Here's a couple of followers I worked on yesterday. These are patterns for a split windshield center bracket. The mounting piece was giving me grief with shrink in the red area even with a riser. I decided to try a vertical pour. This is new to me so looking forward to it. Had to move the flask alignment pins from the ends to the sides. Made a couple plywood backers for the flask and after moulding, removed the end of the flask. The sprue was made with #2 copper wire and carved the slot in the foam for it. After a test mould, decided it was too large and changed to a #6 Aluminum wire. This left my groove a little sloppy. I'll have to work on that. Using a 1/2 (drag side) blind riser. The other follower is for the face plate for the bracket. With this setup I can cast two at a time. Had hoped to cast today but it's raining.
Well, the 1/2 blind riser wasn't enough to stop the shrink problem. I increased it to a full open riser and then it wouldn't fill to the top, had to pour a couple ounces into the riser to top it off. Went back to the original #2 copper wire (3/8" vs 5/16" aluminum). That took care of the filling problem. Shrink problem is solved.
Thanks guys. That used to be a split pattern. I like the ease of the foam followers so much that I glued it back together. One last thing to do, reduce the contact patch of the riser. That's a big chunk of metal to slice off.
That is an interesting setup for making the facing plate for the bracket. If I read the photo correctly, you first use the wood/styro pattern to make the drag. Then you drop the facing bracket pattern pair onto the drag and place a filler piece (a "pattern" piece I guess) into the preformed runner groove. Then, after packing up the cope, out come the pattern pieces and you are ready to go. That is interesting because I think usually people would have some sort of removable pattern piece for the raised sand under the upturned pattern end. Then the pattern, runner pattern, and casting pattern would have been rammed to form the cope. Following that the drag would be rammed using the cope with all the pieces in place except for the upturned drag pattern piece. Your way is easier and better, I think. I really liked that long sweeping sprue made with the copper wire! Denis
Yeah, those face pieces used to be a real pain to cast. The follower took all the work out of it. I just remove the EXP and leave the runner pattern in the sand, it's got a hole drilled to hold the sprue while moulding the cope.
