Sunday, June 24, 2012

PF Servo glimpse

Now that first 2H2012 LEGO Technic sets were found selling into a LEGO Shop and eBay, all kind of so far contained leaks will start popping-up...

Sunnykoomos YouTuber just published a short video, with which seems to be and old photo from part of the new PF Servo. The most interesting part of it, is that it is the first time we get to see it from the backside, revealing the dual output.
Also it confirms the PF Servo has 7 modules lengthwise.

And since we are talking about the novelties...

Lets take a look at a few other pieces of information meanwhile available.
The sets partcount has been at since awhile, and their retail prices are also consistent with those seen at an official LEGO Shop the last days also in Germany.

9393 - Tractor / Buggy
Partcount: 353
Retail Price: 29,99€

9396 - Helicopter / Intermeshing Rotors Helicopter
Partcount: 1056
Retail Price: 89,99€

9398 - 4x4 Crawler / Truck
Partcount: 1225 1327
Retail Price: 169,99€


MattTheTubaGuy said...

Hopefully someone who has a variable speed remote can test the servo motor soon. It better be variable!

mahjqa said...

It's not.


efferman said...

it is proportional

Allanp said...

I would not expect the train remote to give it proportional control. In fact, if it did then it would be not as good as what could be done with a new remote designed to give proper proportional control. So hoefully, instead of trying to bodge it, they might be comming out with a new remote which would be better.

Allanp said...

Whoops! You posted just before me haha! I couldn't read that page, how is it proportional?

efferman said...

it seems that there the speed steps which the remote sends, goes in position steps. and the same as in the speed control wher is no automatic return to center.

Allanp said...

I assume, providing it does not miss any steps, that turn the dial back "to centre" would turn the motor back to cetre. If so you would only have to have a spring on the remote to turn the dial back to cetre. I also wonder if the stop button returns it to centre.

efferman said...

the owner of the 9398 says that the servo goes back to center when the stop button is pressed

efferman said...

there is a vid available

TechnicBRICKs said...

It works as per the known LPF Protocol which is public domain.
With a PF IR Remote it goes full left/right when the sticks are pressed forward/back (depends on polarity switch). When there is no signal arriving it returns to the center like a regular servo. It behaves similarly when attached to a regular Battery Box.

Now if connected to the PF Speed Remote or the PF Rechargeable Battery it receives modulated proportional signals while attached to the IR Receiver or the Battery. Then it turns proportionally according to the received signal. That's why it does not return to the center automatically. The stop button must make it return to center though.

TechnicBRICKs said...


Great find!
Cooking another post... :)

Alex Campos said...

It makes sense: the way the rechargeable battery box and the train remote controller work is by applying a square wave to the PF data pins, with a duty cycle varying between 0% and +-100% (depending on the direction you turned the knob). While a regular motor uses the duty cycle to vary its speed, the servo uses it to vary its axle's position. The "Stop" button knocks the duty cycle back to zero, so the servo interprets it to "go to position zero", which is centre.

If I'm not mistaken, that's also how RC servos work.

eran1243 said...

Great for return to center steering!! using the regular PF remote..

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