1/32 LMS 4-4-0 class 2P

michael mott

Western Thunderer
Today I was able to cut out the first of the valve links these are laminated from a layer of archival Matt board with some .0085” printable cardstock on both sides.
IMG_1951.jpeg

IMG_1952.jpeg

IMG_1960.jpeg
After drilling the .020” holes for clamping bolts the two halves were cut apart with the jewelers saw the laminate was treated with AC glue at various stages to ensure that it was all plasticized. One small step at a time.
IMG_1956.jpeg

Looks like it’s going to work.

Michael
 

michael mott

Western Thunderer
On page 18 of Wild Swan publications No3 The Class 2 superheated 4-4-0s the drawing of the lifting linkage appears to be drawn in error, I know how Stephenson valve linkage works and according to the way this is drawn the assembly cannot be altered from the central position the following two details from the diagram illustrate my point
IMG_1991.jpeg

IMG_1992.jpeg
I think that the lifting arm appears to be either too short or long from the plan it appears that the pin passes through both the bracket connected to the valve rod and the slide, the end cross section seems to confirm this. I would suggest that the lifting link is better to be attached to the bottom of the curved slide link
IMG_1993.jpeg
Then the slide can be raised and lowered with a longer arm the geometry is better than shorter. I would appreciate any feedback from the wisdom of your collective knowledge.
Michael
 

adrian

Flying Squad
I don't think it is drawn in error - I think it's just unfortunate they've drawn it in mid-gear where everything aligns. I making an educated guess but I think the expansion link will be a machined casting, it will have an outer boss to which the lifting link is bolted, but the link block will slide inside this outer boss. It has a seperate pin and not connected to the outer boss.

image21.png

Hopefully this shows them separate.

outside-stephenson-link-motion-as-applied-to-black-5-no-44767-george-stephenson-P67RYB.jpg

Very tenuous and open to interpretation but I'd suggest that the lack of the dotted line here suggests that they are separate pins and not connected.

Screenshot 2023-11-21 at 22.18.59.png
 

michael mott

Western Thunderer
Working on the cross slide bars and front of the cylinder block trying to make the visible parts have some semblance of reality I am hoping that it will all work as planned. I know that it would have been a whole lot easier to have made it all with metal. I wanted to see how far I could push my abilities with unconventional materials in this area.
First picture is of the bar’s glued together then after trimming the spacer it will be glued to the cylinder block.IMG_2001.jpeg
The circular parts of the cylinder block are turned from some English Boxwood and the slide bars are Castillo boxwood. The first set were glued to the insides of the cylinder covers then the outer parts were glued on
IMG_1999.jpeg
IMG_2002.jpeg
I put some wedges in to squeeze the bars to the support plate then using a needle tack glued the plate to the bars. Next I dry fitted them between the frames.
IMG_2005.jpegTomorrow after the pva glue has set fully I can slip it out to finish off the rest of the details and paint it up. I will use a silver sharps pen on the bars on the outside surfaces.

Time for supper.
Michael
 

Roger Pound

Western Thunderer
Michael,

The technicalities are way beyond my skill set, but I am happy to see that you are solving the problem with your usual patience and craftsmanship. Watching this project coming together is not only a pleasure but a true education.

My humble thanks for your publishing the progress, warts and all!

Roger.
 

michael mott

Western Thunderer
Thank you Roger. As Adrian has already said I am also amazed that there are some amazing skilled builders out there who are able to do this work on 7mm models. There are definitely some limitations with using non traditional materials, this would definitely be much more difficult without CA glues which allow the printed card to be plasticized and it capillaries into the white archival Matt board to make it extremely strong. Even so I have to use some metal in a couple of places for purely practical reasons. I am surprised by how much I have been able to get done with the card though.
Michael
 
Top