servo continuous rotation modification

Modify HiTEC ultra torque servo HS-645MG for continuous rotation

in 13 easy steps

HiTEC HS-645MG servo before modification

no soldering, no cutting, no part replacements…..

!!! the modification is reversible (if you keep all the parts and don't damage anything, of course)

step 1: remove the screw which holds the arm

step 2: remove the arm

step 3: remove the 4 bottom screws

step 4: take the top and bottom part of the casing off

step 5: remove the screw which holds the potentiometer in place

step 6: remove the metal gear

* the gear with the pin will come off together with the second gear shown on the piece of paper.

step 7: pull the potentiometer out

* it should come out easily, no force needed

step 8: make a hole in the casing

* the hole should be big enough for the three potentiometer wires to pass comfortably when you close back the casing.

step 9: remove the metal pin from the gear

* hold the pin with a pair of locking pliers. gently hit the top of the gear with a hammer to push the pin out. be careful not to damage the gear.

* you can save the pin, in case you want to modify the servo back to normal

step 10: put the gears back in place

* make sure to put them back all the way so they can move

step 11: put the bottom back leaving the potentiometer outside

step 12: put the top and the bottom of the casing back

* make sure the potentiometer's wires are not caught or pressed

step 13: test the servo!

* connect the servo to a microcontroller and turn the potentiometer until you find a position where the servo doesn't turn. this will be you 90degrees.

* any value bigger than 90 (but smaller than 180) will make the servo spin clockwise. accordingly, values between 0 and 89 will make it spin counterclockwise. the bigger the difference between 90 and the given value, the faster it will turn.

 

testing the rotation here