Legacy Forum: Preserving Nearly 20 Years of Community History - A Time Capsule of Discussions, Memories, and Shared Experiences.

Hitec digital servo won't release

Hitec robotics including ROBONOVA humanoid, HSR-8498HB servos, MR C-3024 Controllers and RoboBasic
5 postsPage 1 of 1
5 postsPage 1 of 1

Hitec digital servo won't release

Post by mmmalmberg » Sat May 01, 2010 7:56 pm

Post by mmmalmberg
Sat May 01, 2010 7:56 pm

Hi. I'm across the country from home installing a robotics sculpture that uses hitec digital servos. Can't tell you the model, they're encased in tooldip... Bought them recently on ebay they have titanium gears, metal horn.

I have two of them running in two identical robots. One of them keeps hanging in a centered position. It idles in an approximate center position and won't release. It's not stuck gears, but it's just not releasing when the microcontroller releases it. Even when I de-power the microcontroller (arduino) the servo, which has it's own power supply, hangs on.

I need to finish this installation and leave it for 6 months, and I need to figure this out asap. Is there a reset command for these? Any ideas what's going on? Only one of the two robots is having this problem, they are identically mechanically and electronically and are running the same code.

HELP PLEASE!
thanks...
Mark M.
Hi. I'm across the country from home installing a robotics sculpture that uses hitec digital servos. Can't tell you the model, they're encased in tooldip... Bought them recently on ebay they have titanium gears, metal horn.

I have two of them running in two identical robots. One of them keeps hanging in a centered position. It idles in an approximate center position and won't release. It's not stuck gears, but it's just not releasing when the microcontroller releases it. Even when I de-power the microcontroller (arduino) the servo, which has it's own power supply, hangs on.

I need to finish this installation and leave it for 6 months, and I need to figure this out asap. Is there a reset command for these? Any ideas what's going on? Only one of the two robots is having this problem, they are identically mechanically and electronically and are running the same code.

HELP PLEASE!
thanks...
Mark M.
mmmalmberg
Newbie
Newbie
Posts: 3
Joined: Sat May 01, 2010 7:55 pm

Post by i-Bot » Sat May 01, 2010 8:42 pm

Post by i-Bot
Sat May 01, 2010 8:42 pm

It is difficult without knowing the servo type. Many Hitec digital servos are programable, and they may have a failsafe set in case of loss of pulses.
You would need a Hitec servo progammer(HFP-20, HPP-21) to change that.
It is difficult without knowing the servo type. Many Hitec digital servos are programable, and they may have a failsafe set in case of loss of pulses.
You would need a Hitec servo progammer(HFP-20, HPP-21) to change that.
i-Bot
Savvy Roboteer
Savvy Roboteer
User avatar
Posts: 1142
Joined: Wed May 17, 2006 1:00 am

Post by mmmalmberg » Sat May 01, 2010 9:00 pm

Post by mmmalmberg
Sat May 01, 2010 9:00 pm

It is a programmable model but I neither have a programmer for it nor do I have more than about 20 hours to fix this. If I depower the servo, it resets and then works fine.

But that's an interesting tidbit, if that's what's happening. Is the default failsafe to go to the zero position and hang on? Cause that's what it's doing... First thing I'll try is to check the signal connection to it.
It is a programmable model but I neither have a programmer for it nor do I have more than about 20 hours to fix this. If I depower the servo, it resets and then works fine.

But that's an interesting tidbit, if that's what's happening. Is the default failsafe to go to the zero position and hang on? Cause that's what it's doing... First thing I'll try is to check the signal connection to it.
mmmalmberg
Newbie
Newbie
Posts: 3
Joined: Sat May 01, 2010 7:55 pm

Post by i-Bot » Sat May 01, 2010 10:15 pm

Post by i-Bot
Sat May 01, 2010 10:15 pm

The failsafe position is whereever it has been programmed to.

It will go to failsafe when it stops receiving pulses.
http://www.modelhelicopters.co.uk/acatalog/HPP-21_Manual.pdf
The failsafe position is whereever it has been programmed to.

It will go to failsafe when it stops receiving pulses.
http://www.modelhelicopters.co.uk/acatalog/HPP-21_Manual.pdf
i-Bot
Savvy Roboteer
Savvy Roboteer
User avatar
Posts: 1142
Joined: Wed May 17, 2006 1:00 am

Post by mmmalmberg » Sun May 02, 2010 3:32 am

Post by mmmalmberg
Sun May 02, 2010 3:32 am

Well I think that's probably the problem. It's most likely the default from-the-factory fail-safe position would be zero. I re-set all the connections and cycled power to the servo and it might be working, will see how it's doing tomorrow, was good the rest of the day. And I was able to get the second servo to exhibit the same behavior by messing with its signal line. So I'm hopeful as well as grateful - thanks!
Well I think that's probably the problem. It's most likely the default from-the-factory fail-safe position would be zero. I re-set all the connections and cycled power to the servo and it might be working, will see how it's doing tomorrow, was good the rest of the day. And I was able to get the second servo to exhibit the same behavior by messing with its signal line. So I'm hopeful as well as grateful - thanks!
mmmalmberg
Newbie
Newbie
Posts: 3
Joined: Sat May 01, 2010 7:55 pm


5 postsPage 1 of 1
5 postsPage 1 of 1