Feathering Shaft Washers

[Planehazza]

Doing some maintenence, one of the washers that sits under the grip bolts just fell out into 3 pieces. Lucky I found it on the bench!

Now, I don't have anything of the same size in my spares box, but I do have a few of a similar shape. Can I use these instead? In the pictures below, the black is the standart part and the silver, if I remember correctly, is a engine mount bold washer from another model. It's the same ID, but the OD is larger, and it is tapered and about 1/10th mm thinner...


Parts compared:




Standard part:


Alternative part:


Probably a silly question, but with it being such a critical part, I want to double check first.

Cheers!

[scallybert]

[...]Probably a silly question, but with it being such a critical part, I want to double check first.

Don't be silly..!

This isn't something to bodge.

[Planehazza]

Don't be silly..!

This isn't something to bodge.

Is that "don't do it" or "it's fine"?

[trillian]

If one fell apart I'd change the washers in both grips while you're at it. I have never heard of such a thing actually. Obviously that washer has to be very strong but that would not give me much confidence in the original part or a replacement thereof.

Is this on the Alees? I think I'd be inclined to replace them with something from a similar size heli that uses roughly the same size washer, like maybe a Trex 700 or something, the point being something with more of a known reliability.

Were they tightened to some insane amount of torque? I've just never seen a grip washer fall apart like that. Is it possible that the bolt has a bit of a wedge shape and split the washer? I think I would replace the bolts as well.

[Planehazza]

If one fell apart I'd change the washers in both grips while you're at it. I have never heard of such a thing actually. Obviously that washer has to be very strong but that would not give me much confidence in the original part or a replacement thereof.

Yeah that's the plan. I have several of the 'alternative' part so they at least can be paired. In case anyone's panicking, I wasn't planning on just replacing one side and having them mismatched

Is this on the Alees? I think I'd be inclined to replace them with something from a similar size heli that uses roughly the same size washer, like maybe a Trex 700 or something, the point being something with more of a known reliability.

Were they tightened to some insane amount of torque? I've just never seen a grip washer fall apart like that. Is it possible that the bolt has a bit of a wedge shape and split the washer? I think I would replace the bolts as well.

It's the Fusion 50. The model has had lots of flights and in honesty, little maintenance. Still though, like you say, I've never seen one of these fail. It wasn't overtightened that I'm aware of but the other side did take a lot of effort to undo. It may that I did over tighten them, but it's like 3+ years since I've had them out the model. Good call on the bolts, I'll do that.

[trillian]

It's the Fusion 50. The model has had lots of flights and in honesty, little maintenance. Still though, like you say, I've never seen one of these fail. It wasn't overtightened that I'm aware of but the other side did take a lot of effort to undo. It may that I did over tighten them, but it's like 3+ years since I've had them out the model. Good call on the bolts, I'll do that.

I guess just one of those freak things that happens sometimes. I did have a spare Outrage 50 feathering shaft, if I could find it and if it has the bolts and washers, I'd send it to you. But at the moment I don't know where it is (I saw it not too long ago though)

[kenny d]

If it was me I'd replace it with the washers you have , if it was still holding with the broken washer then hopefull it would be OK with your replacement washers , I'm assuming your not running insane head speeds , BUT if your worried at all send away for the correct ones , there's nothing worst than every time your flying your paranoid something is going to give , I'm sure someone will shoot me down for my opinion lol

[Peteski]

Being a mechanical engineer by profession I would say those replacement washers will be fine. As for why the original one broke, I would say it was probably due to stress cracks propagating from the sharp edge of the ID which does not appear to have a chamfer on your photo. Does the other black washer have any little hairline cracks in it starting out from the sharp edge on the ID?