Topics

NYC gondola brake details


Eric Hansmann
 

Jerry Hamsmith returns to the Resin Car Works blog with part two of the NYC 50-foot gondola build. Brake system detail are the focus in his latest blog post.

http://blog.resincarworks.com/nyc-50-foot-drop-bottom-gondola-part-2/

 

 

Eric Hansmann

RCW web guy


WILLIAM PARDIE
 


Jerry is doing a great job on this gondola as on all his efforts.  He like many of my modeling friends includes the train line on his models.  Others ignor it completely. While not particularly difficult I do find it rather finicany in drilling the holes for this line in a cast resin underframe.  I would be interested in Jerry's technique  for accurately drilling holes for this line.

Bill Pardie


Sent from my Verizon, Samsung Galaxy smartphone


Nelson Moyer
 

I don’t know how Jerry does it, but I use a long tapered fine pointed dissecting needle from my college biology dissecting kit to gently work holes in cross bearers and crossties.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io [mailto:main@RealSTMFC.groups.io] On Behalf Of WILLIAM PARDIE
Sent: Friday, December 18, 2020 12:04 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] NYC gondola brake details

 

 

Jerry is doing a great job on this gondola as on all his efforts.  He like many of my modeling friends includes the train line on his models.  Others ignor it completely. While not particularly difficult I do find it rather finicany in drilling the holes for this line in a cast resin underframe.  I would be interested in Jerry's technique  for accurately drilling holes for this line.

 

Bill Pardie

 


Schuyler Larrabee
 

Well, Bill, I’ve drilled such holes and have used a couple of techniques.

 

I’ll only mention the one that worked . . . 😊

 

After figuring out that the train line (or whatever line I was thinking about) had to be “this high” off the floor (with the model upside down) and “that far” off the adjacent center sill, I made a very small styrene angle.  One side of the angle was “this thick” and the other was “that thick” (less .010 for a .020” train line).  Then I nestled this angle into the corner made by the center sill and the floor, against the cross bearer or cross tie..

 

Using a drill in my pin vise, probably a No.74m .0225, sticking out of the pin vise as far as I could, I put it into that interior angle and drilled, slowly.  With the small amount of “slop” with the slightly oversized hole, I could get a series of holes that were pretty close to being aligned, enough so that the wire would be straight.

 

Well, worked for ME.

 

Schuyler

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of WILLIAM PARDIE
Sent: Friday, December 18, 2020 1:04 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] NYC gondola brake details

 

 

Jerry is doing a great job on this gondola as on all his efforts.  He like many of my modeling friends includes the train line on his models.  Others ignor it completely. While not particularly difficult I do find it rather finicany in drilling the holes for this line in a cast resin underframe.  I would be interested in Jerry's technique  for accurately drilling holes for this line.

 

Bill Pardie

 

 

Sent from my Verizon, Samsung Galaxy smartphone

 


Dennis Storzek
 

Most hobby grade twist drills are long enough to reach in from the end of the car to drill through the body bolster. I use either #72 (.025" dia.) or # 71 (.026" dia.) to give a bit of rattle room. Casting resin is soft enough that it will drill with a "D" bit; a round rod with a flat ground to 1/2 it's diameter on one end. Most well stocked hobby shops carry straight lengths of .025 piano wire, so it's easy to make a drill four or five inches long  to do the inner cross bearers. The long hole through the body bolster will stabilize it; Schuyler's method will put it spot on if needed.. I run it with a variable speed motor tool.

Dennis Storzek


David Soderblom
 

Dennis:

How do you cut the piano wire without ruining perfectly good pliers. And do you angle the end to make a “bit” out of it?


Sent from my tricorder


Brian Carlson
 

Don’t use piano wire. Use phosphor bronze. The tichy wire is fine and long enough.

Brian J. Carlson

On Dec 18, 2020, at 5:06 PM, David Soderblom <drs@stsci.edu> wrote:

Dennis:

How do you cut the piano wire without ruining perfectly good pliers. And do you angle the end to make a “bit” out of it?


Sent from my tricorder


Dennis Storzek
 

On Fri, Dec 18, 2020 at 02:06 PM, David Soderblom wrote:
How do you cut the piano wire without ruining perfectly good pliers. And do you angle the end to make a “bit” out of it?
Dremel tool with an abrasive disk, same as used to grind the flat. Someone mentioned Tichy phosphor bronze wire. I never tried it, but I bet that would be stiff enough and stay sharp long enough.

Dennis


Jerry Hamsmith
 

Bill and all -

Thanks very much for the kind words regarding the train line.  However, the photo was of the one modeled by Ed Rethwisch.  He used a #70 bit and drilled the holes at a shallow angle.  I do occasionally include train lines on my models, but did not in this particular build.  Also, much of the upcoming description - the complex brake system - follows Ed's excellent modeling of the actual AB brake drawings.

Jerry Hamsmith


WILLIAM PARDIE
 

I have found the New York Central Society to be very gracious and generous in providing plans for NYC equipment. Several years ago they helped .me with the brake layout of the NYC USRA all steel box  car.  This was totally differen from.the Westerfieldi instructions and other articles.

Bill Pardie



Sent from my Verizon, Samsung Galaxy smartphone



James Brewer
 

I use this Xuron hard wire cutter for most piano wire cuts:

https://www.micromark.com/Xuron-Hard-Wire-Cutter

Jim Brewer


Dennis Storzek
 

On Fri, Dec 18, 2020 at 02:06 PM, David Soderblom wrote:
How do you cut the piano wire without ruining perfectly good pliers. And do you angle the end to make a “bit” out of it?

I'm sorry, I missed the second part of your question. No, no angle. D bits (also known as single lip cutters) work by the straight edge formed by grinding half the diameter away scraping a tiny chip from the work piece. Of course, urethane resin is rather soft so it doesn't take much scraping to drill a hole. Here is a youtube video that demonstrates making a larger version:
Grinding a D bit
Ignore the multiple diameters, we just need the first step, and it doesn't need to be very long, just back it off repeatedly to clear the chips. These bits don't self center, which is why I use steel piano wire; it's stiff enough to be guided by the hole drilled through the bolster with a twist drill. Once going from crossbearer to crossbearer it can be guided with a pair of tweezers around the spinning bit, or use Schuyler's angle block method. Behind the grind on the tip there is nothing to catch, it's just a smooth wire.

Dennis Storzek


Lloyd Keyser
 

The Hardware store will have a small pair of cutters that are hard enough to cut music wire.  I  got a small pair at Elliot Hardware  here in Dallas. Not sure the big box stores  carry them only much larger cutters. Be sure and ask for them. I marked mine "steel" so I know which pair they are. Lloyd

On Sat, Dec 19, 2020 at 8:14 PM Dennis Storzek <destorzek@...> wrote:
On Fri, Dec 18, 2020 at 02:06 PM, David Soderblom wrote:
How do you cut the piano wire without ruining perfectly good pliers. And do you angle the end to make a “bit” out of it?

I'm sorry, I missed the second part of your question. No, no angle. D bits (also known as single lip cutters) work by the straight edge formed by grinding half the diameter away scraping a tiny chip from the work piece. Of course, urethane resin is rather soft so it doesn't take much scraping to drill a hole. Here is a youtube video that demonstrates making a larger version:
Grinding a D bit
Ignore the multiple diameters, we just need the first step, and it doesn't need to be very long, just back it off repeatedly to clear the chips. These bits don't self center, which is why I use steel piano wire; it's stiff enough to be guided by the hole drilled through the bolster with a twist drill. Once going from crossbearer to crossbearer it can be guided with a pair of tweezers around the spinning bit, or use Schuyler's angle block method. Behind the grind on the tip there is nothing to catch, it's just a smooth wire.

Dennis Storzek


Tim O'Connor
 


what a great idea ! just make a really long drill bit ! :-)


On 12/18/2020 4:59 PM, Dennis Storzek wrote:
Most hobby grade twist drills are long enough to reach in from the end of the car to drill through the body bolster. I use either #72 (.025" dia.) or # 71 (.026" dia.) to give a bit of rattle room. Casting resin is soft enough that it will drill with a "D" bit; a round rod with a flat ground to 1/2 it's diameter on one end. Most well stocked hobby shops carry straight lengths of .025 piano wire, so it's easy to make a drill four or five inches long  to do the inner cross bearers. The long hole through the body bolster will stabilize it; Schuyler's method will put it spot on if needed.. I run it with a variable speed motor tool.

Dennis Storzek

--
Tim O'Connor
Sterling, Massachusetts