RV7-Factory

One of the needed tools to complete an aluminum airplane that uses flush rivets is a “C-Frame” dimpler. There are several types. Once uses a mallet to smack the dimple dies together and then there is the DRDT-2. Instead of using a mallet, it uses a lever and a fulcrum to produce the pressure between the dies.

Since I have smashed enough fingers in my time with a hammer, I was VERY leery in taking a mallet to hit anything around my new airplane parts. Particularly around the skins that are typically dimpled in a “C-Frame.” There are plenty of guys that have good success, but I did not want to take the chance. Another problem with the mallet type is that if you slip while getting your swing ready, and move the  skins when you hit the plunger head, you can create the proverbial “Figure 8” hole in your skin. Basically, the force is great enough that you drill another hole with the dies right next to the hole you are actually trying to dimple. The DRDT-2 helps eliminate this as you can precisely place the pilot of the male dimple die in the hole and then just pull the lever down to actuate the plunger.

Before I got into any real heavy dimpling, I needed to mount it to something. When I bought the tool many months ago in preparation to build, I constructed a platform/table per the instructions provided by the tool manufacturer. However, the tool itself was never mounted to a bench. Some builders do, some don’t. Having three young children around, I don’t take chances with expensive and heavy tools that can be anchored. It is better to protect the kids and the tools.

When I constructed my benches, I modified the EAA1000 tables to essentially make a single 4’X6′ table. This left a 2’x4′ piece of ply left over. I figured I would simply make a smaller bench to hold my band saw and drill press. That idea lasted a short time when I wanted to place my bench vise and 12″ disk sander on the same bench. Needless to say, real estate was dwindling fast. So I built another 4’X4′ bench to make a 4 tool bench and mount all those tools to it. That left me with this 2’x4′ bench again. In shuffling around stuff when the Tail and Wing crates arrived, I set the DRDT-2 on this extra bench, and it became clear, the DRDT-2 has a home.

So I bolted it down today to the bench with some 5/16″ x 1.5″ bolts and then used some left over carpet from the house that was in storage and covered the support platform. Took me about 20 minutes and shortly after I got busy dimpling the Horizontal Stabilizer skins. The little bench that wasn’t enough earlier was perfect now. Worked like a charm.

So if you are trying to decide between a standard “C-Frame” mallet type dimple frame and a DRDT-2, I cannot comment beyond what I have read on the standard, but I can tell you, the DRDT-2 is great and works as designed. I hope to get my lovely wife on it for the Vertical Stabilizer skins. I am not sure I would say the same if she was using a mallet. 😉