MAIN BEARINGS FOR TRIPLE
by John
Each main bearing consists of 2 gunmetal halves which fit into a slot in the base, and a cap which bolts to the base. There are 6 of these.
I machined the gunmetal castings, and made the caps.
Before I finished the machining or drilled the holes for the bolts, my phase changer failed, so I finished the job on my (single phase) drill press. Not ideal but adequate.
The Phase Changer has failed at least once every year since I bought it 5-6 years ago. It is the least reliable machine in my workshop. Repairs to it seem to take at least 3-4 weeks on each occasion, which is frustrating. I will borrow a 3 phase diesel generator to keep the workshop in action while waiting (again) for the repairs.
One of the 6 main bearings and caps. The hole has been roughed out, ready for accurate boring
The 6 main bearings sitting in their slots. The hold down bolts are ready to be installed. The bearing surfaces will be bored when I have some 3 phase power again.
johnsmachines 
John,
in Europe we can take the 220volt incomming stream and we using a Frequincy regulator to use the 3 phase electric motor on a frequincy off 50 Hertz base. Is that not a possibillity over there to use?
greatings from the Netherlands.
Huib Hoogendoorn
LikeLike
Hi John
With your modified main bearings to the original drawing has that altered the height of the crankshaft. Why did you change it anyway please. 😀
LikeLike
Hi Ian, The height of the crankshaft was as per plans. I do not recall altering the main bearings from the plans. But it was not yesterday. John
LikeLike
It just look different to the bearings and retaining caps in the Model Engineering articles and Bolton drawings. Your top brg caps have an overlap but the original look just a straight flat plate on top. The depth of the main brg housing in the base plate is only 5/8″ and it looks like your brgs are wider hence the stepped cap.
Terrific blog though good job you did it as I don’t think I will manage easily with the Bolton drawing on its own
LikeLike