On December 13, 2019 at 1:23 PM "lrkdbn via Groups.Io" <lrkdbn@...> wrote:

I'm afraid I cannot help you about Ed Kaminski, but I sure would like to know what periodical your article will be in-as I have a great interest in these cars. When I was growing up on the west side of Detroit, the "neighborhood railroad" was the PRR- C&O- Wabash owned Union Belt,They used C&O A-810 and A-812 in their operations up until about 1972.
Sincerely,
Larry King

Just wondering what we are supposed to do with this information?

Bill Welch

I know that a good CNC program is certainly capable of superior work and is done so all the time, but I challenge anyone to find a better HO improved Dreadnaught end than the HO casting I sent a picture of yesterday. Yes, very few do any old school 3D work these days for the reasons you have stated about time. But my challenge I feel is safe from being broken. I look forward to being proven wrong.

-Andy Carlson

Ojai CA

Did anyone acquire Stan's patterns and masters? He had some really unique stuff.

Yours Aye,

Mungo Napier, Laird of Mallard Lodge  🦆

On Thu, Dec 12, 2019 at 2:05 PM mopacfirst <ron.merrick@...> wrote:

Speaking of molded ends, I'm looking for unbuilt reefer kits or molded resin ends, roofs and doors made by Stan Rydarowicz.  If you have any you're willing to part with, please contact me off-list (click on the Private button bottom right, then on the Reply to Sender button that's turned blue on bottom right ) at mopacfirst@....

Ron Merrick

On Dec 12, 2019, at 11:42 AM, Dennis Storzek <destorzek@...> wrote:

On Thu, Dec 12, 2019 at 08:45 AM, Andy Carlson wrote:

I think that in some very important ways the old-school methods of panto reducing down over size patterns with a pantograph can produce parts which the best of CNC tooling has not shown an even match.

-Andy

And I totally disagree. Anything that can be cut by a 3D pantograph can be cut by CNC. In fact, you'll be hard pressed to even find a pantograph in a modern day tool shop, unless the owner is almost retirement age and never gets rid of anything. Toolmaker time is expensive, and a pantograph is a manual machine. The question becomes do you want your toolmaker to spend hours sitting at the pantograph, or be doing something else while the CNC machining center cuts the part unattended.

Pantographs can't reverse the pattern; that is they can't cut a cavity directly from the model of the part. The usual way that was dealt with was to wax the part model, and then pour epoxy around it, thereby producing a pattern of the cavity.

The real problem is one of visualization. It is difficult to see contours in a cavity that are very evident on the part.  In the case of the 1/12 scale end, the pattern maker had the positive pattern to compare to the drawings, and most likely photos of the real end. In my toolmaking work, I cut graphite EDM electrodes, that, while small, are a positive copy of the part, so if contours are strange, they are evident, at least under magnification.

The problem with the IM end is it was most likely cut as a cavity directly into the mold plate, relying on the computer graphics to inspect the shape of the surface, and obviously the programmer got it wrong and didn't catch it. This could have been avoided by using the opposite side of the surface geometry to cut a positive part in plastic or wax. Since CNC files are scaleable, the positive check piece could have been made oversize for easier inspection.

Dennis Storzek