Cutting dovetails-Machinery's Handbook and video

[Janderso]

This is the way I do it. I took plenty of math and am perfectly capable of doing it, but being visual I like to see the situation. Still using the command line in Acad 2000, never cared to learn all those stupid symbols.

It comes from being lazy, I'll put a lot of thought into doing less work.

Unfortunately I am 100% analog. No CAD in my blood.

 

[Janderso]

I suspect some other folks are going to make their own versions of this. It will be interesting to see what they come up with!

One thing I like about the design is that it pushes the workpiece down as it's tightened. Sort of a mini-Kurt scheme, although the fact that the movable jaw slides down the side of the workpiece a little might be an issue for some (there's a potential for marring the edges).

A three-piece clamp with a vertical-moving wedge in the middle would address that, at the expense of a more complex and bulkier design. However, the issue is nonexistent with Hall's version so I think it wins in this regard.

I agree with you sir, pushing/forcing the part downward couldn’t be all bad.
I hesitated in my planning to harden the A2 stock after machining etc.
Then I thought about the part being held and possible damage from the sliding clamp.
Also, galling could occur where the pieces slide against one another.
I therefore decided to harden and grind. One could place a copper shim against the part?

 

[homebrewed]

One could place a copper shim against the part?

Yes! A good solution when you need it. I like simple solutions

 

[shell70634]

I'm new at this so I get to ask stupid questions. Is there a difference in holding ability by making the female dovetail piece stationary and the male piece clamping? I watched the video without sound so I don't know if he explains it. I noticed the video is different from the drawing.

 

[NCjeeper]

I just use a metal shaper.

Does your shaper have auto downfeed? If mine did I would probably use my shaper also.

 

[homebrewed]

I'm new at this so I get to ask stupid questions. Is there a difference in holding ability by making the female dovetail piece stationary and the male piece clamping? I watched the video without sound so I don't know if he explains it. I noticed the video is different from the drawing.

Well, the drawing does say "Rev 2". Maybe the video shows the making of a previous version.

The significant difference I see is that the angle changed. The video says "something around 10 degrees" but the drawing indicates 5 degrees. The smaller angle would have greater mechanical advantage, so perhaps V0 wan't quite up to snuff in its clamping force; or maybe it was done just to reduce the amount of machining (the shallower angle = less material is removed).

The sex of the dovetails won't make a difference as far as clamp forces go.

 

[mcostello]

No auto down feed, just pull up a chair and do some auto mechanic work. (Put My rear end in a chair.)

 

[Janderso]

I'm new at this so I get to ask stupid questions. Is there a difference in holding ability by making the female dovetail piece stationary and the male piece clamping? I watched the video without sound so I don't know if he explains it. I noticed the video is different from the drawing.

I don’t think it would make any difference. Good question though.

 

[Janderso]

I got the pieces cut. I’m in the process of squaring the pairs to each other.
The Pragmatic Lee video showed him cutting the female first but he didn’t really go into how he measured the male piece before he started to cut the dovetail.
I plan on doing the same method but I’ll know the math before I start the male side.

 

[homebrewed]

I got the pieces cut. I’m in the process of squaring the pairs to each other.
The Pragmatic Lee video showed him cutting the female first but he didn’t really go into how he measured the male piece before he started to cut the dovetail.
I plan on doing the same method but I’ll know the math before I start the male side.

Yeah, I noticed the absence of information regarding the male part as well. I guess that's an "exercise left for the student ", right?