I am in the process of assembling Pidog V2. At Step 44, when powering on, the legs go at a strange angle. One leg sticks up somewhat. Another appears to almost stand up. I disassembled all of the legs and painstakingly followed the instructions as I understood them and rewatched the videos. Same result! I wonder if I am misinterpreting instructions 20-29. The way i read it is first while it is powered on, plug servo for a “calf” or lower leg into P11, then insert the shoulder portion of the leg at a 90 degree angle and screwing in place. I even tested each leg assembly by unplugging P11, changing the angle between the two parts of the leg, and then plugging it into P11 and for each leg, it went back to the desired 90 degree position. However, when I got to step 44 where we are instructed to zero the pidog, one leg stuck in the air a bit and another moved to an almost standing position. Since I assembled, disassembled, and reassembled twice following the instructions as I understand them very carefully, I cannot understand why this is the case. However, I do note that the servo zeroing script simple cycles through each servo and sets it to 10 degrees then 0 to zero. The assembly procedure seems to indicated that the upper part of the leg is relative to the lower part since they are assembled together at 90 degrees and we are only asked to plug the servo for the lower leg into P11 during steps 20-29. So does simply cycling through servos 0 thru 11 respect that geometric relationship? Or maybe the legs aren’t necessarily supposed to be in a neutral position at this stage of the assembly process? The video doesn’t show what things are supposed to look like after Step 44.
Thank you for your very detailed description. I believe I now understand the issue.
It seems there may be a misunderstanding of the servo zeroing procedure, especially the relationship between Step 11 and Steps 20–29.
The correct procedure should be:
At Step 11:
Power on the PiDog.
Plug the servo into P11.
Press the ZERO button to set the servo to its neutral position.
Then install the leg at the correct angle (approximately 90°).
For Steps 20–29:
These steps do not repeat the full “power on → plug into P11 → press ZERO” process. They only ask you to plug the servo into P11 as a reference.
What went wrong?
If the servo was not properly zeroed in Step 11 (if you only plugged it in without pressing ZERO), then even if each leg appears to be at 90° individually, the final assembly will still be misaligned.
Your understanding is correct: the geometric relationship between the upper and lower leg segments is relative, so the servo must first be at its correct zero position before attaching the servo horn.
About Step 44
Some mechanical assembly steps are done with the power off, which is why Step 44 is the first time you power on again and perform a full zeroing check.
Documentation feedback
You raised a very good point: the documentation currently lacks a reference image showing what the PiDog’s normal posture should look like after Step 44. This is a gap in our documentation, and we will add it in the future.
Here’s a photo of a correctly zeroed PiDog for reference.
Conclusion
Based on your testing, the servos themselves appear to be working normally. The issue is more likely a servo horn angle offset during installation, rather than a hardware failure.
