Lesson Cutting Male and Female Dovetails in 6061-T6?
- seal killer
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Lesson Cutting Male and Female Dovetails in 6061-T6?
All--
I have been thinking of making my life a little easier regarding the little machines I build that run around the floor . . . and sometimes outside, as well. Construction, cosmetics, and flexibility could be improved if I had some kind of modular system from which I could build frames. So, I am thinking about using 6061-T6 cross-pieces with male dovetails and female "connectors."
Too bad I've never cut a dovetail!
Here is my preconceived notion of how to do it. (I've read about it a little and should have read more but can't find what I read then, NOW.)
The slot should be cut with a regular end mill to depth. The dovetail cutter then cuts first one side of the slot to produce the dovetail and then the other.
How big a bite do you take with, say, a HSS dovetail cutter? Do I use the same cutter to create the male portion by taking material from opposing "outsides" until they look like the female, only different?
Thanks!
--Bill
I have been thinking of making my life a little easier regarding the little machines I build that run around the floor . . . and sometimes outside, as well. Construction, cosmetics, and flexibility could be improved if I had some kind of modular system from which I could build frames. So, I am thinking about using 6061-T6 cross-pieces with male dovetails and female "connectors."
Too bad I've never cut a dovetail!
Here is my preconceived notion of how to do it. (I've read about it a little and should have read more but can't find what I read then, NOW.)
The slot should be cut with a regular end mill to depth. The dovetail cutter then cuts first one side of the slot to produce the dovetail and then the other.
How big a bite do you take with, say, a HSS dovetail cutter? Do I use the same cutter to create the male portion by taking material from opposing "outsides" until they look like the female, only different?
Thanks!
--Bill
You are what you write.
-
- Posts: 3803
- Joined: Wed Feb 21, 2007 9:21 pm
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I leave some 1/32 per side on the width for finish and go some .015" to .020" deeper.
The final dove tail will be the same amount less deep.
That will leave clearance in the center for debris to be in and the friction area much smaller than the whole bottom surface.
The final dove tail will be the same amount less deep.
That will leave clearance in the center for debris to be in and the friction area much smaller than the whole bottom surface.
There are no problems, only solutions.
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa
-
- Posts: 3803
- Joined: Wed Feb 21, 2007 9:21 pm
- Location: Vallejo California
Samples
Here are some sample pictures of a dovetail cut out of a piece of 4140.
There are no problems, only solutions.
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa
- seal killer
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- Joined: Sat Aug 18, 2007 10:58 pm
- Location: Ozark Mountains
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Bill;
I figure the less work the dovetail cutter does the better for two reasons.
First, the less work the cutter does the longer it will stay sharp.
Second, Dovetail cutters seem to like pulling out of the collet or lifting the workpiece thus changing the depth and ultimately the size of the dovetail.
I have machined a lot of dovetail assemblies. Dovetails are just about the most challenging thing to machine. The depth is critical, width is critical and straightness is critical. I have ground a few dovetails but that is not always an option.
Vise I made with dovetail slide.
"Y" axis of my CNC mill.
Jim
I figure the less work the dovetail cutter does the better for two reasons.
First, the less work the cutter does the longer it will stay sharp.
Second, Dovetail cutters seem to like pulling out of the collet or lifting the workpiece thus changing the depth and ultimately the size of the dovetail.
I have machined a lot of dovetail assemblies. Dovetails are just about the most challenging thing to machine. The depth is critical, width is critical and straightness is critical. I have ground a few dovetails but that is not always an option.
Vise I made with dovetail slide.
"Y" axis of my CNC mill.
Jim
Tool & Die Maker/Electrician, Retired 2007
So much to learn and so little time.
www.outbackmachineshop.com
So much to learn and so little time.
www.outbackmachineshop.com
- seal killer
- Posts: 4696
- Joined: Sat Aug 18, 2007 10:58 pm
- Location: Ozark Mountains
-
- Posts: 2281
- Joined: Sat Jan 04, 2003 8:33 pm
- Location: 40 Miles West of Chicago/near DeKalb
- Contact:
Bill;
Machining dovetails takes a little practice but it is excellent experience. They usually end up a hand fit.
I usually use a black felt tip marker and ink up one of the dovetails. Try to mate the two dovetails then examine places the ink was removed to identify interference. File, stone or mill the high spots then try to reassemble. Watch for interference in the sharp corners.
Take your time. You may attempt mating the dovetails 15-20 times before they mate.
The problem with dovetails is you can remove more material but you cannot put more on.
Jim
Machining dovetails takes a little practice but it is excellent experience. They usually end up a hand fit.
I usually use a black felt tip marker and ink up one of the dovetails. Try to mate the two dovetails then examine places the ink was removed to identify interference. File, stone or mill the high spots then try to reassemble. Watch for interference in the sharp corners.
Take your time. You may attempt mating the dovetails 15-20 times before they mate.
The problem with dovetails is you can remove more material but you cannot put more on.
Jim
Tool & Die Maker/Electrician, Retired 2007
So much to learn and so little time.
www.outbackmachineshop.com
So much to learn and so little time.
www.outbackmachineshop.com
- seal killer
- Posts: 4696
- Joined: Sat Aug 18, 2007 10:58 pm
- Location: Ozark Mountains
-
- Posts: 3803
- Joined: Wed Feb 21, 2007 9:21 pm
- Location: Vallejo California
If you need a dovetail that need a better fit than what the cutter can give, then consider lapping the two parts to fit.
You can lap the gib as well. Lots of elbow grease !!
You can lap the gib as well. Lots of elbow grease !!
There are no problems, only solutions.
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa
When working to a print with tolerances on it I always like to cut the female first so I can measure it with dowel pins and gauge blocks. I guess fit is more important than size to you unless you want to interchange you're parts you make.
Last edited by CANINDUST on Wed Feb 10, 2010 6:15 pm, edited 1 time in total.
There is 1000 ways to skin a cat
Some people grind a tool and work all day, some work all day grinding tool.
There is a difference between scratching your a__ and tearing is to pieces.
Some people grind a tool and work all day, some work all day grinding tool.
There is a difference between scratching your a__ and tearing is to pieces.