Message 4 Se7ven and Meltdown

KHR-1, KHR-2HV, KHR-3HV, ICS servos, RCB controllers and other Kondo products
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5 postsPage 1 of 1

Message 4 Se7ven and Meltdown

Post by Guest » Wed Nov 30, 2005 5:46 pm

Post by Guest
Wed Nov 30, 2005 5:46 pm

PROBLEM PERSISTING

Hi!

It took a while, but at last I received the cable for setting servo
parameters (my kondo features ICS 786 RED)

As Se7ven suggested, I switched the DAMPENING parameter from 2 to 1 for servo channels 1, 2, 3 - left arm – and channels 7, 8, and 9 – right harm.
Actually, now Kondo doesn’t jitter as before, but ONLY when motions are
low-paced by setting low speeds (2,3,4). Kondo STILL JITTERS at slow
speeds (5 and 6).

I varied the dampening value only on arms servos, for it was my
impression than only those servo jittered, but actually this symptom affects all servos. But, as a matter of fact, vibrations cannot be perceived on legs servos just because legs servos are “loaded” by the weight of Kondo torso:
as soon as you lift kondo from the ground and initiate a motion…it is
DISASTROUS!!!!

So, to avoid proceeding by trial-and-error – servomanager allows you to
set several parameters- I hope there exists a textbook combination of
values allowing optimal servo adjustment.

Please let me have a set of optimal, appropriate parameters to
solve my problem once for all.

P.S. I cannot understand why the head servo (channel 6) NEVER VIBRATES although it is not loaded.

I hope you can help me,

Thanks and regards,
Ninja
PROBLEM PERSISTING

Hi!

It took a while, but at last I received the cable for setting servo
parameters (my kondo features ICS 786 RED)

As Se7ven suggested, I switched the DAMPENING parameter from 2 to 1 for servo channels 1, 2, 3 - left arm – and channels 7, 8, and 9 – right harm.
Actually, now Kondo doesn’t jitter as before, but ONLY when motions are
low-paced by setting low speeds (2,3,4). Kondo STILL JITTERS at slow
speeds (5 and 6).

I varied the dampening value only on arms servos, for it was my
impression than only those servo jittered, but actually this symptom affects all servos. But, as a matter of fact, vibrations cannot be perceived on legs servos just because legs servos are “loaded” by the weight of Kondo torso:
as soon as you lift kondo from the ground and initiate a motion…it is
DISASTROUS!!!!

So, to avoid proceeding by trial-and-error – servomanager allows you to
set several parameters- I hope there exists a textbook combination of
values allowing optimal servo adjustment.

Please let me have a set of optimal, appropriate parameters to
solve my problem once for all.

P.S. I cannot understand why the head servo (channel 6) NEVER VIBRATES although it is not loaded.

I hope you can help me,

Thanks and regards,
Ninja
Guest offline

Post by Meltdown » Sat Dec 03, 2005 3:37 am

Post by Meltdown
Sat Dec 03, 2005 3:37 am

One possibility is that your computer is sending out erratic signals due
to interference, unstable serial port or a ground problem.
Also switch off any wifi, bluetooth modules if you have them.
I had this problem with a laptop driving my cnc mill which is basically the same as driving a KHR-1.
If your on a laptop try both powering your laptop with adapter or battery only and see
if things change.
Best is to try a second computer to eliminate this possibility.

Second possibility and more likely:
You shouldn't have to tinker with the servo settings.
This is not the problem.
For me the problem only occurred when using the gyros.
I think it's power related.
Either to little or to much volts.
To much volts can also cause this but i won't go into this yet before
you tried the solutions below.

What do you use as the power source?
If it's the stock battery just dump it. It's useless as is the charger.
Get yourself a decent Nimh GP 1200mha cell pack and a decent nimh charger (you cannot charge nimh with the stock charger!) at your local radio control model hobby shop.
These shops have the best batteries and chargers in the business.
Or a stabilized powersupply of at least 6 amps continuous.
I think your problems will cease then.

Why?
A little info on batteries.
Nimh keeps it's voltage (6v under load) until the the battery is empty.
Nimh doesn't have memory problems.

NiCad (the stock battery) has memory problems.
This means that it will be impossible to charge fully every time you charge when the battery wasn't fully empty'd.
NiCad looses it's voltage as soon as a few minutes after use.
And it keeps dropping all the time.
The KHR-1 electronics have a threshold voltage for them to keep working properly.
A NiCad pack will reach this threshold way before the pack is empty.
So you charge it again.
It will not charge fully due to the memory problem.
The problem becomes worse everytime you recharge.
And so on and so on.
You can guess what this will mean for the KHR-1.
Also the stock charger is junk AND CANNOT BE USED TO CHARGE NIMH!!
I think that's the problem.
I know all this because i have raced rc cars in competition for 20 years now.

Remember that the robot is useless without a decent power supply.
It's the most important upgrade you can do.

i Use a 7amps laptop adapter now which solved all my power related problems
Also i build 2 li-poly 1800mha packs into the foot soles for remote operation.
Each driving a rcb-1.
Li-poli has all the positive things and much more like nimh but
have also a few problems.
NEVER EVER TRY TO USE LI-POLY IF YOU DON'T KNOW EVERYTHING
THERE IS TO KNOW ABOUT THEM.
THEY ARE VERY VERY DANGEROUS!!

For those who want to know about Li-poly just ask.
One possibility is that your computer is sending out erratic signals due
to interference, unstable serial port or a ground problem.
Also switch off any wifi, bluetooth modules if you have them.
I had this problem with a laptop driving my cnc mill which is basically the same as driving a KHR-1.
If your on a laptop try both powering your laptop with adapter or battery only and see
if things change.
Best is to try a second computer to eliminate this possibility.

Second possibility and more likely:
You shouldn't have to tinker with the servo settings.
This is not the problem.
For me the problem only occurred when using the gyros.
I think it's power related.
Either to little or to much volts.
To much volts can also cause this but i won't go into this yet before
you tried the solutions below.

What do you use as the power source?
If it's the stock battery just dump it. It's useless as is the charger.
Get yourself a decent Nimh GP 1200mha cell pack and a decent nimh charger (you cannot charge nimh with the stock charger!) at your local radio control model hobby shop.
These shops have the best batteries and chargers in the business.
Or a stabilized powersupply of at least 6 amps continuous.
I think your problems will cease then.

Why?
A little info on batteries.
Nimh keeps it's voltage (6v under load) until the the battery is empty.
Nimh doesn't have memory problems.

NiCad (the stock battery) has memory problems.
This means that it will be impossible to charge fully every time you charge when the battery wasn't fully empty'd.
NiCad looses it's voltage as soon as a few minutes after use.
And it keeps dropping all the time.
The KHR-1 electronics have a threshold voltage for them to keep working properly.
A NiCad pack will reach this threshold way before the pack is empty.
So you charge it again.
It will not charge fully due to the memory problem.
The problem becomes worse everytime you recharge.
And so on and so on.
You can guess what this will mean for the KHR-1.
Also the stock charger is junk AND CANNOT BE USED TO CHARGE NIMH!!
I think that's the problem.
I know all this because i have raced rc cars in competition for 20 years now.

Remember that the robot is useless without a decent power supply.
It's the most important upgrade you can do.

i Use a 7amps laptop adapter now which solved all my power related problems
Also i build 2 li-poly 1800mha packs into the foot soles for remote operation.
Each driving a rcb-1.
Li-poli has all the positive things and much more like nimh but
have also a few problems.
NEVER EVER TRY TO USE LI-POLY IF YOU DON'T KNOW EVERYTHING
THERE IS TO KNOW ABOUT THEM.
THEY ARE VERY VERY DANGEROUS!!

For those who want to know about Li-poly just ask.
Meltdown offline
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Post by ninja » Sat Dec 10, 2005 8:24 am

Post by ninja
Sat Dec 10, 2005 8:24 am

Hello Meltdown, nice to meet you

thanks a lot for your precious advice.
I will purchase the transformer you recommend and let you know about the results.
Meet you here very soon,

bye,

Ninja
Hello Meltdown, nice to meet you

thanks a lot for your precious advice.
I will purchase the transformer you recommend and let you know about the results.
Meet you here very soon,

bye,

Ninja
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Post by Meltdown » Sun Dec 11, 2005 1:09 am

Post by Meltdown
Sun Dec 11, 2005 1:09 am

Nice to meet you too.
The Robosavvy shop seems to have nice powersupplies too now.
You may look into it.
Nice to meet you too.
The Robosavvy shop seems to have nice powersupplies too now.
You may look into it.
Meltdown offline
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Location: Holland

Message to Meltdown by Ninja

Post by ninja » Sun Dec 11, 2005 12:22 pm

Post by ninja
Sun Dec 11, 2005 12:22 pm

Meltdown, while I look for an appropriate power supply, can you help me understand the mail sent to me by Kondo guys with regards to servo vibrations?
Here is the mail, along with my request for clarification:

Mail from Japan say:

>Overshoot means to control to converge the degree of motor axis as you know.
>Please adjust the overshoot damping parameter.
>In general, servo motor controls the motor using PD
control.
>Overshoot is adjusted by P and D parameter in the
kondo servo motor.
>If P parameter and D parameter are mismatch, the
motor shows
vibration.

************MY QUESTIONS***********

Could you please provide me with further details?

- Does P stand for pulse stretch, and D for
deadbandwidth?
- If yes, In SERVOMANAGER program there are 5 radio buttons for each of the abovementioned parameters.

I understand I have to assign the same values to both pulse stretch and deadbandwidth. Is it correct?
Could you tell me which one, among these 5 radio buttons, do I have to select?
Furthermore, with regard to the pulse stretch specifically, on which pulse stretch set (1, 2 or 3) do I have to select the radio button?
Do I have to define this "radio button" value for all three pulse stretch sets?

And for each pulse stretch set to be defined, which speed value (1,2,3) do I have to assign?

Do you know how to solve this?

By the way, you said you use a 6V & 7A power supply which is definitely fine. I saw on this website that a 6V & 12A supplier - recommended by Kondo - has been added to the catalogue.
Do you know what is the difference between the two?
What are the impacts of using a 12A supplier on Kondo?

Thank you for your valuable advice,
Regards,
Ninja
Meltdown, while I look for an appropriate power supply, can you help me understand the mail sent to me by Kondo guys with regards to servo vibrations?
Here is the mail, along with my request for clarification:

Mail from Japan say:

>Overshoot means to control to converge the degree of motor axis as you know.
>Please adjust the overshoot damping parameter.
>In general, servo motor controls the motor using PD
control.
>Overshoot is adjusted by P and D parameter in the
kondo servo motor.
>If P parameter and D parameter are mismatch, the
motor shows
vibration.

************MY QUESTIONS***********

Could you please provide me with further details?

- Does P stand for pulse stretch, and D for
deadbandwidth?
- If yes, In SERVOMANAGER program there are 5 radio buttons for each of the abovementioned parameters.

I understand I have to assign the same values to both pulse stretch and deadbandwidth. Is it correct?
Could you tell me which one, among these 5 radio buttons, do I have to select?
Furthermore, with regard to the pulse stretch specifically, on which pulse stretch set (1, 2 or 3) do I have to select the radio button?
Do I have to define this "radio button" value for all three pulse stretch sets?

And for each pulse stretch set to be defined, which speed value (1,2,3) do I have to assign?

Do you know how to solve this?

By the way, you said you use a 6V & 7A power supply which is definitely fine. I saw on this website that a 6V & 12A supplier - recommended by Kondo - has been added to the catalogue.
Do you know what is the difference between the two?
What are the impacts of using a 12A supplier on Kondo?

Thank you for your valuable advice,
Regards,
Ninja
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