Planned centercab transfer unit bash

[Baronjutter]

Wouldn't the visibility be pretty bad on this?

[up1950s]

The only thing I have left from that early attempt back in 2005 is a master and molding set for the left and right sideframes in resin, and I 'designed in' the changes in wheelbase to fit the Alco C630/C628 truck from Atlas.  It also has embedded brass .010 wire for the brake rigging, so at least for now, I think I'm better than RP, but probably not for long.   I do the truck sideframes for $8 a set of 4.

Email sent , 2 sets please .

[Jamesn320]

James you have a sale with me , maybe 2 . Please make The Railwire aware when we can get these .

Yep, I will let you know.

-James

[randgust]

Looks like I'll be firing up the casting line again this weekend for this one, and blow the dust off of them.

Oh, and not only was visibility bad, but remember that the Baldwin units had air-operated MU, so they couldn't MU with anything else other than some other Baldwins.   That was just more more nail in the coffin that earned them early retirement. 

The use of them as pushers in Arizona was short-lived but memorable, sort of like the hinged monster 2-10-10-2's in the same service earlier - I think the district was in and out of Ash Fork, mostly east up the hill to the Arizona Divide, then turned on the wye in Flagstaff.   That was the portion of the railroad that was bypassed with the Crookton-Williams line relocation in the 60's.

[Dave Schneider]

Hello James and welcome to TRW,

Your design looks very nice. Is the intent to use a 3d printing service like Shapeways to produce this shell? If so, here is something you might consider. I have ordered a couple of very well designed FM switchers from a designer on Shapeways. Like many models, it suffers from printing artifacts, the most difficult of which to deal with are "rough texture shadows" which appear on vertically printed surfaces "beneath" overhanging objects (not sure if I am describing this properly).

For example, note the door which is inset from the rear cab wall.


If you are going the Shapeways route, you might want to consider rendering the basic shell with a minimum of detail and consider overlays for things like side access doors and louvers. These could be done in etched brass or surface decals (for the louvers). I strongly suspect that if you print this as designed, the shadow from the louvers will affect the side doors. Same thing with the door hinges. These are difficult to clean up by sanding. Just some thoughts for consideration. Good luck with your project.

Best wishes, Dave

[C855B]

... Is the intent to use a 3d printing service like Shapeways to produce this shell? ... it suffers from printing artifacts, the most difficult of which to deal with are "rough texture shadows" which appear on vertically printed surfaces "beneath" overhanging objects (not sure if I am describing this properly). ...

Not speaking for James, but as somebody who has bought several of his designs, yes, he uses Shapeways, and yes, the models exhibit the problem you describe. I had one pair of DD35s where important end detail was obliterated by this artifact, and requested (and received) a re-run in a different orientation. It moved the problem to another location, but fortunately one I could better deal with. The frustration is that this artifact is inconsistent, and certainly doesn't "shadow" like this everywhere on the model - just one or two locations, and then not all the time.

[Baronjutter]

3d printing is amazing but I really don't think it's quite "there" yet for our hobby, at least not at the level of quality you'd expect for an injection-moulded kit.  But it will get there!

[Jamesn320]

Hi all,

Yep, Shapeways for now is my intention.  As C855B says this problem is intermittent, for example I had a DD35 shell arrive yesterday that was perfect yet the C855B's where not (I have seen the photos).  It great that Shapeways have such good customer service and reprinted them for him, that's one of the reasons why I use them.

I guess what we need to remember is this is a relatively new medium and it will improve but compared to the alternatives it's fairly cheep.  Anybody in the industry will now that injection molding dies cost tens of thousands to setup. 

Dave, thanks for the welcome by the way, what did you use to clean that particular print?

-James

[Dave Schneider]

James,

The short answer is Bestine. It is a rubber cement thinner and available at most art supply stores. A good overall cleaner and recommended by David K Smith, who rarely if ever gives bad advice!

A longer answer is contained in this somewhat epic thread.
https://www.therailwire.net/forum/index.php?topic=28137.0

Actually there is quite a lot of good discussion, an occasional off topic digression or two, and a some lively debates. If you are a drinking man, I suggest having a double of your favorite in hand prior to reading. 

Best wishes, Dave

[Iain]

If you note my Lima renders, there's no detail.  There's a reason for this.

[randgust]

Yeah, Iain, I can see that you're designing brass overlays all over, particularly for the cab.  For the end product, that's a great way to go, particularly for grabs, handrails, cut levers, rounded sheet metal, and thin parts.  I did my CF7 as a combination of resin and brass trying to use the best of both medias, I'm happy with it...   In this model, things like the cab roof, yeah, that's EXACTLY where RP still falls down and brass is the way to go.   At least now, with the Shapeways process resolution and lack of orientation control. 

Except...

Unlike the RP process where the expended energy of (possibly free) drafting time is the sunk cost and there's no volume cost variance,  if you intend to make more than a handful of parts in brass you're going to have setup and development costs that can surprise you.  What really surprised me was that you pretty much have to DESIGN AND DRAW for the actual machine you're running it on in a production environment; your allowances by material thickness vary.  And the way you draw for a two-surface photoetch process (say like Micro-Mark) is completely different than a production photoetch machine with CAD layers.   The drawing models are not transferrable, they have to be redone.   And if you make a mistake somewhere you're possibly stuck with a lot of parts that are wrong.   I had to design for 12"x24" sheets, but the end part quality was absolutely spectacular.  I wanted to use the Micro-Mark system to do 'proofs' and then send the tested design to a commercial service and that, bluntly, is not feasible.

So right up front you have to decide if you're tinkering with one or two, or making a full launch.   Make sure you make those decisions up front, swallow hard when you get the numbers, and hope this crew hangs with you on the process.   I went so far as to take the CAD proofs of my CF7 and print them on .005 styrene, cut them out, and put them together to make sure that this thing was going to actually work before I sent the 'big check' in for the first run of brass parts.   No changes.  But it was a really scary thing to do!    Having done my first Shapeways model out for sale was relatively calm in comparison.   Much less $$$ at stake, and mistakes far easier to fix.

Now mind you, this is still a transitional period, but until I can print grabs and handrails in something as tough as Delrin, and get a cab roof smooth enough that it's reflective like steel, there's still a hybrid approach here that I solidly agree with.   It's even more noticeable with steam on what needs to be done, but there, printing out a raw boiler with minimal detail in metal and putting on brass parts, that's almost too tempting not to try at least once.

[PGE-N°2]

Oh, and not only was visibility bad, but remember that the Baldwin units had air-operated MU, so they couldn't MU with anything else other than some other Baldwins.   That was just more more nail in the coffin that earned them early retirement. 
 

They had an air operated throttle system, and Baldwin had its own MU connections that could only mate with other Baldwins. It was possible to buy a loco from Baldwin with standard MU, but that was considered an optional extra feature. If it had been standard, maybe Baldwin might have sold more locos, or if they had been able to come up with a single, standardized model line that could be mass produced along with replacement parts. But, aside from their carbody models like Sharknoses, Baldwin seemed to like going for one-off designs, with individual models built to order, rather than ready made, off the shelf and easy to sell.

Still, I have always loved the look of the big center cabs. This is a really interesting project.

[Iain]

Actually, Baldwin's MU was electric.

[jmlaboda]

Actually, Baldwin's MU was electric.

This simply is not the case.  Baldwin's use of  pneumatic controls is quite well documented both in print and on the web (recommend Googling "Baldwin Locomotive air throttle" for more on this subject on the web).  While later units were sold with an option for electrical m.u. so that they could be m.u.ed with other builders' locomotives the early units, as built, could not.  Seaboard was one road that took the time to rebuild their Baldwins to electrical m.u., allowing for units such as their Centipedes to be operated with other makes but it was late in their locomotive production that compatible m.u. became a standard.

Fairbanks Morris was another user of the air throttles on their units, making m.u.ing an impossibility.  Early C-liners, the Erie-builts and units such as the H20-44s and early-H15-44s could only m.u. with other FMs and were usually targeted as trade-in fodder because of this issue.  Despite having quite a collection of types obtained from mergers and acquisitions the FMs on thw N&W were limited in their ability to m.u. with other makes and models, making them far less desirable in keeping them running.  Seems like I remember that even the famous Virginian Train Masters could not m.u. with other types but would have to research this a little more.

Electrical m.u. for some builders was simply something not considered important which cost them in the long run...

[Iain]

This simply is not the case.  Baldwin's use of  pneumatic controls is quite well documented both in print and on the web (recommend Googling "Baldwin Locomotive air throttle" for more on this subject on the web).  While later units were sold with an option for electrical m.u. so that they could be m.u.ed with other builders' locomotives the early units, as built, could not.  Seaboard was one road that took the time to rebuild their Baldwins to electrical m.u., allowing for units such as their Centipedes to be operated with other makes but it was late in their locomotive production that compatible m.u. became a standard.

Fairbanks Morris was another user of the air throttles on their units, making m.u.ing an impossibility.  Early C-liners, the Erie-builts and units such as the H20-44s and early-H15-44s could only m.u. with other FMs and were usually targeted as trade-in fodder because of this issue.  Despite having quite a collection of types obtained from mergers and acquisitions the FMs on thw N&W were limited in their ability to m.u. with other makes and models, making them far less desirable in keeping them running.  Seems like I remember that even the famous Virginian Train Masters could not m.u. with other types but would have to research this a little more.

Electrical m.u. for some builders was simply something not considered important which cost them in the long run...

Notice the mu receptacle below the drop step, standard issue BLW.  I'm trying to find a close up I have of it open, showing the electrical connection pins.  When I discovered this, I was very much surprised.