Esky servo 8g 0.12 1.3@4.8v yes yes yes  
Blue Bird BMS-380 MAX 16g 0.16 4.1@4.8v hard   yes Good weapons servo rather than drive


Other servos, some to aviod, others with notes

Naro HP BB, used to be the drive servo of choice but better servos have since come along

Saturn S62, wobbly output gear, easy to strip gears

HS-50/55, best avoided. Easy to strip gears and break

TowerPro 5g, useless

Towerpro sg50, ok for 360 mod, unable to speed hack

Towerpro sg90, easy to mod. Servo board burns out

HS-81, gears strip easily

HS-81MG, metal gears but output gear is only a half-gear so unable to get 360 degrees. Ok for a weapon servo


Old Servo list

Below is a list of servo's under 40g in ascending weight.

I have found that the Futaba SD200's and SuperTec NARO HP's are both very good servo's.  I'm not too keen on HS-55's for drive as they tend to wiggle a bit too much due to a lack of ball bearings (BB) on the output shaft.  As for HS-81's, avoid as the final output gear is very thin and the teeth easily strip. 

For a weapons servo I used the SuperTec S136L, the reason is 8kg/cm @ 4.8v, bit slow but for 17 you can't go wrong. 

Servo Weight Speed s/60 Torque kg/cm Notes
Hitec HS-50 5.8g 0.09s @4.8v 0.6 @4.8v
SuperTec PICO 6g 0.12s @4.8v 0.7 @4.8v
Hitec HS-55 7.8g 0.17s @4.8v 0.9 @4.8v
Futaba S3106 9.5g 0.11s 1.2
SuperTec NARO 9g 0.11s @4.8v 0.8 @4.8v
SuperTec NARO HP 9g 0.09s @4.8v 1.4 @4.8v 1BB
Futaba SD150 9g 0.16s 1.5
Futaba SD250 9g 0.11s 0.8
JR NES-371 9g 0.23s 1.3
SuperTec NARO MAX 14g 0.15s @4.8v 1.8 @4.8v 1BB
Hitec HS-60 14g 0.2s @4.8v 1.1 @4.8v
Futaba SD200 16g 0.14s 2.5 BB
Futaba S3101 17g 0.18s 2.5
JR NES-331 17g 0.28s 3.1
Hitec HS-81 18g 0.12s @4.8v 2.3 @4.8v Avoid, very thin output gear
JR NES-341 18g 0.24s 2.3
Hitec HS-85BB 20g 0.16s @4.8v 3.0 @4.8v 1BB
Futaba S3102 22g 0.25s 3.2 Brass gears, 50
Hitec HS-81MG 22g 0.12s @4.8v 2.3 @4.8v Metal Gear
JR NES-321 22g 0.23s 2.3
SuperTec mini 24g 0.23s @4.8v 3.2 @4.8v 2BB
Hitec HS-85MG 24g 0.16s @4.8v 3.0 @4.8v Metal Gear
JR NES-351 25g 0.24s 2.3
JR NES-3121 26g 0.22s 3.8


JR NES-3125 26g 0.13s 3.2


JR NES-3321 27g 0.36s 4.3
Hitec HS-225BB 28g 0.14s @4.8v 3.9 @4.8v 1BB
Futaba S135 29.5g 0.15s @4.8v 1.9
Futaba S3002 29g 0.2s 3.3 2BB, brass gears, 50
Futaba S9601 31g 0.15s 2.4 2BB, coreless, 60
Futaba S9602 31g 0.09s @4.8v 2.7 2BB, coreless, 60
Sanwa SRM141HR 31g 0.7s 3.2 1BB, coreless, 49
SuperTec S9102F/2BB 32g 0.09s @4.8v 2.5 2BB, low profile
Sanwa SRM141AL 33g 0.2s 3.2 1BB, coreless, metal gear, 58
SuperTec S136L/2BB 34g 0.33s @4.8v 8 @4.8v 2BB, low profile
Futaba S9001 37.2g 0.23s 3.2
Hitec HS-75BB 37g 0.5s @4.8v 6.4 @4.8v 1BB, low profile
Hitec HS-77BB 37g 0.18s @4.8v 4.6 @4.8v 1BB, low profile
Futaba S3004 39g 0.23s 3.2 1BB