Biped scout-making it stand

I had the kit for biped scout (12 servos 6 for left & same for right).I assembled it as per the tutorial given & as per website itself i loaded the SS-32 configuration but while it is not standing on playing the config.

Even though not powered the horn of servo rotates sometimes while screwing it & sometimes due to weight of bracket itself.So there is not neutral position or home position while i am assembling it.Is that the cause of problem,if yes plz suggest some measures to overcome it.

Not quite sure what you are having problems with. Maybe need to read more on servos. An unpowered servo will rotate if you move the horn as it needs power to hold position.

I’d recommend taking a look here and then trying again. I don’t really think anyone here has any idea of what you’re referring to.

The servos have a gear train, and there will be considerable resistance to “back driving” the R/C servo. With a servo horn installed the standard 475/485 sized servo can be turned by hand.

Screwing in the self-taping metal screw into the servo shaft to secure the horn will often be enough torque to turn the servo unless one carefully holds the servo horn.

Adding a leg or arm to the servo horn give it a “lever arm”, and it only takes a little torque (weight) to cause the joint to rotate. Applying power and a PWM signal should allow the servo to maintain the commanded position.

I didn’t follow the “config” comments.

Alan KM6VV

I find this system works well, when trying to find the center home position (1500) of a servo. and also stops the horn from turning when screwing it down.

When you recieve a servo it should already be pretty much at its center point, but on some occasions they might be off.
anyway…

Install the servo horn on the servo shaft. does not have to be at its center at this point. in this case i have just put it to center for the picture.

Then rotate the horn clockwise till it stops.
At this point you can see how far out it is out.

Then unscrew the horn and pull the horn off. Then align the horn so the holes are at 12,3,6,& 9’o clock.

Once you have set the horn to its rightful position you can tighten it up. the horn will not rotate as the shaft has rested against its stop point.

After this step, rotating the horn the other way will confirm an even center.

Hope this helps. :wink:

Your servo should now be a its center.

Please note you will still have to use servo off sets with in your program to find the servos true center!

a link to this can be found here:
viewtopic.php?f=31&t=7015

Whoa! 8) Nice one Jonny!

I followed the following link for assembling

lynxmotion.com/images/html/build53a.htm

& this link for loading the ss-32 configuration(configuring max,min & mid position for servos)

lynxmotion.com/images/html/build109.htm.

So after doing the above two when I played the sequencer to make my scout stand it didn’t.
My doubt is that after I assembled my scout, I am not aware in what position various servos are & then configuring them as per the second tutorial I am not getting the desired result.

Any pictures?

Its 1:26am here,so I cannot go to the lab & get the pic but its looking the same as a completely assembled scout as in the assembly guide.The only difference is that mine one is lying on table & not standing at all even on playing through SS-32

Only 1:30 AM? What’s stopping you? ;>)
Hobby robotics is a 24/7 job! Just don’t let my wife hear that…

Alan KM6VV

We are asking for images to look for mistakes, errors, or you know, how did I miss that?

Have the servos ever held position?

I read a bit more about servos & now I am able to make my SCOUT stand.

Plz correct me if I am wrong servo position adjustment for walking sequence does depend on home position of servos while the BIPED is standing.I found a code for biped walking sequence but it doesn’t works.I think its because my I have fixed different position of servos while it is standing.