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Preface: I've been going through my fleet over the last year or so and converting everything to Kadees. Many thanks to folks here for lots of good info. I am mostly done with rolling stock now, and starting to look at engines...

I decided my first attempt would be with my trusty old Williams CN GP9. This is one of my oldest and most favorite engines. It is a simple model, and not very detailed, but it always runs and pulls great. It was also my initial test unit for my conversion to DCC a few years ago, so it seemed like a good place to start for converting my engines to Kadees. I do a lot of mechanical design work professionally, so I figured I'd have a go at doing this using some 3d printed parts. I thought others might be interested in the process, as well as just the finished parts, so i'll include some detail on that for starters.

The first step for something like this is to model up the engine chassis, in order to define the interface for the new parts, as well as things like where the coupler needs to end up, how high everything is off the track, keep out envelopes for trucks/wheels, etc. The chassis for this model is a simple stamped steel sheet that forms the base of the engine as well as the front, rear, and side handrails. The CAD model of the chassis looks like this:

 chassis

The red and blue parallelograms are reference planes that define things like the center, front and rear of the chassis, as well as key features like the kadee mounting height and railhead height.

I also needed a detailed CAD model of the Kadee 740, which is what I'm using as my standard coupler. I contacted Kadee about that, but they understandably did not want to share theirs, so I developed my own. The coupler model articulates, so I can check clearances against my new pilots, from engine to cars, etc. Here is what the coupler assembly looks like:

kadee740

I also spent a lot of time on railpictures.net, looking at photos like these:

http://www.railpictures.net/viewphoto.php?id=490248

http://www.railpictures.net/viewphoto.php?id=490249

http://www.railpictures.net/viewphoto.php?id=490372

http://www.railpictures.net/viewphoto.php?id=523919

Lots of great ideas on that site! So, after a lot of thought about how I wanted to approach things (and the fact that my CN definitely needed a plow on it!), I fired up my favorite CAD tool. A week or two later, here are the front and rear assemblies:

 gp9 pilot frontgp9 pilot rear

I wanted them to be fairly realistic, even for this simple model, as I have a number of other engines I am planning to do in the future, so I wanted to make this a real, eh... pilot program, if you will, for future parts. So I added details like the coupler cut lever, different hoses here and there, grating on the steps, rivets, and so on. I wanted to see what I could really get out of the 3d print.

Of course, the whole point of the exercise is to be able to mount Kadee couplers, so the mounting interface for those is a key part of the design. I designed it to nominally require one Micromark Kadee shim, to allow for tolerances, slop in the chassis and trucks, etc. I also added a few locating features to pick up key points of the chassis, so that there is no guesswork involved in locating the parts when bonding them on. Here is a view of the rear pilot from the underside showing the coupler mounting interface. You can see the shim in tan below the coupler:

kadee mount

So with the design basically done, the next step is to submit the files for 3d printing. I am using Shapeways these days, and have been pretty happy with the products so far. They have some good automated checks that get run when you submit your model, so you can get feedback on any issues quickly, and make any needed changes. You can also share the model with others for review.

I selected the Frosted Ultra Detail acrylic material, which has good resolution and physical properties, at a reasonable cost.

So, after waiting (not so) patiently for things to arrive in the mail, here is what the bare parts look like:

IMG_5694IMG_5695

The only post-processing required on the parts is tapping the four holes for the kadee mounting screws. The holes themselves are part of the model, so it's just a matter of running a 2mm tap down each of them.

I should mention at this point that it is very important to make sure the chassis of the engine is true, so that everything fits as intended in the end. In the case of my GP9, there were a few issues that needed to be corrected. First, the chassis was not flat, and had a slight twist to it. It is a ductile steel, so that was easily corrected by laying it on a flat surface and tweaking it until it was perfectly flat. Second, one end of the chassis was actually slightly higher than the other with respect to the track. This was due to a small difference in the plates on top of the trucks that hold the side frames on - the features on the plate that set the height of the chassis were about 1/32" lower on one of them. A few shims under the plate on that truck corrected that issue. Finally, there is quite a bit of lateral slop between the chassis and the trucks, which means the couplers can shift a bit from the centerline of the track. It remains to be seen if this will be an issue, but it is also correctable with some shimming inside the engine.

After addressing these issues, here is the initial test fit of the rear pilot:

IMG_5586IMG_5590

The initial airbrushing on the front:

IMG_5696

Assembly to the trued and freshly repainted chassis:

IMG_5699IMG_5702

And finally, the completed project!

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Everything fit exactly as intended, so I'm pretty happy with the design, as well as the quality of the printed part. I did come away with a few lessons learned, for future parts. First, the coupler cut levers are very small and delicate - I designed them to be 1" scale diameter, so they are 0.021" on the model. One of the parts was actually damaged in shipment (thanks to Shapeways for replacing it at no cost), and I'm a little worried about how long they will survive normal handling, etc. So I am increasing the diameter of those to 1.5" scale, or 0.031" on the model. Second, having all the hoses designed as integral parts of the pilot made detailing them difficult, so I am going to make them separate parts in the future. I expect painting them individually will be much easier, and will also facilitate weathering and nicer details on the pilots themselves.

That's about it, I think! If anyone is interested in these parts for their own engines, I'd be happy to share. A quick look at the Williams line up of diesels suggests that they may fit a number of other models in addition to the GP9. If there's any interest, I'll figure out how to set things up on Shapeways so that they are available there.

Now on to my MTH SD90, SD45, and a few others... 

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Last edited by OGR CEO-PUBLISHER
Original Post

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theteejmiester posted:

But seriously. If you make these for Atlas GP35,GP15,SD40,SD35 or GP9 as well as Lionel GP30,GP9 or SD40 I want. My only concern would be having a way to mechanically attach them vs adhesive . Do you think the parts are strong enough to hold up to 30 car trains?

Atlas GP35s are all set...

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I want these parts for my 1996 TMCC Geeps

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Last edited by CentralFan1976

Wow, thanks everyone for all the interest and positive responses! Where to start?

Tom D. posted:

Those look really nice.  About how much did they cost if you don't mind my asking?  Any plans to do a BL-2 pilot?

Each of the parts cost around $32 in the material I used. However, I submitted them as two separate jobs, as I was still trying a couple different materials at first. I think if I submit them as a set, the price will be more around the $45 range for the pair. For example, I submitted a set for the SD90 parts yesterday that came in at $46.

theteejmiester posted:

Oh. My. God.....do want! Make me some and take my money!

Lol, when you put it that way...  I will have to see about setting up a way to share these, apparently.    Shapeways has a 'shop' feature that I should be able to set up so that folks can just order them directly. I will look into that when I get a chance.

theteejmiester posted:

But seriously. If you make these for Atlas GP35,GP15,SD40,SD35 or GP9 as well as Lionel GP30,GP9 or SD40 I want. My only concern would be having a way to mechanically attach them vs adhesive . Do you think the parts are strong enough to hold up to 30 car trains?

The mounting interface for the coupler is pretty stout. I can't say I've load tested it, but I don't think there will be any issues in regard to load capacity. As to mechanically mounting it, you could certainly drill and mount it, although there aren't any features as it stands to accommodate that.

Mike DeBerg posted:

Fantastic work!  Definitely interested in MTH pilot conversions SD40-2, SD9043MAC to start.

Well, the modeling for the SD90MAC (http://mthtrains.com/20-2370-1) parts is done. I will start a new thread on that, and see if there is any feedback on them before I submit them for printing. Once I have installed them and checked them out, I'll post them on the shop.

I will probably do the SD45 (http://mthtrains.com/20-20460-1) and the ES44AC (http://mthtrains.com/20-20285-1) next. After that, who knows...

Laidoffsick posted:

The detail on those are incredible. Snow plows, MU hoses , air hoses... WOW. MTH Dash 8's, Dash 9's, F units, PA's, E units lol the list is long

I'd love to, haha! May take a while...

As far as fitment of these parts to other makes/models:

It'd be awesome if people are able to use these on other models! First, though, I want to update the parts based on my 'lessons learned' above, as well as adding a few things that weren't really needed for the Williams (holes for full length handrails, for example). That much is straightforward (apart from the time!). The harder part is - these were made specifically to fit the Williams GP9 chassis that I have. I doubt they will fit other models directly, for a few reasons. First, I added a few features to them to locate the parts on the chassis during bonding. Those are not likely to fit other models. Second, the overall height of the parts, and particularly the mounting plane of the coupler, is dependent on the height of the chassis above the railhead. I imagine the Williams may be a bit higher, for example, than an Atlas. So the model would need to be updated to generalize it a bit. This is tricky to do without having access myself to other makes/models, but if people want to post details of their models, we might be able to come up with overall dimensions that would work well for most. I'll follow up with another post on what I'd need to do that.

Eric

Very, very nice work. I will definitely be interested in your SD90 project; I've got one awaiting the treatment, but only so much time. Trust me, I agree with Doug, about the variations in doing these things, but on the other hand, some MTH models use common pilots (for example the SD90, SD60 and SD70s all seem to use the same pilot), so I expect that parts like these will ease the job. And those are very nice parts.

RM

oohhh I forgot to mention the Atlas GP60's, 60M, 60B, and Dash 8 BW's, because I want mine to look as good as the ones Rich did. Mine have been sitting on the shelves for years because it's a ton of work to do all six of them. I wonder if the Atlas GP60's are the same as the GP35s? other than the fact that Santa Fe uses a different style snow plow than Southern Pacific and Union Pacific.

These are just hideous:

20160106_162214

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Last edited by Laidoffsick
Laidoffsick posted:

Definitely true Eric, every model is unique and would require it's own version. Ask Mario, even making the Kadee mounting shims..... there is no one size fits all. Everytime I buy a new Atlas car, the floor is different, or the thickness required has changed. 

Rich Montague posted:

Very, very nice work. I will definitely be interested in your SD90 project; I've got one awaiting the treatment, but only so much time. Trust me, I agree with Doug, about the variations in doing these things, but on the other hand, some MTH models use common pilots (for example the SD90, SD60 and SD70s all seem to use the same pilot), so I expect that parts like these will ease the job. And those are very nice parts.

RM

Yeah, there are a lot of ways to get it wrong and end up with something ugly or useless, that's for sure. To be honest, it's not so much managing multiple configurations of the parts that worries me (within reason, lol). If, for example, an Atlas chassis is 0.050" lower than an MTH chassis, that's pretty easy. The trick is getting all the measurements in the first place - that's the real key to having everything fit and work well in the end.

I think what might work is if I put together a more general model of the things, for starters. Then I can throw a drawing up here with the critical dimensions needed from the chassis. If the interested parties take that drawing and mark it up with measurements of their units, along with some pics, parts diagrams, and whatever else for reference, we might be able to make that work.

Eric

What this really shows that there is an bigger interest then a couple of years ago.  I remember when Mario first offered his shims and replacement bolsters. That in itself filled a void in replacement parts and ready made shims. As he continued to convert his engines to fixed pilots, he also made those parts available to others.  I myself took advantage of it and was able to show that his Lionel GP/30/40 kadee mounts could be made to work on others Manufactures engines.   https://ogrforum.ogaugerr.com/t...73#61965511445937073

Doug and his how to posts and You Tube videos on Kadee conversions.  Now we have a product and options for Williams engines(GP9) and more pilots are on the way.  If anything for people who have been on the fence about conversions  will definitely start coming off. Especially those who skills in there own eyes was lacking or thought it was too hard ( Actually it is a lot easer then it looks) Mario can tell you that he hasn't made a fortune but he has made a significant  contribution to the hobby with his products by giving people options. This is even better.     In another thread  Ron H ,   theteejmiester, Mario, and others   https://ogrforum.ogaugerr.com/t...8-turnouts-to-3-rail ,    https://ogrforum.ogaugerr.com/t...nbsp;  are working on 3RS track. ( Which has caused me to s*** can my original choice of track for my new layout.)  So with all of this forward movement.  Maybe now 3RS will finally take off instead of a niche within 3R . 

Amen brother. Never enough time. I work 60 to 80 hours a week and getting more than a couple hours a week on modeling requires some planning. That's why these entire printed pilots appeal to me so much. Cost isn't really a concern. Just time. I have had the pilot shims that Mario designed for over a month and no time to get them on my GP30. And my SD40 is still in pieces too.

Laidoffsick posted:

I personally like the one piece design better. I usually build the entire pilot and coupler assembly as one piece and paint all the details by hand anyway. I would rather spend the time painting details part by hand as all one piece vs painting parts, then assembling all those small parts. That's just me

Noted, but I was actually referring to the design with the separate pilot and coupler mount, vs. the one piece guy here. This design worked well for the Williams GP9 chassis, because the body shell just sits on top of the chassis, and because there are no handrails and so on to worry about. So there's really no need to separate the two functions. But that's a pretty basic model. I think for models with more detail, the separate structural coupler mount approach would work better, for the reasons described in the other thread.

Ah gotcha. Well if the coupler mount is all part of the pilot, when you screw the coupler to the frame, the entire pilot is secure. 

I think it will really depend on the model again because many of them dont have room for a full sized draft gear box without modifing either the draft gear box or the truck. Or both. Especially on smaller engines, you have to remove the 3 rail coupler mount tab from the truck, and shorten the draft gear box. 

Last edited by Laidoffsick
Laidoffsick posted:

Ah gotcha. Well if the coupler mount is all part of the pilot, when you screw the coupler to the frame, the entire pilot is secure. 

I think it will really depend on the model again because many of them dont have room for a full sized draft gear box without modifing either the draft gear box or the truck. Or both. Especially on smaller engines, you have to remove the 3 rail coupler mount tab from the truck, and shorten the draft gear box. 

I think the shaved box/short-box approach should work. Shaving the coupler mounting boss off the power trucks is an option.

AGHRMatt posted:
Laidoffsick posted:

Ah gotcha. Well if the coupler mount is all part of the pilot, when you screw the coupler to the frame, the entire pilot is secure. 

I think it will really depend on the model again because many of them dont have room for a full sized draft gear box without modifing either the draft gear box or the truck. Or both. Especially on smaller engines, you have to remove the 3 rail coupler mount tab from the truck, and shorten the draft gear box. 

I think the shaved box/short-box approach should work. Shaving the coupler mounting boss off the power trucks is an option.

I usually do both anyway, just so I don't have to go back after the fact and fix it.

So I was curious, as some other folks here were, about the strength of the 3d printed parts (Shapeways has a material data sheet online, but that doesn't always tell the whole story). I also wanted to verify the strength of the bond to the acrylic part, as some plastics don't bond particularly well. I had a little time the other night, so I set up a simple load test.

I bonded a spare pilot to a 0.5" wide brass strip using gap filling CA glue. I prepped both surfaces by gently wire brushing with a dremel, followed by an acetone wipe. I then applied the adhesive, clamped the parts, and let the assembly cure overnight. I installed a steel lanyard around the central post in the kadee gearbox, with which to apply the load. The kadee was mounted using the shim and four screws and described above. The test setup looked like this:

IMG_5750

On to the test! I figured I'd go in five pound increments up to failure. Here is the setup with the first five pounds hanging on it:

IMG_5741

And with ten pounds (you get the idea...)

IMG_5742

By the time I had hung a 35 lb plate on it, I got bored and called it quits. That's enough for any train I have, lol.

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CentralFan1976 posted:
suzukovich posted:

I was looking at the frame of the older PW style Lionel GP9s. I noticed that the frame is the same set up. So for those who might want to. These pilots should also fit. So see there is another manufacture that this should work on.

6-6-2014 MTH LIONEL 017

 

 

YES PLEASE!!!!

I'm actually working on this now.. I will post pics and  information as soon as I work it out to my satisfaction.. Once I 'get out of my own way', this should be relatively easy conversion!!

CentralFan1976 posted:

Can you do an ALCo set, too please?

image

Maybe a correct GE set, please?

1-DSCF48391-DSCF4840

*photo courtesy of Suzukovich!!!!

Mario  Here's better pic with final configuration.. I do have my pride.    Kitbash U30b  Shortened Lionel U30C shell, Weaver U25B frame and running gear.   Same pilot would also work on Lionel U30C. 

1-DSCF4841

 

 

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suzukovich posted:
CentralFan1976 posted:

 

Mario  Here's better pic with final configuration.. I do have my pride.    Kitbash U30b  Shortened Lionel U30C shell, Weaver U25B frame and running gear.   Same pilot would also work on Lionel U30C. 

1-DSCF4841

 

 

You nailed it! exactly why I want mine to look like yours...

Can't find correct Weaver or Atlas O Alco/GE pilots anywhere!  All I can get are these pointed Atlas 2-rail pilots.

I've got a U33C coming to cut up and the pilots are awful.

Picture1Picture2

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