Axle broke

[Jim Lee]

Result: no damage (other than the axle).

Haven't flown the Phoenix for a few months, too busy flying the EB29R in the World Championships (6th place- Open Class).

Swapped out the regular wheel and tire for the large wheel and bush tire (26 inch).  May have over torqued the axle nut.  Did not install the wheel cover bolt which in retrospect fills the hollow end of the axle, and provides additional strength.

While taxiing, heard a faint "pop" through the headset.  Thought, that's weird, haven't heard anything like that before.  Pulled into a nearby tie down spot, shut down, got out, and found the broken axle.  Nothing was keeping the wheel and tire from falling off.  If this had happened on take off or landing......  Lots of damage.

I will place an order for both axles and a couple of brake discs with Kaspar in Prague.  Kaspar builds the wheels and brake systems for the Phoenix.

The purpose of this note is to make everyone aware of the potential problem, and ask if anyone needs brake parts which I can order and piggyback onto my order with them.  I think that perhaps the Boulder group had a similar occurrence a few years ago?

Cheers,

Jim

[Andreas]

Hello Jim,

Something similar happened to me a few years ago. I was on my bush wheels and had just changed back to the standard wheels. My mistake was that the washer installed on the Phoenix (mine is 49U15) has an orientation (marker). If you flip it you create a risk that the washer is in contact with the cage of the bearing and your're actually tightening the nut when you roll forward on you RH wheel. This is leading to a fracture probably right after the thread at the weakest point. Is this the same that happened to you?

Fly safely, Andreas

[Jim Lee]

Hi Andreas,

I examined the washers and both were correct.  My A&P thinks that the larger tires put more side twisting on the nut than the smaller tires, and may have contributed to the failure.  He also says that the axle should be solid instead of hollow.  The axle is hollow all the way through.

I have tried to order new axles from Kaspar in Prague but they don't answer me.  I will continue to try to reach them.

I will also have my local machine shop (owned by a pilot of a Columbia 300) make me some solid axles to replace them.  It may be that I can have several made to reduce the overall price per unit.  Anyone else out there interested in a set?

 

[Tom Clary]

I am in. 

 

Tom

[Alex Ress]

This might be one of those items where if you have to ask the price, you shouldn't be in the shop but...  if your shop has a ballpark figure, please let us know.

If you're considering it, I am too.  Thanks for sharing the event and picture with the group.

[Andreas]

Hello Jim, is this the washer that's been used on your U15?

[Jim Lee]

Yes, that is the washer.  I just got the quote from Burns Machinery, and to make 10 axles (that are solid, not hollow inside), the cost is $275 per axle.  I gave them the go-ahead.  The current price for an axle from Kaspar is $195 USD.

I have two Phoenix owners who want axles.  So there are 2 more pairs available.  Let me know if you want a set.

Cheers,

Jim

[Garry Farris]

I will take a set of axles..

Garry