I spoke to Acme staff after sharing the above video links via email. The response, “… don’t see an issue with the videos you sent.”
Do others have movement in their stinger assembly? Am I nuts to be concerned?
If you lifted up on the tip of your wing and the fork and strut attach fitting had that much play would you call it a day if the strut manufacturer said all is good?:roll:
While not an engineer, I agree with Tcraft, the elongation is there, and not going to fix itself, and no matter how much you over tighten it, with the tail loaded, unloaded or standing on your head with washers jammed in between, the elongation is going to continue to get worse until the point of failure. That may take a million more hours, or it may happen next week, that is for folks like Tcraft to determine. As is, either the part should be deemed a consumable item and have a wear limit assigned to it, redesigned, or it will ultimately fail.
If you have a catastrophic issue as a result of a failed part you were having issues with I would think they would have to make good on it
That is a wonderfull notion .... if you dismiss the places this cub has already been, and will continue to go. I was on the ground in a saddle the outfit Ted used to? fly for in the Wrangles serviced to some degree, when one of the original T3's lost half of it stinger in a totally benign landing. The manufacturer stood by it, and 'made it good' (once he got back to the L48 on a pawnee stinger I flew in to him).... I hate to imagine how that would have played out if there wasn't another aircraft on the ground? I'm not being melodramatic, I guess now days most that venture that far out carry a sat phone, but all that country was 'airplaned' for years without the need of a satellite overwatch in the name of experimenting.
I generally think experimental owners need to cut manufacturers more slack than the certified crowd. After all, they are 'experimenting' which infers they will have some experience to gain along the way. But I also happen to think that when an experimental owner brings a valid concern to the table with a manufacturer, the manufacturer should probably be a little (or in this case a lot) more pro active. Because like Steve P alluded to there is a bunch already riding on it. It is my understanding that the T3 stinger (at least on that model) was addressed by a change in the alloy or design of that stinger.
Like the T3 failure, the one coming here is foreseeable, and preventable. permanently repairing what's there, is probably not in the cards, although maintaining (temporary and continuing fixes) what's there until it ultimately 'cycles out' may be.
Relying on 'squeezing' the ears to capture the heim will not solve the problem, and will likely lead to a new problem of compromising the ears. Not squeezing the ears, but simply relying on a press fit of the heims in between them is not going to solve the problem, it is only going to delay it some.
As long as there is any slop anywhere in the assembly (even .0001"), be it between the bolt and the fitting, the bolt and the heim, or the heim and the fitting, the problem will show again. If the slop needs to be there for manufacturing, or design, the only thing that will negate this problem is for the fittings to be of the same hardness as the bolt, and that just slows the process and spreads the wear over two items.
This failure is as easy to predict as the one that took out the original T3 stinger. To be fair, in that case it was partly the owners failure to realize the importance of maintaining an appropriate spring rate to the load so as to not bottom out the spring violently. which in turn tried to make a spring out of the swing arm. In this case, softer aluminum vs hardened steel, slop, and jarring. You don't even need to land tail first for this to happen, the jarring of taxiing will eventually do it, or there would be no need for a shock back there.
I will watch this one with interest. Mostly because I like outfits with good customer service, but also because I like watching problem solvers, and regardless of how big or small anyone perceives this to be, there is a problem, and there is no doubt a solution.
Take care, Rob
