mustang wrote:
Don't you have the type of countersink with the little probe thingy that slides down into the pilot hole??
You mean one of these?
With those babies, the countersink can never walk anywhere.
Want to bet your tail kit on that? These absolutely
WILL walk on you, especially if you dont do it right as I did. If you look at those flutes its not hard to imagine that they will turn into side cutters especially if you have the depth a tad too deep. My problem was that I didnt realise when the cutter was finished and I continued to hold it in the plunged position. Occassionally my hand would move just a bit (that I couldnt detect) and it would cut sideways.
You can also screw up your part if you go in not perpendicular to the surface and then correct it. The countersink will happily cut its way around as it traces an arc while you correct. And note Im not talking much movement at all. Put that thing on the end of a drill and youve got a nice lever. It was hard to tell I was screwing up the part at all. And the last bit of advice is to make sure the tool is fully seated before you pull the trigger. I would just barely engage the tip and then start it allowing me to wiggle on the way down.
The new technique that worked very well was to seat it fully and press down. Pull the trigger and stop the second the air motor on the drill started to unload. That worked out well.
Good thing I never said I was a good builder. Maybe I can help save someone else from replacing a part though.
Also, the part may not be trash. You may want to increase the size of that one fastener. Do you think that is a possibility?
Thats why Im taking it to the local EAA meeting tonight. We have some patriarchs that have been A&P's and Tech Counseors for 20+. Ill see if they think its salvageable. Im not holding my breath because the one hole is enlongated towards the spar web. The others I think I could probably fix with "oops" rivets.
-- John