To start remove the batteries and then the 4 screws marked by the red arrows.
(The blue arrows mark the position of the hidden switches in the back that are referred to sometimes)
Next we pull out at the bottom of the case then carefully pry apart the top handle as there are little pins in there that are a bit tight, then fold the back plate towards you.
If you look in the next pic the blue arrows are showing the hidden switches again, the green arrows are showing where the Potentiometers (or pots) are located. The yellow arrow shows the plate that causes the ratchet effect on the throttle stick movement (I have already flipped mine over as I don't like the ratchet effect)
the red arrows shows the plate for the buddy box plug that needs to be removed if you want to get the centre pots out (and remove the antennae) and the other red arrows are the 4 screws that need to be removed if taking out the bottom pots (as the circuit boards get in the way of it coming out)
In the next pic the yellow arrow is pointing to the pot, the blue arrow is the back end of the trim tab pivot arm and the red arrows are showing the parts that I found to be causing the problem.
What these plates do is actually act as a secondary pivot to rotate the pot angle and therefore trim a small amount of movement in the pot. The problem with them is that they are only joined together by being melted at the top but this can slowly break and the 2 halves can move independently of each other and let the pot move or sometimes jitter in the movement of the stick.
what this is causing in the heli is either twitching servos or the servos move incorrectly as the trim isn’t holding where it should (so you may have 1 servo moving less than the others and cause the heli to go off in the wrong direction or cause twitching which will just make the heli very unstable).
Here are a few shots of the offending plates, the 3rd shot shows how they can start to come apart, the 4th shows how they have a grove melted into them and the 5th is the 2 plates separated.
before we fix it we have to get them out all you have to do is use a small flat screwdriver to undo the threaded brass collar shown by the red arrows in the pic (the blue arrows are showing the melted grove again)
keep wriggling the pot a little at a time until you get it fully undone, don’t forget you will need to remove the lower circuit boards if doing the bottom pots and the buddy box plug board if doing the centre ones, also rotate them a little as you pull them out to clear the other pot.
once you have them off the fix is simple, clean off all the grease and glue them together with some superglue, ensuring that the 2 parts are put together square around the outside and the space around the centre (marked by the red arrows) is even all around
Before you put it all back together you may as well clean the pot while it is out.
Some people just spray cleaner into the small opening in the pot case indicated by the red arrow in the 1st pic below and just work the pot around quickly, I take the back of the case off on mine and clean right inside.
In the second pic the red arrows show the tabs you carefully bend back to remove the casing (the blue arrow shows the flat spot on the shaft you will need to line-up with the cage for the stick I will mention on re assembly)
The following pic shows the little contact plates, marked with the red arrows and the tracks they run on marked with blue. you need to carefully clean the tracks and plates with a piece of tissue and a fine screwdriver and try to get the tissue to slide under the plates, then put on some contact cleaner and put it all back together ensuring you fold the case tabs back down correctly.
Some more expensive (and better quality) pots have dual layers of contacts on either side of the board.
when you reassemble it all put a small amount of vaseline or silicone grease on the pivot plates then you put the pivot plates onto the shaft of the pot and line it up onto the small tab that sticks out the side marked with the blue arrow and ensure the plastic pin marked with a red arrow is facing away from the pot.
The yellow arrows are pointing to the flat spot on the shaft and the cage it lines up with so you have to make sure the stick is centred and the flat spot is strait up. you have to wiggle the stick a little as you screw in the threaded brass collar and keep going until it is done up tight.
Then put it all back together. Be careful not to pinch any of the wires inside between components.
WARNING you shouldn’t have any spare screws left over - honest its true LOL.
Below is a pic of the small hidden switches and where they should be for normal operation. (in Mode 2) A should be DOWN, B should be UP, 1 should be OFF and 2 should be ON
I hope this helps someone in their quest sort out some of Esky's mistakes anything you want to add feel free. Also while you have it open, have a careful look for any dry solder joints as their job isnt that great.
mark
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Ever been in an Iriquoi (Huey) and had to make someone spew inside their jumper so it dont hit the windscreen? MMMMM
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My Pic is me in an Australian Blackhawk
Last edited by Weetbix on Sun Feb 15, 2009 1:14 am; edited 5 times in total
