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View Full Version : Any one tried curved dovetails? (on pupose)



1-800miner
01-22-2013, 10:18 AM
I have one of those do nothing machines with the two crossed dovetail slots and a handcrank connected to two male sliders that reciprocate.

I got to thinking about a round one with the sliders chasing themselves.

Maybe split the base,start the dovetail then clamp the base together to finish the circle?

rode2rouen
01-22-2013, 11:22 AM
Say what??


Rex

Jim2
01-22-2013, 04:44 PM
You got a lathe? ;)

Jim

1-800miner
01-22-2013, 05:45 PM
Lathe and mill.
I was thinking of the mill and rotab to cut a circular female dovetail groove in a block of something(wood for the first try).
Then cut a male counterpart at the same radius to go round and round in the base.
I have never seen a curved dovetail and wondered 'Why not?'

RLWP
01-22-2013, 05:50 PM
How do you arrange the gib strip?

Sounds a fun project

Richard

Lew Hartswick
01-22-2013, 06:06 PM
How do you arrange the gib strip?

Sounds a fun project

Richard

Gibs on a "do nothing" toy?????? Come on be serious. :-) What's the term.
"rattle fit". ? :-).
...lew...

Mcgyver
01-22-2013, 07:13 PM
the Christen drill grinder has one, or at least half of one.....the other side is flat. Its not a bearing, just part of adjustment mechanism. Does the Quorn grinder use one? or is that a round T slot?

Toolguy
01-22-2013, 07:38 PM
Angle plates and other rotary positioning tools often have a segment of a round dovetail in them. No reason you can't make your own. You could cut a hole in the bottom of the dovetail to put the chasing pieces in, then they would be retained by the crank from the top or you could plug the hole. If you make the dovetail at the top the same size or bigger than the dovetail cutter you could mill a circle with a regular end mill, then go down and in to cut the inside and down and out to cut the outside.

rohart
01-22-2013, 07:48 PM
The Quorn has what I'd call an annular T-slot. If we're stretching circular dovetails to include dovetail profiled T-slots, then I'm sure I've come across that before. It's possible the head on my Centec mill is secured in rotation by something like that. I can't see the advantage of that over genuine T-slots.

The only sensible application I can see for circular dovetails is when you want circular motion but you can't use the pivot area. Like those new-fangled motorcycle wheels with nothing in the middle.

metalmagpie
01-22-2013, 08:52 PM
I have never seen a curved dovetail and wondered 'Why not?'

You have apparently never seen the way the compound mounts onto a South Bend lathe apron. Male circular dovetail.

1-800miner
01-23-2013, 08:47 PM
I like the hole in the bottom idea.Now,how to seal it up so people wonder how it was made?

Toolguy
01-23-2013, 09:05 PM
Use a close fitting plug and sand or otherwise finish to hide the circle. Are you making this out of wood or metal?

1-800miner
01-25-2013, 08:41 PM
I think the first attempt should be wood.
I think I will cut the curved slot wide enough that the cutter can go in from the top. Put the sliders in with a hole from the bottom, plug the hole,then send the cutter back in to clean up the plug.