AXE CP ball link conversion... ideas?

[Ray K.]

Hey everyone!

So I've been thinking of doing a ball link conversion on my Axe to ditch the z-bend links. They've been a pretty consistent source of frustration for me, and they have got to go. Not only is there play in the servo horn where the link goes through the hole, but it also looks to me like the horns themselves deflect under load, eating up servo input to the swash, and also causing non-linear swash movement. It feels like it might also be making control inputs a little vague, sloppy, and unpredictable.

So I'm looking for ideas, and I think that if a few of us put our heads together, we can come up with a good solution.

As far as I can tell, these are going to be the requirements for such a setup:

1) The servo horns need to be pretty stout, at least twice as thick as the stock parts. Aluminum, maybe?

2) There's not much point in making the balls on the horns any bigger than the balls on the swash. Those are 3mm balls, aren't they?

3) It would be really great to make it so that the link rod is threaded on both ends, so that super-fine adjustments can be made. So far, I'm having a hard time finding appropriate links that are pre-made. I'm not crazy about the idea of having to tap wire that small. It'll be really easy to screw that up.

4) After putting my calibrated eyeball on the links, It looks like the best way to do this is going to be to put the ball on the *inside* of the horn, so that it's closest to the servo. This would allow the links to stay pretty close to parallel with the fuse. This means that the ball and link would have to be pretty small. Otherwise, the ball would go on the outside, and there would have to be a mild z-bend in the link to get it straight under the swash. To me, that's another potential problem area as far as deflection goes.

There's got to be a good way to do this that won't cost a fortune to do. Anybody have any ideas?

Thanks!

Ray

[sgt jake]

Ray K.

I've been thinking about do the samething. After doing some checking the balls at 2.85mm and the rods are 1.25. Searching through most of the RC stores online, I can find 2.85mm balls, but not the links. I check my LHS and they don't have anything close to that either or the rod.

[Ray K.]

I wonder if TRex links would work? I've only seen photos of them, but it looks like they might work. TRex 450 is only a little bigger than ACP, and those links will probably be close enough to make work. What were you going to do for horns?

[sgt jake]

I have the straight horns.

They don’t seem too bad; it’s the slop at the z-bend and in the servos over all the flight time that’s starting to show up. I have some hs55 servos to replace them with, I just want to put the balls on them when I replace them.

I’ve wondered if the Trex parts would work like these (http://www.horizonhobby.com/Products/RelatedParts.aspx?ProdID=AGNH1100&Category=Parts%20Listing), about mid way down the page.

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[Ray K.]

Yeah, that's the same stuff I've been eyeballing too. Even if they're a little too long, they could probably be trimmed down to work without cutting off so much thread that they won't work. And five or six bucks makes for a pretty low-risk experiment, so that may be what I end up doing. I'm just not sure how critical it is that the link is at a right angle to the swash... It seems like you could probably be off by a bit before it becomes a problem. As long as there is no binding, you should be in business, right?

I was asking about what horns you're going to use because I'm a little concerned that the balls may not adequately clear the servo body if they're put on the inboard side of the horn. I'm also concerned that putting the ball on the outboard side of the horn may be too much of an offset angle going up to the swash. I don't know, I'm not an expert, but it seems like it could be trouble to me. It may also have no effect at all on flight performance.

I'll have to put my thinking cap on.

Let me know how you make out!

Ray