Mellotronists

So I have been working on about a half dozen projects at once but I am  
nearly done with the 4-Track. I am going to post some more pictures on the 
Yahoo  site, but I wanted to share some information about what I have discovered 
along  the way.
 
As I said in a previous post, I think this could have been the best  
Mellotron yet if it had reached the production stage, but there are a bunch of  
screw-up that make no sense. It seems obvious that there were some shortcuts  
taken here and the way some of the components are assembled doesn't make  
sense.
 
I posted a little (self serving) video on You Tube that shows the method I  
used to align the tape head, which were all over the place when I really 
took a  good look at them. None of the techniques I used are applicable  to a 
M-400. I think they will prove to be correct, but I'm feeling my way along  
as I go.
 
_http://www.youtube.com/watch?v=-RgDmI4tmQ8_ 
(http://www.youtube.com/watch?v=-RgDmI4tmQ8) 
 
So here are some photos and their descriptions. I will post them on Yahoo  
later tonight.
 
 
          
Part of my shop. There  are 4 other Mellotrons down here, two behind me and 
two more in the  other room that are not in need of service (one being the 
M4000) The  pretty white one is #600, back for a new set of pinch rollers, a 
 little tune-up and a couple of mods. On the rack is the guts of  the (
formerly blue) Mellotron and the 4-track main  frame.
   
The rubber on all of  the pinch rollers is in good shape, but notice that 
the rubber is  not glued to the hub. So if someone were to really crank down 
the  set screw, the rollers become egg-shaped as they turn. I may get  some 
rubberized CA glue and try and glue them to the hubs. Martin  was right, 
they are cheap shit... but  soft.
   
The pressure pad rest  is so low that even when the key is released the 
tape is in constant  contact with the pressure pad. I removed the spacer on 
each end  between the rods and the frame. This solved the problem.  
  
The head block is  fixed. I used the piece of aluminum stock and the piece 
of spruce to  properly align all of the heads. Interestingly, Even if the 
center  heads are in perfect alignment with the tape guides, They are a  
little off (a few thousandths) near either end. I adjusted the head  height the 
best I could and I think it will be substantially better  than it was. You 
can learn more in the  video.
   
The heads are all  pushed against the aluminum rail to get them straight 
and to zero  the azimuths. The same was done on the back  set.
   
The piece of spruce  was stuck back though the metal take guides and used 
to align the  spill box.
   
Oddly, there were no  felt isolator pads on either the pressure pad springs 
or the key  springs. Every time you depressed a key you got a nice click,  
though. I will go back and individually adjust each pressure pad as  I 
install each key. The pressure pads were all bent up and no two  were the same. I 
made a some little wood jigs so I could get them  all the same. The short 
ones are bent a bit different at the tips  then the long ones so that they 
press properly against the  heads.