Need to cut a small keyway

[verbotenwhisky]

I need to duplicate this keyway on another shaft. The shaft mild steel, diameter is 0.625in nominal. The key dims are 0.118in wide x 0.5in long x 0.080 deep.

Looks like the original was cut with an endmill, but all I can envision is a lot of broken endmills and ruined work if I were to try this with such a small diameter tool.

Can someone please advise the proper tool and procedure?

View attachment 476951

I get my best results on those by drilling a hole a size smaller than I need were the point of the bit doesn't go deeper than the bottom of the slot then plunging a 2 flute end mill to depth and feeding slowly in the direction it needs to go.

 

[MikeInOr]

I usually ramp down into them, even with a centre cutting endmill.
It seems to feel/sound better than trying to plunge then feed.
Brian

Sounds good. How do you ramp down into the cut? Do you hold the rod at an angle? Do you work the Z axis while moving along the X axis?

 

[Huub Buis]

An end mill to mill a key way, has 2 flutes. It is a hair smaller in diameter than a 4 flute end mill. Prepare the slot using an end mill that is smaller than the end mill to finish the slot. For a tight fit, reduce the cutting forces by reducing the RPM and use a modest feed. Blow the chips out of the hole for a better finish.

 

[Larry$]

How do you ramp down into the cut?

Use the hand wheel on your quill (not the lever, the handwheel is more controllable) you can do that while the feed is engaged at a slow rate. If you set your feed stops on the table you won't risk going too far.

 

[Smithdoor]

I need to duplicate this keyway on another shaft. The shaft mild steel, diameter is 0.625in nominal. The key dims are 0.118in wide x 0.5in long x 0.080 deep.

Looks like the original was cut with an endmill, but all I can envision is a lot of broken endmills and ruined work if I were to try this with such a small diameter tool.

Can someone please advise the proper tool and procedure?

View attachment 476951

You look at Woodruff cutters and keyway.
They very easy for very thin and or small keyway.

I have in pass for very small parts

Dave

 

[brino]

Do you work the Z axis while moving along the X axis?

Use the hand wheel on your quill (not the lever, the handwheel is more controllable) you can do that while the feed is engaged at a slow rate.

Exactly what I do, too.
Brian