Products for USB Sensing and Control
It is currently Sat May 27, 2017 5:04 pm

All times are UTC - 7 hours [ DST ]

Post new topic Reply to topic  [ 1 post ] 
Author Message
PostPosted: Tue Jul 12, 2011 4:58 am 

Joined: Sun Jun 05, 2011 5:15 am
Posts: 32
I'm building a plotter at the moment using Phidget servo controller 1061 along with Hitec 422 servos. I'm seeing some strange results when I command lots of changes in velocity .. when the pen is up I run the servos at full speed, however when the pen is down I'm using velocity to try and get diagonal lines by controlling the x&y velocity proportionally.

I notice that I get very erratic results when switching from a full speed pen up move to a slowed down pen down move, which leads me to believe that the velocity isn't being set correctly. Even if I put some sizable pauses in my code this still seems to be the case.

I'm setting the velocity using :

PhidgetMotorCtrl.servos[0].Position = XTarget;
PhidgetMotorCtrl.servos[0].VelocityLimit = XPower;
PhidgetMotorCtrl.servos[1].Position = YTarget;
PhidgetMotorCtrl.servos[1].VelocityLimit = YPower;

I then put a small pause in to ensure the servo's velocity has been set :


And then I engage the servos :

PhidgetMotorCtrl.servos[0].Engaged = true;
PhidgetMotorCtrl.servos[1].Engaged = true;

Is this the correct way to set the speed of the servos ?.

Also I worry that as I'm engaging the X axis a millisecond before the Y axis I'm always going to get small inaccuracies .. does anyone know a way to trigger the servos at the exact same moments ?.

Thanks in advance.

 Profile Send private message  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC - 7 hours [ DST ]

Who is online

Users browsing this forum: No registered users and 3 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group