Sm2-sähkömoottorijuna

[jukki]

Hey, I would be interested in 1 or 2 complete sets if these become available.

[Aleksei]

Dear Jukki,

Thank you! I will post here all the process, but I can't promise, that the process will be fast.

With best regards,
Alexey

[Aleksei]

Dear railway enthusiasts,

I’m trying to figure out the train numbering system and can’t understand it. That is, the first digit is always 6, the second digit is 0 for a motor car, and 2 for a trailed car, and then the serial number of the train? If a motor car has a number, for example, 6092, then the trailer car will be 6292, or do motor and trailer cars not necessarily work as part of the same electric train and can be intercoupled?

With best regards,
Alexey

[LOK]

Hi Aleksei!

You have understood the numbering of Sm2-Eioc pairs pretty much correctly: The Sm2 motor units are numbered from 6051 to 6100. The corresponding Eioc trailer car number is gained by adding value 200 to the motor car number. For example, Sm2 6051 and Eioc 6251 are a pair, and Sm2 6100 and Eioc 6300 are another pair.

Sm2 and its Eioc wagon cannot be decoupled during normal operation. I'm not sure if these original Sm2-Eioc pairs have ever been mixed.

Cheers,
LOK

[LOK]

I read from Valtionrautatiet 1962-1987 book (pages 406-408) that VR bought Sm2 trains in 4 batches: The first 20 Sm2 trains were ordered in 1972 and these Sm2 units were numbered from 6051 to 6070. Corresponding Eioc trailer cars were numbered between 6251 and 6270. VR ordered more Sm2 trains in 1975, 1977 and 1978. Each of these later batches contained 10 Sm2 trains so the total amount of Sm2 trains was 50 units. The completed trains were handled to VR between June 1975 and December 1981.

This batch production of Sm2 trains might explain why some units seem to have different chassis structures. Perhaps Sm2 blueprints were updated as VR and the manufacturer gained experience from the first Sm2 trains. The book also has a picture of Eioc 6281 in yellow-brown livery without any markings of the cabin door in the front. Perhaps the later Sm2 batches were built without the front doors thou there is no clear mention about it in the book.

[Aleksei]

Thank you very much for your answers!

[Aleksei]

Hi all!

Here's the first attempt at version 2.0:

1.jpg

It was possible to achieve a very high quality of surface and elaboration of small details on the car body. The roof now mates properly with the cabin, as I showed in my 3D models earlier. I was very afraid for this place.

2.jpg

3.jpg

The quality of these parts does not compare to what I milled in 2017. How far technology has advanced. For comparison, I show macro photography of the same place in the first version of the model.

4.jpg

I am very pleased with the result!!!

In addition, we managed to get a three-dimensional number! The number, of course, for each model can be made as desired.

5.jpg

This car body, however, unfortunately cannot be used due to problems with deformation. This photo clearly shows the deformation of the walls. I already have ideas on how to deal with this.

6.jpg

When the problem is solved, I will show you the result.

With best regards,
Aleksei

[tv_tyyppi]

Walls between the compartments (just like there are in real life) may help as well as thickening parts of the walls to provide some additional support may help a little. No guarantees and I am quite sure you have more experience.

Looks great by the way.

[Aleksei]

Hello everyone!

tv_tyyppi, thank you for your reply. I had no experience in stereolithography either:) I am also a beginner in this matter. The walls are indeed a very logical solution, but I would not like to use them because the model provides for the presence of lighting in the passenger compartments, and it is not clear how to do this with the walls, so I want to make the walls on the inner frame.

After experimenting with different materials, exposure times and supports,

IMG_20240810_170738.jpg

I finally got a car body without deformations!

IMG_20240810_161659.jpg

In addition, small details turned out well, such as the Scharfenberg coupling and equipment on the roof.

IMG_20240810_134549.jpg

IMG_20240810_134949.jpg

On Monday, we have the hottest day this summer in Krefeld: up to +34. I will leave the body on the balcony in the open sun that day, I will see what happens to it. If nothing happens, then I will consider the experiments with the material complete and will move on to the next issues: electrical boards and traction drive.

[Aleksei]

Hello together!

The next necessary technological operation is the turning of grooves for rubber bands on wheel pair bandages. The solution has been found:

WhatsApp Image 2024-09-01 at 13.28.02.jpeg

WhatsApp Image 2024-09-01 at 13.28.02(1).jpeg

With best regards,
Aleksei

[Aleksei]

Hello together!

I found and already received and try to assembly all the components for the motor wheel set. I found gears with a module of 0.2! So such a gear should be quiet... Since I do not know how well the SLA-plastic will behave in a friction pair, I decided to make a motor bogie on rolling bearings.

Wheelset_SM2_HO.jpeg

Next, it's up to the motor and then I will develop the frame of the motor bogie. I'm going to try a core less motor, it will be first experience with such motors.

With best regards,
Alexey