KeithB
Resident Half Fast Machinist
Got the soft jaw cut yesterday.There are two cavities, the one on the left holds the piece upright like a regular T, the one on the right holds the piece with the crossbar oriented vertically. The left cavity is used for the third operation on the CNC mill. During this step the crossbar is milled flat to clean up using a 2" face mill, the ends are milled to make a radius, and the guide rod holes and top punch hole are drilled and reamed to size.
Here is a part mounted in the soft jaws. A hard photo to take, this is a shot from inside the machine looking out the access door. My vise has the fixed jaw near the handle, the movable jaw is pulled into the piece.
An edge finder was used to touch off each end of the part to find the center. The edge finder was also used to touch the front of the part so that the offset to the center of the part could be entered. I programmed the piece with X0, Y0 at the center of the top punch hole and Z0 is the finished top of the crossbar.
Here is the part after the crossbar has been clean up milled, the ends radiused, and the holes drilled and reamed.
The part after the third step, ready to get the handle slot cut.
Here is the part held in the right hand cavity of the soft jaws to enable cutting the handle slot.
Here is the finished piece, it needs to be deburred and cleaned up and have some sort of surface treatment applied.
The original part was more triangular shaped, it measured about 1-1/8" wide across the base of the handle slot and about the same distance from the top of the ear to the bottom of the slot. The original part was cut on a horizontal mill using a 1/4" wide circular saw-type cutter. I don't have a horizontal mill and cutting 1-1/8" deep with a 1/4" end mill is pushing things a little. A standard 1/4" end mill will cut a little over 3/4" deep, so I redesigned the part to make it 3/4" across the base of the slot and I turned the piece 90 degrees so a vertical mill with a standard 1/4" end mill could be used. By knowing my tooling and it's limitations I was able to make a minor change to the part that allowed it to be made completely in our shop using existing standard tooling.
Here is a part mounted in the soft jaws. A hard photo to take, this is a shot from inside the machine looking out the access door. My vise has the fixed jaw near the handle, the movable jaw is pulled into the piece.
An edge finder was used to touch off each end of the part to find the center. The edge finder was also used to touch the front of the part so that the offset to the center of the part could be entered. I programmed the piece with X0, Y0 at the center of the top punch hole and Z0 is the finished top of the crossbar.
Here is the part after the crossbar has been clean up milled, the ends radiused, and the holes drilled and reamed.
The part after the third step, ready to get the handle slot cut.
Here is the part held in the right hand cavity of the soft jaws to enable cutting the handle slot.
Here is the finished piece, it needs to be deburred and cleaned up and have some sort of surface treatment applied.
The original part was more triangular shaped, it measured about 1-1/8" wide across the base of the handle slot and about the same distance from the top of the ear to the bottom of the slot. The original part was cut on a horizontal mill using a 1/4" wide circular saw-type cutter. I don't have a horizontal mill and cutting 1-1/8" deep with a 1/4" end mill is pushing things a little. A standard 1/4" end mill will cut a little over 3/4" deep, so I redesigned the part to make it 3/4" across the base of the slot and I turned the piece 90 degrees so a vertical mill with a standard 1/4" end mill could be used. By knowing my tooling and it's limitations I was able to make a minor change to the part that allowed it to be made completely in our shop using existing standard tooling.
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