What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Drilling out tie down ring

F

FLY6

Well Known Member
Patron
I believe I have read forums on using tie downs to jack the plane but that is what I have down for 5 years. Well yesterday while doing my annual just before lowering the plane, not even touching the plane, down she came. A small dent where the ring bent over and pushed in the lower wing skin. I tried to straighten he ring enough so I wouldn't further damage the wing. You guessed it, the ring broke. I have started to drill the bolt but was wondering while drilling this material( I think stock ring) should I drill slow, fast or what is the best method. Thanks for your help, Al
 
The ring is steel. Standard protocol is drill steel at slow speed, high pressure, with a coolant if needed. Drill aluminum at high speed, low pressure. The stock tie down rings are fairly soft steel, and could drill fairly easy. I decent easy out in a 1/8"-5/32" pilot hole should do it.
 
In general stainless steel must be run slow with high feed, otherwise you get work hardening and life gets very difficult.

Steel generally medium speed, medium feed.

Only time I drill with high speed is with very small drills.

I believe my hook is steel, not stainless but I could be wrong and you could have something different also.
 
Thanks

Thanks guys, I beleive it is steel so I will continue to drill and use an easy out as suggested. I didn't want to keep drilling until I knew because I didn't want to end up work hardening the bolt.
 
Always error on the slower speed if your not sure. Not too much can go wrong with too slow aside from lack of progress.
 
May I suggest you get a left twist drill to do this, if it catches it will try to force the broken off shank deeper into the mount, and in many cases will actually remove the broken stub.

You really do not want to have to replace the mount.
 
Another method

I've had excellent success walking broken bolts out if there's no tension. Usually the bolt leaves a ridge where it breaks. Use a tiny pin punch and tap lightly on the ridge with a small hammer. Position the punch so it makes the bolt rotate the direction you want. Walk it out enough to grab the end and back it out.
I actually got a broken head bolt out that way. Only took a few minutes.
 
The big box stores are selling kits with names like 'speed out' and 'grabit' that have various sized left hand bits on one end and an easy-out on the other of each tool. Might be quicker than M-C.

The upside left hand bits is that they don't try to tighten the broken bolt as they cut. Sometimes the bolt will actually back out as you drill.

Charlie
 
To add to what Larry said, I've sometimes had good luck taking a Dremel tool and cutting a slot in the broken bolt and taken it out with a screwdriver.
 
I saw on this site how one poor RV owner's tie down bolt broke and the jack went through the bottom of his wing. So I changed my method to jacking like in the picture below.

35krkgw.jpg
 
I have a couple modified bolts I put in the tie-down locations. They are half-spheres (mushroom looking) and sit in the cup of the ram on the jack. Made them by chucking up a bolt in a drill and taking it to the grinder. I think bolts would be a lot stronger than the ring since they are supposedly of a known strength (grade 5 or 8 or whatever). I have no idea what stuff my rings are made of, they were bought form a reputable vendor that advertises on this site, but trust the rings better in tension (functioning as a tie-down) than compression or side loading. (Note-I do think side loading needs to be limited as much as possible to keep the jack from perforating the wing, but there's bound (pun intended :D) to be some.)
 
Bolt out

Thanks everybody for your response. A drill with an easy out worked fine. The stub was not in very tight so it was really a non issue.

Al
 
You must log in or register to reply here.
Back
Top