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Hello,

I recently bought a dovetail cutter for my Unimat but
having never used something like this before, I want
to make sure I will not screw up and/or damage the tool.
(they are expensive !)

I was planning to just practice with something soft
like brass before I move on to aluminum. The dovetail
has a .5in base. I don't have a collet but I made a simple
end mill holder for it.

What is the best advice you can give me before I
turn on the switch on the Unimat?


thanks in advance,

Norm

To cut dovetail slots, first use an ordinary endmill to cut most of the metal away. Then cut the DT one side at a time. On the Uni, this is best done in small increments. Brass is easier to cut, as a rule, than some Al alloys, especially the soft gummy stuff found in hardware stores. On Al, be sure to use a cutting fluid. WD-40 works, and there are lots of others.
Mert

mertbaker@...

On Fri, 26 Jan 2007 03:08:56 -0000, you wrote:

Hello,

I recently bought a dovetail cutter for my Unimat but
having never used something like this before, I want
to make sure I will not screw up and/or damage the tool.
(they are expensive !)

I was planning to just practice with something soft
like brass before I move on to aluminum. The dovetail
has a .5in base. I don't have a collet but I made a simple
end mill holder for it.

What is the best advice you can give me before I
turn on the switch on the Unimat?

For cutting an inside dovetail, one with the walls slanting in, about
the only way to cut it is to cut a slot for the shaft first, then use
the dovetail cutter.

For an outside dovetail, with the walls slanting out. I milled to the
outside dimensions first, then cut in very gradually.

I'd use a rigid setup, and I'd use that end mill holder you made.

For brass, well, brass is odd. Aluminum would be cheaper to work
with, and more predictable. Just use some cutting fluid to keep the
chips from gumming up the cutter and pressure welding.

I used one in steel to make an adjustable tool holder. Since the
inside slot was wider than the cutter, I got away with milling a slot
and taking the whole thing gently.


Harvey

thanks in advance,

Norm





Yahoo! Groups Links

On Fri, 2007-01-26 at 03:08 +0000, Norm wrote:

Hello,

I recently bought a dovetail cutter for my Unimat but
having never used something like this before, I want
to make sure I will not screw up and/or damage the tool.
(they are expensive !)

I was planning to just practice with something soft
like brass before I move on to aluminum. The dovetail
has a .5in base. I don't have a collet but I made a simple
end mill holder for it.

What is the best advice you can give me before I
turn on the switch on the Unimat?

thanks in advance,

Norm

Hi Norm,
First, trench out the majority of the dovetail with a plain endmill. Go
to the full width of the top of the dovetailed slot, and leave maybe
0.1mm on the bottom. This way the dovetail cutter will only be making
the angled cut, and clean up the bottom. This will relieve both the
cutter and your uni motor a great deal.
Other than that, the usual steady as she goes. Actually, you'll find
that the aluminium is softer than brass, but can tend to be a bit
"chewy", depending on the particular alloy.
A little kerosene applied with a brush will go a long way to lubricate
the cutters, preventing chips sticking, and will also give a much higher
finish.

Clay.

Harvey & Mert,
Thanks for the replies.

If used in small increment, with cutting fluid (on AL) and
careful feeding rate vs speed, this dovetail cutter
should last me for many years to come I hope.

This news group is a great source for people like me.

Norm


--- In UNIMAT@..., "Mert Baker" <mertbaker@...> wrote:

To cut dovetail slots, first use an ordinary endmill to cut most of

the metal away. Then cut the DT one side at a time. On the Uni, this
is best done in small increments. Brass is easier to cut, as a rule,
than some Al alloys, especially the soft gummy stuff found in hardware
stores. On Al, be sure to use a cutting fluid. WD-40 works, and
there are lots of others.

Mert

mertbaker@...
----- Original Message -----
From: Norm
To: UNIMAT@...
Sent: Thursday, January 25, 2007 10:08 PM
Subject: [UNIMAT] any advice for first time milling with dovetail

cutter ?

Hello,

I recently bought a dovetail cutter for my Unimat but
having never used something like this before, I want
to make sure I will not screw up and/or damage the tool.
(they are expensive !)

I was planning to just practice with something soft
like brass before I move on to aluminum. The dovetail
has a .5in base. I don't have a collet but I made a simple
end mill holder for it.

What is the best advice you can give me before I
turn on the switch on the Unimat?

thanks in advance,

Norm





[Non-text portions of this message have been removed]

On Fri, 26 Jan 2007 18:24:15 -0000, you wrote:

Harvey & Mert,
Thanks for the replies.

If used in small increment, with cutting fluid (on AL) and
careful feeding rate vs speed, this dovetail cutter
should last me for many years to come I hope.

I actually was rather aggressive in the cut/tooth rate, and may or may
not have used tapping fluid to lubricate the tool. I was cutting a
dovetail for an adjustable tool holder for a lathe. I was also rather
chary of taking a big cut in the material, so I was relatively
delicate with the overall depth of cut.

Details are at www.dragonworks.info under machining and adjustable
tool post.

Not done with a unimat, but perhaps it will help.

Harvey

This news group is a great source for people like me.

Norm


--- In UNIMAT@..., "Mert Baker" <mertbaker@...> wrote:

To cut dovetail slots, first use an ordinary endmill to cut most of

the metal away. Then cut the DT one side at a time. On the Uni, this
is best done in small increments. Brass is easier to cut, as a rule,
than some Al alloys, especially the soft gummy stuff found in hardware
stores. On Al, be sure to use a cutting fluid. WD-40 works, and
there are lots of others.

Mert

mertbaker@...
----- Original Message -----
From: Norm
To: UNIMAT@...
Sent: Thursday, January 25, 2007 10:08 PM
Subject: [UNIMAT] any advice for first time milling with dovetail

cutter ?

Hello,

I recently bought a dovetail cutter for my Unimat but
having never used something like this before, I want
to make sure I will not screw up and/or damage the tool.
(they are expensive !)

I was planning to just practice with something soft
like brass before I move on to aluminum. The dovetail
has a .5in base. I don't have a collet but I made a simple
end mill holder for it.

What is the best advice you can give me before I
turn on the switch on the Unimat?

thanks in advance,

Norm

Yahoo! Groups Links

Hello Norm,

When cutting the dove tail one side at a time with the center
already milled don't forget about changing direction of the cutting
when you change sides. What I am getting at is never use climb
milling on any Unimat. They just are not rigid enough. Use only
standard milling.

Best, Cary Stewart

--- In UNIMAT@..., "Norm" <nccyr1@...> wrote:

Harvey & Mert,
Thanks for the replies.

If used in small increment, with cutting fluid (on AL) and
careful feeding rate vs speed, this dovetail cutter
should last me for many years to come I hope.

This news group is a great source for people like me.

Norm


--- In UNIMAT@..., "Mert Baker" <mertbaker@> wrote:

To cut dovetail slots, first use an ordinary endmill to cut most

of

the metal away. Then cut the DT one side at a time. On the Uni,

this

is best done in small increments. Brass is easier to cut, as a

rule,

than some Al alloys, especially the soft gummy stuff found in

hardware

stores. On Al, be sure to use a cutting fluid. WD-40 works, and
there are lots of others.

Mert

mertbaker@
----- Original Message -----
From: Norm
To: UNIMAT@...
Sent: Thursday, January 25, 2007 10:08 PM
Subject: [UNIMAT] any advice for first time milling with

dovetail

cutter ?

Hello,

I recently bought a dovetail cutter for my Unimat but
having never used something like this before, I want
to make sure I will not screw up and/or damage the tool.
(they are expensive !)

I was planning to just practice with something soft
like brass before I move on to aluminum. The dovetail
has a .5in base. I don't have a collet but I made a simple
end mill holder for it.

What is the best advice you can give me before I
turn on the switch on the Unimat?

thanks in advance,

Norm





[Non-text portions of this message have been removed]

I didn't know about this one.
Great tip!
Thanks for sharing,,

Norm