Date   
Re: D&RGW 68038 12 panel 40' box car

Garth Groff and Sally Sanford
 

Andy and friends,

Attached is a shot of D&RGW AX68032, probably at Glenwood Springs circa 2000 (yes it's fuzzy, but it was shot from the moving California Zephyr). This car was originally in the same class as your photo, except it is one of the famous "Cookie Box" conversions. As built, there were five blocks of these D&RGW 12-panel cars, all with the full side sills, 10' 4" IH, and Duryea underframes (all from Pressed Steel Car Co.): 

68000-68399 delivered in 1939 with 4/5 ends, Youngstown doors, 7-rung ladders and wood running boards

68400-68899 delivered in 1940 with 4/5 ends, Youngstown doors, 7-rung ladders and various steel running boards

68900-69399 delivered in 1941 with 4/5 ends, Youngstown doors, 7-rung ladders and various steel running boards

69400-69899 delivered in 1942 with 4/5 ends, Superior 7-panel doors, 7-rung ladders and various steel running boards

67500-67999 delivered in 1946 with 4/4 ends, a mix of Youngstown or Superior doors, 8-rung ladders, ASF A3 trucks

The "Cookie Boxes" numbered 60000-60076 were heavily insulated conversions drawn from various groups of the above cars rebuilt in three lots, 1954-55, 1959 and 1961. Our group of particular interest as steam-era cars is 60000-60036, the 1954-1955 group which were drawn at random from the first four blocks cited above (four cars from the 1946 group with the 8-rung ladders and 4-4 ends were from the 1959 or 1961 conversions, so don't go there). These cars were loaded at the Keebler bakery in Denver, and sent to distribution centers throughout the west, though I've read this was principally to Salt Lake City. More research needed here by those who care! AFAIK, there never were wood-sided "Cookie Boxes" as Silver Streak would have had us believe.

Most of the above information comes from Jim Eager's RIO GRANDE COLOR GUIDE TO FREIGHT AND PASSENGER EQUIPMENT (Morning Sun, 1996). There was an article chiefly on the D&RGW cars, plus photos of other 12-panel boxcars, in an issue of MODEL RAILROADING (no date or author on the pages--my copy is clipped from the magazine). This was followed on the same issue by Bill Wright's kitbash article using cut-down 50' sides from a Pacific HO/Walthers car, mixed with a roof and modified ends from an Athearn 40' boxcar. Not up to modern standards, but perhaps useful background information. I made my car using a C&BT Shops 10' 6" model with a scratch-built Duryea underframe (what's 2" among friends?).

Yours Aye,

Garth Groff  🦆


On Wed, Dec 25, 2019 at 4:56 PM Andy Carlson <midcentury@...> wrote:
I found some pictures today which added to my understandings of the D&RGW fleet of 12 panel riveted steel box cars. A class in the 68xxx series were built pre-war and had inside height of 10'4" and had 4/5 Dreadnaught ends with above average spacing between the top rib and the end top. Enclosed is a RRPHOTOGS scan of DRGW #68038 with a build date of 9-39 (?) and reweigh date of 5-54. Still has its pre-war Youngstown door and rectangular panel roof. Like the later Rio Grande 12 panels, this car also has a full length side sill. Was this a RG added feature as not many 1939 era box cars seem to have straight side sills?
-Andy Carlson   Ojai CA



Re: 1930s Runbys of freight trains

Thomas Evans
 

Why do they feel they have to put those very annoying time stamps on these things! - Tom

Re: D&RGW 68038 12 panel 40' box car

Bill Welch
 

With Improved Dreadnaught ends this is not the same car although it does demonstrate the the D&RGW like the straight sills.

Bill Welch

1930s Runbys of freight trains

gary laakso
 

This is a wonderful, fast paced vid on Midwest steam and streamliners in the 1930s with a couple of Runbys of freight trains from the cab of the Zephyr:

 

https://archive.org/details/86544RailwaySectionsEscapeToLifeMDRexferMosVwr

 

Gary Laakso

Northwest of Mike Brock

Re: D&RGW 68038 12 panel 40' box car

Barry Bennett
 

Andy

attached builder photo.

Barry

On Wed, 25 Dec 2019 at 21:56, Andy Carlson <midcentury@...> wrote:
I found some pictures today which added to my understandings of the D&RGW fleet of 12 panel riveted steel box cars. A class in the 68xxx series were built pre-war and had inside height of 10'4" and had 4/5 Dreadnaught ends with above average spacing between the top rib and the end top. Enclosed is a RRPHOTOGS scan of DRGW #68038 with a build date of 9-39 (?) and reweigh date of 5-54. Still has its pre-war Youngstown door and rectangular panel roof. Like the later Rio Grande 12 panels, this car also has a full length side sill. Was this a RG added feature as not many 1939 era box cars seem to have straight side sills?
-Andy Carlson   Ojai CA



D&RGW 68038 12 panel 40' box car

Andy Carlson
 

I found some pictures today which added to my understandings of the D&RGW fleet of 12 panel riveted steel box cars. A class in the 68xxx series were built pre-war and had inside height of 10'4" and had 4/5 Dreadnaught ends with above average spacing between the top rib and the end top. Enclosed is a RRPHOTOGS scan of DRGW #68038 with a build date of 9-39 (?) and reweigh date of 5-54. Still has its pre-war Youngstown door and rectangular panel roof. Like the later Rio Grande 12 panels, this car also has a full length side sill. Was this a RG added feature as not many 1939 era box cars seem to have straight side sills?
-Andy Carlson   Ojai CA



Re: SN Boxcar 2150

Garth Groff and Sally Sanford
 

Bob,

SN 2319 was one of the ex-WP steel-end cars from series that came to the SN in 1947/48. Most, if not all, appear to have come from WP series 316001-318500, and were 16001-18500 boxcars that were not converted to Andrews trucks as the ban on archbars neared (the series does not appear in the 1940 ORER I have, but is my next one from 1943). They were not allowed in interchange except with WP's wholly-owned subsidiaries, Sacramento Northern and Tidewater Southern. Strangely, most of the ex-WP cars sent to the SN I have been able to identify were actually the retreaded ventilators rebuilt circa 1929 as plain boxcars with added steel ends. On the SN they were renumbered 2301-2328, as I noted in the earlier post. The sale to the SN is covered by AFE 3-47, dated 5/7/48, which does not mean much, and on the WP/SN was often just a paperwork filing date. I see no AFE covering the conversion of these cars to AB brakes, which could mean that had already been done by the WP, or it could mean that the AFE was lost by the time the list was compiled (there are many gaps in my list).

SN 2129-2153 (less three cars that were lost earlier) were retired on AFE 1-47, dated 12/31/47, which was a common date for WP/SN bookkeeping. The were unretired on AFE 10-48 dated 10/9/48, had AB brakes installed and were returned to service as 2329-2350.

AFAIK, conversion of archbar trucks to Andrews did not start until 1954, unless there are missing AFEs. My list ends in 1957, and nothing about truck replacements is specifically mentioned. Many cars later photographed on Andrews trucks were last reweighed in 1954. No such cars on the SN were ever converted to so-called Bettendorf trucks, and I have seen no evidence that any on the WP were either.

Yours Aye,

Mungo Napier, Laird of Mallard Lodge  🦆


On Wed, Dec 25, 2019 at 11:22 AM Bob Webber <rgz17@...> wrote:
Possibly Oakland......  Not sure if these were the series mentioned...

At 07:14 AM 12/25/2019, you wrote:
These cars served in original condition on the reorganized Sacramento Northern Railway until circa 1948 when the surviving 22 were retired. They still rolled on arch bar trucks and had K-brakes. They were replaced by 28 similar boxcars with steel ends from the WP, renumbered SN 2301-2328 (see below).

Eshelman Tank Cars

Matt Goodman
 

Hi all. I’m modeling Circleville Ohio, which contained one of the John W Eshelman & Sons feed mills - a substantial facility. I recently came across multi-paged booklet (printed 1947-ish) that contains a few photos of their facilities and “modern methods of transportation” which included the attached photo of a tank car lettered in the company name. I presume this was used to transport molasses.

The car number is GATX 24626 (or close). What type of tank car is this, and has anyone produced a decal set for it? Molasses cars have been discussed in detail on this list, but before discovering this, I didn’t think I had a need to know about them.

As an aside, the company had facilities in Lancaster, PA, Tampa, FL, Circleville, OH, and one other location. The company was eventually sold to Carnation once a generation that showed no interest in running the business surfaced. The mill in Circleville eventually burned to the ground (in the nineties, I believe).


Matt Goodman
Columbus, Ohio, US

Re: SN Boxcar 2150

Bob Webber
 

Possibly Oakland......  Not sure if these were the series mentioned...

At 07:14 AM 12/25/2019, you wrote:
These cars served in original condition on the reorganized Sacramento Northern Railway until circa 1948 when the surviving 22 were retired. They still rolled on arch bar trucks and had K-brakes. They were replaced by 28 similar boxcars with steel ends from the WP, renumbered SN 2301-2328 (see below).
_._,_._,_

Bob Webber

Re: SN Boxcar 2150

espee4441
 

Stayed overnight in West Sacramento this Sunday. Was wondering if it was all SN or SN/WP and how the heck did they keep the Friendly out since the Cal-P main ran through Yolo County? Surprising to hear they didn't have a scale in West Sac with the port being there, so did the WP yard on the other side of downtown have one and the SN ran transfers? My apology if this strays from the list rules.

Tony Pawley

Re: SN Boxcar 2150

radiodial868
 

I have 6 of Martin's kits in the stash and are targeted for a 2020 start, so close up detail pics like this are greatly appreciated Garth.
RJ Dial
Burlingame, CA

SN Boxcar 2150

Garth Groff and Sally Sanford
 

Good Friends,

Happy holidays to you all! Today I have a gift for you all, a pair steam-era survivor photos from which we hopefully can all learn something, or at least have some fun. Both photos are of the same boxcar at different stages of its life. 

The first photo shows Sacramento Northern 2150 in a close-up of its lettering. The photo was taken by Kenneth C. Jenkins, likely at Yuba City, California, early in 1947. (I own a large block of his SN negatives). I am reasonably certain Jenkins also shot the car in its entirety, but only this partial view was among the photos that came to me. (GRRR!)

In 1919 and stretching into 1920, the Sacramento Northern Railroad received 25 boxcars from Mt. Vernon as SNRR 2129-2153. These 40' cars had steel underframes, 2723 cubic-foot wooden superstructures with an 8' IH, and a capacity of 80,000 pounds. A vertical sliding lumber/grain door was built into the A end. 

These cars served in original condition on the reorganized Sacramento Northern Railway until circa 1948 when the surviving 22 were retired. They still rolled on arch bar trucks and had K-brakes. They were replaced by 28 similar boxcars with steel ends from the WP, renumbered SN 2301-2328 (see below). The ex-WP cars were rebuilt with AB brakes and Andrews trucks for general service (they were apparently all still on arch bar trucks and in restricted-service series 316001-318500). For some reason unknown to me, the 22 wood-bodied cars were returned to service in 1948 and renumbered 2329-2350. In 1954 there was a general housecleaning of these cars. Some were given Andrews trucks and probably AB brakes at this time, suggested by 1954 reweigh dates in photos. Others went into MW service on archbar trucks and survived into the 1970s. Apparently the last on the SN was a stationary tool car MW02335 at Yuba City. This car became a gift shop in Yountville, California (and may still be there for all I know).

As for our friend, SN 2150, it was renumbered 2349 (the renumbering was at random). In 1954, it was one of the cars which went into MW service as MW 92, one of the last SN cars to get new MW numbers. (Conversions after MW 94 just had "MW 0" added to their original numbers). MW 92 was one of several SN boxcars which surfaced in the mid-1970s at a shopping plaza in Alameda, California, known as "The Factory". The venture failed, and some of the cars were scrapped, including MW 92, though its arch bar trucks are now under sister SN 2350 at the California State Railroad Museum in Sacramento.

The SNRR cars were identical to Western Pacific's series 16001-18300, delivered in two batches in 1917 and 1918, and similar to WP ventilators 30001-30200 (later rebuilt as plain boxcars and filling the original series out to 18500). The WP cars were all rebuilt around 1929-1931 with steel ends, and many soldiered on into the 1950s in revenue service. A few lasted in various forms as maintenance cars until the UP take-over in the 1980s. WP sold 28 (mostly former ventilators) to subsidiary SNRY in 1948 which became 2301-2328, and at least two of these survive in museums.

There has been some speculation that the SNRR cars were an add-on to the WP order. At this time the SNRR was still independent of the WP. The SNRR might have gotten a price break on their cars since the assembly line at Mt. Vernon was probably still "hot", so to speak, but the additional order was not directly connected to the WP.

Mt. Vernon also built identical cars in 1915 for the QA&P as 500-524. There were more cars built for the U.S. Army and for the Compania de Real del Monte Y Pachuca, presumably a line in Mexico. I have seen builder's photos of the later two examples, but don't know how many cars were built, or when they were delivered. Some of the WP cars were sold off in later years to shortline operators. Known second-hand owners were the Stockton Terminal & Eastern, Pickering Lumber Company, and Tucson, Cornelia & Gila Bend. The lone ST&E car is preserved at the California State Railroad Museum, and a Pickering car is at Railtown 1897.

Martin Loftin/Sunshine offered several variants of the SN and WP cars, and QA&P examples as well.

Now back to our photo. There are some interesting things to learn here. Though it is hard to read, the car was repacked at Yuba City, apparently on 1-3-47. For some reason, the car does not have a light weight or a reweigh date, just the YC station code. AFAIK, Yuba City had the SN's only car scale, at least in later years (there should have been another serving the line between Sacramento and Oakland, but I have found no references to it). Repacking should not have been enough to change the weight, so some other modification might have been performed, or the car's weight time might just have run out. So apparently the car is awaiting a reweigh and remarking, which is why I am reasonably certain it was photographed at Yuba City. The original starred load limit data seems to be fading out to the right. The lettering at lower left says "ARCH BAR TRUCK, DO NOT LOAD, BEYOND RAIL OF, WPRR-SNRY-TSRY."  TSRY is the Tidewater Southern, another WP-owned shortline. On other cars this warning is painted on a light-colored panel, presumably yellow. Here it is painted directly onto the mineral red car side. Also note the metal patch just below the second "A" in Sacramento.

The second photo, my own, shows the car in Alameda shortly before its inglorious end. The brake staff and wheel are missing. There appears to have been some sort of equipment added to the end below the running board, possibly a post-retirement light fixture. "MW 92" on the side is faded, but can still be read. Note the lack of a brake platform; there were no brake platforms on either the wooden or steel-end cars.

I hope this exercise has been of interest to you all.

Yours Aye,

Mungo Napier, Laird of Mallard Lodge  🦆

Re: Photo: Wabash Gondola 13000

G.J. Irwin
 

Thanks for sharing.  I just did a compare to the N Scale Roco aka Atlas First Generation / Roco / Walthers tooling... The 1:160 car is not bad for a model first offered more than fifty years ago, but not a match.  The Roco cars have a short ladder versus grab irons on the right, and exaggerated spacing in the wood sides.

Cheers,
George Irwin

Re: 3D printing (Was: New early P&R steel.....)

Dennis Storzek
 

On Mon, Dec 23, 2019 at 01:37 PM, <dalemuir2@...> wrote:

That means accuracy should be within approximately 0.1% to 0.2%

For reference, Shapeways specification for Fine Detail Plastic is way looser: ±0.3- 0.7 mm for every 100 mm

I don't do 3D printer work, but I do know something about designing plastic parts. I'm also familiar with "jobbing" work out to other shops.

It doesn't make any difference what tolerances the Polyjet SHOULD be able to hold... Shapeways has told you what THEY guarantee to hold, and that's all you can expect to get. They publish that their maximum shrinkage is .7%. If your parts are shorter than this, they owe you replacement parts. If not, you got what you paid for.

It may come as a surprise to some people, but injection molded parts also have problems with differential shrinkage. The resin manufacturers publish guidelines for shrinkage, always as a range, typically .004 to .006 inch per inch for high impact styrene, almost four times that for acetal. The part designer has to take this into account for any parts that will be used in assembly. Slotted holes are a must for long parts. These should be easy to do in the solid model, and the printer will faithfully replicate them. Likewise, unlike the old saw about not forcing a square peg into a round hole, that's exactly what you want to do (more typically round pegs into square or hex shaped holes). This allows some space for an overly tight peg to displace material into. There is no model building material that can guarantee "line-on-line" fits, not even photoetchings. The part doesn't shrink, but there is always the possibility of over or under etch.

If the ends of long parts need to visually align and you don't have control of the process that makes them, you have to design in someplace where you can take a little tuck if needed. If the end plates of your girders have exposed rivet detail, maybe they should be separate parts so the main girders can all be sanded to the same length, then the ends applied. I ran into this when I was designing brass replacement sides to fit under Rivarossi passenger car roofs. I measured three random roofs, and came up with an .018" difference, so, on the theory that I hadn't found the longest possible, I made the letterboards .006" longer than the longest, with the instruction that the modeler must file them to fit the roof HE has, then center the doors in the resulting opening. .012" over the width of a .280" wide door isn't going to be noticeable, but a .012" gap at the corner of the letterboard certainly would be.

The good designer anticipates the problems and chooses where he wants to deal with them.

Dennis Storzek

Re: 3D printing (Was: New early P&R steel.....)

C J Wyatt
 

re: Formlabs 3L

Looks impressive to me:

https://formlabs.com/3d-printers/form-3l/

Probably has an impressive price, too.

Jack Wyatt

Re: 3D printing (Was: New early P&R steel.....)

Tom Madden
 

I worked for a 3D printing company from 1995 through 2016 and will back up Ryan's comments 100%. I'll also stress the point that parts that have to match or fit together have to be printed together, and in the same orientation. That's also true for resin casting because there is typically some small dimensional variation from batch to batch. 

These jet printers are touchy machines if you want the best surface quality, and the material is very expensive. I had access to two Stratasys Polyjet printers, a large Connex and a smaller, earlier model. For HO Pullman sides I had much better luck with the smaller machine, but only because the production folks would let me sneak in one "test" run right after a full nozzle alignment and purge sequence. After that first run the machine was fine for production printing for quite a while, but that first run gave the best prints.

I share Ryan's puzzlement about why anyone would use Shapeways' Fine Detail Plastic for production parts unless there was absolutely no alternative - i.e. very small and complex parts, figurines, etc. The material is expensive, has poor structural qualities, is dimensionally unstable and brittle, will cold flow if unsupported, and despite Shapeways' claim that it's "heatproof to 132 degrees F", it certainly softens at a considerably lower temperature. 

Shapeways works for me because I work with what they _can_ do, not with what I think they should do. And except for very small appearance items like the little pump and brake cylinder I showed earlier, everything they print for me is intended to be a resin casting master. All my jobs are also "print it anyway" so they bypass Shapeways' design audits and go directly to the printers. That means I get my parts faster but there are no free reruns if the print is unsatisfactory. Also I can't offer print it anyway parts to others, but that's OK because I don't trust the Fine Detail Plastic material enough to be comfortable selling such parts to others.

Tom Madden

Re: 3D printing (Was: New early P&R steel.....)

Ryan Mendell
 

Ok here goes.

1. Yes, Parts can come out different sizes if printed along its length or across its length.

2. Out of the printer I can say it will hold +\- 0.002” over an inch, but it can shrink or bend when in the wax removal oven.  It will shrink different percentages depending on the print orientation in my experience. It can also vary between bottles of material. I think Shapeways has taken into account the other variables in their spec.  3D Systems is giving best case scenario, remember they are trying to sell printers.  Shapeways or anyone else is going to have the same issues if trying to print so many of the same part, especially if they are using more than one printer to print your order.  Its very possible some parts were printed along the length and some across it.

3.  As for making masters for resin, I never have to print more than two of a part(two sides or two ends for example) and I print them both at the same time in the same orientation. If the size is a bit off, no big deal as long as they are the same.
 
 I am a bit perplexed why you are printing so many of the same part, it would be much more cost effective to make a mold of each part you need and cast the rest.  Prints are expensive compared to casting.

  As for using 3D prints for low volume production, a bit too expensive at this point. A 2 kg bottle of material for the Projets costs almost a thousands bucks. Support material is about half that.  They also purge a lot of material  to keep the jets that aren’t used in each pass from clogging up.  Casting Resin is way cheaper.  

 I know some others are printing full body cars on printers like the Form2, for me the parts show too many layer or support effects.  Too each there own.

4.  The Form printers and others like it make very nice parts like figures and such. But as Dennis pointed out they are made like paper printers, I don’t see the accuracy coming out of these.   I have printed an End I have designed on more than 20 different printers now including the Form2.  They were all unusable, except for the parts from the Projets or the Multijet printers from Stratasys like the Connex series. 

In fact the master pattern I use for one of my kits uses this End and has three pairs on it. Two sets were printed on the Strataysys Connex and the other set on the Projet, I challenge anyone to figure out which came from what printer.

The ends from all the other cheaper consumer level printers come out with massive warps or poor resolution.

  The Form3 has peeked my interest but I am not buying one until I can test print the same End on it and see if it comes out warped or not and with the same quality as the jet style printers. These style printers are challenged by thin flat parts like ends and doors IMHO,  I really hope it’s a break through though.

Printing an end with an easily removed box on the back may solve the warping issues, something to try out as it may help resist the peel effects when the head raises.

Also I don’t work in the 3D printing industry per se, I manage a Machine shop at a University where we make specialized devices for research.  We have every tool under the sun and a bunch of 3D printers.  I’ve worked with almost every type of 3D printer over the last fifteen years. The best part though is how every company is trying to sell us there latest 3D printer,  I get them to test print my same End as a comparison to our other printers.😜  It makes it easy for me to compare them and I get to do some side research to see if it’s worth it for me to buy one personally.  I haven’t bought one yet.

Ryan


On Dec 23, 2019, at 4:37 PM, dalemuir2@... wrote:



Hi Ryan,

It's great to hear from a subject matter expert that actually works in this industry . Thank you for your excellent explanation.

 

For reference, here is a quote from both Projet 3600 and Projet 5500 specs:

Accuracy (typical) ±0.001-0.002 inch per inch (0.025-0.05 mm per 25.4 mm) of part dimension. Accuracy may vary depending on build parameters, part geometry and size, part orientation, and post-processing.

End quote

That means accuracy should be within approximately 0.1% to 0.2%

For reference, Shapeways specification for Fine Detail Plastic is way looser: ±0.3- 0.7 mm for every 100 mm

 

Would you please answer these questions?

 

1.       Is part orientation a factor in process control?

2.       I've had multiple copies of the same 205mm long model made in Smoothest Fine Detail Plastic vary in length -0.5mm to about -1.0mm, even from the same order. Yet, about 60% of the same part are the correct length. I've been stonewalled by Shapeways' Quality Control person , saying that the lengths are within specification. So the question to you is "Are these dimensional inconsistencies a limitation of the machine, or could Shapeways do something better?"

3.       If I interpret the specs correctly, my 205mm long part should be within ±0.2mm to ±0.4mm of 205mm, or between 204.6mm and 205.4mm. A difference of 0.8mm would mean the parts might not fit another printed part or a part from another source. 0.8mm is almost 3 inches in HO scale. My question then is "How can such 3D parts be used to create masters or molds?" "How can 3D printed parts be used for low volume parts instead of injection molded parts?"

4.       Finally, as you probably know, Formlabs is coming out with the Form 3L late next year. I didn't see any specification on accuracy for the Form3 on their web site. In your opinion, would a  Low Force Stereolithography (LFS) machine like the Form3 give more accuracy?

 

Thank you for taking the time to answer these questions. My hope was to be able to create low volume kits for items I need and share these with others. However, I can't do that with large parts due to the accuracy limitations with large parts, such as a passenger car or bridge girder.

 

Dale Muir

Geneva, IL

 

 

From: main@RealSTMFC.groups.io [mailto:main@RealSTMFC.groups.io] On Behalf Of Ryan Mendell
Sent: Saturday, December 21, 2019 12:26 PM
To: main@realstmfc.groups.io
Subject: Re: [RealSTMFC] 3D printing (Was: New early P&R steel.....)

 

I would like to offer to shed some light on the Jet printing Process, as it seams there is a genuine interest by this group to further understand the process.  At work I manage and run both a 3D Systems Projet 3600 and Projet 5500 printers.  These are what are know as ‘Polyjet' or ‘Multijet' 3d printers and is what Shapeways uses for their Fine Detail processes.  The 3600 has a build area of about 8" x 12” inches and the 5500 16” x 20”. 

 

The print head on these printers has two rows of jets, one for the model or body material as Tom called it and another for the wax or support material.  The print head on the Projet 5500 has 2400 jets across a width of 8”.  This works out to 300DPI.  To achieve higher resolution the print head shifts sideways by a pixel width and makes two passes for each layer to achieve 600DPI.  For 750DPI it makes three passes for each layer and shifts both left and right of the first pass by 0.66 of a pixel width.  I may have the math wrong for 750 DPI but I hope you get the idea.

 

After each layer is deposited at what ever DPI selected, the head has a spinning roller that pushes or forces the deposited resin down into the previous layer.  Behind the roller is a knife blade that slices the resin layer to the choose layer thickness. The final step is the head has a UV light that turns on and cures the layer.  The 5500 head is only half the width of the build plate and must make a shift half the build plate width to print the entire 16” width.  The 3600 print head is the full width of the build plate.  

 

Part print orientation is critical to get better printed parts. The head moves in the x axis.  Thus if you want to orient your part along or across the print direction you need to pick which side of your part aligns with the X axis in your CAD file.  I always design models as flat kits with the show side facing up on the build plate so no wax is used to support the critical faces of the part.  

 

To answer an earlier question as to the rigidity of these machines.  They are built like machine tools.  They have heavy frames, use servo motors(not stepper motors) and linear guide way bearings just like the CNC mills we have at work also.  The Projet 5500 weighs in at 3000lbs. 

 

As far as process control.  There really isn’t any.  You load the part into the software, Orient it the way you want and press the print button.  The only human involvement is the support removal.  The wax is melted off in an oven, and then the last of it is removed in an ultrasonic cleaner.  The big issue is warpage caused when the part is in the oven.  I no longer remove wax for model parts in the oven.  I remove it with a hobby knife and a dissolve the last of it with alcohol.  Thus avoiding warpage.  Unfortunately Shapways doesn’t offer manual removal of support material.  If your part is not symmetrical, or has thin sections and thick sections there is a good chance it will warp in the support removal oven.  You end up with bent parts or dimensional issues. 

 

I hope this explains things a bit.

 

Ryan Mendell

 

 

 

 

 



On Dec 21, 2019, at 1:25 AM, Tom Madden via Groups.Io <pullmanboss@...> wrote:

 

Fine detail is a jet printing process. I believe the jet printers Shapeways is using are 600 x 600 DPI X & Y, and at 16 microns per layer the Z is 1600 DPI. (3D Systems has 750 x 750 DPI machines with 13 micron layer capability, and 1600 x 900 but only for 32 micron layers.) 

If these don't sound like very high resolution printers, remember that there are two jet nozzels per pixel - you can place either wax or body material at each location. 

Tom Madden

 

Re: 3D printing (Was: New early P&R steel.....)

dalemuir2@...
 

Hi Ryan,

It's great to hear from a subject matter expert that actually works in this industry . Thank you for your excellent explanation.

 

For reference, here is a quote from both Projet 3600 and Projet 5500 specs:

Accuracy (typical) ±0.001-0.002 inch per inch (0.025-0.05 mm per 25.4 mm) of part dimension. Accuracy may vary depending on build parameters, part geometry and size, part orientation, and post-processing.

End quote

That means accuracy should be within approximately 0.1% to 0.2%

For reference, Shapeways specification for Fine Detail Plastic is way looser: ±0.3- 0.7 mm for every 100 mm

 

Would you please answer these questions?

 

1.       Is part orientation a factor in process control?

2.       I've had multiple copies of the same 205mm long model made in Smoothest Fine Detail Plastic vary in length -0.5mm to about -1.0mm, even from the same order. Yet, about 60% of the same part are the correct length. I've been stonewalled by Shapeways' Quality Control person , saying that the lengths are within specification. So the question to you is "Are these dimensional inconsistencies a limitation of the machine, or could Shapeways do something better?"

3.       If I interpret the specs correctly, my 205mm long part should be within ±0.2mm to ±0.4mm of 205mm, or between 204.6mm and 205.4mm. A difference of 0.8mm would mean the parts might not fit another printed part or a part from another source. 0.8mm is almost 3 inches in HO scale. My question then is "How can such 3D parts be used to create masters or molds?" "How can 3D printed parts be used for low volume parts instead of injection molded parts?"

4.       Finally, as you probably know, Formlabs is coming out with the Form 3L late next year. I didn't see any specification on accuracy for the Form3 on their web site. In your opinion, would a  Low Force Stereolithography (LFS) machine like the Form3 give more accuracy?

 

Thank you for taking the time to answer these questions. My hope was to be able to create low volume kits for items I need and share these with others. However, I can't do that with large parts due to the accuracy limitations with large parts, such as a passenger car or bridge girder.

 

Dale Muir

Geneva, IL

 

 

From: main@RealSTMFC.groups.io [mailto:main@RealSTMFC.groups.io] On Behalf Of Ryan Mendell
Sent: Saturday, December 21, 2019 12:26 PM
To: main@realstmfc.groups.io
Subject: Re: [RealSTMFC] 3D printing (Was: New early P&R steel.....)

 

I would like to offer to shed some light on the Jet printing Process, as it seams there is a genuine interest by this group to further understand the process.  At work I manage and run both a 3D Systems Projet 3600 and Projet 5500 printers.  These are what are know as ‘Polyjet' or ‘Multijet' 3d printers and is what Shapeways uses for their Fine Detail processes.  The 3600 has a build area of about 8" x 12” inches and the 5500 16” x 20”. 

 

The print head on these printers has two rows of jets, one for the model or body material as Tom called it and another for the wax or support material.  The print head on the Projet 5500 has 2400 jets across a width of 8”.  This works out to 300DPI.  To achieve higher resolution the print head shifts sideways by a pixel width and makes two passes for each layer to achieve 600DPI.  For 750DPI it makes three passes for each layer and shifts both left and right of the first pass by 0.66 of a pixel width.  I may have the math wrong for 750 DPI but I hope you get the idea.

 

After each layer is deposited at what ever DPI selected, the head has a spinning roller that pushes or forces the deposited resin down into the previous layer.  Behind the roller is a knife blade that slices the resin layer to the choose layer thickness. The final step is the head has a UV light that turns on and cures the layer.  The 5500 head is only half the width of the build plate and must make a shift half the build plate width to print the entire 16” width.  The 3600 print head is the full width of the build plate.  

 

Part print orientation is critical to get better printed parts. The head moves in the x axis.  Thus if you want to orient your part along or across the print direction you need to pick which side of your part aligns with the X axis in your CAD file.  I always design models as flat kits with the show side facing up on the build plate so no wax is used to support the critical faces of the part.  

 

To answer an earlier question as to the rigidity of these machines.  They are built like machine tools.  They have heavy frames, use servo motors(not stepper motors) and linear guide way bearings just like the CNC mills we have at work also.  The Projet 5500 weighs in at 3000lbs. 

 

As far as process control.  There really isn’t any.  You load the part into the software, Orient it the way you want and press the print button.  The only human involvement is the support removal.  The wax is melted off in an oven, and then the last of it is removed in an ultrasonic cleaner.  The big issue is warpage caused when the part is in the oven.  I no longer remove wax for model parts in the oven.  I remove it with a hobby knife and a dissolve the last of it with alcohol.  Thus avoiding warpage.  Unfortunately Shapways doesn’t offer manual removal of support material.  If your part is not symmetrical, or has thin sections and thick sections there is a good chance it will warp in the support removal oven.  You end up with bent parts or dimensional issues. 

 

I hope this explains things a bit.

 

Ryan Mendell

 

 

 

 

 



On Dec 21, 2019, at 1:25 AM, Tom Madden via Groups.Io <pullmanboss@...> wrote:

 

Fine detail is a jet printing process. I believe the jet printers Shapeways is using are 600 x 600 DPI X & Y, and at 16 microns per layer the Z is 1600 DPI. (3D Systems has 750 x 750 DPI machines with 13 micron layer capability, and 1600 x 900 but only for 32 micron layers.) 

If these don't sound like very high resolution printers, remember that there are two jet nozzels per pixel - you can place either wax or body material at each location. 

Tom Madden

 

Re: ATSF Bx-48 running board

charles slater
 

The Santa Fe Folio sheet for the Bx-48 does not list the type of running board used except it says it is steel. However on large orders for cars, 750 in the Bx-48 class, it is not unusual for Santa Fe to use several different types, just depends what was available at the time. Now in my photo collection I have photos of cars; 274199, 274312, 274625 and 274714 in original paint and lettering and all of them have Morton roof walks.
Charles Slater SFMM

Sent from Outlook



From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> on behalf of Tim O'Connor <timboconnor@...>
Sent: Sunday, December 22, 2019 12:22 PM
To: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io>; Ed Hawkins <HAWK0621@...>
Subject: Re: [RealSTMFC] ATSF Bx-48 running board
 
Ed

Bx-48
ATSF 274714, at least, appears to have had a MORTON running board and brake step.

The photo date is 1977, but the car is almost certainly original.

Tim



On 12/22/2019 2:21 PM, Ed Hawkins wrote:



On Dec 17, 2019, at 6:24 PM, Lester Breuer <frograbbit602@...> wrote:

Hello Ed,

I have a question on ATSF Bx -48 on the running board.  In your spreadsheet on Steam Era Freight Cars you state the ATSF Bx-48 has U.S. Gypsum (expanded metal) and Pierre in his kit 105.1 states Apex Tri-Lok.  Do you know if Pierre’s choice is correct correct? 

I appreciate your comments.  Thank You.

Happy Holidays,
Lester Breuer

STMFC,
I have corresponded off-list with Lester about this question. For the STMFC discussion group I offer the following information.

For the ATSF Bx-48 box cars 274000-274749, my STMFC roster with file name "Postwar AAR 4-4 IDN & NSC (1945-1950s).pdf" that states G1 (U.S. Gypsum of the expanded metal design) is incorrect. My apology for the error, and I have made a correction to my list to denote M* for Morton running boards/brake step. The asterisk indicates the possibility than one or more other types may have been used on the order of 750 cars. 

 For anyone who has downloaded the file, please annotate your copy accordingly.

The ATSF box car diagrams denote many specialties but do not specify the running boards/brake steps for the Bx-48 cars. I also lack having ATSF or Pullman-Standard documentation for these lot 5832 cars that specifies the type(s) of running boards/brake steps applied to the entire series. For a long time, my only photo from the Bx-48 class was a side view of 274332. From this photo I originally identified the running boards/brake step as U.S. Gypsum, but a closer look shows Morton.

The only other Bx-48 photo I’ve seen is the Pullman-Standard builder photo of 274199 published on p. 345 of the 1949-1951 Car Builders’ Cyclopedia. The print quality makes it difficult to discern that the car had a Morton running board & brake step. Patrick C. Wider published the same photo obtained from the Library and Archives Canada on p. 207 of RP CYC Volume 31-32. 

If members of the STMFC have other photos of ATSF Bx-48 box cars with a clear view of the running boards/brake step, please share in order to help determine if Morton was the only type used.

Regards,
Ed Hawkins

Re: Photo: Wabash Gondola 13000

Tim O'Connor
 


Thank you Gary


On 12/23/2019 9:21 AM, Gary Roe wrote:
Tim,

The painting diagram shows they were No. 10 Red.

gary roe
quincy, illinois




On Sunday, December 22, 2019, 2:15:16 PM CST, Tim O'Connor <timboconnor@...> wrote:



Were these cars painted black, or oxide red, when they were new?

Tim O'Connor


On 12/22/2019 12:25 PM, Bob Chaparro via Groups.Io wrote:

Photo: Wabash Gondola 13000

From the Decatur, IL, Herald & Review archives:

https://bloximages.chicago2.vip.townnews.com/herald-review.com/content/tncms/assets/v3/editorial/8/fd/8fd30101-1d09-50bb-bfcc-22400f6f6da3/578e9b1837e00.image.jpg?resize=1200%2C957

Caption: H&R file photo 5-16-1944 Local Wabash car shops have just completed the first of 250 new composite gondola cars and will be busy until after July 1 turning out this order at the rate of about four cars a day. The shops have built about all other types of cars but this is the first composite gondola for them.

Bob Chaparro

Hemet, CA



--
Tim O'Connor
Sterling, Massachusetts

--
Tim O'Connor
Sterling, Massachusetts