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[January 7, 2006]


I finished dimpling the skin tonight. Next was onto dimpling the trailing edge so I can countersink the ATX wedge. I was dimpling using the pneumatic squeezer and tha standard yoke set. After 5 dimples, I noticed that the dimples looked offset - like the hole was 1/32's off center. I looked at the ribs and spars and they looked equally bad. An aweful thought crossed my mind - are all of my dimples in the whole project screwed up?

I started with the basics - I looked at how the dies met in the pneumatic squeezer. They were off - by about 1/32's of an inch. I then got out a straight edge and saw that the yoke itself looked like it was every so slightly twisted. Next I got out the longeron yoke and tried that - it worked fine. Must be the yoke! So I email Clear Air tools with my problem, and also the RV7 yahoo group to see if there is any harm in this offset.

After dimpling the rest of the trailing edge with the longeron, I started to find my countersink depth. I did a little, and it wasn't enough. I did a little more and it just wasnt looking right. Hmmm. I got out the "test" countersinking plate that I made the other day. The #40 hole slid right into my countersink - in fact the countersink was a little too much. Then I looked at how my test piece looked to the real deal. The test piece has a nice #40 dimple in it, and the trailing edge had a big old nasty dimple...looked like a #30 female die.....DOH! Yup. I had a #40 male dimple die and a #30 female dimple die. As bad as that might sound, it could be A LOT WORSE if I did it the other way around. So I took out that nasty #30 die, slammed in a #40 and did a test correction. Wow, looked great. I dimpled the rest. Looked great! I am glad I figured this one out when I did. My only problem could be that I might of countersunk 1-2 holes too much on the wedge piece trying to get it to match up to a #30 dimple. I am not going to sweat one or two bad countersinks that are just a little too deep.

That was enough of a scare for the night. Time for a beer.

This is a pic of my offset dimple problem. It is hard to see, but there is definitely an offset.


This is another shot of the dimple problem. My old school camera is selective about using the flash tonight.

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