9 replies to this topic

[legolijntje]

Hi,

I found this, this and this documents on the Lego site. Is this new from lego?

I think they should make more of these documents; they're very clear and interesting to read  

Edited by legolijntje, 02 August 2012 - 07:14 PM.

[Zblj]

Great find, I wonder how this compares to Philo's meauserments.

Btw how did you find this?

[legolijntje]

Zblj, on 02 August 2012 - 07:31 PM, said:

Btw how did you find this?

Every few weeks I use Google advanced search to search for the newest pdf files on cache.lego.com

[Zblj]

I managed to find it too on Lego PF info page. Good work!

[DLuders]

On that Powerfunctions.Lego.com website that legolijntje and Zblj found, it says that "SM (Servo Motor) -- The Servo Motor will not be available through LEGO.com until March 2013" and "LM (Large Motor) -- The Large Motor will not be available through LEGO.com until March 2013."  If you have not bought the 9398 4x4 Crawler set yet, it may be the only way to obtain these new PF motors for 7 months!    

There is no mention about the new "Version 2" 8884 Power Functions Receiver in the PF Products lineup -- I guess the existing supply must be bought-out before The Lego Group offers them for sale....

[Traktor]

The XL motor seems like the most battery efficient motor, even under minimal load. I guess it is because it is not "wasting" energy on rpm, as you can clearly see under the "no load" part. And the XL motor is much more efficient at the top of the watt curve than the L-motor, 42% vs 27%. Which in my opinion is the second most important after the strength and actual output power of the motor.

Edited by Traktor, 03 August 2012 - 01:19 AM.

[DLuders]

Zblj, on 02 August 2012 - 07:31 PM, said:

I wonder how this compares to Philo's meauserments.

  

On his "LEGO® Power Functions Servomotor" webpage, Philo (Philippe Hurbain) measured the response of the SM to the Power Functions Receiver's signals.  He wrote that "Spikes of current at 8.5N.cm load reaches 600mA."  

On this Powerfunctions.Lego.com webpage, The Lego Group wrote that "The Servo Motor delivers a maximum torque of 250 mNm (300mA). Without load it rotates with 360 degrees per second. This corresponds to the output turning from center to horizontal position in 0,25 seconds.

"The current consumption will depend heavily on the load it is driving. Under normal conditions it can be around 150 mA and it should never exceed 300 mA."

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On his "LEGO® 9V Technic Motors compared characteristics" webpage, Philo wrote that the PF L-Motor rotated at 390 rpm at no load.  At 9V, the current was 0.49 Amp and its "stalled current" was 1.3 Amps.

On this Powerfunctions.Lego.com webpage, The Lego Group wrote "It delivers a maximum torque of 45,4 mNm (430mA). Without load its rotation speed is around 384 rotations per minute [VERY CLOSE to what Philo had measured].  

"The current consumption will depend heavily on the load it is driving. Under normal conditions it can be around 225 mA and it should never exceed 430 mA."  

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Philo wrote that the PF XL-motor rotated at 220 rpm at no load.  At 9V, the torque was 14.5 Newton-cm and the current was 0.55 Amp.  Its "stalled current" was 1.8 Amps.

The Lego Group wrote that it "delivers a maximum torque of 90,4 mNm (406mA). Without load its rotation speed is around 224 rotations per minute."  [Very close to Philo's measurements]  

"The current consumption will depend heavily on the load it is driving. Under normal conditions it can be around 300 mA and it should never exceed 406 mA."  This is a bit lower than what Philo measured.

Edited by DLuders, 03 August 2012 - 01:40 AM.

[timslegos]

Wow definitely a great find.  I wounder what prompts this sudden "transparency" of technical data.

tim

[DLuders]

Today, TLG has replaced the old picture of the Power Functions Receiver to the "Version 2" (v2) one, but the downloadable specification is from 2010.    

[Crtlego]

This is very interesting to see the specifications that Lego has just provided (why now?) and to compare it with existing technical data. I've downloaded the existing specs for further reading but I'm curious to know why none were provided for the M-motor? Could they be phasing out the M-motor and replacing it with the L-motor, (presumably next March when the L-motor supposedly becomes available from Lego.com)? It is the only existing Power Functions motor to have studs so that does give mounting options that are not available for the L-motor (even with its additional holes).. I would like to see it stay but if they do get rid of it, I hope they will bring the L-motor's price down to that of the M-motors or something close to it.

Edited by Crtlego, 03 August 2012 - 08:25 PM.