Author Topic: Tug's Corliss Tandem Compound Project  (Read 92417 times)

Offline john mills

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Re: Tug's Corliss Tandem Compound Project
« Reply #495 on: October 26, 2020, 08:43:34 AM »
hi Tug

thats a wonderfull model  i have followed the project and it is wonderfull to see it running .
    John

Offline tangler

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Re: Tug's Corliss Tandem Compound Project
« Reply #496 on: October 26, 2020, 12:16:12 PM »
Tug's video reminds me of this wonderful clip from "Industrial Revelations" with Mark Williams.

https://youtu.be/5ny2Pizgfls?list=PL0QJlKdyUzw0mH1qKhU9SNp92PZYmyU9t&t=719

Rod

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #497 on: October 26, 2020, 01:17:45 PM »
Thanks for reminding us of what such an enjoyable program that was Rod. Personally don't think anybody could do the subject matter any better than Mark Williams did in those series  :ThumbsUp:  Er! by the way, though mesmerised by the linkage on the Throp I did fall short of dancing to it - maybe that will help get it in synch  :Lol:

Thanks for your comments John  :ThumbsUp:  Sue and I were wondering - you wouldn't happen to be the same John Mills from Essex we met many years ago who built a really super steam lorry - 'J MILLS' on the cab side?  If so sincere regards from both of us and hope you are keeping well.

Tug

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline john mills

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Re: Tug's Corliss Tandem Compound Project
« Reply #498 on: October 26, 2020, 09:28:03 PM »
Hi   tug

no I am in Melbourne   Australia  .
there are lots of John   Mills   around    i have worked in place where there were 2    and 13   John 's
great to see your engine  running   t is easy to think of the full site large engine starting  the preure in the cylinders rising and the vacuum rising as the engine comes up to speed and under full load.

    regards John

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #499 on: October 26, 2020, 10:22:59 PM »
Thanks John - bit like those 'Tug Wilsons' eh  ;D

I met the other John on an engineering course - saw him with a copy of Model Engineer in his hands. He was building a steam lorry - Foden I think - and several years later there it was on the cover of ME. Our paths would cross occasionally at shows but I haven't seen him for a long time now - bit of a long shot but I thought I'd ask.

Decided to sort the valve setting out before progressing with the final touches so made a start this afternoon. The inlet sequence appears fine but having marked the opening positions on the side of the cylinder it's easy to see that the exhaust valves are closing way too early - before the cut off in fact!.  After moving it either side the eccentric position looks to be correct as drawn so tomorrow I'm starting at the rocker and making sure that all movements are as equal as possible but it does look as if the exhaust valves, as drawn, will need to be modified to get a longer opening.

For now - Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #500 on: October 27, 2020, 08:52:55 PM »
Hi guys,

Well I'm really pleased to report I have managed to make a significant improvement to the running :).

I began by getting everything as symmetrical about the centre stroke as possible then modified the HP exhaust valve by 0.5mm to get a later closing. I was then able to close those drain valves off and the engine ran very evenly in both directions and very slowly - a timed 60 rpm . It does need a lot of pressure - far more than anticipated but I think I may be able to reduce that some.  I finally fitted a gauge to my shed regulator and was very surprised to find the lowest pressure it would run on was 45psi  :o At a steady beat with the stop valve right open it was 65psi :o :o. I would think it requires this amount of pressure because the cut offs are possibly too early - at a lower pressure there simply isn't enough volume of air to move the piston the full stroke.

So, I took another video only to just find that I didn't ::)

It's obvious that what I actually did do was begin to record as I put the camera down after taking the 'non video'!! You have a an 18.54 minute video of the corner of my gauge block case to the sound track of the much steadier engine beat but I don't think that will make for scintilllating coverage :lolb:  You'll just have to take my word for it ..... Per?  :D

So, I do feel I can now continue with the rest of the cosmetic parts knowing that it runs as well as I could wish for - I'll tweak the cut off to give a longer opening when it's all done.

Back soon then - another engine project is begining to look an attractive follow on but not until this is one is 'completely' done

Regards all - Ol Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline crueby

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Re: Tug's Corliss Tandem Compound Project
« Reply #501 on: October 27, 2020, 09:16:01 PM »
Excellent news!   Engine timing much better, camera timin not so much!  Not that I ever did the same thing. Today anyway...   :wallbang:

Offline john mills

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Re: Tug's Corliss Tandem Compound Project
« Reply #502 on: October 27, 2020, 09:17:37 PM »
Hi Tug
it is good to see you could improve the vale events .wanting to run at higher pressure , it is a compound engine
the air has to expand and lower the pressure  then  move to the low pressure cylinder  to expand and drop the pressure further what is the pressure in the low pressure cylinder  then it is meant to exhaust into the vacuum
created by the condenser .if it does not start with a little bit of pressure how would the rest work. thats my thoughts.it is a pleasing result.
             John

Offline deltatango

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Re: Tug's Corliss Tandem Compound Project
« Reply #503 on: October 27, 2020, 09:52:51 PM »
That's great news Tug!

When you say you "modified the exhaust valve by 0.5mm" does that mean machining 0.5 off the flat face of the valve(s)?

David
Don't die wondering!

Offline Admiral_dk

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Re: Tug's Corliss Tandem Compound Project
« Reply #504 on: October 27, 2020, 09:59:44 PM »
Oh I'm not complaining here - and just to clarify - I make more than my share of errors ....
+ the only reason I can guarantee that I haven't made that video ups .... is that I do not have a video camera ...!

Great to hear that you got a better result  :cheers:

Offline flopearedmule

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Re: Tug's Corliss Tandem Compound Project
« Reply #505 on: October 28, 2020, 01:52:12 AM »
Tug
I just spent close to an hour looking through and reading your build.  (I've been gone for awhile)
I have to say, the fine detail you have on this engine is pretty awesome!  Thanks for sharing.  Can't wait to see a video of it running.

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #506 on: October 28, 2020, 08:28:59 AM »
Thanks guys, good to hear from you all :ThumbsUp:

'Flop ear' - good to see you back on MEM - we all have to take a break at times  :ThumbsUp:.

Per - :) Hope you are well, give John my regards - Loved the Danish expression BTW  ;D

David - Yes, bit of a relief really. I gingerly took 20 thou off the leading edge of the HP valves to make the opening earlier. The LP didn't seem to require any so decided not to and see what happened - as said it improved it considerably but I would think that it could be further improved by slight modification to those also. I intend to revisit those on 'finals' .One thing I would recommend you doing - Make a clear mark across the back of the valve to indicate the position of the flat and scribe small but defined marks of the opening points on the side of the cylinder. (obviously these need to be shorter than the width of flanges (I used masking tape marked up but defined marks would have been so much better).

I appreciate your thoughts on this John, obviously air works different to steam in the compound principle but it does have a 'long way to travel' and if the vents aren't in perfect synch then restrictions will be there if not so obvious now. All my previous engines run well on very low pressure so was hoping this might be the case here to but I'm sure it can be further improved

And as for being in synch Chris - well I really got that one arrs about face eh  ;D

Thanks guys - I'm starting on the handrail stanchions today - quite a few small items to make to tidy this project up but it's the home straight now.

Back soon with pics and a vid once its all done

Regards - Tug

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Hugh Currin

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Re: Tug's Corliss Tandem Compound Project
« Reply #507 on: October 28, 2020, 02:35:04 PM »
Tug:

That reminds me of a video my wife took of an HPV (bicycle) race some time ago. She got out of sync with the "go" button. The result was the video shows the camera being raised to take a shot and as soon as stable turns off. Then come on again as it's lowered showing her feet and the ground. Cycled like this for 15-20 minutes. Ah, technology.

Congratulations. Wonderful build, thank you for sharing.

So, I took another video only to just find that I didn't ::)
Hugh

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #508 on: October 29, 2020, 08:52:32 AM »
Hello Hugh - nice to see you here, thanks for looking in  :)

Yes easily done I guess. Well before digital cameras I took a whole roll of film of four of us walking in Snowdonia - thing was there was no film in the camera  :facepalm: Quite the popular boy I was  ::)

Hope you are well, stay safe - Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Roger B

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Re: Tug's Corliss Tandem Compound Project
« Reply #509 on: November 07, 2020, 12:12:18 PM »
Excellent  :praise2:  :praise2: I do like watching all the complicated linkages and motions  :wine1:
Best regards

Roger

 

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