
Kab_Art
USA
Asked
— Edited
Hey guys. I'm not sure if I am the only one with this problem. Every time I start up my robot, and the EZ Robot bulider, the servos jerk around on my robot for the first couple of times before it goes to normal. This has caused the eyes to break a couple times, I have to reset the mouth all the time, and the head jerks into places it's not suppose to go. Anything I can do to fix this?
You can do this by manually moving the servo to the position before startup. But BE CAREFUL, and take it slow. It is commonly frowned upon to move the servo manually, but you can do it slow and be safe.
This is on first power up. If your servos are moving a few seconds after the power up, either your power connection is loose or there is something wrong.
Now, when you start ARC you should also have an int script start before any other scripts and set the starting servo speed and servo position for each servo.
Only after thouse two steps can you expect a smooth start up. There are some other things you can also do but start here first.
Yet another possibility just for the linkage problem would be to insert a small spring in the connection. The spring should be stiff enough to move the eyes as usual, but flexible enough to absorb the startup jerk by expanding a bit.
In my robot I have many servos but only one was jumping at power up. It's a big HD servo and I was getting real bad damaging movement like you when I powered up the robot. Centering the servo's linkage, setting the servo up properly in ARC with the proper limits, position and speed helped a lot. However I still got a little jump at power up. This was unacceptable to me so I built a TIP switch. I ran the servo's power through it and had the EZB switch power to this servo on after the INT script in ARC set the servo's min and max limits, position and speed.
Just a thought.
The servos always jump the same direction when power is applied. Check which way they are jumping and create a script the moves them to the furthest reasonable opposite direction.
Then, when power is applied, they won't jump last the threshold.
Run the power wires to a separate switch from your power supply and have only the servo signal wires connected to the EZB.
I have 2 EZB's on my InMoov, one is wired as above and the other has the power for the servo's going thru the EZB.
The one wired with the power for the servo's coming thru the EZB does exactly as you described. They all go the extreme positions when I connect to the EZB and then to the position defined in my Init script.
The one with the power for the servo's not going thru the EZB does not do this, they simply goes to the positions defined in my Init script.