Re: End Mill Advice for ABS Plastic


Matt Goodman
 

Hi Jeff.  The first car will definitely be an experiment - both with the model and tooling/setup. With new side ribbing (vertical and horizontal), a change to the arch ends and other above-the-sill changes, I hope to get to at least a passing resemblance.

My medium-term goal is to build a train that resembles one in a 1936 aerial photo that shows a nice variety of gondolas, short/high 55t HPs and long/low 70t HUs - and a nice variety of coal grades in each.

But first, I need to cut those H2a ribs off! 

Matt Goodman
Columbus Ohio, US

On Apr 19, 2019, at 5:18 PM, Jeff Coleman <traininsp@...> wrote:

Matt

The HU was rebuilt and reclassified H3. Similar to H2/H2a but none look anything like the HU.
I've been wishing for that hopper 35 years. 

Jeff Coleman

On Fri, Apr 19, 2019, 4:48 PM Matt Goodman via Groups.Io <mgoodman312=icloud.com@groups.io> wrote:
Hi all.  I recently purchased a set of BLI N&W H2a hopper cars with the intent of back-dating them to something resembling an HU. Based on what I know, H2a’s are identical to H2s, which were rebuilt HUs.  So I figure the car is as good as any for a starting point, from a dimensions point of view.  Back dating the three hoppers to four might be a problem, but I’m ignoring that minor detail for now.

One of the back-dating steps is removing the vertical side ribs - the HU had fewer side panels than their offspring. I’m considering doing that with my mill.  Here’s my ask: I’m looking for advice on an appropriate end mill cutter type for use on plastic. My limited experience with milling has been confined to aluminum and brass, and on projects where surface finish wasn’t a driving factor.

I suspect I would need four flute, relatively small diameter mill to reduce bite and the possibility of tearing?  Advice on that and other related guidance is greatly welcome.

Matt Goodman
Columbus Ohio US



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