The core attached to the top and bottom tanks. These tanks have been fabricated from brass and copper using silver solder. The caterpillar emblem has been engraved from a drawing traced from a photograph by David Micklethwaite who supplied me with a DXF file. Dave has a program for converting bitmap files to vector files. These tanks are joined by square headed bolts yet to be made.
The core under construction. The tube plates where jig drilled by CNC. The tubes are 3/16 thin wall copper salvaged from a Caterpillar tractors oil cooler. There are 100 tubes 5 rows of 20 soft soldered to the tube plates.
The radiator side frames where made from brass angle and flats silver soldered
This image shows the sixty logo being engraved. On this model these engraved signs are soft soldered in the frames .
This photo shows trial machining of the logo using a 1mm four flute end mill running at 12,000 rpm at a feed rate of 100mm per minute. The method was to pocket the sign and later profile each letter with different offsets to adjust their thickness. The final logo was inserted into a pocket machined in the top tank. This machine is an old BCA mill I converted to CNC using a Gecko 540 stepper driver. The Z axis is new with high precision NTN angular contact bearings. The original head with plain bearings was scrapped.
The core attached to the top and bottom tanks. These tanks have been fabricated from brass and copper using silver solder. The caterpillar emblem has been engraved from a drawing traced from a photograph by David Micklethwaite who supplied me with a DXF file. Dave has a program for converting bitmap files to vector files. These tanks are joined by square headed bolts yet to be made.
The core under construction. The tube plates where jig drilled by CNC. The tubes are 3/16 thin wall copper salvaged from a Caterpillar tractors oil cooler. There are 100 tubes 5 rows of 20 soft soldered to the tube plates.
The radiator side frames where made from brass angle and flats silver soldered
This image shows the sixty logo being engraved. On this model these engraved signs are soft soldered in the frames .
This photo shows trial machining of the logo using a 1mm four flute end mill running at 12,000 rpm at a feed rate of 100mm per minute. The method was to pocket the sign and later profile each letter with different offsets to adjust their thickness. The final logo was inserted into a pocket machined in the top tank. This machine is an old BCA mill I converted to CNC using a Gecko 540 stepper driver. The Z axis is new with high precision NTN angular contact bearings. The original head with plain bearings was scrapped.
