Locating resistance in the control system

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The troubleshooting technique is so simple I never really felt it needed a page to describe this but I continue to find others with less then optimal performance due to tight links, tight bolts, crooked guides, non-oiled shafts. Things you will notice from a poor setup include decreased battery runtime, tail not holding good, sticky feel to the cyclic, etc. Basically all I do to locate the problem areas is to split them up in sections. For instance with the rotor head you can remove the links from the bottom of the swashplate to find out if the resistance is in the rotor head or in the servo side.
Note: Before you begin a quick technique to check the tightness of links is to twist them. If they do not easily twist on the ball then the link needs to be resized. This can be done with a bought tool or one you make. I use the JR resizing tool JRP960219 but you can make one with any threaded ball link such as the ones in this picture:
One is from a MA Xcell helicopter and the other is from a JR Vigor. Anything like this will work. Just screw this onto a metal frame post or anything else you have for a handle then using a pair of diagonal cutters to put a couple of marks on the ball. As you turn the ball in the link, the cut areas will grind the inside of the link. With the link snapped on the helicopter it should be free enough that it will fall with its own weight.
Tail:
I'll start with the tail since this is the most common. First to find out if you have a problem in this area remove the link from the rudder servo. Now push/pull the link. It should slide with very little resistance. If you place your finger on the ball link and lightly push it toward the tail then it needs to move easily. If as you push the link does not move then as you continue applying more force then the link suddenly moves, then this means it is too tight. To figure out if this a problem in the rod/guides or the tail section remove the link from the control lever on the tail case. Now check it again. If you still have resistance then the problem is in the guides on the tailboom.
Front half:
I have found the guides out of place due to them having been bumped during transport. After you have the proper alignment you can put some thin CA glue along the edges of the guides to hold them in place. Do not put a lot or you will have trouble taking them off when you need to change the tail boom. To check the alignment sight down the control rod from the back, you can easily see if they are inline. To fine tune this, push/pull the rod while slightly rotating each guide until you find the least resistance. Also keep in mind the holes in the guides might be a little tight, I had to use a small drill bit one time to enlarge these but in most cases they are fine. Another area for resistance is the front guide built into the frame. The rod has to bow downward to reach the rudder servo arm and this causes resistance on that guide. I fix this by putting about a ten degree bend in the rod so the rod is no longer at an angle in the front guide.
Tip: The guides should be aligned from back to front. Start by rotating the back guide so that the control rod is at the same height as the ball on the tail control lever. Then adjust the other guides to keep the rod parallel with the tail boom. You can tell if it is parallel by looking at the boom at an angle so there is only a thin gap of light between the rod and the boom. This gap needs to be equal from the back to the front.
Back half:
To begin with I see a lot of people that do not oil the tail shaft regularly. If the shaft has dried oil (or worse, someone used grease) then clean this off and apply new oil as this is often the only problem I find. I use Tri-Flow on this and the main shaft both. If this did not fix it then the next thing is to split the problem in half. Remove the two pins in the tail pitch arm <item 13>, if that did it then examine the pitch arm closely. I once found a pitch arm that was screwed on crooked and this put the pins at an off angle. Next is to rotate the grips. I have never seen these have resistance so most likely you will find the problem is in the pitch arm side. If the screw going into the lever <item 26> is too tight then this could be the problem. Loosen the screw a turn and see if that did it.
Rotorhead:
To see if you have a problem here remove the links from the aileron and elevator servos and feel of how much force it takes to move them. If they don't move freely then remove the four links from the bottom of the swashplate. Now see if the resistance is still there. If not then grab the swashplate and move it, if you don't free resistance in either side then the problem is in the elevator links (A-arm links). Otherwise this will tell you if the problem is up in the rotorhead or before it.
Bottom half:
The common problem in this half is the fit of the pins in the bottom of the elevator links (A-arms). Some people think you have to glue these but they need to pivot freely on the A-arms. I have never had a problem with the pins coming out but have heard of a few report this. If this is a problem you could drill a small hole in the center of the elevator lever <item 15> then install the pin and drip some CA in the hole. The pin normally does not need this and has enough resistance in the elevator control arm to hold its place.
Top half:
A common problem here comes from the rubber dampeners not having been pushed all the way in the head. This causes it to drag on the grips. You can remove the links from the grips to find out if this is where the resistance is from. As above you can pin point the problem area by removing links until you eliminate the resistance. Also don't forget what I posted in the first section, twist the links to find out if one is too tight on the balls. In this setion most of the time I find the bolts in the mixing arms where too tight and I have also found the same for the bolts going in the see saw hub.
Note: swashplate - Tip contributed by Richard Briedis
I was just trouble shooting the heli for why my collective would be sticky in only a certain direction when combined with cyclic input. Turns out that one of the screws that go into the washout base was not in entirely straight (1-2 degrees out). This has casued it to flex under load and bind on the main shaft when the swashplate is tilted in a certin direction.