Part 31: The Pistons and Piston Rods
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- Опубликовано: 16 окт 2024
- Welcome to Part 31 of my long term series of videos covering the build of Don Young's Hunslet 0-6-0 Saddle Tank Locomotive in 5" Gauge.
In this video I cover off the machining of the Pistons, Piston Rods and finish off the Crossheads.
Given the nature of these sorts of projects, new videos will be posted as I progress through the build but there will be no regular cadence, rather their frequency will be dependent upon time available and of course real progress on my part.
If you like what you see, please do give me a thumbs up and subscribe.
Enjoy!
Mark not fair !!!!! Leaving us on tender hook's
Great video.
As usual, superb video Mark.
I tried making a new piston for my Royal Scot (previously mentioned), and made it too small in diameter ( no idea how).
Still not plucked up courage to try again yet.
I am a little surprised that there is only one packing groove called for on your model.
Some modellers suggest the fit is right, when the "oiled piston" will slowly slide down the "upturned cylinder", under its own weight.
You make it look so simple, and accurate.
Thanks for the videos..
Have another go at the piston for the Royal Scot, even if you get it wrong again you will learn and get there eventually. It's how we all learned.
I think the single groove with packing is quite common on the simpler models.
As for my pistons, they are much looser than how you describe 😁
Thanks for the feedback and comments 👍
Mark
Mark please read the comments I made yesterday on part 22. I think you will find them helpful. Cheers!
Nothing for 2 months. I hope you are well.
All good thank you Nigel. Life has been getting in the way, but the next video should be up soon 👍
Really lovely and very satisfying! May I ask a question about the edge finders you are using? I know you are using a DRO and a half function, so you wait for the wiggler to become offset. When I’m using my dials do I still want to wait for it to become offset? All the last possible moment that it’s concentrically rotating?
Hi William,
The point at which the edge finder or wiggler breaks away is what you're looking for. At that point it is half its diameter away from the edge. I have seen one contributor on RUclips that appears to work to the edge finder visually running concentric which I'm pretty sure it's not correct.
Cheers, Mark
Hi Mark Do you think the tolerance of the piston is a bit tight? As you will have heat expansion which will be greater on the piston.
The Million Dollar question :-)
According to Tim Coles in his book Model Steam Locomotives - "turn the piston to a sliding but shake free fit in the bore". My initial impression is that both pistons feel a bit loose in the bores, but the packing will certainly help (I won't pack the pistons until I'm close to running on air).
Time will tell!
As a side note, Tim does also explain that the piston rod be pressed into the crosshead, which I guess will explain Don's lack of detail in this area - I'll stick with my threaded approach for now.
Cheers
Mark
@@markshomeengineering5243 Hi Mark I also thread my my piston Rods it just feels safer. Pistons are one of those things that makes me nervous, it's a fine line of a great job or a bloody disaster. With many cast iron pistons in the junk box from letting hand act before the brain. Enjoying the build and await the next issue.