Engines > From Plans
Another Pennsylvania A3 Switcher
JCvdW:
Thanks Per and Chris for checking in. Silver soldering the boiler still looms somewhere in the distant future...
The truck side bars were cut from mild steel sheet using an angle grinder, and then milled to size on the mill. The mill vice was too small to hold the pieces, so a temporary vice was devised using a few lengths of cold rolled flat bar that were on hand.
The bending jigs suggested by Kozo made bending the side bars straight forward. The sharp edges of the v-slot in the jig were rounded on the belt grinder to prevent marks on the side bars.
The jig to cut the sloped slots in the bolsters was made from mild steel. To mill the 3 degree slope on one side of the jig blocks, a wooden jig was first made on the table saw with the blade set at a 3 degree angle.
Stainless steel coil spring wire was sourced from a local spring manufacturer. The coil springs were then turned on a mandrel in the lathe as described by Kozo. It took longer to select the correct gearing for the required pitch, than it took to actually make the springs.
And finally the two trucks were assembled, with all parts numbered, as suggested by Kozo!
Next step is painting, before starting with the frame. I am unsure about this. The side bars fit tight in the bearing block slots and will most likely not fit if painted first. Inserting the bolsters will however require disassembly after painting, which may also be problematic. Any advice will be appreciated.
Kim:
Sorry, I seemed to have missed one of your posts in August! You've made a lot of great progress and have some fine looking trucks there!
As for painting, I masked off the notches in the journal boxes where the arch bars fit, and of course, all of the sliding portions of the columns and bolsters. But I painted all of the arch bars. I didn't seem to have any problem making things fit after painting, though I may have had to sand down a little on the edges of the bars to make them fit if the paint was too thick. I don't remember for sure, but that is certainly something I've done on this build. I am using powder coat rather than spray paint though, and powder coating adds a bit extra thickness. If you're spray painting, I can't think that it will add enough thickness to cause you too much issue. If so, just sand a bit off so it will fit :embarrassed:
Wonderful looking trucks for sure!
Kim
Admiral_dk:
Another great step forward - looks good :ThumbsUp:
Per :cheers:
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