LBSC Dot/Diana Cylinder Castings

[Roger HahnParticipant @rogerhahn99807]

I had started building the Diana Gauge 1 locomotive many years ago.  I had machined the cylinders but made an error with one. I am contemplating restarting work on it but am unable to source the castings. I believe I had bought them through Reeves’ back then but they do not sell them now.

Is anyone still selling the castings or completed cylinders?

Roger

[JasonBModerator @jasonb]

They don’t look hard to cut from solid or fabricate and probably cost a fraction of what a casting would

[WearyParticipant @weary]

As an alternative to fabrication and/or cutting from solid is your existing ‘damaged’ cylinder salvable?   What is the nature of ‘the error’ p’raps?

Phil.

[Howard LewisParticipant @howardlewis46836]

Is the component totally beyond reclaim?

If the cylinder bore is oversize, could you bore out a little larger and then liner and rebore to finished size?

If a thread is out of position, would it be possible to tap oversize and plug before drilling and tapping in the right position?

Howard

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Rodger, like JasonB says, they probably wouldn’t take much doing from a solid block, and most likely easier than a pair my father made sometime back in the 1940’s.

Regards Nick.

[Roger HahnParticipant @rogerhahn99807]

Thank you all for your responses.

The bores on the cylinders do not align across either the port face or the frame mounting face. It’s difficult to measure the difference but it is noticeable to the eye.  Thinking about, perhaps the differences may not throw off the geometry by enough to make a significant difference.

Roger

[JasonBModerator @jasonb]

For that small an amount you could probably set them up again and rebore true to the two flat faces. Does not look like you would have to go much oversize and at least worth a try before making new.

Putting them on a single mandrel or shaft like you have in the photos rear end to rear end and skimming the faces would be another option as there is not much to come off, just adjust other parts in the valve gear to compensate for any reduced dimenmion.

[duncan webster 1Participant @duncanwebster1]

What’s important is that the cylinder bore is parallel to the frame. If the valve port face is a bit off, it doesn’t actually matter as long as the valve spindle is parallel to the frame. Also, the back face of the cylinder needs to be square to the bore. You can always use shims to correct Cl to frame dimension

[John PurdyParticipant @johnpurdy78347]

Roger

I had a similar problem with the cylinders of a 5″gauge model I had been given. The cyl frame mounting face relative to the bore was about 80 thou out across the 3″ length of the cyl. I machined the face back parallel to the bore and then shimmed the cylinders out to maintain the correct distance, worked well.

John

[Roger HahnParticipant @rogerhahn99807]

I believe the bore is parallel to the flat faces and perpendicular to the ends.  It seems like things aren’t as bad as thought.  I will check the distance from bore to frame and mill a little off or shim as necessary.

 

Thanks again for the input.

 

Roger

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