Post by DavidT on Feb 1, 2004 14:42:41 GMT -5
I have finished my CAD drawings and I get the following results. 1 1/2" scale at 7 1/2" gauge
Outside of frame is 8.111 inches. Truck offset 1.046" or 26.576mm. Book shows 30mm.
7 1/4" gauge Frame at 7.86" outside Offset .915 or 23.237mm. The boiler dimensions shown will fit into the 7 1/4 ga frame. Do not let blowdown bushing exceed 3/16". For 7 1/4" ga, frame material must be .5" any larger and boiler will not fit. The frame spacing called out in the book for the larger scales are not true upscales from 3/4" scale. I suspect this is to allow for standard materials in the boiler or to put the left frame over the left wheel journal. If use use the 30mm offset from the book at 7 1/2 ga the engine will be out of alingment with the right journals by about 1/8" towards the inside. Post under "Erratta" is incorredt
Outside of frame is 8.111 inches. Truck offset 1.046" or 26.576mm. Book shows 30mm.
7 1/4" gauge Frame at 7.86" outside Offset .915 or 23.237mm. The boiler dimensions shown will fit into the 7 1/4 ga frame. Do not let blowdown bushing exceed 3/16". For 7 1/4" ga, frame material must be .5" any larger and boiler will not fit. The frame spacing called out in the book for the larger scales are not true upscales from 3/4" scale. I suspect this is to allow for standard materials in the boiler or to put the left frame over the left wheel journal. If use use the 30mm offset from the book at 7 1/2 ga the engine will be out of alingment with the right journals by about 1/8" towards the inside. Post under "Erratta" is incorredt