substandard
Well-Known Member
- Joined
- Apr 29, 2009
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- 65
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Being stubborn and dense, I decided it was time to take on an engine from castings. I bought the PM Research #5 Coke bottle engine set, and now I am lost........
I figure the best place to start is fly cutting the frame base to be flat and square. To do this I have a 9x36 mill and a Southbend 9" lathe. I have yet to figure out a way to hold the casting and to find a way to measure to make sure the base is going to be cut square.
I tried chucking the casting in my 4 jaw on the lathe, but I was only able to chuck onto the small diameter. The spindle bore won't let the casting enter any further. This doesn't give the casting any real support to keep it from moving about while cutting. I thought about a mandrel thru the center hole of the casting, but how do I know the hole is square to the base?
My milling machine vise doesn't hold the casting any better than the 4 jaw. The vise clamps to the small end diameter, leaving the bulk of the casting unsupported. I am almost certain the casting will move once the cutter strikes it. I had thought about using the method below in the image. Lay the casting on it's side sitting on some 1/2" lathe bit blanks. Indicate the casting true to the machine and side mill the face.
Problem being..actually problems being, where do I take my measurements from to see if the casting is more or less square to the machine axis? Also I don't have an end mill long enough to side mill the entire face. I would need to machine half the face, then flip it 180 and mill the other half. Or buy a long end mill, which I don't want to do unless I am sure it would work....
Any help, suggestions, pity, or criticism would be appreciated. Thanks and sorry for being so long winded.
I figure the best place to start is fly cutting the frame base to be flat and square. To do this I have a 9x36 mill and a Southbend 9" lathe. I have yet to figure out a way to hold the casting and to find a way to measure to make sure the base is going to be cut square.
I tried chucking the casting in my 4 jaw on the lathe, but I was only able to chuck onto the small diameter. The spindle bore won't let the casting enter any further. This doesn't give the casting any real support to keep it from moving about while cutting. I thought about a mandrel thru the center hole of the casting, but how do I know the hole is square to the base?
My milling machine vise doesn't hold the casting any better than the 4 jaw. The vise clamps to the small end diameter, leaving the bulk of the casting unsupported. I am almost certain the casting will move once the cutter strikes it. I had thought about using the method below in the image. Lay the casting on it's side sitting on some 1/2" lathe bit blanks. Indicate the casting true to the machine and side mill the face.
Problem being..actually problems being, where do I take my measurements from to see if the casting is more or less square to the machine axis? Also I don't have an end mill long enough to side mill the entire face. I would need to machine half the face, then flip it 180 and mill the other half. Or buy a long end mill, which I don't want to do unless I am sure it would work....
Any help, suggestions, pity, or criticism would be appreciated. Thanks and sorry for being so long winded.