General Category > Oddball

A Mini Tower Clock

<< < (75/75)

pgp001:
Hi Chris

You are making some very impessive progress there.

Looking at your collection of four engines, one thing I noticed is that some of the valve rods are operated via a lever, how does this affect the gland seal etc where they enter the steam chest.
It looks like the valve rod will not be running in a straight line due to the arc of the lever. It obviously works because you have already done it, but just curious if that is how the full size one was designed.

Phil P

crueby:

--- Quote from: pgp001 on December 06, 2025, 11:26:51 AM ---Hi Chris

You are making some very impessive progress there.

Looking at your collection of four engines, one thing I noticed is that some of the valve rods are operated via a lever, how does this affect the gland seal etc where they enter the steam chest.
It looks like the valve rod will not be running in a straight line due to the arc of the lever. It obviously works because you have already done it, but just curious if that is how the full size one was designed.

Phil P

--- End quote ---
Hi Phil,


That is exactly how the full sized engines were made. I first encountered it on the Lombard Log Hauler valve rods for its main engine. The lever only moves a few degrees so the rise/fall of the arc, which is centered on the travel, is tiny. The gland packing would allow that small wobble, and the way the rod goes through a slot in the valve does as well. They did not slot the connection from the lever to the valve rod.


I'll  put up a couple pics in a little while.
EDIT: Here are the pictures of a couple examples. First, the Lombard log hauler, which has the same kind of lever arrangement to the valve rod on top of the cylinder, the lever on the right end has a firm link to the valve rod, but since it moves just a few degrees you can't really see the rise/fall on the rod, which has enough flex and play in the gland to handle that:

This is the steering engine on the Marion, which is exactly the same as the slew/crowd engines, just 1/3 smaller and mounted vertically:

and the slew engine from the 91:

I have factory plans from a couple of the manufacturers showing the same thing. So, not uncommon!

pgp001:
Chris

Thanks for that information, very interesting. I have not come across that arrangement before.
I bet modelling in CAD was a challenge, that arrangement would be tricky to animate as an assembly.

Phil P

crueby:

--- Quote from: pgp001 on December 06, 2025, 03:07:41 PM ---Chris

Thanks for that information, very interesting. I have not come across that arrangement before.
I bet modelling in CAD was a challenge, that arrangement would be tricky to animate as an assembly.

Phil P

--- End quote ---
True on the CAD animation, that connection would have to be jointed as a pin-slot type probably, even though it isn't one. I did not animate those engines, so did not have the problem!   :)

Navigation

[0] Message Index

[*] Previous page