3D Printed Loco Bodies

[animotion]

Here are two 3D printed masters for Camkits, the left loco is for the Midland Railway A Class kit and the one on the right is for the Cambrian Railway 73 Class kit. They will be cleaned up to an injection mold finish before being sent to the casters in Birmingham.

 

 

[Paul_sterling]

On 29/04/2021 at 18:33, animotion said:

Here are two 3D printed masters for Camkits, the left loco is for the Midland Railway A Class kit and the one on the right is for the Cambrian Railway 73 Class kit. They will be cleaned up to an injection mold finish before being sent to the casters in Birmingham.

 

 

 

Looks very nice. If you increase the angle in relation to the slice height, you will likely find the surface finish will require much less work. With 0.4mm slice, the nominal angle is 40.25 degrees. thinner slices can go to shallower angles, thicker = steeper. 

[animotion]

Hi Paul thanks for your comment. These locos need to have a very flat bottom to them and I find that if I add supports to the bottom of the locos there can be a slight distortion to the bottom surface and plus the fact that the supports need removing which leave a small dimple on the surface that needs sanding down. Because I am printing at 0.03mm layer thickness I do not have to worry about the surface finish and the bodies get sanded with wet and dry paper afterwards. At .4mm layer thickness the sides of your loco probable look ok but I would imagine the boiler looks quite striated. I have also noticed that you have had to add a support for the chimney which makes cleaning up the delicate chimney a lot more difficult. Once the two loco have been post processed I will post the images to show how it is possible to get an injection moulded finish.

[Paul_sterling]

On 06/05/2021 at 14:30, animotion said:

Hi Paul thanks for your comment. These locos need to have a very flat bottom to them and I find that if I add supports to the bottom of the locos there can be a slight distortion to the bottom surface and plus the fact that the supports need removing which leave a small dimple on the surface that needs sanding down. Because I am printing at 0.03mm layer thickness I do not have to worry about the surface finish and the bodies get sanded with wet and dry paper afterwards. At .4mm layer thickness the sides of your loco probable look ok but I would imagine the boiler looks quite striated. I have also noticed that you have had to add a support for the chimney which makes cleaning up the delicate chimney a lot more difficult. Once the two loco have been post processed I will post the images to show how it is possible to get an injection moulded finish.

 

thanks, 

 

to get a flat surface whilst maintaining an angle, if you look at the running plate of LH&JC No.5 that I posted earlier, there is a sacrificial "knife edge" frame that I model into the cad, but has a very thin cross section where it meets the actual model, this gives long rails to structure the support tower onto, be perfectly flat surfaces on the part, even when built at an angle. I also use this method for starting on an edge, such as a buffer-beam. 

 

The chimney doesn't show any evidence of the support tower, though the dimple on the boiler does have to be sanded. It can print without it, but its my belt and braces approach to support the chimney. Boiler surface finish is really good to be honest, for the reason I explained before able angle. at 0.4mm slice, and 40 degree angle, the affect of the layers on the boiler surface is greatly minimised, and I haven't had to sand any loco boiler printed in this method. 0.3mm doesn't display a marked improvement in finish on these prints, especially with the angle optimised, so whilst I used to use 0.3 for "finisher" models, I don't bother now, as there was nothing to split the finish. The only advantage of 0.3mm for me, was that you could run at shallower angles, and hence save on print height, but this advantage couldn't be had on longer locos Like Lambton No.5, as 52 degrees was the shallowest angle at which it would fit. 

 

The attached file to this post probably shows it better. Its a really simple, but very effective solution. 

 

Thanks, Paul. 

 

 

 

 

Edited May 10, 2021 by Paul_sterling
Further info added.

[JCL]

Now that is genius!