Introduction: Add Hinge Pin to Servos for Joint Motion

Picture of Add Hinge Pin to Servos for Joint Motion

So trying to build and design my own biped robot leg I bought some servos and started tinkering only to find I needed pass-thru axel attachments to use the typical "C" bracket.  I looked around online and found some that were poorly rated and the recommendation to just buy the right servo.

Not my style so I decided to hack in the second point that I needed to get the ones I already bought into working form.

This should take you only about 5 minutes and cost only a few cents in parts.

What you will need

1) 1pc - Standard Size Servo (TP995 is what I used)
2) 1pc - Machine screw (0.1" diameter x ~0.5"L)
3) 2pc - Machine nuts to match #2
4) Sticky foam tape
5) Small philips screwdriver (for servo screws)
6) Drill bit(~0.11") /sharp knife point
7) Calipers (helpful for centering drill hole)

Step 1: The Process

Picture of The Process

1) Use Screwdriver to remove the 4 screws on the bottom of the servo case and remove the plate

2) Using Calipers, make a mark on inside of plate just removed where the shaft center should be located.

3) Using drill or knife point, cut hole (keep as small as possible) in plate

4) Add nut to machine screw, threading on about half way

5) Pass machine screw thru hole with head on outside, thread 2nd nut onto screw.  Adjust so screw does not protrude thru nut body

6) using tape, affix nut to inside of plate

7) Screw plate back onto servo using original screws removed in #1

8) remove machine screw and attach servo horns as required using second nut as a spacer from servo body.  thread machine screw back into servo body.

9) Enjoy



Comments

wella saad (author)2014-06-27

what is the need of the outer nut? and the new hinge will be between the screw head and the outer nut ? and this hing will be free between them?

sbalakrishnan2 (author)2014-02-07

I am currently trying to do the same. Quick question, how did you estimate where the hole needs to be drilled? To me, this is the most critical part.

dloranger (author)sbalakrishnan22014-02-08

Scribe a line down the center of the removed plate on the outide near where the hole will be located.

Using calipers or etc measure distance from the shaft to some other feature that is common to both pieces, make a another mark horizontally. You should now have a cross hair to use for the center

Rob311 (author)2012-07-17

So simple, yet such an important fix for common robot designs...