TRIPLE SH*T
by John
The Bolton 9 triple expansion steam engine has 6 eccentric cams which drive the steam valves, 3 forward and 3 reverse.
The cams are each made as a split, offset disc. The disc is machined after 2 pieces of brass are soldered together (soddered if you are north American), then the solder is melted so the eccentric discs can be attached to the crankshaft.
I spent a day machining the brass pieces and soldering it, and turning the discs.
The brass rod with the soldered join, and the discs turned to accurate size
Another view of the eccentrics, still soldered together, ready for insertion of screws then melting of the solder.
Today I spent a couple of hours setting up the threaded holes to joins the disc pieces after the solder is melted away.
In the process of doing this I hit a wrong button, and fu**ed the whole job. So I turned off everything in disgust, and spent the remainder of the day cleaning up my Quorn tool and cutter grinder, in preparation for an exhibition next weekend.
Sh*t happens when metalworking. At least it will be quicker when I repeat this exercise in a day or two, if I can learn from the mistakes.
Or you could fit the bolts first, then remove them, slit the eccentric and then bolts it together and machine it.
john f
Yes, after yesterday’s debacle I did consider that method. Following your comment I will give it some more thought. John V.