Carsten Groen

Thanks Dave,
guess I'm not going crazy (yet ), explains what I have found!
I tried all the different update rates on the Weatronic receivers (goes down to 3 mSec update rate), but no matter what I choose, the problem persists (maybe it's a little better at 6 mSec updates, at 3 mSec the servo stops responding)

Anyone that needs 10 pcs MP80T at a good price ? [:-]

Dave Wilshere

Carsten

Little

We had to exchange to 8911 the first customer who found the Futaba problem. We have a note on our web shop saying not for Futaba...maybe need to add not for Weatronic either! On JR they are fantastic, super smooth, I some here going in my CARF Edge 540 and a customers Ultra Bandit sitting on my office roof!

Regards

Dave

HarryC

My Feedback: (1)

That's a pity Carsten. The Futaba FASST problem is caused by them using a particularly low voltage on the data pin. I would be surprised if Wea was using a data voltage that is borderline low, but perhaps they are and perhaps at the same time JR has set an unusually high threshold for the discrimination for the brushless servo, hence the problem. Wea needs to know so they can adjust their design, but Alwin can be rather deaf to information that his product is less perfect, your best bet is to let Gerhard know (the USA Wea importer) as he will check and confirm it and tell Wea. It won't solve your problem now but it might at least get Wea to consider changing their design in the next decade!
H

Carsten Groen

Thanks Harry,
yes, they should fix that IMHO, but you are probably right, not something that would happen "overnight"
Basically, it should be fixable with a buffer between the servo and receiver, I will try and do some measuring of the control signal, and see if it can be helped with a higer voltage on the control pin

Carsten Groen

Been doing some tests here.
1) Using a Micro 12 Weatronic receiver, the signal look like the first picture, the supply voltage is 5.8V (stabilized), and the control voltage is 5.04V. With this setup, the servo "jitters" like crazy. (don't think that this means that Weatronic is "low on the control signal")

2) Using a Hitec servotester (HFP-20) the picture looks like the second one. Supply voltage is 5V, and control signal is 3.5V. With this setup, the servo runs much better.

I tried lowering the control voltage on the Weatronic setup, no difference. Also tried raising it a little, no difference.
So, I still don't get it, the only difference is the Wea does 55 Hz updates, the servo tester does 50 updates. Don't think the difference is in that, if I change the Wea to a higher/lower rate than the 55 Hz, nothing changes....

Still puzzled....

HarryC

My Feedback: (1)

Oh well, definitely not low data voltage! One for Weatronic to investigate.
H

Carsten Groen

Yep, I have just sent them an email, hope they will get back on this one !
I have two planes (UL/Futura) almost ready for a trip to the south of France in 4 weeks time, would be nice to have them with me []
Guess the immediate solution for me is to change to 8911/8511, but I do feel something should be done to this, guess we will see more brushless servos in the future....
(anyway, this ended to be a little OT, should have been moved to the Wea thread, sorry for that )

Dave Wilshere

Carsten

All good info for people.

We have a great deal on 8911...

Dave

Carsten Groen

maybe, but not as low as "some others" out there
(but you are welcome to PM me )

Carsten Groen

got PM, and I stand corrected, actually a good deal