Copper State Railway SD40-2 progress report

[6axlepwr]

Tonight I designed a new coupler pocket for the Kato SD40-2 model. I did not want just a square hole in the pilot. I wanted something to represent a coupler pocket. It is a tad oversized, butthat is because of the hol eneeded to get the Kato coupler in place. I think it will look OK and add some good detail to the pilot. I also have some Coupler lift bar brackets that I had etched a while ago. They are scale size.

Got word today that at least three of my decoders are on the way. The fourth one will follow next week.

[6axlepwr]

Tonights update

I'll get my first test coupler pocket on Monday. This one is setup for the Kato coupler. I already have a second coupler pocket designed and setup for the LE coupler. The second one is the one I will use. It is really nice and because the LE shank is thin, I can setup the coupler pocket to be in the correct location on the pilot face. The coupler pocket for the Kato coupler sets to low because of the Kato coupler shank thickness. But the Kato coupler pocket will at least give me an idea of how it fits and if the design works. I designed them so I can either use a screw to secure them or simply use the Kato coupler clip. Photos will be posted when I get the pockets in.

Tonight I am working on the truck side frames. I designed a little tool that will allow me to precision bend the brake lines from brass wire. Tomorrow I will print them up at work and tomorrow night I can transfer the prints to a plastic tool that I will make. Also, I removed that unsightly mold parting line that runs horizontally across the face of the side frame. Have to be caeful when doing this. The casting above each journal needs to blend into the side frame face. I also drill the casting hole at the rear of the side frame where the side frame curves around the back. Although I cannot go to the extents that I do in HO with detailing the truck frames, I still want to spruce them up a little. I'll be able to use my speed recorder etchings as well so I can have a speed recorder set in its proper place. Photos will follow when I get these done as well.

Still waiting on the decoders, but they are in the mail.

[reinhardtjh]

I haven't seen it mentioned (but I may have missed it) - the picture looks like the Kato Mid-Production SD40-2.  That's the one with the "screw-less" chassis, right?  just curious.

I really like how you've done the decoder/speaker install.  When I get around to mine I will have to find a way to do something similar.

[6axlepwr]

I haven't seen it mentioned (but I may have missed it) - the picture looks like the Kato Mid-Production SD40-2.  That's the one with the "screw-less" chassis, right?  just curious.

Yes. But it has screws in it now. 

[6axlepwr]

Today I was really looking forward to my decoders coming in, but not so. Instead the first test shot of my coupler pockets or otherwise known as buffer plates arrived. Overall I am very pleased. They do work as designed. A couple edits need to be made to the file, but they are transparent.

As you can see in this first photo, the buffer plate fits into the existing rectangular hole in the pilot plate. The drawback to this buffer plate is that the backside of the plow needs to be carved out a bit for the plow to fit properly. The buffer plate sits to low. That is because of the thickness in the Kato coupler shank. The height of the opening is about 0.002" more in height than the coupler shank thickness. Due to the coupler shank, the buffer plate is taller than what it should be by more than 0.002". More like about (just guessing right now) 0.040". It is not prototype height. It is a little wider than prototype width because the back end of the coupler needs to fit through. The buffer plate opening is just barely large enough to slip the rectangular back end of the Kato coupler through. That makes the buffer plate wider than prototype width. Depth IS prototype. The back end of the coupler head is just barely off the face of the buffer plate. I had to trim about 0.002"/0.003" off the back of the coupler head and now the coupler swings freely.



In this photo you get a good idea of the buffer plate height. The design fits up nicely against the pilot plate. I do need to make the rectangle that fits into the hole just a bit larger. When printed, the rectangle comes out about 0.005" smaller in width than what was designed. I'll increase the size to compensate. The pocket can then be glued in with CA and then sand the seams to make it all flow together seamless when painted.



And here you can see the top view showing the curved buffer plate. Also you can get an idea of how smooth the printed surface is. Again, overall I am very pleased with this test. I think it looks much better than just a flat pilot plate. When the pilot is detailed with a coupler lift bar (whicjh I have scale lift bar brackets etched for) and MU hoses, I think the detail level will be kicked up a notch. 



The next test I am doing is for the Lee English coupler. This one will be much better because the buffer plate IS scale size in all directions. It will clear the plow as well. The coupler shank is much thinner which allows for the  buffer plate to be drawn to scale size. I am very excited about the LE coupler buffer plate because it will cement the use of LE couplers on all my equipement.

Both version of the buffer plate retain the use of the coupler clip to hold the coupler in place. With the LE coupler buffer plate I will have the choice of using either the clip or a screw.

I am waiting on one dimension from a friend who works in the BNSF mechanical shops before I get the new buffer plate made. I need to know the distance from the deck to the bottom of the buffer plate so I can get it properly placed on the model.

I hope you all like this. Maybe if there is enough interest, I can turn it into something.

[peteski]

Brian,
to be honest, I don't know why you even bothered to do all the work for the Kato coupler. IMO, it wasn't worth the trouble.  As you said, it is terribly oversize, and it looks the part. But the coupler pocket with a Z scale coupler will command my attention.

[crrcoal]

I'm with Pete; I'd rather see your work with the Z scale coupler. With the kato coupler I think the pilot passes the "good enough" test.

A bit OT but, why did you switch scales? Your HO models were incredible.

[GaryHinshaw]

Nice.  I'm curious to see the FT/LE version as well.

[6axlepwr]

Brian,
to be honest, I don't know why you even bothered to do all the work for the Kato coupler. IMO, it wasn't worth the trouble.  As you said, it is terribly oversize, and it looks the part. But the coupler pocket with a Z scale coupler will command my attention.

Pete,

I whole heartedly agree with you. I tried to stop the first test, but by the time I found out the LE coupler would actually work, there was only about an hour left on the printing so I was commited to the Kato pocket. The new pocket will get done some time next week. It at least showed me that the pocket idea fits nicely.

I donto know if I have already thanked Ed Nadolski, but I want to again thank him for sending me 6 pair of LE couplers a while ago. If not for Ed, I probably would still not have any.

[peteski]

Pete,

I whole heartedly agree with you. I tried to stop the first test, but by the time I found out the LE coupler would actually work, there was only about an hour left on the printing so I was commited to the Kato pocket. The new pocket will get done some time next week. It at least showed me that the pocket idea fits nicely.

I donto know if I have already thanked Ed Nadolski, but I want to again thank him for sending me 6 pair of LE couplers a while ago. If not for Ed, I probably would still not have any.

I see.  Now I understand.
Not many people have direct access to 3D printers.  I'm curious what kind of printer you have access to (how does it compare, resolution-wise, to the printers Shapeways uses for their FUD printouts).

[6axlepwr]

I can't eloborate on where I get them printed, but the resolution is infinitely better than Shapeways. It is being done by perfactory instead of stereolithography. The resolution is something like 0.0004" per layer or something close to that. Maybe 0.0006" per layer.

[cnw mike]

The print is very clean, don't get me wrong, but for a part that simple why not make a pattern and just cast it?

[6axlepwr]

The print is very clean, don't get me wrong, but for a part that simple why not make a pattern and just cast it?

That is exactly my plan. If th eprints work, then make a master print. I have a son in law that is a dental technician. He owns his own dental casting company. I'll send the parts to him and have metal masters made. Then I have a good master to cast form.

[ednadolski]

Say Brian, the test pocket is looking really good.  I'm really looking forward to seeing the LE version - do you think it likely would fit onto other Kato (or perhaps even non-Kato) locos?

Re:  the LE samples, you are of course more than welcome.  It's a real treat to see the work that you're doing 


Ed

[6axlepwr]

Say Brian, the test pocket is looking really good.  I'm really looking forward to seeing the LE version - do you think it likely would fit onto other Kato (or perhaps even non-Kato) locos?

Re:  the LE samples, you are of course more than welcome.  It's a real treat to see the work that you're doing 


Ed

A lot of it depends on the opening for the other models. It would certanly be easy to make other buffer plates though. I want to make some for the GE Dash 9's, AC44000's and other GE's. Problem is I do not have the dimensional information for the modern GE buffer plates. If somehow I can get my hands on one to measure, I will do that.

The way this current pocket is setup, the centerline of the coupler is dead on for an MT coupler gauge. In this new buffer plate, the LE coupler is fully supported so there will not be any coupler droop. The shank is supported all the way out. Just got an email that the new LE buffer plates are being printed today.