Date   

Re: Model brake component size comparison to prototype

Tony Thompson
 

Paul Woods wrote:

My casting supplier tells me the shrinkage occurs in the rubber mould, not the metal casting because the column of molten brass in the cast keeps pressure on the mould as it cools, helping reduce shrinkage.  

      Sorry, this is nonsense. The entire volume of the metal is shrinking as it solidifies and cools, and nothing in ordinary life can constrain it. The molten column AND the part are all shrinking equally.

Tony Thompson
retired metallurgist




Re: Model brake component size comparison to prototype

spsalso
 

Paul,


I will disagree with your statement that shrinkage does not occur in the metal casting process.

If we assume the mold is filled out with molten brass, and the brass cools down to its phase change temperature of 920 degrees C., thermal contraction will occur as the solid cools from just under 920 degrees to 25 degrees C.  The piece will pull away from the walls of the mold.  The "column of molten brass", if it even still remains liquid, will be trying to compress a solid.  That solid will not compress significantly.

As I said, the shrinkage during the casting process for brass is 1.7%.  Roughly.


Ed

Edward Sutorik


Southwest Scale Productions Boxcar Doors

Steve and Barb Hile
 

Following on on some previously posted material, attached are two formats of a document describing the post WWII boxcar doors produced by Southwest Scale Productions, with photos of both the prototype and model for each one.
 
I am unable to load them to the files area, but hopefully they will find a home there.
 
Steve Hile


Re: Illinois Central 40' ss boxcar information

Chuck Cover
 

Thanks Tim.  Nice photo.

 

Chuck Cover

Santa Fe, NM


Re: Model brake component size comparison to prototype

Paul Woods <paul@...>
 

Hi Folks

For the benefit of anyone not familiar with the brass investment casting process: I do CAD design work for cast brass model railroad parts, along with other methods (laser, photoetch); the 3D-printed master is made 2% oversize and a rubber mould is made from it.  Today the rubber is transparent, and the mould is poured as one block then cut in half with a scalpel.  I always do my 3D-printed patterns with sprue gates but sometimes an area won't fill with metal properly, and any additional sprue gate can simply be carved out of the mould to correct the problem.  A special hard wax is then injected into the mould, making as many wax copies as required.  These waxes are then 'treed up', that is, stuck on a wax cylinder so that they look like branches on a tree, then the whole lot is dipped in high-temp plaster repeatedly to build up sufficient thickness.  The plaster mould is heated to run the wax out (hence the term 'lost wax'), so that molten brass, bronze or whatever can be poured into the resulting cavity.

My casting supplier tells me the shrinkage occurs in the rubber mould, not the metal casting because the column of molten brass in the cast keeps pressure on the mould as it cools, helping reduce shrinkage.  I usually see shrinkage i.e. low spots where the surface should be flat, where a large cavity is filled through a smaller sprue gate and so the metal in the sprue gate can freeze before the metal in the cavity, preventing more metal from flowing in.  Uneven cooling is the sworn enemy of metal casting of any kind, so large thick sections should be avoided; it will usually give a better result if a large part is either hollowed out or assembled from smaller parts.

It can be an expensive waste of time trying to burn styrene parts out of plaster moulds because styrenes can include fillers to make them harder, and these are not always combustible.  The ash can get pushed into the smaller nooks of the mould by inflowing metal, preventing the fine details from filling.

To the best of my knowledge, wax masters cannot be used for spin-casting pewter, because the type of rubber compound used (at least, by my local supplier) to make the mould produces heat as it sets, sufficient to soften or even melt styrene, so wax doesn't stand a chance.  This similarly rules out the use of 3D-printed resin masters, so if metal masters cannot be made by hand then the process has to be plastic master - brass casting - pewter casting.  This can still be worthwhile but you have to require huge numbers of something, such as tieplates, to justify the effort.  The tricky part is judging the amount of shrinkage to allow for because the brass casting process involves shrinkage and then so does the pewter casting process, so one multiplies the other.  I would love to find a spin-caster who can use wax patterns because that would reduce the costs quite a lot.

Regards
Paul Woods

Whangarei, NZ
NYCSHS #7172


Re: Reboxx 1.035 wheels

Schleigh Mike
 

How many sets do you need, Brian?

Mike Schleigh in Grove City, Penna.

On Sunday, April 5, 2020, 05:37:17 PM EDT, Brian Carlson via groups.io <prrk41361@...> wrote:


Does anyone know where any Reboxx 1.035 33“ wheels might exist on a hobby shop shelf or workbench someplace never to be used. I am looking for some for a project, either single or double insulated.

I miss reboxx wheels.

Brian J. Carlson



Re: Reboxx 1.035 wheels

Dave Parker
 

I found the same website last week,  They only seem to offer 0.110" wheels.  Reboxx were all 0.088" IIRC.

I really miss Reboxx.
--
Dave Parker
Swall Meadows, CA


Re: Reboxx 1.035 wheels

James Brewer
 

Brian,

I don't  have any Reboxx wheels in my stash; but I've noticed an ad in the last few issues of RMC for "JB Wheelsets" that says "slightly different name...same great product!"  There is a web site listed www.jbwheelsets.com

Other than noticing the ad I have no connection with this vendor.  Good luck on your search.

Jim Brewer


Reboxx 1.035 wheels

Brian Carlson
 

Does anyone know where any Reboxx 1.035 33“ wheels might exist on a hobby shop shelf or workbench someplace never to be used. I am looking for some for a project, either single or double insulated.

I miss reboxx wheels.

Brian J. Carlson


Re: circa 1946 freight car images

 

A color photo of these two has made the rounds before.

 

 

Thanks!
--

Brian Ehni

 

 

From: <main@RealSTMFC.groups.io> on behalf of Eric Hansmann <eric@...>
Reply-To: <main@RealSTMFC.groups.io>
Date: Sunday, April 5, 2020 at 2:12 PM
To: <main@RealSTMFC.groups.io>
Subject: Re: [RealSTMFC] circa 1946 freight car images

 

The second handhold on the left end of the car sides became a practice in the early 1930s.

 

I model 1926 and I need to remove the second handhold detail from many resin and plastic models.

 

 

Eric Hansmann

Murfreesboro, TN

 

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Tim O'Connor
Sent: Sunday, April 5, 2020 1:25 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] circa 1946 freight car images

 


And wouldn't that be a violation of the Safety Appliance regulations of the 1920's ??

I am amazed - thanks for pointing that out. The shop date is clear - dated 1950.




On 4/5/2020 2:14 PM, John Larkin via groups.io wrote:

For a fan of details, note the single handhold on the first car versus the double handhold on the second.  These are two otherwise similar (in gross detail) cars and the picture is a great way to show the sometimes minor differences off.

 

John Larkin

 

On Saturday, April 4, 2020, 11:49:12 PM CDT, john oseida via groups.io <xseinc@...> wrote:

 

 

There was a recently concluded eBay listing that had a number of images that might be of interest to the group including one of those not often photographed poultry cars:

 

 

Eight (8) b&w negatives of Vintage Freight Cars (PFE & Western Union inc...

Find many great new & used options and get the best deals for Eight (8) b&w negatives of Vintage Freight Cars (P...

 

 

 

 

Regards,

John Oseida

Oakville, ON

 

 

On Saturday, April 4, 2020, 2:06:52 p.m. EDT, Tim O'Connor <timboconnor@...> wrote:

 

 



Thanks Drew for the clarification. I'd love to see this done. It seems to be an
almost forgotten art at least for HO models.


On 4/4/2020 11:35 AM, Drew wrote:

Tim,

   I worked in a prototype model during my high school years. We used lost wax a few times. First a master is made and a mold made off that master, the mold was usually RTV rubber. Wax was poured in to that mold to make a second master which did shrink a bit. That wax master was then placed in foundry sand and hot metal poured in to the sand mold. The wax melted/vaporized and metal took its place, hence the name lost wax. It's been 20 years since I last did that but I do recall there was a bit of shrinkage in each step.

Drew Marshall in Philly, PA

Modeling the pre-Depression years.

Sent from TypeApp

On Apr 4, 2020, at 09:15, Tim O'Connor <timboconnor@...> wrote:


As I recall, all Cal-Scale detail components were OVERSIZE because they were used
for lost wax casting! In that process the plastic parts are for the molds and are
destroyed in the casting process, and the shrinkage produces parts that are closer
to scale.

Or am I wrong? :-)

Tim O'Connor

========================================

On 4/4/2020 9:00 AM, Lester Breuer wrote:

A comparison of several manufacturers’ model brake component measurements to Westinghouse prototype brake component measurements prepared by George Toman was sent to me for my use.  I asked George to share his measurements comparison on my blog.  If you are interested in the  comparison measurements, they are now available on my blog I have to share photos and writeup of projects on my Minneapolis & Northland Railroad Company. If would like to take a look please do at the following link:

 

http://mnrailroadcab100.blogspot.com/

 

Lester Breuer

 


--
Tim O'Connor
Sterling, Massachusetts


--
Tim O'Connor
Sterling, Massachusetts


--
Tim O'Connor
Sterling, Massachusetts


Re: Illinois Central 40' ss boxcar information

Eric Hansmann
 

Thanks, Ray!

 

 

Eric Hansmann

Murfreesboro, TN

 

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Ray Breyer via groups.io
Sent: Sunday, April 5, 2020 2:55 PM
To: main@realstmfc.groups.io; main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] Illinois Central 40' ss boxcar information

 

1941-1942, not 1934. Most of the IC's single sheathed cars were rebuilt during the war years, and it does appear that all of them with wood doors (40' and 50'') got the rienforcing plate at the bottom of the doors.

 

Ray Breyer
Elgin, IL

 

 

On Sunday, April 5, 2020, 02:42:56 PM CDT, Chuck Cover <chuck.cover@...> wrote:

 

 

Hi Eric,

 

In the Ted Culotta article in RMC that was referred to in Ben Hom’s response to me states that all of the car doors received steel reinforcing plates at the bottom of the doors during the 1934 rebuilding project.

 

Chuck Cover

Santa Fe, NM

 


Re: Illinois Central 40' ss boxcar information

Eric Hansmann
 

Thanks, Chuck. I also have this kit. I think I’ll cut the current door out of the side casting and remove all the door hardware. A Tichy replacement will be installed with companion half-door to reflect the as-built prototypes.

 

Then I’ll need new decal artwork….

 

 

Eric Hansmann

Murfreesboro, TN

 

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Chuck Cover
Sent: Sunday, April 5, 2020 2:43 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] Illinois Central 40' ss boxcar information

 

Hi Eric,

 

In the Ted Culotta article in RMC that was referred to in Ben Hom’s response to me states that all of the car doors received steel reinforcing plates at the bottom of the doors during the 1934 rebuilding project.

 

Chuck Cover

Santa Fe, NM

 


Re: Illinois Central 40' ss boxcar information

Ray Breyer
 

1941-1942, not 1934. Most of the IC's single sheathed cars were rebuilt during the war years, and it does appear that all of them with wood doors (40' and 50'') got the rienforcing plate at the bottom of the doors.

Ray Breyer
Elgin, IL


On Sunday, April 5, 2020, 02:42:56 PM CDT, Chuck Cover <chuck.cover@...> wrote:


Hi Eric,

 

In the Ted Culotta article in RMC that was referred to in Ben Hom’s response to me states that all of the car doors received steel reinforcing plates at the bottom of the doors during the 1934 rebuilding project.

 

Chuck Cover

Santa Fe, NM

 


Re: Illinois Central 40' ss boxcar information

Chuck Cover
 

Hi Eric,

 

In the Ted Culotta article in RMC that was referred to in Ben Hom’s response to me states that all of the car doors received steel reinforcing plates at the bottom of the doors during the 1934 rebuilding project.

 

Chuck Cover

Santa Fe, NM

 


Re: circa 1946 freight car images

Tony Thompson
 

John Larkin wrote:

For a fan of details, note the single handhold on the first car versus the double handhold on the second.  These are two otherwise similar (in gross detail) cars and the picture is a great way to show the sometimes minor differences off.

     What's actually odd about the photo is that the cars carry the post-1946 paint scheme of PFE, with both railroad emblems on both sides, yet that single grab iron has not been updated to the two required, fully a decade earlier. In general, PFE shops were pretty vigilant about things like this, so the foreground car is a surprise.

Tony Thompson




Re: circa 1946 freight car images

Eric Hansmann
 

The second handhold on the left end of the car sides became a practice in the early 1930s.

 

I model 1926 and I need to remove the second handhold detail from many resin and plastic models.

 

 

Eric Hansmann

Murfreesboro, TN

 

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Tim O'Connor
Sent: Sunday, April 5, 2020 1:25 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] circa 1946 freight car images

 


And wouldn't that be a violation of the Safety Appliance regulations of the 1920's ??

I am amazed - thanks for pointing that out. The shop date is clear - dated 1950.




On 4/5/2020 2:14 PM, John Larkin via groups.io wrote:

For a fan of details, note the single handhold on the first car versus the double handhold on the second.  These are two otherwise similar (in gross detail) cars and the picture is a great way to show the sometimes minor differences off.

 

John Larkin

 

On Saturday, April 4, 2020, 11:49:12 PM CDT, john oseida via groups.io <xseinc@...> wrote:

 

 

There was a recently concluded eBay listing that had a number of images that might be of interest to the group including one of those not often photographed poultry cars:

 

 

Eight (8) b&w negatives of Vintage Freight Cars (PFE & Western Union inc...

Find many great new & used options and get the best deals for Eight (8) b&w negatives of Vintage Freight Cars (P...

 

 

 

 

Regards,

John Oseida

Oakville, ON

 

 

On Saturday, April 4, 2020, 2:06:52 p.m. EDT, Tim O'Connor <timboconnor@...> wrote:

 

 



Thanks Drew for the clarification. I'd love to see this done. It seems to be an
almost forgotten art at least for HO models.


On 4/4/2020 11:35 AM, Drew wrote:

Tim,

   I worked in a prototype model during my high school years. We used lost wax a few times. First a master is made and a mold made off that master, the mold was usually RTV rubber. Wax was poured in to that mold to make a second master which did shrink a bit. That wax master was then placed in foundry sand and hot metal poured in to the sand mold. The wax melted/vaporized and metal took its place, hence the name lost wax. It's been 20 years since I last did that but I do recall there was a bit of shrinkage in each step.

Drew Marshall in Philly, PA

Modeling the pre-Depression years.

Sent from TypeApp

On Apr 4, 2020, at 09:15, Tim O'Connor <timboconnor@...> wrote:


As I recall, all Cal-Scale detail components were OVERSIZE because they were used
for lost wax casting! In that process the plastic parts are for the molds and are
destroyed in the casting process, and the shrinkage produces parts that are closer
to scale.

Or am I wrong? :-)

Tim O'Connor

========================================

On 4/4/2020 9:00 AM, Lester Breuer wrote:

A comparison of several manufacturers’ model brake component measurements to Westinghouse prototype brake component measurements prepared by George Toman was sent to me for my use.  I asked George to share his measurements comparison on my blog.  If you are interested in the  comparison measurements, they are now available on my blog I have to share photos and writeup of projects on my Minneapolis & Northland Railroad Company. If would like to take a look please do at the following link:

 

http://mnrailroadcab100.blogspot.com/

 

Lester Breuer

 


--
Tim O'Connor
Sterling, Massachusetts


--
Tim O'Connor
Sterling, Massachusetts


--
Tim O'Connor
Sterling, Massachusetts


Re: Anyone Want A First Generation SFRD Mechanical Reefer?

Charlie Vlk
 

All-
Why do an interchange freight car prototype that had a hundred or less examples?
Have we completely run out of missed cars with broader multi road application?
I don’t think we have many production single sheathed door and a half box cars and many of them had very long service lives and numbered in the thousands on many lines...and went all over.
Charlie Vlk

Don’t be fooled by the Lionel F3 syndrome- while a great railroad with attractive equipment, nothing else sells like it without Warbonnet paint....ATSF freight units sell about the same as high middle other roads. Even a ATSF layout might not “need” a scarce car that was quickly obsoleted.


Re: circa 1946 freight car images

Tim O'Connor
 


And wouldn't that be a violation of the Safety Appliance regulations of the 1920's ??

I am amazed - thanks for pointing that out. The shop date is clear - dated 1950.




On 4/5/2020 2:14 PM, John Larkin via groups.io wrote:
For a fan of details, note the single handhold on the first car versus the double handhold on the second.  These are two otherwise similar (in gross detail) cars and the picture is a great way to show the sometimes minor differences off.

John Larkin

On Saturday, April 4, 2020, 11:49:12 PM CDT, john oseida via groups.io <xseinc@...> wrote:


There was a recently concluded eBay listing that had a number of images that might be of interest to the group including one of those not often photographed poultry cars:






Regards,

John Oseida
Oakville, ON


On Saturday, April 4, 2020, 2:06:52 p.m. EDT, Tim O'Connor <timboconnor@...> wrote:




Thanks Drew for the clarification. I'd love to see this done. It seems to be an
almost forgotten art at least for HO models.


On 4/4/2020 11:35 AM, Drew wrote:
Tim,
   I worked in a prototype model during my high school years. We used lost wax a few times. First a master is made and a mold made off that master, the mold was usually RTV rubber. Wax was poured in to that mold to make a second master which did shrink a bit. That wax master was then placed in foundry sand and hot metal poured in to the sand mold. The wax melted/vaporized and metal took its place, hence the name lost wax. It's been 20 years since I last did that but I do recall there was a bit of shrinkage in each step.

Drew Marshall in Philly, PA

Modeling the pre-Depression years.

Sent from TypeApp
On Apr 4, 2020, at 09:15, Tim O'Connor <timboconnor@...> wrote:

As I recall, all Cal-Scale detail components were OVERSIZE because they were used
for lost wax casting! In that process the plastic parts are for the molds and are
destroyed in the casting process, and the shrinkage produces parts that are closer
to scale.

Or am I wrong? :-)

Tim O'Connor

========================================

On 4/4/2020 9:00 AM, Lester Breuer wrote:

A comparison of several manufacturers’ model brake component measurements to Westinghouse prototype brake component measurements prepared by George Toman was sent to me for my use.  I asked George to share his measurements comparison on my blog.  If you are interested in the  comparison measurements, they are now available on my blog I have to share photos and writeup of projects on my Minneapolis & Northland Railroad Company. If would like to take a look please do at the following link:

 

http://mnrailroadcab100.blogspot.com/

 

Lester Breuer



--
Tim O'Connor
Sterling, Massachusetts

--
Tim O'Connor
Sterling, Massachusetts

--
Tim O'Connor
Sterling, Massachusetts


Re: Illinois Central 40' ss boxcar information

Bill Welch
 

that has has always been my assumption. I have several photos of this car and they all have the metal plate.

Bill Welch


Re: circa 1946 freight car images

John Larkin
 

For a fan of details, note the single handhold on the first car versus the double handhold on the second.  These are two otherwise similar (in gross detail) cars and the picture is a great way to show the sometimes minor differences off.

John Larkin

On Saturday, April 4, 2020, 11:49:12 PM CDT, john oseida via groups.io <xseinc@...> wrote:


There was a recently concluded eBay listing that had a number of images that might be of interest to the group including one of those not often photographed poultry cars:






Regards,

John Oseida
Oakville, ON


On Saturday, April 4, 2020, 2:06:52 p.m. EDT, Tim O'Connor <timboconnor@...> wrote:




Thanks Drew for the clarification. I'd love to see this done. It seems to be an
almost forgotten art at least for HO models.


On 4/4/2020 11:35 AM, Drew wrote:

Tim,
   I worked in a prototype model during my high school years. We used lost wax a few times. First a master is made and a mold made off that master, the mold was usually RTV rubber. Wax was poured in to that mold to make a second master which did shrink a bit. That wax master was then placed in foundry sand and hot metal poured in to the sand mold. The wax melted/vaporized and metal took its place, hence the name lost wax. It's been 20 years since I last did that but I do recall there was a bit of shrinkage in each step.

Drew Marshall in Philly, PA

Modeling the pre-Depression years.

Sent from TypeApp
On Apr 4, 2020, at 09:15, Tim O'Connor <timboconnor@...> wrote:

As I recall, all Cal-Scale detail components were OVERSIZE because they were used
for lost wax casting! In that process the plastic parts are for the molds and are
destroyed in the casting process, and the shrinkage produces parts that are closer
to scale.

Or am I wrong? :-)

Tim O'Connor

========================================

On 4/4/2020 9:00 AM, Lester Breuer wrote:

A comparison of several manufacturers’ model brake component measurements to Westinghouse prototype brake component measurements prepared by George Toman was sent to me for my use.  I asked George to share his measurements comparison on my blog.  If you are interested in the  comparison measurements, they are now available on my blog I have to share photos and writeup of projects on my Minneapolis & Northland Railroad Company. If would like to take a look please do at the following link:

 

http://mnrailroadcab100.blogspot.com/

 

Lester Breuer



--
Tim O'Connor
Sterling, Massachusetts

--
Tim O'Connor
Sterling, Massachusetts

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