Dimpling

[mbetti]

Hi,
I'm new to the group and read at another posting about dimpling and countersinking. What's the difference? I thought they were the same.
I just finished a Murphy Elite and now in process of building an RV10 tail kit for a friend. The Murphy used all pulled rivets, so this process is new to me.
Mike

 

[Geico266]

Welcome to VAF

Dimpling is deforming the metal (skins, stiffeners, ect.), counter sinking is removing the metal with a counter sink drill.

 

[mbetti]

Ok thanks, what screwed me up was someone said they dimpled instead of countersinking. I thought it was the same thing, but understand now.
Mike

 

[rvbuilder2002]

Proper terminology....

Actually both processes are countersinking.

Cutting away material is referred to as Machine Countersinking.

Making a formed dimple in the skin or flange of a sheet part is referred to as Dimple Countersinking (or sometimes form countersinking).

 

[wv4i]

CS vs Dimple

See Van's Construction manual, Section 5, re thickness of various materials and deciding whether to countersink or dimple.

 

[AX-O]

Actually both processes are countersinking.

Cutting away material is referred to as Machine Countersinking.

Making a formed dimple in the skin or flange of a sheet part is referred to as Dimple Countersinking (or sometimes form countersinking).

That took me a long time to figure out. I still get confused once in a while when I read Vans instructions.

 

[Rick S.]

Mike,

I think sometimes we forget how many questions we had when we started. I'll try to provide a tad more info than the other posts . Dimpling is usually done to the thinner stock using dimple dies. The die are made up of one male and one female and come in sizes relative to the rivet being used. Once the hole is drilled and deburred, the dies are pressed together in the hole using either a hand squeezer, pneumatic squeezer or C-frame (I know the DRT2D???why confuse ) if both pieces are thin enough then both get dimpled with the same dies, if the other piece is thick enough or to heavy to dimple then it is machine countersunk to accept the dimple from the thinner stock. This is done with a machine countersink which has a sized cutter that cuts and removes metal to make the countersink. This tool is adjustable in depth. There are variables for two or three sizes/pieces being riveted together and as the others have said the Van's manual gives you more info on this. You are correct that they are both forms of counter sinking, just depends on the thickness and the application on which to use.

The archives here should also have a bunch more info on this, and to venture into the danger zone, Dan Checkoway did a great series of basice metal working in Kitplanes magazine , it would be well worth the cost of the back issues for anyone just starting out.

I hope I understood you question and didn't over simplify the answer .