This ugly reproduction part needed be remade to look like the quality of a good original Stickney part. Stickney's pattern shop was top notch and their castings were always first quality.
Making the pattern.....
A glued up block of wood was centered in the 4 jaw chuck.
Son Devin is running the center tool in to allow use of a live center for support.
From square to round....
The external ribs have been cut out.
The pattern with 1 1/2" core prints on each end.
This small tab that guides the fuel pump sucker rod has been milled out and will be glued on after sanding a little draft into it.
The tab has been glued on, fillets created, primed, and sanded. The pattern part is complete.
This pattern will be cast loose and to assure the drag and cope will meet at the part centerline, a follow board is needed to aid ramming the drag half. You can just see 1 of the 2 spanners that support two of the steps on the pattern.
And here is the pattern in the follow board exactly on centerline.
Making the core box.....
Another block was dialed in and the core plug turned.
Here 4 slots at 90° apart have been milled.
And the 4 pieces made to be glued into the slots.
The OD of the slots has been turned to the same OD of the pattern. These will create the "windows" in the finished part.
Both the pattern and core shape to show how they will work together.
The core plug was sawed so that exactly one good, full half was remaining. This was mounted on a board.
Another view of the core plug that will be used to make the core box.
Here is the box that the urethane will be poured into. The pour holes in the bottom are not drill yet, but they were just 1 1/2" diameter holes. The core plug & plate get mounted on this box, then flipped upside down, and filled with the 2 part urethane. I used Repro 1 product from Freeman Supply.
The finished core box with the core plug removed.
And a slightly different angle. Despite plenty of draft, 3 coats of carnoba wax, and 3 applications of release agent, the wooden core plug had to be destroyed to get it out. Oh well at least I've got a good core pattern!
It's time to send some patterns to the foundry!