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Ok, so finally getting back to this one after a long delay, here is the design for the ES44AC pilot and coupler mount set. The specific model I am working with is http://mthtrains.com/20-20285-1.

From the front:

front1front2

From the rear:

rear1rear2

The blue and gray parts are models of the existing chassis and body shell. Everything else is part of the new assembly. The pilot is intended to be bonded to the body shell, so that the joint can be made seamless, and so that full length handrails can be permanently attached to it (0.020" mounting holes are provided for this). The various air hoses and the front plow are separate parts, to facilitate painting and weathering. The cut lever is part of the main part and is fixed. The MU cable and junction box for the front is a separate part that can be added if desired.

Here is a view of the assembled unit from the underside:

frontunderside

The coupler mount is a separate part from the pilot. This approach provides a way to disassemble the engine without having to make any changes to the original parts. It also provides a good load path from the coupler to the chassis - the pilot, plow, and body shell are purely cosmetic and carry no load. The engine can even be run, tested, etc. without the body shell installed, but with the couplers in place. Although the coupler mount is designed to be bonded to the engine chassis, I have also provided locating holes for screws in the event a less permanent installation is desired. For this engine, the coupler mounting tab on the truck may need to be removed to provide clearance to the back of the Kadee housing - I'll update with details after I get the parts installed.

The pilots are intended to be bonded to the body shell first, and then serve to locate the coupler mounts on the chassis during their bonding to ensure reliable alignment of everything, as shown below:

couplermount

Here is what the body shell looks like fully assembled and removed from the engine:

frontshell1frontshell2

And here is how it comes apart for maintenance, once everything is installed:

exploded

So there it is. As before, comments, suggestions, ideas for tiny-but-cool details to add, whatever - let me know.    I'll get a Shapeways page set up for it once any final changes are incorporated.

Eric

 

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Original Post

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There are screw mounts on some/most newer MTH shells that MTH uses to mount their fixed pilots to. I believe you're showing that your fixed pilots must be glued in place? That may provide for a superior finish once attached. I also get the fact that your design frees the pilots of load stresses.

 It seems to look good in concept so I can only wait and see how it looks once finished. I do like the idea. So we would have to drill the metal frame to accept the coupler mounts on these? I usually have to cut off the backs of KD coupler boxes to clear the MTH truck tabs. So I usually mount the coupler with the 2 screw holes towards the sides of the KDs.

I hope you can apply the same to the EMD versions which seems to lack a bit on the stock MTH ones. I feel they did their best job on these modern GE versions. The GE AC6000 I got long ago wasn't available with fixed pilots like this was though. I wonder if these would align?

Eric, 

your CAD work is incredible! Have you compiled a list of engines you have made parts for? I'd love to see one if you have. I and others would love to see a post where you list out what engines could be next and or take requests for future work. I would love to see what you can do with the MTH GE 44 tonner 

enginEErjon posted:

Eric, 

your CAD work is incredible! Have you compiled a list of engines you have made parts for? I'd love to see one if you have. I and others would love to see a post where you list out what engines could be next and or take requests for future work. I would love to see what you can do with the MTH GE 44 tonner 

Hi Jon, here are the ones I've done so far:

Williams GP9 (as well as one with a generic mounting interface)

MTH SD90

MTH Great Northern S2 (coupler adapter for the tender)

And now the one in the current thread for the ES44.

MTH SD45 will be next...

The threads above include pics of the finished parts, as well, btw.

I could start another thread along the lines of what you suggest, if folks think that would be worthwhile, but it's not like I'm cranking out something new every week, lol. 

Last edited by thor73
trainroomgary posted:

Hi Eric: Excellent exploded view drawings.  What software did you use to create these drawings?

Let me guess: Auto CADD • Auto Desk or Adobe Illustrator. ??????????? 

Cool, no very cool. 

Gary

The designs are done using Creo Parametric, which I also use extensively on a professional basis. It is a very powerful tool, but not for the faint of heart in terms of either the learning curve or the price tag...

Engineer-Joe posted:

 It seems to look good in concept so I can only wait and see how it looks once finished. I do like the idea. So we would have to drill the metal frame to accept the coupler mounts on these? I usually have to cut off the backs of KD coupler boxes to clear the MTH truck tabs. So I usually mount the coupler with the 2 screw holes towards the sides of the KDs.

To clarify, the coupler mount is intended to be bonded to the chassis, with no drilling or modification required. It can also be drilled and screwed to the chassis using the pilot holes provided, if you want it removable. The body can still be removed in either case. The pilot assembly, once bonded to the body, serves to locate the coupler mount on the chassis. Any combination of the four standard kadee mounting holes can be used to mount the coupler itself.

There are pics of the finished and installed parts in the threads linked above.

enginEErjon posted:

Eric,

Just to satisfy my curiosity, how long does it take for you to do one of these fixed pilots?

Probably best if I don't think about it, lol...

But since you asked, it breaks down something like this:

So all told, anywhere from 20-30 hours, I'd guess, depending on the model.

David Minarik posted:

Will you have the premier es44ac up soon?

Thanks,

Dave

If a few weeks counts as soon, then yes.

I want to give this thread a few more days for folks to comment, then I'll finalize and submit the first print job. Once I have that in hand and I'm able to confirm the fit and finish with it installed on the model, I'll add it to the store.

However, that schedule is influenced by an imminent two week vacation for sailing and scuba in the British Virgin Islands.  



Too many hobbies, too little time...

Last edited by OGR CEO-PUBLISHER
thor73 posted:
Mike DeBerg posted:

Eric,  Not only do I have some ES44ACs now waiting for some pilots, I have some SD70M-2's and SD70ACe's.

Hah, cool. Have you looked at the SD90 pilots? I wonder if those might also fit the SD70s. My SD90 is a pretty old model, though. Details are in that thread.

Eric, I have checked they are different enough they will require some modifications.  I can send you a photo if you like?

Update:

I got the first set of parts just before Christmas, and managed to do a fit check over the holidays. I ended up making a few minor changes to the design. First, the coupler cut bar was broken on one of the parts. Shapeways will send replacements for things like that, but I think in this case I may have been asking a little too much of the material. So the cut bar is now a separate part, like the hose assemblies. This has the added benefit that it is replaceable at a later date if it gets damaged (as happened on my GP9). There were also some minor clearance issues between the pilot and the detail wires on the trucks, so I made some changes to improve that.

No real impact on the appearance, though:

front1rear1

I also changed the coupler mount so that it can now either be bonded to the chassis or screwed to the existing bosses on the body shell:

couplermount

The mounting boss on the truck for the electrocoupler does interfere with a kadee 740 when installed as pictured. I have cut the bosses off the trucks on my other engines, where needed. I like to be able to use the metal gearbox 740 and all four mounting screws. Alternatively, one could leave the truck bosses and shave the back off a kadee 740. This fits fine, and allows the standard travel and swing of the 740, but without the innermost mounting screw. Or finally, take the really easy route and use a 743. The truck boss clears the coupler mount in any case.

I've submitted the updated model for fab, so I'll update again hopefully in a week or so when it arrives.

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David Minarik posted:

Eric,

Just a side note:  You can easily remove the old coupler mounting boss on the premier 2/3 rail truck by unbolting them.  I only learned this after cutting MANY off. LOL

Thank you for doing this!  I cannot wait to get my hands on a set!

Dave

That is a great tip, and not something I had thought to look into, thanks!

 

thor73 posted:
VGN64 posted:

I have some of the MTH NS Heritage units in 2 rail.  How do I go about ordering your pilots for them?

Thanks

The forum mods have asked that I not post links to stuff on my Shapeways shop, as I am not a sponsor here.

It's not like it's hard to find anyways. I see the GP9 and SD45 pilots. When will the ES44 pilots be up?

fredswain posted:
thor73 posted:
VGN64 posted:

I have some of the MTH NS Heritage units in 2 rail.  How do I go about ordering your pilots for them?

Thanks

The forum mods have asked that I not post links to stuff on my Shapeways shop, as I am not a sponsor here.

It's not like it's hard to find anyways. I see the GP9 and SD45 pilots. When will the ES44 pilots be up?

Good news, the updated parts should be delivered today!

I need to do a final fit check before I make them available. Unfortunately, I am going out of town in a day, and may not be able to get to them before that, so it will probably be after next week.

 

David Minarik posted:

Eric,

Just a side note:  You can easily remove the old coupler mounting boss on the premier 2/3 rail truck by unbolting them.  I only learned this after cutting MANY off. LOL

Thank you for doing this!  I cannot wait to get my hands on a set!

Dave

Dave,

This is good to know. I took a quick glance at a six-axle 3/2 truck and it wasn’t apparent how to “unbolt” the mounting boss. (I also scared up this picture from the MTH site, and again can’t see any mounting hardware).  What am I missing? Is it inside the bottom cover plate?656CB086-FDD7-4B7B-ABFF-CB64A2F09450

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 I don't remove the 3 rail coupler tabs on the ends of the trucks. I usually cut the end off of the back of the regular KD coupler boxes. There was an engine that had to have the short KD version as the trucks are mounted so close to the ends of the engines that there's less room. I forget which engine that was right this second?

https://kadee.com/htmbord/page743.htm

 I bought a used engine from a member that already had the truck tabs cut off. It seemed like so much more work than just using the right coupler or cutting the KD box.

Last edited by Engineer-Joe

 I grabbed the closest engines and snapped some pics. The GE's have more room I think?

for some reason? I used the KD 743 short boxed coupler on the GE ES44 that has the most room? First pic.

Second pic is the U28, third pic is another GE with the full sized KD box and the rear cut off.

The SD50 in the last pic has the least of this group. It still fits a full sized KD box with just the rear cut off.

DSC_0133DSC_0134DSC_0135DSC_0136

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Joe,

I usually trim the standard Kadee box when I want or need to fit a medium shank coupler. But the MTH SD45 is so tight that won’t work. Only a short shank coupler and small draft gear box fits (unless you remove the truck boss). I’ve used 806s on the SD45s, but MTH designed the pilot with the coupler pocket much too low. I want to switch them to an offset coupler to remedy that problem, but the Kadee offset model has a medium shank. I’ve been meaning to cut the truck boss to swap in the new couplers, hence my interest in Dave’s experience. 

RM284AE2A8-35DA-44E5-8916-378F301EBE65EBF51F2D-A759-4594-AAC2-8CC2DE5AB4C4

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Thanks Rich. Now that you mention those, I have 2 of them on deck that I never got to 2 railing! So the SD50 was the closest. It must have a hair more room as it works.

 You can see by your work that the MTH truck is a cast piece so the only thing I can think of easier, would be to cut a small area off the tab with a radius to create the room. I don't know what engine Dave spoke of that would have that tab removable?

 Can you machine off some of the mounting blocks on the stock pilots? I had a MTH engine like that and I remember grinding something to raise the coupler??

If the body is low you could shim it slightly to help?

Edit: I have another BN SD45 that I did convert. I used the KD 843 short box. The difference maybe that I made my own shims and mounted the couplers to the original pilots. So I could adjust the height and how far the box sticks out on mine. It just fits and rubs a bit when handled off of the track in the front only.

DSC_0137DSC_0138

It's getting bad around here? I don't know what I did!

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Last edited by Engineer-Joe

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