Roundhouse 0-6-0 vs DCC/Sound

[sailormatlac]

Hi upgraded my design according to picture and CN diagram. Most notable features are located with about 1-2mm precision. I think it's acceptable when you think it's done with ready-made components. I rearranged the dome placement and lowered the cab.

I tested the model and it ran fairly well for a standard line engine. Tender pick up should make it bullet proof. They really improved the drive, it is now made in a similar fashion to other Bachmann better famed engine like the 2-8-0 and 2-6-0. The shell didn't get better, but I don't care it will be cut in 5 parts and reassembled. Once again, Bachmann LED have the most crazy colors you can imagine: dark amber... I once got a green one! Remembers me when my brother used to replace light bulb in my F9 with christmas light, the green one wasn't the best choice!

The engine weight is similar to their 2-6-0, somewhere around 6 oz. It should be possible to add about 2 oz with lead weight and brass details to make it a better puller.

Now it's time to draw plans for a 3D model of the tender... and of course, get some detailling parts. My objective is definitively to learn new skills and makes better kitbashes.

Matt

[sailormatlac]

I started to make plan for the slope back tender in CAD. Objective is to make a 3D model of it and print it. If it works well, I may try to do the cab and domes.

How was the rivet pattern on the sloped part of the tender. I can't find clear photos of this detail. I've got a Bachmann and a MDC shell, but bot only have rivets on the side... Is it right?

Thanks!

Matt

[sailormatlac]

I started modelling the tender. After four hours, I've done the generic main tender shell plus detailled version of water hatch and coal bunker extension. I need to add a plate to the bunker extension bracing attaching it to the deck.

So far, it's going quite fine, no more different than scratchbuilding. I decided to draw everything at 1/87 to take in account every dimensionnal limitation of 3D printing. 0.2mm (0.008") tolerance for small details is quite enough for this purpose. I feel like drawing the tender real size would have been a technical error. I prefer to adapt the model right now than afterward. I'm following Lynn Wescott old articles about steam locomotive. It's better to understand what you make.

Here's a quick snapshot of the overall progress.



I had a lot of fun making the water hatch. I'll try to make the most detail possible to save on brass casting.



Rivets location was set by overlaping a rectified picture of the prototype. Makes life easier! And cost less than Archer's rivets. ;-)

I'm actually thinking about entirely replacing the Bachmann shell (boiler and cab) with a new one that would fit the drive. It may sound crazy, but I feel like I would have more control over the finish product. The Bachmann USRA shell would need a lots of brass casting and splicing too. Cost wise, it's better to design everything from scratch and save on brass as much as possible.

Matt

[doctorwayne]

....How was the rivet pattern on the sloped part of the tender. I can't find clear photos of this detail. I've got a Bachmann and a MDC shell, but bot only have rivets on the side... Is it right?

I have drawings showing rivet lines running lengthwise on the sloped deck: a row near each side, just inboard of where the side sheets are rolled over, and two additional rows, dividing the width of the deck into three roughly equal sections.
Another drawing shows two lines of double (staggered) rivets running crosswise on the sloped deck, and again dividing the deck into three roughly equal sections.
A third drawing shows rivets only along the side edges of the sloped deck, just inboard of the rolled edge.

Unless you have photos of your prototype's sloped deck, it looks like you have multiple choices.

Wayne

[sailormatlac]

....How was the rivet pattern on the sloped part of the tender. I can't find clear photos of this detail. I've got a Bachmann and a MDC shell, but bot only have rivets on the side... Is it right?

I have drawings showing rivet lines running lengthwise on the sloped deck: a row near each side, just inboard of where the side sheets are rolled over, and two additional rows, dividing the width of the deck into three roughly equal sections.
Another drawing shows two lines of double (staggered) rivets running crosswise on the sloped deck, and again dividing the deck into three roughly equal sections.
A third drawing shows rivets only along the side edges of the sloped deck, just inboard of the rolled edge.

Unless you have photos of your prototype's sloped deck, it looks like you have multiple choices.

Wayne

Thanks Wayne,

You confirm what I saw on Pat Durand's U.S. 208 mogul (2 rivets lines running lenghtwise). His model depict the third option. They were aligned with the coal bunker side which make sense. I'll take this approach since I've got no picture of the deck.

I checked other pictures from O-12-f and O-12-a (similar tender) and finally realized the water hatch was located between the toolbox and the coal bunker extension. The hatch was quite high (about 18 inches) as shown on my CAD drawing.

Matt

[Schraddel]

Hello Matt!

Perhaps it may help you:




On this PRR slope back tender there are rivets only at the very edges. The Bachmann slope back tender is a "lean to" on this PRR design.


The sloped portion of the deck of an slope back tender. Here are two double row of rivets.

Both tenders have high water hatches because they are located on the slope. And water has an even lever ever...
If you plan it printing in 3-D choose the highest quality level available. The critical point are the vertical areas. The printing here is not complete difined and rivet details may not be printed or printed rudimentary only. Also the surface will become very rough here.
Better is you have a flat design in parts for the shell, i mean it is better in this case to print all sidewalls separate and mount them later on.
That may also be better for the cab.

Lutz

[sailormatlac]

Lutz, thanks for the pictures. It will help!

If you plan it printing in 3-D choose the highest quality level available. The critical point are the vertical areas. The printing here is not complete difined and rivet details may not be printed or printed rudimentary only. Also the surface will become very rough here.
Better is you have a flat design in parts for the shell, i mean it is better in this case to print all sidewalls separate and mount them later on.
That may also be better for the cab.

Thanks for the input. I was also concern by the layering process artifacts. Breaking the model in flats make sense.

In this respect, do you think printing a cylindrical boiler would be a bad idea? I thought it could be printed lengthwise don't have stepped circular sections.

Some quick renders:





Matt

[Schraddel]

Matt!

A link to a German 0-Gauge Forum:
<!-- m --><a class="postlink" href="http://forum.spurnull-magazin.de/spur-null-markt-entwicklungen-trends/3d-druck-shapeways-ein-versuch-1700/#post12090">http://forum.spurnull-magazin.de/spur-n ... #post12090</a><!-- m -->
Text in German only, sorry.
But take a look to the pictures, especially the vertical planes. Sometimes the vertical surfaces are very crude.
Note the "rounded" cab roof. It is a row of rectangles.
Take a look to the bonnet, this may happen to a cylindrical structure also.
Printing a boiler upright may cause a crude surface because in this case it is mainly a vertical structure.
And this open top little green critter was printed with the cheapest material. There nearly all the rivet details (0-Scale!) have vanished, better said, not printed.

Lutz

[sailormatlac]

Matt!

A link to a German 0-Gauge Forum:
<!-- m --><a class="postlink" href="http://forum.spurnull-magazin.de/spur-null-markt-entwicklungen-trends/3d-druck-shapeways-ein-versuch-1700/#post12090">http://forum.spurnull-magazin.de/spur-n ... #post12090</a><!-- m -->
Text in German only, sorry.
But take a look to the pictures, especially the vertical planes. Sometimes the vertical surfaces are very crude.
Note the "rounded" cab roof. It is a row of rectangles.
Take a look to the bonnet, this may happen to a cylindrical structure also.
Printing a boiler upright may cause a crude surface because in this case it is mainly a vertical structure.
And this open top little green critter was printed with the cheapest material. There nearly all the rivet details (0-Scale!) have vanished, better said, not printed.

Lutz

Lutz! Thanks for your invaluable help. Google Translate does a decent job at translating webpages. I've been reading a lot in the recent days about these processes. I'm happy to see reviews from people who actually tried to make a steam locomotive. Many factors must be taken in account, but the flat seems to be the way to go.

I think making the boiler with some plastic tubing is the way to go. The dome can be 3D printed. I don't care if they are less than perfect, I just need to have the overall shape correctly done. Rectification with putty and sanding can fix it up.

Anyway, even if I were to scratchbuilt the tender, I find the 3D model a great way to visualize a lot of things we can't see in 2D.

***EDIT*** Another concern is material stability. If not achieved, well...

Matt

[sailormatlac]

Well, finished reading a lot on the subject. Thanks again Lutz, I wouldn't be there without your help. I must agree, flats are the way to go. It's also the only way to get rounded perimeter good. I think too much people struggle in making the body in one shot. The concept is thrilling, but it doesn't use the tools at their best. It should be used the same way you laminate photo etched brass parts to get a relief.

Doing a boiler is a no go. I would rather follow e-paw technic than going this way!!!!! Why pay high price for a cheap plastic tube you can find anywhere. I could also use a metal (brass, copper, steel) tubing of O.D. 21.5mm to make the boiler. It would add free weight to the engine.

My philosophy would be to make flats with cost-efficient/detailled enough/strong enough material and use more costly and accurate material for very small details that must be almost perfect i.e. a water hatch, sand and steam domes. I also think I should make the tender sloped deck out of styrene and add two line of Archer rivets. I'd save on cost and greatly improve the appearance.

Using flats will also help me to get CNR cab sides with raised numerals like the prototype.

These projects are quite interesting: <!-- m --><a class="postlink" href="http://interurban.blogspot.ca/">http://interurban.blogspot.ca/</a><!-- m -->

You can see the limitation of the process, but still, many details went out pretty nicely (rivets, etc.).

I see a lot of potential for box cars and gondolas for my next QRL&PCo projects.

Matt

[sailormatlac]

QUESTION:

I see often threadplate on running board on tender built circa 1918-1920. Was it really use by this time? I always thought it was more modern and that paint with sand was used back then (like anti-skid paint used on some reefer roof).

Matt

[sailormatlac]

Hi,

I checked many picture of this class of locomotive. I'm puzzled by the tender rear end. When you look at it, it's like there's any steps/end beam (then no place for handhold and lift bar)... which seems rather impossible. Also, the horizontal handhold on the side sides to make and elbow toward the rear as if the rear and side handhold were one item. I'm quite at lost.

Personnally, I'm thinking about using a P2K 0-8-0 tender frame for general dimensions of the underframe.

Any picture of these slope back tender depicting the detail with more precision would be really appreaciated.

Thank you.

Matt

[Sumpter250]

Schraddel's picture of the brass slope back tender posted in this thread, shows all the "rear end detail", of a typical tender of this design.

[sailormatlac]

Sumpter. Well, I'm trying to capture the prototype, but indeed, it probably follow the standard from the brass tender. I'll follow this way. It's probably the angle of the photo that makes this detail hard to interpret.

Matt

[sailormatlac]

@ Lutz.

From what you know about 3D printing. Do you think it would be better to make spheric rivets heads or les prototypical cylindrical rivet heads?

Cylindrical shapes are also easier to handle in with software.

Matt