4060MAY
11-26-2007, 08:13 PM
I'll try to write this as best as I can, I'm not good at words in writing.
The mould blocks were made out of the test slip from a stamping die block, about 12 x 6 x 8inches, sawn into strips about 2" square. My part of the job is to machine the blocks to the required size, make them square, cut the slot for the handles, install the alignment pins using 3/16" hardened dowel pins.
The sprue plate is ordered from Lyman as a rebuild kit for $5.00 or so from Midsouth, includes all the hardware, screws etc. I don't like spring washers on the mould and use a metric washer to allow the sprue plate to swing.
The hard part is having a DRO Mill, enter my friend, Steve. Mould maker since 1963, mostly investment casting stuff.
In his shop we set the blocks up in a vise with stops to be able to insert the blocks back into the same place.
The Center is found and a hole is predrilled to allow the cutter to do the nose first, then the body is cut with another cutter ground for the dia required.
The cutter on the left is the large dia, in this case .399 which is .001 under my bore dia, allowing me to patch to groove dia of .408
After reading Brent's website about PP, it looks like a step is a good way to set up the patch, hence the nose cutter is made about .005 smaller in dia., the nose was kind of copied form a 311299.
Hope this helps.
Chuck
The mould blocks were made out of the test slip from a stamping die block, about 12 x 6 x 8inches, sawn into strips about 2" square. My part of the job is to machine the blocks to the required size, make them square, cut the slot for the handles, install the alignment pins using 3/16" hardened dowel pins.
The sprue plate is ordered from Lyman as a rebuild kit for $5.00 or so from Midsouth, includes all the hardware, screws etc. I don't like spring washers on the mould and use a metric washer to allow the sprue plate to swing.
The hard part is having a DRO Mill, enter my friend, Steve. Mould maker since 1963, mostly investment casting stuff.
In his shop we set the blocks up in a vise with stops to be able to insert the blocks back into the same place.
The Center is found and a hole is predrilled to allow the cutter to do the nose first, then the body is cut with another cutter ground for the dia required.
The cutter on the left is the large dia, in this case .399 which is .001 under my bore dia, allowing me to patch to groove dia of .408
After reading Brent's website about PP, it looks like a step is a good way to set up the patch, hence the nose cutter is made about .005 smaller in dia., the nose was kind of copied form a 311299.
Hope this helps.
Chuck