N scale CPR/BCR Royal Hudson build thread

[CNR5529]

I went through all of the posts and coud not find a picture of the locomotive you are referring to WRT to this thread.

I guess we could have started with that! 





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Here are some good primers on the subject of Royal Hudsons, with many pictures:

http://www.trainweb.org/oldtimetrains/photos/cpr_steam/royal.htm
http://rapidotrains.com/hudson-master-class/

CPR's hudson fleet was made up of 65 locomotives in 5 classes: the first 20 were non streamlined, in the H1a and H1b class, such as 2816 "the Empress". The other 45 hudsons, in the H1c-d-e classes, were semi-streamlined and were used on everything from fast freights to the CPR flagship passenger trains. These streamlined locomotives are called "Royal Hudsons" because in 1939, the royal family came to Canada for a tour of the country, and a pair of the locos (2850 and 2851) pulled the royal train and pilot train without needing any major maintenance or engine changes for well over 3000 miles. King George, a bit of a rail fan, granted the CPR permission to use the royal designation for these locomotives because he was so impressed by their performance.

There are a number of differences within the three classes, and there are other details that changed with time, including two styles of pilots, 3 styles of smoke stacks, and three types of tenders (coal, coal converted to oil and oil). Some of these details were swapped between locomotives too, so a loco built with one pilot may have ended up with the other style, same with the stacks. There are also a number of road number specific details that we are finding.

Craig wants to build a model of 2860, the H1e that ran in excursion service in the 70s-90s between North Vancouver and Squamish BC, and I want to build an H1c as it appeared in every day service in Montreal in the 50's, as well as possibly 2850 as it appeared during the royal tour in royal blue livery. This all means we need to build the model up as a modular kit, allowing us to plug in the appropriate details we are after. Basically, each RH we build will be unique, even though they are all essentially the same locomotive.

[Lemosteam]

Thanks that will be quite nice!

An idea from one designer to another, there is a supplier of 1.5mm Stainless steel grommets that make a great headlight housing for some Fiber optic strand to get back to the LED on your mechhanism:

http://www.firemountaingems.com/itemdetails/h20a7872fn

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I chucked mine in a drill press to file down the flange and thin its face a little. 

[CNR5529]

An idea from one designer to another, there is a supplier of 1.5mm Stainless steel grommets that make a great headlight housing for some Fiber optic strand to get back to the LED on your mechhanism:

http://www.firemountaingems.com/itemdetails/h20a7872fn

Thanks, I'll keep those in mind! I can think of at least 2-3 other locomotives that could use them as well.

[craigolio1]

Wow, neat idea. Thanks for posting.

[CNR5529]

Work has been progressing on the tender frame. The rough shape is ready, and there are only a few small other features to include before we can send the part to the printers. We will likely be printing this part in steel, to provide extra weight so that there is lots of room in the tank for sound installations. Most exposed surfaces will be covered by photo etched parts, so the surface finish of the printed steel will not be an issue.

This frame is for the H1c and H1d class, with the commonwealth trucks. Next will be a slightly modified frame for the H1e, which has the buckeye truck and slightly shorter truck centers. Finally another version of this frame will be made where the drawbar pocket has been replaced with a regular coupler pad to make 2860's auxiliary tender.

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[craigolio1]

I've been working away literally counting rivets.  The left side of the Royal Hudson coal tender is almost done.



Craig

[narrowminded]

If you guys need a few small machined parts like those headlight grommets or bushings or whatever, contact me.  I might be able to help with that.

[CNR5529]

If you guys need a few small machined parts like those headlight grommets or bushings or whatever, contact me.  I might be able to help with that.

Thanks for the offer, we will definitively get in touch if we need some parts machined!

[CNR5529]

Using Craig's etching drawing I was able to create side walls in 3d and start the assembly model. I will not include all the rivets and etched details in this 3d model, for graphic speed sake, but it will allow us to see the model take shape digitally. It actually looks like something now!

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[CNR5529]

Along with the CPR F unit detail parts, I got the test prints of the Royal Hudson tender frames from Shapeways. The one on the left is for the H1c/d, and the one on the right is for the H1e class. They are slightly different because of the truck mounting position. The 3 spares are for some testing @craigolio1 will be carrying out shortly. Once we are done with the tests, we will print a set in metal.

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[Lemosteam]

Along with the CPR F unit detail parts, I got the test prints of the Royal Hudson tender frames from Shapeways. The one on the left is for the H1c/d, and the one on the right is for the H1e class. They are slightly different because of the truck mounting position. The 3 spares are for some testing @craigolio1 will be carrying out shortly. Once we are done with the tests, we will print a set in metal.

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@CNR5529 Yep- need metal.  But in case you've never printed metal yet, watch out- enlarge your model by 1.008 in all three dimensions.  I'm on my third stainless steel test fit tender frame.

[CNR5529]

@CNR5529 Yep- need metal.  But in case you've never printed metal yet, watch out- enlarge your model by 1.008 in all three dimensions.  I'm on my third stainless steel test fit tender frame.

@Lemosteam Thanks for the info! I have printed in metal before, both bronze and matte black steel, however no features on the base parts were dimensionally critical. Machining took care of the important features. BTW, this "steel", which is actually a steel/bronze matrix, is pretty tough stuff to work with... I had to re-tap a hole 3 times because the material would compress and deform rather than cut.

Have you found that scaling factor to be fairly consistent across your tests?

[Lemosteam]

I will put it this way- its my third try and it had better be right at $20 a pop!

Ii just hope its consistent for my customers when (if?) they buy my kit.  The variance from one print to the next is fairly consistent mathematically, but with only two parts in hand the sample size is to small to tell you with any confidence.

[CNR5529]

Fair enough. The one thing working in our favour in this case is that the shell straddles the frame like a saddle would on a horse. The tank walls come down to cover the sides of the frame, but the front and back of the frame extend beyond the tank. Those bits of the exposed frame will then get local wraps of sheet metal to create a clean surface, which will extend back to hide under the tank. This way, if the frame is a bit shorter or longer, it wont really affect the assembly or look of the model. Scaled up, the 0.8% difference would amount to 3.5 actual inches longitudinally and under an inch laterally (.022" and .006" on the model).

I will still modify it per your recommendations so we are as close as possible to the target dimensions, but I am also hoping that slight variations wont affect the build in our case because of the way we are assembling the model.

[Lemosteam]

Remember that all three dimensions are affected- your shell design may be afftected by the width as well.  Hope you fare better- mines not bad, I'm just not happy with the fact that I have to keep test- printing it.

Here is my FXD shell straddling the metal frame.  It has catches inside that spead over a shoulder on the casting.  This was the too small version that made me make the second too large, making me reduce to the value I gave you: