Check this at your next annual

[Dave12]

Originally Posted by PilotBrent

Add me to the list of broken brackets. Saw it this weekend (420h) but it may have been there in the past and I never noticed it. Credit this post for even knowing where to look. Really don't think I have excessive vibration although I've never had the propeller balanced. Might be an argument to do that.

Never balanced eh?

[RFSchaller]

FYI my prop was dynamically balanced and the little bugger still broke!

[PilotBrent]

Been meaning to post this. I went ahead and fabricated a very basic replacement ignition coil bracket from some scrap aluminum angle I had in the hanger. But, before installing it a friend at the airport dropped by, who has a machine shop and also an amazing basement workshop, and insisted that we fabricate a more durable replacement out of 4140 steel that would be less prone to break again. I shot this short video for our EAA chapter (we're going to visit his basement in a few months). He added a third side to the bracket to strengthen it, but (not in the video) I needed to remove much of that in order to be able to get a small wrench in there to reinstall the bracket on the engine. Those of you have have had to make this repair know how tight it is in there.

Over engineered. YES. But was really interesting to see a skilled machinist in action. After weeks of maintenance in abnormally cold spring weather, several SBs, and this last repair, the annual inspection that wouldn't end is finally done...

P.S. if you check Lockwood's website, the replacement bracket (# 851260) can be purchased for something like $11 (surprisingly cheap compared to most Rotax part prices). So if this one fails, I'm obviously just going to buy the next one.

https://youtu.be/dFLTrf4WRl4

[Dave12]

I don?t think that one wil break pal! Obviously this is the gent you were telling us about?

[wjb]

Great video! I'd love to have access to a shop like that.

[Dave12]

Originally Posted by wjb

Great video! I'd love to have access to a shop like that.

If it?s who I think it is, all that great equipment is in his basement. Impressive!

[EXflyer]

I see a great item taking care of a problem nothing over engineered here just done to fix a problem like Rotax should have done years back. The metal remaining is more than enough to take care of the problem. Well done and hey guys, a small milling machine and a mid sized lathe are in my garage and have been used on many things other than my large scale trains.

[RFSchaller]

My German cousin is a ROTAX mechanic. He got me a couple of replacement brackets, and he said this issue is not common to other aircraft types. Seems weird we are so ?blessed? in the RV-12 world.

I took all the dimensions on the ROTAX parts so I can make replacements in the future.

[Piper J3]

It looks like most ignition mounting bracket failures are the stubby 90 degree brackets on the back of the ignition coils. I have not had this failure, but now at my latest oil change (325TT), I noticed the long front bracket has failed just below the 90 degree bend. This is PN 29 in the attached drawing. The bracket is 0.080” Stainless Steel. I have fabricated a new bracket from 1/8” mild steel and added 1/8” to the overall width for additional strength.

Attached photos show broken bracket and 1st iteration of new bracket to test fit. A second more professional bracket is now installed on the engine.
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[Dave12]

It?s a shame you don?t know Brent?s buddy.