[December 10, 2005]

Today I went to my old house and picked up my bench grinder and drill press. The drill press was a bear to move...the things weighs a good 150 lbs. Anyways, I lugged those things into my basement and set them up.

I didn't have that much time to work on stuff tonight, so I thought I could at least get the dimpling done on the spars and ribs. I first tried the hand squeezer since I had it setup. I did both right spars with the hand squeezer and my hands were killing me. It then occured to me to break out my pneumatic squeezer. I setup that thing, and did the rest of the dimpling in no time. I have to say that it took me about 10 mins to do two spars with the hand squeezer, and then 10 mins to do all the ribs and the other spars with the pneumatic squeezer.

One bit of advice I got from a bulletin included with my pneumatic squeezer from Clear Air Tools was to NOT hook it up to an automatically oiled line. It stated that the oil would wear away the grease that was in the squeezer. The recommended maintenance is to re-grease when it needs it. When I started using my squeezer, it used significantly less air than the drill does. It makes me understand why the drill needs oil and the squeezer doesn't.

One thing that I notices was each of my dimples had a slight circle on the metal where the dies came together. I do not know what caused this. I tried backing off the distance between the dies, but didn't make the dimples deep enough (I tested with a AN426 rivet). This doesn't bother me too much for the insides of the HS, but I am a little concerned about marring up the outside of the skins.

I asked the following question:

Hey guys, I just started dimpling my ribs and spars for my HS and one thing that concerned me was there was a slight imprint of a circle in the metal after I dimpled it. I do not remember this from my RV builders class, but then again, that was a while ago. I tried using a pneumatic and hand squeezer and I got the slight circle with both methods. I don't think it is a big deal for the inner parts, but I am concerned with having these slight circles on my skins when I use a DRDT-2 to dimple them. Any advice on dimpling the skins with the DRDT-2? Thanks, Mike Bullock http://www.rvplane.com


They are in mine too. Just a small mark in the very soft Alclad, doesn't penetrate the Alcald though. See it in a lot of RV's. Drive on! Les Dial Manufacturing Engineer Staff F/A-22 Manufacturing Engineering ----------------------------------------------------------------------- Circle = normal = done right )_( Dan RV-7 N714D (721 hours) http://www.rvproject.com ----------------------------------------------------------------------- You WANT to see the circles. I means you have done it right !! Keep on pounding !! Simon RV7A PH-SCP (reserved) ----------------------------------------------------------------------- Hi Mike, You are doing good! How not to dimple: http://caura.dyndns.org/gallery/How-Not-to-Dimple Happy Dimpling! //elson Austin, TX RV-7A - Fuselage (center section) ----------------------------------------------------------------------- Mike Try one a bit looser, with no circle. Hold it up to the light & you will see that the skin is not flat around the dimple. As everyone has said, the circles are good! Bill Swaim RV7 Slow Build Fuselage N615KS Reserved

My drill press finally moved into the shop. It is adjustable speed from 380 - 8550 RPM.

Old school craftsman bench grinder.

Using the yokes, it was impossible to get the ends of this one rib...i think it is the outer rib. So I just bent the flanges out, dimpled, then bent them back to perpendicular.

This is my most favorite tool yet! I am glad that I hand dimpled some of the holes first to appreciate how nice this is.



Last Modified: September 4, 2017