LAMPSguy
Well Known Member
Today I started some countersinking and almost immediately I noticed them coming out over size. Long story short, the cage was not moving, but the shaft inside it was out of round by .005 (confirmed with dial indicator and slowly rotating it). This runout made the bit itself move in an orbital motion and enlarge the hole (the cutting surface goes a bit too far down the guide for my taste, I have a photo below to describe the fix. I figured it out pretty quickly and switched to a better CS cage and finished up the work I had to do today.
So, I have a few holes on the outboard edge of my spar (last 5 rows maybe) that are just a touch too big all the way to alot too big. Please tell me the spar is not done and I just fill it with the rivet and it will squeeze into the void and be fine!
In the photo below, you can see the -3 rivet in a fresh hole with the worst hole directly beneath it. It is not quite the size of a -4 rivet, and it has not been CS too deep, just widened a bit.
In the next photo the rivet is inserted from beneath so you can see how bad it ended up. These are the holes that will take the skin dimples.
My thoughts are:
a)Drill it one larger to accept a -4 rivet (the CS should be fine for the skin dimple
b)Keep it and just us a a 0.5 longer rivet to fill the space
c)Something else I haven't thought of?
The picture above is the worst, there are maybe 5 total with the rest being less extreme as this picture. Additionally, they are the most outboard part of the wing if that matters. I plan to call Vans next week, but thought I would start here.
Additionally, there were a few others on the other wing where the CS ended up a little deep/ They are more deep by a few thousandths than the others, noticeably so, but there is still just a little bit of metal left to hold the rivet...it is not a knife edge I mean. The middle hole shows the amount of remaining metal underneath the CS...maybe .008" I am guessing.
So, I have a few holes on the outboard edge of my spar (last 5 rows maybe) that are just a touch too big all the way to alot too big. Please tell me the spar is not done and I just fill it with the rivet and it will squeeze into the void and be fine!
In the photo below, you can see the -3 rivet in a fresh hole with the worst hole directly beneath it. It is not quite the size of a -4 rivet, and it has not been CS too deep, just widened a bit.
In the next photo the rivet is inserted from beneath so you can see how bad it ended up. These are the holes that will take the skin dimples.
My thoughts are:
a)Drill it one larger to accept a -4 rivet (the CS should be fine for the skin dimple
b)Keep it and just us a a 0.5 longer rivet to fill the space
c)Something else I haven't thought of?
The picture above is the worst, there are maybe 5 total with the rest being less extreme as this picture. Additionally, they are the most outboard part of the wing if that matters. I plan to call Vans next week, but thought I would start here.
Additionally, there were a few others on the other wing where the CS ended up a little deep/ They are more deep by a few thousandths than the others, noticeably so, but there is still just a little bit of metal left to hold the rivet...it is not a knife edge I mean. The middle hole shows the amount of remaining metal underneath the CS...maybe .008" I am guessing.