Dimple Dies

[Captain Avgas]

Your problem is the DRDT-2...not the dimple dies. What you require is dimples with well defined angular shoulders...not rounded shoulders.

There are two ways to form dimples. Firstly you can do it with a device that applies a static pressure (like the DRDT-2) and secondly you can do it with a device that applies a dynamic pressure (like a C-throat). The first is a squeeze, the second is an impact. Only the impact will give you truly well defined angles at the shoulders as opposed to curves.

If you want show quality deep seated rivets you need to use a C-throat and preferably give each dimple 2 impacts.

I know the DRDT devices are popular...they?re easy to use, convenient, and quiet...unfortunately they just don?t produce high quality dimples.

Get hold of a C-throat from someone or go over to someone?s place that has one and do some dimples to compare....you?ll see the difference immediately.

[JDA_BTR]

Bob, I imagine a couple hundred people are going to disagree after I do. But to each their own. The speed and excellent results I get from the DRDT-2 make me wonder how anyone does it different. I don't think my shoulder would take a few hundred double whacks a few afternoons in a row. I also doubt that many production aircraft are built with hand-dimpling processes.

[RussellT]

Originally Posted by Captain Avgas

Get hold of a C-throat from someone or go over to someone?s place that has one and do some dimples to compare....you?ll see the difference immediately.

Plus 1 to this, use a steel hammer and your Cleaveland dies, yes it's noisy and slower but... best in show dimples!
Russell

[MS1095]

Originally Posted by RussellT

Plus 1 to this, use a steel hammer and your Cleaveland dies, yes it's noisy and slower but... best in show dimples!
Russell

I agree. The C-Frame a big @ss hammer with one firm solid whack and you will have perfect dimple everytime. It took me a bit of time and practice to figure this out. Don't be afraid of hitting it too hard.

[wirejock]

Count me in. Need a poll. C-frame and a 2lb dead blow. Harbor Fright lifetime warranty. I blew up four of them.

[1001001]

Originally Posted by Captain Avgas

Your problem is the DRDT-2...not the dimple dies. What you require is dimples with well defined angular shoulders...not rounded shoulders.

There are two ways to form dimples. Firstly you can do it with a device that applies a static pressure (like the DRDT-2) and secondly you can do it with a device that applies a dynamic pressure (like a C-throat). The first is a squeeze, the second is an impact. Only the impact will give you truly well defined angles at the shoulders as opposed to curves.

If you want show quality deep seated rivets you need to use a C-throat and preferably give each dimple 2 impacts.

I know the DRDT devices are popular...they’re easy to use, convenient, and quiet...unfortunately they just don’t produce high quality dimples.

Get hold of a C-throat from someone or go over to someone’s place that has one and do some dimples to compare....you’ll see the difference immediately.

I think I disagree with the assertion that the DRDT-2 creates inferior dimples due to some inherent flaw. My DRDT-2 creates excellent dimples. The trick for me was making sure to set it up right so that it compresses properly. When I received mine (purchased from another builder), it made rounded dimples, but after adjustment, which I only ever had to do once, it is great. The ram guide and the lower die holder have to be aligned well, and the ram has to be set to go over center properly. It can take some effort to move the handle with the ram set up right, but it works great. I can apply more force with the DRDT-2 than with my pneumatic squeezer and it makes better dimples.

[Captain Avgas]

Originally Posted by JDA_BTR

Bob, I imagine a couple hundred people are going to disagree after I do. But to each their own. The speed and excellent results I get from the DRDT-2 make me wonder how anyone does it different. I don't think my shoulder would take a few hundred double whacks a few afternoons in a row.

Dudley, the problem with this type of thread is that often the opinions simply come down to defence of choice. Another problem is that people give opinions when they have no relativity because they have only used one technique.

This thread was started by a builder who is using a DRDT-2 and is unhappy with the quality of his dimples. It?s a very common occurrence...just look back through the archives.

I?m a TC so I see many RV projects and some of the builders are using a DRDT and most are happy with the tool and with the quality of the dimples that it produces. But mostly they just don?t know anything different. They just don?t know what they don?t know. Quite often they?re satisfied with dimples that I personally would not tolerate. But it?s not an issue of safety...it?s just a matter of how fussy one is.

I?ve used a C-Frame, a pneumatic squeezer, and a DRDT, and there is no question in my mind that the C-Frame produces a dimple with better definition thus ensuring a more deep seated rivet. This is particularly true in thicker aluminium gauges.

Finally, there are a couple of different issues being discussed here and the two are being confused. One revolves around convenience, and the other centres on quality. No doubt the DRDT is very convenient...but it is the C-Frame that produces the better quality.

Originally Posted by JDA_BTR

I also doubt that many production aircraft are built with hand-dimpling processes.

Maybe, but I doubt that many production aircraft are built with DRDTs either.

[Tom023]

Originally Posted by Captain Avgas

Your problem is the DRDT-2...not the dimple dies. What you require is dimples with well defined angular shoulders...not rounded shoulders.

“The thread was started by a builder who is using a DRDT-2 and is unhappy with the quality of his dimples”...using the Cleavland dies. Maybe it’s a combination of the Cleaveland dies and the DRDT-2 because the OP clearly stated he doesn’t have the problem with the Brown dies and the DRDT-2. I used both a DRDT-2 and C-frame, as well as Cleaveland and other brands of dies and had the same issue as the OP with the Cleaveland dies. My .02 keep the DRDT-2 if you are satisfied with the results...ditch the Cleaveland dies since they are not working well for you. There are only a few dimple aficionados that will scrutinize your dimples under a magnifying glass, but what is important is how they look to you not them.

[JDA_BTR]

I suppose DRDT vs C-Arm could be a primer war... I agree do what works...

I had a tour at the GenDynamics Fort Worth jet factory when my HS friend and college roommate went to work there; amazing place (1986). I wish I could go back now and see how they do all the things I do on a build. I took the Boeing tour and while it was amazing we were a long way from the work. In 86 I got to walk the shop floor for a day; so cool. I'd like to see how the factory deburrs, for example. Thread creep......

[vlittle]

Originally Posted by Tom023

?The thread was started by a builder who is using a DRDT-2 and is unhappy with the quality of his dimples?...using the Cleavland dies. Maybe it?s a combination of the Cleaveland dies and the DRDT-2 because the OP clearly stated he doesn?t have the problem with the Brown dies and the DRDT-2. I used both a DRDT-2 and C-frame, as well as Cleaveland and other brands of dies and had the same issue as the OP with the Cleaveland dies. My .02 keep the DRDT-2 if you are satisfied with the results...ditch the Cleaveland dies since they are not working well for you. There are only a few dimple aficionados that will scrutinize your dimples under a magnifying glass, but what is important is how they look to you not them.

There are three variables here:
Dimple dies, the DRDT-2 and builder technique.

They are interconnected and not independent. If the Cleaveland dies are a different thickness, even by a few mils, the DRDT-2 would need to be adjusted to make good dimples. A c-frame does not have this issue, but technique is more important. I would get an experienced builder involved pronto, and get the diagnosis within 5 minutes.

V