Re: Earlier runs often better than late runs

Dennis Storzek
 

On Wed, Nov 13, 2019 at 10:27 AM, Garth Groff and Sally Sanford wrote:
Several of Accurail's earlier cars are a close match for Front Range models.  Were these cars recut with new dies by Accurail, or is the old aluminum still holding up?
 
Garth,

They are the original Front Range cavity inserts. 7075 Aluminum holds up well, so long as it is treated gently. Used where it won't close on parts, or drools, or flash stuck to the mold parting line, it holds up well. Not so much if there are sliding shut-offs or other mechanicals involved. There are, of course, five IIRC sets of sides that share a common roof and ends. The roof and ends weren't doing so well, so we mated the sides with steel ends we already had, and built new roofs, also steel. We have built a few things out of aluminum; the 40' plug door RBL and the 40' combo door boxcar sides are aluminum that run with steel ends and roofs. We made the judgement that neither was going to be a high mileage tool. Those taught us that we really weren't saving much, since I'd rather EDM small details in rather than dink around with tiny milling cutters, and if the work is going to be EDM'd, it might as well be steel. Back in the nineties it seemed there was a savings being able to put the rivets in with a .010" diameter ball nose end mill, but the introduction of affordable diamond coated miniature end mills has made cutting electrodes to do the rivets cost competitive, and I haven't done anything in aluminum in years.

Dennis Storzek

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