Conference vmszoo::rc

1638.0. "Servos move slowly" by CSC32::HAGERTY (Veni, Vedi, $Cmkrnli, Rebooti) Tue Nov 15 1994 09:36

    Hello, Fellow RCites
    
    	I was helping a fellow the other day, and I ran across an
    interesting phenomonon.  I noted that his servos were moving rather
    slowly.  Nonplussed, I checked his batteries.  They were ok (at the
    bottom of the green, but ok).  I went ahead and put his batteries on
    the field charger and brought them to 85% (ACE R/C charger).  Still
    pretty slow.
    
    	I used the throttle as a test and disconnected the servo arm.
    It still seemed a bit slow to my eye.  I happened to notice a couple
    of things that is the heart of my question.
    
    	a) He had S-138 servos
    	b) He had some sort of AM 4-channel receiver.  This is to
           say it said Futaba, but it only had 5 sockets in it
    	   (4+battery)
    	c) The receiver had been gold-stickered (he claimed).
    
    The guy had bought the plane & radio from a "friend".  Sorry, I don't
    know the receiver model number.
    
    Here are my working theories:
    
    	a) The receiver can't react fast enough.  Buy an AM receiver of
    	   more recent manufacture.
    	b) Despite the batteries showing ok on my meter, they are flaky.
    	c) There is something inherent in the 138 servos (I have only ever
    	   used 128 and 148 servos, have no experience with 138s.
    
    	Which theory would you claim most likely (add your own if you
    like)?
    
    
    					Dave()

hi dan,

you can rule out a). there is nothing like a response speed or difference
in response speed between am and fm.

b) might be (i am in the rhiming(sp?) mode today:-))

c) i dunno, but how about

d) if the equipment is old (which i suppose because of am) then the lubricant
in the servos is it as well and might be binding the gears instead of
lubricating. to test this, take one servo apart, clean the gears in
alcohol (not methanol!) and relubricate. old also might mean corrosion on
the battery and/or servo connectors, so you might want to check there also.


hope you finf the bug!

cheers
joe t.

    I can't remeber using these type of futaba servos.  After 20 years of
    flying Rc, I have used all the Futaba radios.  I do remeber the older
    Kraft and World Engines servos moved slow but reliable.
    regards,
    Ron

Welcome to the file, Ron. You should introduce yourself in topic 4

I have a shelf full of those old 4 wire servos as well. I traded my Blue Max in
in one of the 1991 upgrade deals.