UP 1960s Double Diesels

[C855B]

Over in the AC6000 thread, @LarryN and I were discussing a couple of recent Shapeways shells for modeling UPs double-diesels of the 1960s in N. It dawned on me that with the new release of a U50C shell, all seven of these monsters - or depending on your POV, monstrosities - are now represented in N. In order of 1:1 chronology:

EMD DD35, 1963 - Shapeways, James Train Parts
GE U50, 1963 - Con-Cor, various releases, http://www.spookshow.net/loco/ccu50.html ; Hallmark, http://www.spookshow.net/loco/hmu50b.html ; Shapeways, 3D Locomotives & Trucks
Alco Century 855, 1963 - Shapeways, James Train Parts
Alco Century 855B, 1963 - Shapeways, James Train Parts
EMD DDA35, 1965 - Shapeways, 3D Locomotives & Trucks
EMD DDA40X, 1969 - Bachmann, various releases. http://www.spookshow.net/loco/bachdd40ax.html ; Overland, two versions. http://www.spookshow.net/loco/omidd40.html
GE U50C, 1969 - Shapeways, 3D Locomotives & Trucks

In that discussion I mentioned unhappiness with the cab profile of the U50 having recently acquired one, but after looking at it again I was definitely wrong - it's a nice model. I was looking at it with the thought in mind, "How in the heck do I power this thing?!?  " It won't fit the Con-Cor chassis, and while it is comfortable with current Atlas frames, shortening an Atlas wheelbase to power the two inner trucks will be a bit of fun. Wheels are spinning as I type this, tho', so we'll see.

Anyway, our last thought in the other thread:

Yes, I am using the latest Bachmann DDA40X chassis for the DD35 series. I do believe that the air cylinders on the trucks are different on the '35's verses the 40x's, so I will have to address that at some point. That first cut through the chassis is always the hardest, but it does work out well in the end. I run just DC, so the electrical issues are not so troublesome. Some shell and  chassis grinding is needed. I am hoping to try and recycle a lot of the handrails from the DDA40X too. GM stanchions are nearly universally placed at 4' intervals.

Yes, you're right about the brake cylinder difference. The DD35 and DDA35 trucks had the old-style Flexicoil arrangement with the cylinders underneath, inside the frame. I'm somewhat amused the fellow doing the DDA35 missed that in his artwork, at least the artwork represented in the 3D preview on Shapeways. Otherwise we have to cut the cylinders off the DDA40X trucks, as well as the brake shoe hangers at each end of the truck sideframe.

That's a good idea on trying to recover the DDA40X handrails. I'll compare and see how it works for me. One difference is I plan to model the pre-modified versions without the walkway sandboxes, so I have a fistful of Gold Medal stanchions and phosphor-bronze wire to roll my own.

For grins, here's as far as I got with a running C855B before I screwed-up the paint (twice!) and had to start over:

[Ed Kapuscinski]

I'll take one of each in PRR, thanks. 

But seriously, I think it's awesome that it's possible to do these signature things that play so well to N scale's strengths.

[eric220]

I'll take one of each in PRR, thanks. 

I think that's my line. I'd actually consider the GE's if I had any inclination to model the 1960's.

[C855B]

You guys are about right. I've also pondered what Pennsy would have been like if it weren't for their 1960s death spiral. I think Pennsy DDs, etc., would be perfectly plausible in an alternate universe, running right alongside EMD electrics like the oh-so-cool GM6C and GM10B.

Anyway, for us Pennsy-of-the-West fans , it's a dream come true that this niche is suddenly covered. But there's a downside to that, diminishing the possibility that commercial models of any of them would be produced. OTOH, we're realizing the promise of 3D printing becoming the "brass of N scale" for specialty and weird diesels.

U50 is a case in point. I mentioned a while back that several years ago Athearn was sniffing around, thinking about porting their HO design to N. Jim Conway (Con-Cor) got wind of this during a National Train Show, and blurted-out during the manufacturers' breakfast that he was going to re-issue his. Beyond promises and pre-order lists it never happened of course, but Athearn was waved off anyway. Plus now we have a decent shell, courtesy of a pretty good Shapeways designer. Well, crap.

I'm also concerned about the DD35. Scaletrains.com has put feelers out about an HO version. Problem there for N is the DD35 is one of the easier (if not easiest) Shapeways kitbashes, with a well-documented how-to. The Shapeways designer even has brass frets for handrails and other details. So anybody who wants one... or several... has a not-difficult path.

The C855s (...as everybody here knows... ) is not as easy, but the promise of completed models is not impossible, despite my flailing around.

Does anybody else have experience with or otherwise know the designer "3D Locomotives & Trucks"? What hit me as odd is the N loco shells are also offered in TT. Anyway, there is no mention of details frets with any of the models, so you're evidently on your own there, as is powering.

[LarryN]

All,

There are pictures of DD35A's from UP on the PRR by Waverly yard in New Jersey (Pennsy Diesel years Vol.1, Yanosey, Morning Sun, page 15). Supposedly, they were exploring the possibility of run though operations. 
The shells by 3 D models do not provide much in the way of hints for powering them up. I have found the walls thick enough to require careful grinding. But, how else will we ever get these beasts?

Larry N

[C855B]

The shells by 3 D models do not provide much in the way of hints for powering them up. I have found the walls thick enough to require careful grinding. ...

Over which frame? The Bachmann? I checked the U50 last night against an Atlas SD24 frame and it was a remarkable fit - width was glove-perfect, and the length was almost as well-fitted between the radiator bays. I was surprised that it was this close, despite the SD24 chassis not being useful in terms of bolster distance. But it did seem to confirm that Atlas frames are possibly the intended starting point for hacking.

Incidentally, I apparently broke off and lost one of the side ladders in checking frame fit. I'll check the floor one more time. 

It appears my DDA35 shell will arrive in the mail tomorrow. I will check against the Bachmann frame and the Atlas. If the Bachmann is too tight of a fit but the Atlas is OK, I would actually rather mill the frame than carve on the shell, and if the motor cans are then too wide, replace with Atlas or Kato motors.

I guess the main reason I started this thread was to compare notes on resources and techniques to make these shells operable and maybe a little more accurate. I don't think any of them will qualify as "easy" conversions. A recurring thought is to bite the bullet and polish my own CAD skills to make the missing bits available to myself and others using these shells, in both 3D printing and metal etch frets. One I'm already working on is correct pilots for the C855s. They are operable with the U50 donor pilots, but my discerning eye objects. Same goes for the DD35.

[Xmtrman]

I have my pair so I can reveal my source:

I scored trucks for the U50C just like the prototype - from the Scale Trains turbine run. They had extras.

 

[C855B]

I am still considering asking ScaleTrains.com since I've had conversations with them about producing a U50C. It would be nice if they have a bunch of extra trucks since I would need three pair; they typically ran in trios during my modeling era. Failing that as a source, I have no easy answers yet about how to use the sideframes supplied in the Shapeways kit.

[C855B]

... It appears my DDA35 shell will arrive in the mail tomorrow. I will check against the Bachmann frame and the Atlas. If the Bachmann is too tight of a fit but the Atlas is OK, I would actually rather mill the frame than carve on the shell, and if the motor cans are then too wide, replace with Atlas or Kato motors.

Well, it arrived this morning (Saturday) after five days in transit. I can't beef too much about free shipping, but if they want to return to using "UPS Mail Innovations" as their "standard" $5 shipping, then I have a bone to pick with 'em. But that's another discussion.

The DDA35 shell expects a 0.375" chassis width, which is Atlas' current standard. The Bachmann DDA40X chassis is 0.425". Honestly, I don't know how you're shaving the shell to force it to fit the unmodified Bachmann. If you are doing it per the dimension difference, I think you're lucky in not breaking through since you need to shave 0.025" from each side (0.040" to start with). Anyway, my plan remains milling the Bachmann frame. It looks like I can take 0.010" off the outside of each half and then reduce the halves spacer to 0.010" from 0.040". The motors cans are 0.395", so I may also have to carve a little bit on the shell unless I repower it.

This appears to be a very nice shell, but I won't know for sure until it finishes the Bestine soak. I wish the designer hadn't make the rear sandboxes part of the walkway piece. It makes painting more difficult, but, also, these were not added by UP until after ~1976. IOW, the prototypes spent most of their service life without the sandboxes. I like the truck sides included with the Shapeways version. Much better detail and profile than the Bachmann trucks. How I get them to work with the snap-on sideframes is another issue.

[LarryN]

C885B.

Quote:"The DDA35 shell expects a 0.375" chassis width, which is Atlas' current standard. The Bachmann DDA40X chassis is 0.425". Honestly, I don't know how you're shaving the shell to force it to fit the unmodified Bachmann. If you are doing it per the dimension difference, I think you're lucky in not breaking through since you need to shave 0.025" from each side (0.040" to start with). Anyway, my plan remains milling the Bachmann frame. It looks like I can take 0.010" off the outside of each half and then reduce the halves spacer to 0.010" from 0.040". The motors cans are 0.395", so I may also have to carve a little bit on the shell unless I repower it."

Yeah I gingerly ground down the inside of the shells, as well as the chassis on the (shortened) DDA40X chassis to get a fit. I will try and post pix, but the bottom line is it will work, but is ulcer producing. I run DC, so I am not sure what one can do with the Bachmann detector board (assuming you want to use it. I doubt it will take kindly to grinding off the edges...

Larry N

[C855B]

No worries on hacking the decoder. The Bachmann decoders (previous to the Soundtraxx version) are bare-bones and don't speed-match well, so I was replacing them anyway. Besides, the decoder died on the one sound-equipped Centennial I have, so that's the donor for my first DDA35 project.

Today I am weighing the possibility of fabricating a frame from scratch out of brass bar stock. Not a milling job, but building it up from pieces. In the end it may be less work. I've started to prep the old frame for milling and splicing regardless, so we'll see how that goes first. There's a fair amount of time before a running frame becomes a need since I've just begun the work on the shell, which in my world is going to take a few weeks as I flit from project to project.

[C855B]

Now that the DDA35 is out of the first Bestine soak, I'm having second thoughts about the work involved to get to a running model. There are numerous errors on the sill component I find distracting, again from having experienced the real thing. It is almost as if the designer had one or two photographs as reference, and then both from the engineer's side. Overlooked important (to me) details include no middle ladder on the fireman's side, two air tanks on fireman's side, missing sill fairings on all five ladders, sill too thin... I could go on. Rivet-counting and nitpicking aside, even cursory glances at the available online photos would be telling.

After the second soak I'll have a better sense of the body shell. If the shell passes muster, I'll entertain the notion of doing my own sill and underframe, either scratchbuilding or Shapeways.

[peteski]

Mike,
I'm curious: did that shell have a digital 360 degree preview on it (which would show the inaccuracies you noted)?  Could you contact the designer and ask them to revise the design to correct the discrepancies?

Then you could always just wait for Scale Trains to produce a model of that loco. 

[C855B]

Yes, it had a virtual preview, but I have no confidence in its rendering accuracy especially of small details. The air tank and left side middle steps I would have only caught in a side-by-side with a 1:1 photo, anyway. That happened with the model in-hand and I noticed something funky with the steps. I went to rrpicturearchives.net to double-check my recollection and the discrepancies started jumping out at me.

I plan to contact the designer with my concerns after the shell is out of the 2nd pass through the Bestine and had its first coat of Tamiya Fine Filler. The uneven translucency of the resin makes spotting details difficult, although one problem noted so far is no representation of the middle window frame. That's easy enough to fix. Maybe he figured a real modeler was going to want to represent the sliding panes. 

FWIW, I was carving on the Bachmann donor frame this evening and got a reality check on what it will take to make it work with this particular shell. Milling the entire length of the frame is not going to happen, at least not with what's in my workshop. I think a built-up frame out of brass bar stock is going to be my answer. I can use the Bachmann frame for the James Train Parts DD35s I have on the bench, which are designed to use the B'mann frame.

[LarryN]

Hello all.

Well, here goes me trying to post my pix of Double Diesel projects. These first ones are from the DD35A, using the Shapeways shell (walls thinned) and Bachmann shortened (and thinned) chassis. Fuel tanks modified too. Still have to Bestine the shell, fab handrails, etc.

Larry N