1. Summary
  2. Files
  3. Support
  4. Report Spam
  5. Create account
  6. Log in

Servo motor from 9398 4x4 Crawler

Discussion specific to the intelligent brick, sensors, motors, and more.

Servo motor from 9398 4x4 Crawler

Postby tabbycatrobots » 14 Oct 2012, 20:01

Has anyone tried the Power Functions servo motor from the 9398, with the NXT controller? I just
finished building the main model - some good ideas and parts for a robot dump truck I plan to
build. Before tearing the model apart and experimenting with the servo motor, I thought I'd ask if
anyone here had tried this motor connected to an NXT. (Why reinvent the wheel?) Thanks for any
info.
tabbycatrobots
 
Posts: 96
Joined: 27 Dec 2010, 19:10

Re: Servo motor from 9398 4x4 Crawler

Postby mattallen37 » 15 Oct 2012, 05:20

See here for related information.
Matt
http://mattallen37.wordpress.com/

I'm all for gun control... that's why I use both hands when shooting ;)
User avatar
mattallen37
 
Posts: 1818
Joined: 02 Oct 2010, 02:19
Location: Michigan USA

Re: Servo motor from 9398 4x4 Crawler

Postby jwiger » 16 Oct 2012, 01:10

It will work, just a matter of having the cables to do it. And using the power level to control its position.
JimmyJam
"The more you know, the more you know, the less you know."
User avatar
jwiger
 
Posts: 122
Joined: 24 May 2011, 20:41
Location: Where ever the military sends me (currently Central Texas)

Re: Servo motor from 9398 4x4 Crawler

Postby tabbycatrobots » 16 Oct 2012, 01:28

Thanks for the pointers to the details. Interesting that it can turn to intermediate
positions, not just 90 deg left or right.
Yes, I have some adapter cables from LEGO Education that I think will work.
Thanks.
tabbycatrobots
 
Posts: 96
Joined: 27 Dec 2010, 19:10

Re: Servo motor from 9398 4x4 Crawler

Postby hassenplug » 16 Oct 2012, 12:41

I'm not sure the regular adapter cables will work. I don't know if it says anything on Philo's page, but I suspect the servos require both the +v and the variable voltage, but the NXT->9v cables will only pass the variable voltage.

My guess is that you could make a custom cable that may allow you to run them from an NXT.

Steve
---> Link to lots of MINDSTORMS stuff under my picture --->
User avatar
hassenplug
 
Posts: 346
Joined: 27 Sep 2010, 03:05

Re: Servo motor from 9398 4x4 Crawler

Postby jwiger » 18 Oct 2012, 11:45

Oooh, that's a good point. I was just wondering how it would get enough power to provide good torque at low duty cycle PWM.
JimmyJam
"The more you know, the more you know, the less you know."
User avatar
jwiger
 
Posts: 122
Joined: 24 May 2011, 20:41
Location: Where ever the military sends me (currently Central Texas)

Re: Servo motor from 9398 4x4 Crawler

Postby tabbycatrobots » 18 Oct 2012, 19:43

I've been studying Philo's page, particularly the NXC code and it looks like he is using
NXT port A for the 9v and NXT port B for the control. I can imagine what the cable may
look like, but didn't see a diagram on his web pages. I did post a question on his page,
asking if he could post a diagram of the cable he used. I also proved to myself that the
LEGO adapter cables don't work, but don't harm the motor. It still does work, and
quite well with the train RC 8879. Controlling the 9398 with the 8879, allows good
speed and steering control.
But having to use 2 motor ports to control the servo motor negates its pluses. Maybe the
next Mindstorms will interface nicer to PF.
tabbycatrobots
 
Posts: 96
Joined: 27 Dec 2010, 19:10

Re: Servo motor from 9398 4x4 Crawler

Postby mattallen37 » 18 Oct 2012, 21:08

See this page for a diagram of how the wiring works. The PF-S get's it's power through 0V and 9V, and it's control through C1 and C2. In order to power it through port A, and control it through port B, you would need to connect PF-S 0V and 9V to port A (pins 1 and 2), and PF-S C1 and C2 to port B (pins 1 and 2). Just be sure the supply polarity is correct; I would use a diode to be sure I didn't burn out the PF-S.
Matt
http://mattallen37.wordpress.com/

I'm all for gun control... that's why I use both hands when shooting ;)
User avatar
mattallen37
 
Posts: 1818
Joined: 02 Oct 2010, 02:19
Location: Michigan USA

Re: Servo motor from 9398 4x4 Crawler

Postby jwiger » 20 Oct 2012, 13:36

mattallen37 wrote:...The PF-S get's it's power through...

For a moment I thought there was a "PF-Small" I haven't heard of yet. If we start calling the servo PF-S what would we call a small motor? It can't be "Little" or "Mini" (PF-L and PF-M are taken).

Here's some ideas http://thesaurus.com/browse/small?s=t

Sorry for the tangent.
JimmyJam
"The more you know, the more you know, the less you know."
User avatar
jwiger
 
Posts: 122
Joined: 24 May 2011, 20:41
Location: Where ever the military sends me (currently Central Texas)

Re: Servo motor from 9398 4x4 Crawler

Postby mattallen37 » 20 Oct 2012, 18:38

I'm quite sure I didn't make up "PF-S" to mean servo. I remember thinking the same thing when I first saw it (which was probably on the TechnicBRICKs blog).

Perhaps "Tiny"? Or for the fun of it, "Diminutive" would also work.
Matt
http://mattallen37.wordpress.com/

I'm all for gun control... that's why I use both hands when shooting ;)
User avatar
mattallen37
 
Posts: 1818
Joined: 02 Oct 2010, 02:19
Location: Michigan USA


Return to Mindstorms Hardware

Who is online

Users browsing this forum: No registered users and 1 guest

cron