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Is it OK to use hobby servos on Robonova?

Hitec robotics including ROBONOVA humanoid, HSR-8498HB servos, MR C-3024 Controllers and RoboBasic
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Is it OK to use hobby servos on Robonova?

Post by Kelpy » Sun Jan 09, 2011 6:11 pm

Post by Kelpy
Sun Jan 09, 2011 6:11 pm

I want to put a camera on my Robonova, inside a "head" to replace the original.
I want this to be able to scan right and left and up and down.
I have a number of small digital hobby servos (spares from my helicopters), which would be a perfect fit.

The specs are:-

Standard Voltage: DC 5V±1V
PWM Input Range: Pulse Cycle 20±1ms,Positive Pulse 1~2ms
Speed:0.1S/60º
Torque:≥1.0Kg/cm (VCC=5V)
MAX Corner:150º
Operation Temperature: -20℃~75℃
Weight:7.5g
Dimensions:22.8mm x 11.5mm x 20.8mm
Color: Black

Can I safely use these with the Robonova controller?
If so, can anyone think of any problems I may have?
I want to put a camera on my Robonova, inside a "head" to replace the original.
I want this to be able to scan right and left and up and down.
I have a number of small digital hobby servos (spares from my helicopters), which would be a perfect fit.

The specs are:-

Standard Voltage: DC 5V±1V
PWM Input Range: Pulse Cycle 20±1ms,Positive Pulse 1~2ms
Speed:0.1S/60º
Torque:≥1.0Kg/cm (VCC=5V)
MAX Corner:150º
Operation Temperature: -20℃~75℃
Weight:7.5g
Dimensions:22.8mm x 11.5mm x 20.8mm
Color: Black

Can I safely use these with the Robonova controller?
If so, can anyone think of any problems I may have?
Kelpy
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Post by Kelpy » Wed Jan 12, 2011 1:50 pm

Post by Kelpy
Wed Jan 12, 2011 1:50 pm

Anybody??
Anybody??
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Post by i-Bot » Wed Jan 12, 2011 4:19 pm

Post by i-Bot
Wed Jan 12, 2011 4:19 pm

It is OK to use standard servo, though they tend to be a bit more jerky. Also you will not be able to read back the position.
It is OK to use standard servo, though they tend to be a bit more jerky. Also you will not be able to read back the position.
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Post by Kelpy » Wed Jan 12, 2011 5:55 pm

Post by Kelpy
Wed Jan 12, 2011 5:55 pm

Many thanks, i-Bot.
I suppose not having feedback will be a problem, but initially, I'm only looking to learn RoboRealm before trying this out on my Bioloid. When I do, I will follow your advice and buy a couple of AX12's for that robot. Then, hopefully, I can do it properly :?
Many thanks, i-Bot.
I suppose not having feedback will be a problem, but initially, I'm only looking to learn RoboRealm before trying this out on my Bioloid. When I do, I will follow your advice and buy a couple of AX12's for that robot. Then, hopefully, I can do it properly :?
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Post by Kelpy » Wed Feb 02, 2011 4:31 pm

Post by Kelpy
Wed Feb 02, 2011 4:31 pm

Well, I've managed to squeeze a servo into his new head (and a camera!), and another in his chest, combined which give me pan and tilt.
I do have a problem, though, and wondered if anyone had any ideas.
Occasionally, I get serious servo "jitter" from these two hobby servos, which will stop as soon as I touch the head.
Does anyone have any idea what may be causing this, and how I can cure it?
Well, I've managed to squeeze a servo into his new head (and a camera!), and another in his chest, combined which give me pan and tilt.
I do have a problem, though, and wondered if anyone had any ideas.
Occasionally, I get serious servo "jitter" from these two hobby servos, which will stop as soon as I touch the head.
Does anyone have any idea what may be causing this, and how I can cure it?
Kelpy
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Post by PaulL » Sat Feb 05, 2011 12:10 pm

Post by PaulL
Sat Feb 05, 2011 12:10 pm

The jitter can be caused by a few things:

* Stressed leads in the servo. If the leads are stressed to the control board from the potentiometer, it can mess with the potentiometer. If the servo leads are stressed, it can flex the board and the potentiometer leads (had this problem on some micro servos).

* Noisy potentiometer. If the servos are used, they may have krud in them, use an electronics-grade cleaner to blow them out (not acetone!!!).

The "center" of the servo gets the most wear in the potentiometer, and this can cause jittering on aged servos.
The jitter can be caused by a few things:

* Stressed leads in the servo. If the leads are stressed to the control board from the potentiometer, it can mess with the potentiometer. If the servo leads are stressed, it can flex the board and the potentiometer leads (had this problem on some micro servos).

* Noisy potentiometer. If the servos are used, they may have krud in them, use an electronics-grade cleaner to blow them out (not acetone!!!).

The "center" of the servo gets the most wear in the potentiometer, and this can cause jittering on aged servos.
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Post by Kelpy » Sun Feb 06, 2011 11:24 am

Post by Kelpy
Sun Feb 06, 2011 11:24 am

Thanks for those tips, RN1AsOf091407.
I think I'll strip them down and inspect them, although, they have had very little use and when they are off the RN, they don't jitter at all.
I must admit, they are not the best quality.
Thanks for those tips, RN1AsOf091407.
I think I'll strip them down and inspect them, although, they have had very little use and when they are off the RN, they don't jitter at all.
I must admit, they are not the best quality.
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Post by PaulL » Sun Feb 06, 2011 12:02 pm

Post by PaulL
Sun Feb 06, 2011 12:02 pm

With the ones I recently had trouble on, all I had to do was put a little pressure under the case by the board, and they'd go nuts. :) My solution was to rewire the potentiometer to the board with very fine and flexible silicone wire. :)
With the ones I recently had trouble on, all I had to do was put a little pressure under the case by the board, and they'd go nuts. :) My solution was to rewire the potentiometer to the board with very fine and flexible silicone wire. :)
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