Author Topic: Twin cylinder mill engine, slightly rusty.....  (Read 7916 times)

Offline Charles Lamont

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #75 on: January 20, 2025, 10:50:40 PM »
Correct on the timing sequence - centering travel first, then adjust the eccentric to open just after TDC (and close before BDC). Each side gets same adjustments, relative to its own ports/crank.  It can be fiddly, tiny adjustments, or sometimes it just falls into place and runs!

... open just before TDC, surely. When it closes will depend on the valve lap, if any - could be well before BDC.

Offline crueby

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #76 on: January 20, 2025, 11:04:11 PM »
Correct on the timing sequence - centering travel first, then adjust the eccentric to open just after TDC (and close before BDC). Each side gets same adjustments, relative to its own ports/crank.  It can be fiddly, tiny adjustments, or sometimes it just falls into place and runs!

... open just before TDC, surely. When it closes will depend on the valve lap, if any - could be well before BDC.
If running fast, yes. For a slow running steam engine, you want it to open after tdc, or the steam can stop the piston. And yes, the amount it closes before bdc will effect the efficiency of the  engine. I  was just giving general guidelines for model steam engines which often have little to no lap. F9r more efficient  running, its a very deep topic. I like to set mine up so they just barely tick over at very slow speeds. For a h8gh speed engine, it can be very different.

Offline Jasonb

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #77 on: January 21, 2025, 07:06:42 AM »
I never look at when the valve starts to open. After setting it for equal movement each side I put the chest cover back on and just set the eccentric usually to 30deg ahead of the crank and adjust from there if needed. Only time it needs a bit mor ethought is if there is a bell crank or rocker in the run from eccentric to valve which can alter the direction the valve moves in.

They all seem to tick over nice and slowly and will also go like the clappers when the regulator is opened up. And from a few psi when running for display to a bit more if I want them to work.

Online redhouseluv

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #78 on: January 21, 2025, 07:21:05 PM »
Well I'm genuinely surprised by what has happened, 'Esther' is alive and runs! Given the original condition and the fact everything was seized solid I didn't actually think she'd ever be a runner.

It's clunky, leaky, wobbly and noisy and but hey, if I was that old I would be the same!  ;)

Here's a question, given the eccentrics are locked onto the crankshaft using keyways, how do I alter their postion to adjust the valve timing, I don't think I can? I've decided not to paint her and just to find a nice bit of wood to mount her on and call it a day..............

<a href="https://www.youtube.com/watch?v=PuSdBIu17fY" target="_blank">http://www.youtube.com/watch?v=PuSdBIu17fY</a>
Best regards

Sanjay

Offline Jasonb

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #79 on: January 21, 2025, 07:27:23 PM »
You can't easily adjust them but does not look like it needs them adjusting.

What's next?

Online redhouseluv

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #80 on: January 21, 2025, 07:31:13 PM »
Ha, exactly 'What's next' - I have a growing pile in the 'What's Next' backlog - I'll dig something out!  :D
Best regards

Sanjay

Offline Admiral_dk

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #81 on: January 21, 2025, 07:34:42 PM »
Great to see that you got it running again  :ThumbsUp:

Per   :cheers:

Offline crueby

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #82 on: January 21, 2025, 07:36:24 PM »
The old gal can still run!   :cartwheel:

Offline Charles Lamont

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #83 on: January 21, 2025, 08:34:48 PM »
Nice work!

Offline Kim

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #84 on: January 21, 2025, 11:04:06 PM »
Beautiful!  Nicley done!
Kim

Online Dave Otto

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #85 on: January 21, 2025, 11:36:34 PM »
Nicely done!

Dave

Offline Michael S.

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #86 on: January 22, 2025, 05:21:05 PM »
I congratulate you on this beautiful engine. He will now survive for the next 100 years.

Michael

Online redhouseluv

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #87 on: January 22, 2025, 08:34:32 PM »
Thanks all, appreciate your kind words and yes, Michael, its nice think that hopefully these things will be around for another 100 years or so and people will still value them.

Finally, I have a nice piece of wood coming, but my woodworking skills are not great. I'm going to have to cut a slot for the flywheel using a series of holes; luckily the base plate will cover any mistakes, so fingers crossed it will look ok!
Best regards

Sanjay

Offline Roger B

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #88 on: January 26, 2025, 08:52:44 AM »
Excellent work, congratulations on a runner  :praise2:  :wine1:
Best regards

Roger

Offline Jasonb

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Re: Twin cylinder mill engine, slightly rusty.....
« Reply #89 on: January 26, 2025, 10:00:13 AM »

Finally, I have a nice piece of wood coming, but my woodworking skills are not great. I'm going to have to cut a slot for the flywheel using a series of holes; luckily the base plate will cover any mistakes, so fingers crossed it will look ok!

You can always mill the flywheel slot, sharp cutter and fastest speed.

 

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