DRDT-2 dimpling ?

gbumga · #1 01-04-2009, 06:36 PM

Hi, I've been using the DRDT-2, I am dimpling .025 and .016 right now and I've done the no preload 1/2 turn 1 turn past contact of the dies ect. I hold it up to reflect off a 4 ft light to see deformation and it is as it's supposed to be with no preload. If I preload all I see is the rivet sets a little deeper in the dimple. My ? is if the rivet is just a smidge recessed on no pre load and I get a good reflection why the heck would I want to add more preload like all the instructions says too. If it is setting ok with no preload what am I missing. I'm happy with the looks but according to the guru's I'm not setting up to specs. I get the halo of the die and the correct reflection, the rivet is recessed what else is there to it? Maybe the different make of dies act differently in the tool. I use Cleaveland. Gene

Auburntsts · #2 01-04-2009, 06:52 PM

I've been using my DRDT-2 basically the same way - a little turn past contact and have absolutely no issues and I've completed 100% of the riveting on my tailcone. If your rivets are sitting the dimples nicely and there's no cracks in the dimples, I say press and build on.

Dan Langhout · #3 01-04-2009, 08:13 PM

Quote:

Originally Posted by gbumga

Hi, I've been using the DRDT-2, I am dimpling .025 and .016 right now and I've done the no preload 1/2 turn 1 turn past contact of the dies ect. I hold it up to reflect off a 4 ft light to see deformation and it is as it's supposed to be with no preload. If I preload all I see is the rivet sets a little deeper in the dimple. My ? is if the rivet is just a smidge recessed on no pre load and I get a good reflection why the heck would I want to add more preload like all the instructions says too. If it is setting ok with no preload what am I missing. I'm happy with the looks but according to the guru's I'm not setting up to specs. I get the halo of the die and the correct reflection, the rivet is recessed what else is there to it? Maybe the different make of dies act differently in the tool. I use Cleaveland. Gene

Take a look at this photo . . . . .

I did this test on some .032" stuff after my horizontal stabilizer dimples turned out a little "dished" after using the DRDT-2 with 0 turn preload. The light reflecting off the metal tends to accentuate the effect a bit but it was obvious that 0 turns preload left a definite dish; 1/4 turn was better but still dished; 1/2 turn to 1 turn seemed to yield "dishless" results. I have run my DRDT-2 at 1 turn preload ever since and I get perfect dimples every time.

Note that there are two holes over on the left side of the photo that I did with the pneumatic squeezer just for comparison. The squeezer seemed to benefit from a bit of preload too!

airguy · #4 01-04-2009, 08:31 PM

That answers I questioned I raised in my own mind just today about my pneumatic squeezer using the dimple dies - I noticed a slight dishing on some thin material (.016, aileron skins) do to no preload. I'll change my technique to preload the squeezer just as my DRDT-2 is.

T.O.Craig · #5 01-04-2009, 09:59 PM

For what it is worth. I started with a drdt and had great luck with it, but I still believe that the C frame will make a much crisper dimple.

rzbill · #6 01-05-2009, 10:04 AM

The DRDT-2 is robust. Go ahead and put some pressure on the dies.
The top bar will definitely move upwards visually as it builds "spring pressure" during the dimpling operation.

I honestly don't pay attention to "turn of the screw" as much as I do the feel of the handle. The last few inches of handle travel should "pop" as the clamp toggle goes over center. I usually set it for a little handle snap with no skin in the dies and then "go to town".

I am at the 12000 rivet stage, and I have absolutely no complaints with the dimple crispness provided by the DRDT-2. Your photo of the 1 turn dimples is what you should expect all the time

llavalle · #7 01-05-2009, 11:28 AM

I also add a bit of preload. This way, I can get the handle to go all the way down(it pops down at the end) and all the dimple will look exactly the same.

Make sure you dies are aligned properly.

About the flexing : mine does no flex. I did not have 3/16 material so I used thicker steel. It weights a lot but works great.

It's not pretty but it cost me $60 total for the frame!