Author Topic: Tug's Corliss Tandem Compound Project  (Read 78578 times)

Offline Jakdaw43

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Re: Tug's Corliss Tandem Compound Project
« Reply #135 on: January 30, 2018, 04:17:48 PM »
Hello Ramon,
A Corliss Mill engine has been on my 'bucket list' for some years now....had the castings about 10 years from a club sale.
Decided in mid November 2017 to start the project. 
What I had were two Corliss cylinders (HP & IP), bedplates to suit with the single width flywheel and the condenser castings.
I machined up the condenser, two GM blocks, crankshaft and flywheel as a starter for the project.
I then decided to add a S/V LP cylinder, which I will fabricate.
I made up the baseboard (preliminary) and got the engine basically placed so that I could fling the flywheel....runs nice and true !!
The same kind of 'pushticuff' feeling you get when the loco chassis is pushed up and down the bench for the first time !!  (You can see that I was heavily influenced by Ivor the Engine !!)
After 20 locos and three traction engines it's nice to do something different, returning, as I have done for many years, to stationary/marine engines.
Having just been put onto the Home Engine Maker site by Bob Potter, it's great to see like minded people around the globe enjoying our hobby....or is it an obsession !!
Stuart
Stuart alias 'Jackdaw'

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #136 on: January 31, 2018, 08:46:35 AM »

Hi Bertie, Dave, Pete, Sco and Kerrin, Thanks for your comments. Thanks too ‘Jackdaw’ for looking in – unlike ‘Tug’ no prizes there for guessing how that nickname came about eh ;)

Pete (10k) -  Here’s a pic of the sectional view. It has valves each end fitted with O rings.


In ‘proper use’ the LP exhaust comes in from the top, cooling water injection from the side. The ‘air pump’ then evacuates this condensate through either end into the end chambers then down into the sump from where it drains back into the cooling water reservoir. Obviously all redundant on air – I’m thinking of making a new piston without packing as it really isn’t necessary and as I’d like this to run on as little pressure as possible any reduction in friction is a bonus.

JB Weld (again) I looked into  getting a tech sheet but could only find safety data sheets (all eleven pages!) so the only ‘tech’ info I have is the two specs on the card – 3960psi tensile strength and 550F temp. When I looked here http://www.jb-weld.co.uk/j-b-weld-epoxy-adhesive/j-b-weld-original-epoxy-adhesive I was surprised to find the statement that this product could no longer be sold in the UK because the packaging did not meet European standards – momentary anxiety attack till Ebay was opened to find there was more available than you can shake a stick at. Duly ordered a couple of packs.

The backing card has changed slightly and I notice the strength is now given as 3900 but the temp remains the same. The card now has a small impressed triangle which I guess now makes it European Regs compliant.


One fact I did notice in the new instructions is the recommendation to allow it to sit for an hour before using to prevent slumping. A problem experienced before on a couple of uses, some may recall. Makes sense so will try that in future.

The new card also includes a free matchstick, which, I assume is a mixing implement – wow. One thing I forgot to mention is that I believe the best results will be achieved if the two parts are thoroughly homogenised into a uniform dark grey and not just mixed by stirring into each other with something like a matchstick! Though it will still cure I believe the effective strength will be diminished. I base this on something a member of the Norwich MS once stated at a meeting – he had just been on a course at Cieby Geigy and relayed the fact that he had that stressed to him. I’ve always kept to that principle since on anything epoxy and always ensured a thorough mixing.

I note that the 'high heat' version is an epoxy putty - worth investigating I guess

Despite my intention to take a break – I have realised that before I can take it to bits I really need to sort out the pipe work so as to deal with anything under the base before it’s reassembled – so I will be getting back to it sooner than thought!

Stuart – ‘Jack’ - It looks like we approach things in a similar manner :) I look forward to hearing about the rest of you build  – with your background you should have no problems with the small challenges it throws up – one things for sure yours is going to be one heavy model but I guess you are used to that :D

Regards to all – Oyl be bek in tha ol shid suuna thun layta ;D

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 MJM460

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Re: Tug's Corliss Tandem Compound Project
« Reply #137 on: January 31, 2018, 10:46:18 AM »
Hi Ramon,

I look forward to your return.  I am thoroughly enjoying reading your posts.  And it is a very interesting engine.  I am sure there are many others.

MJM460
The more I learn, the more I find that I still have to learn!

Offline 10KPete

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Re: Tug's Corliss Tandem Compound Project
« Reply #138 on: January 31, 2018, 03:59:45 PM »
Thanks for the picture, Tug. That explains it. A simple double acting pump but very clever arrangement with the valves at each end. Nice!

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline kvom

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Re: Tug's Corliss Tandem Compound Project
« Reply #139 on: January 31, 2018, 04:13:00 PM »
If it doesn't do anything you don't need any piston at all.   :shrug:

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #140 on: January 31, 2018, 06:17:32 PM »
Ha, your comment brings a wry smile 'kv'   ;D

It has been considered - at the outset the thought occurred as to whether to leave out the plumbing and just have this running on one cylinder either LP OR HP , leaving out the other piston and that in the airpump.
It was dismissed as quickly as thought - primarily as it wouldn't be a twin and airpump without a piston wouldn't be an airpump. A charlatan in other words.

So, piston it is - whether it's a plain one is up for grabs as I received that new packing today and it's far superior to what's already been used - more on that a bit later.

You're welcome Pete  :ThumbsUp: and thanks your kind comments MJM - a couple of days away with it constantly hovering at the back of my mind has convinced me that I need to stay focused ;)

Back afore too long - Tug

PS - 'Whiskey' - can you check your PM's  ;)


"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 kvom

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Re: Tug's Corliss Tandem Compound Project
« Reply #141 on: January 31, 2018, 07:05:16 PM »
The piston rod is in  effect a piston, just with a very small diameter.   :D

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #142 on: January 31, 2018, 10:01:43 PM »
Ah kv, but would it move enough air to make those valves make their nice 'popping' sound  :D

The packing I used on this airpump piston was bought at the Guildford show a few years back but this was the first time I have used it on a project. Prior to that I had used a similar type of braided PTFE packing but that was much firmer in section. Bought originally from Reeves I think, the last of it was used on the Stuart D10 in the Wide a Wake.

This packing, bought at Guildford some time back is very soft, not very consistent in section and somewhat greasy to the touch. I am pretty sure that's why it's causing some drag in that, unlike the previous material, it's softness is allowing small amounts to move into the small annular gap. The pistons in the Waller, McOnie, D10 and Double Diagonal, all with the original packing, move extremely freely but with a very good seal.

The new packing came today and shows great promise. Very consistent in section, robust and very 'slippery' to the touch I think this will be a huge improvement.

The old - it looks dirty because it is, it's greasiness making it virtually impossible to prevent it picking up the slightest amount of dirt from anything ::)


Although 'square' in section there's no real definition and it's not uniform either


The new stuff on the other hand is totally different ...


... and it's section is a very consistent 4mm square.


Chalk and cheese I'd say


An added bonus is cost - under a tenner including post for a full metre - some charge the same for a foot :o

That's it for tonight  - Tug
« Last Edit: January 31, 2018, 10:33:27 PM by Ramon »
"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 Stuart

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Re: Tug's Corliss Tandem Compound Project
« Reply #143 on: February 01, 2018, 07:50:14 AM »
Tug

That soft packing looks good stuff

But don’t be shy where did you get it from ?

Your sentiment with all parts of the miniature should work as the full sized one did is the same as mine it’s the small details that make the miniature correct

Stuart


My aim is for a accurate part with a good finish

Offline Tennessee Whiskey

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Re: Tug's Corliss Tandem Compound Project
« Reply #144 on: February 01, 2018, 11:34:23 AM »
Tug, I have and now replied, Thanks. Man that first packing looks more like wicking for a burner from the pictures. Actually, it looks like the material used for "rope seals" around a crankshaft at the front and rear. Glad you decided to defer the deferring of the project :LittleDevil:.

Whiskey

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #145 on: February 01, 2018, 01:28:21 PM »
Hi Stuart,

I got this off Ebay here https://www.ebay.co.uk/itm/GLAND-PACKING-ROPE-SHAFT-SEAL-SOLD-PER-METRE-PTFE-Pure-Virgin-Various-Sizes/182850857559?ssPageName=STRK%3AMEBIDX%3AIT&var=690153347675&_trksid=p2057872.m2749.l2649

4mm square is the smallest they did but I found some 3mm (more practicable really) here https://www.ebay.co.uk/itm/222087697987 so will be ordering some of that too.

It appears to be braided PTFE and not PTFE Impregnated braided yarn which is what I have used in the past so will have to see how it works out.

Whiskey - yeh it's not very good at all but it was needs must at the time and I thought I was getting a good deal too ::).
As you know I may have a small distraction along the way - I've been digging out some ali too  ;) - I'll reply later.

For now it's back to tha ol shid fer the arternewn  ;)

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 Stuart

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Re: Tug's Corliss Tandem Compound Project
« Reply #146 on: February 01, 2018, 03:32:29 PM »
Tug.  Thanks for the info

Stuart
My aim is for a accurate part with a good finish

Offline Ramon Wilson

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Re: Tug's Corliss Tandem Compound Project
« Reply #147 on: February 06, 2018, 10:56:20 AM »
Hi  guys - as a well known MEM 'character' might say - 'How ya'll doin'  :D

Not much actual progress on the Throp to report about but it has been a bit of a 'testing' time as you will see :)

When Simon first raised his concern over the possible failure of the JB Welded soft jaws I didn't cursorily dismiss it out of hand despite my confidence in the product. I still think they will hold way beyond their intended use but then Kerrin raised the question of machining allowance (I realise now that I read that as had I used a conventional fixing with JBW used cosmetically so something I did not actually answer - sorry K) I began to muse that whilst I had great confidence in the product based on previous use I did not actually know what sort of situation JB would break down at - or tolerate.

I had this thought in mind as I began to think about the pipework required and how I would assemble it - above and below the base - and the need to make sure the component parts could be held in their correct attitudes whilst silver soldering. Musing on some complicated fixtures the thought occurred well if it was all assembled with JBW then all that could be overlooked. Question was how good would JBW be in that application.

So this is what I've been playing with before I get to the pipework proper - hope it will answer any lingering doubts, as it certainly has mine.

I intend to use 10mm dia commercial copper pipe and copper elbows for the pipe work so the potential of joining these with JBW required to be established. First off was to silver solder a plug and a connector into the respective parts. The fixing area was abraded with coarse emery.



A liberal coating of JB applied to both surfaces


This was left overnight on a radiator to cure and then left for a few days before testing


Filled with water by syringe it was then pressure tested to 50 psi then at 100 and 200 psi .....


.. to the gauge maximum of 300 psi. (the gauge was checked against the boiler testers gauge when the WaW boiler was tested so I'm happy that's a fairly accurate reading)


Left at that pressure while I had a cup of tea only a slight creep back of the needle occurred but most importantly no evidence of water was found on the blue paper - a very good tell tale for this purpose. I am more than satisfied that this will be more than adequate to handle any pressure this engine is likely to see so I will use JB to finalise the pipework connections in situ.

Ah but you ask what about temperature effect - well....


Realising the Kerrin was asking if an allowance was required in machining as opposed to a primary means of holding I began to think about the condenser flanges which were fundamentally just 'glued' in. Time for another test!

An old piece of mild steel bar was faced off (with that new carbide cutter - a nice finish, I think you'd agree) and some holes put through - tapped 1/4 x 40 on one side and on the other counter-bored 12mm diameter. Three holes (two were 'spare') were then machined to the same dimensions as those for the flanges in the condenser and three 'plugs' made to suit. All had a pressure resisting surface of 12 mm diameter - the three 'feet' on the central plug was to ensure this remained.


The fits are 'loose' but not 'rattle' fit - .05 / 08mm (2-3 thou) on diameter


A nice coating on all surfaces ..


... and once cured the fillets fettled much the same as those on the condenser.


Done at the same time as the pipework this was well cured before testing was carried out yesterday.


Each test piece was done in turn and taken up to 300psi as before. Each test was left at 300psi for several minutes with no significant pressure drop or leaks occurring, the paper once again bearing witness. 


Once all three had been tested at room temperature the exercise was repeated again with total success but this time allowing the whole bar to come up to the temp of boiling water


The bar after the test



JBW appears, using a scriber as a probe to have suffered no degradation so I think I can safely say that for me I am more than happy to continue to use this product in the manner described - for the task in hand. This was not done in order to advocate it as some kind of magic cure all but I do think it has great potential in 'casting assimilation' on engines that will see little work. How far someone would wish to take that is down to the individual I guess but I have satisfied myself that it is as good as I thought it is.

Well, I realise they are not as scintillating pics as perhaps some would have but I hope they serve to inform - hope you weren't too bored.

Now, I guess, I can continue on that pipework  :) However whilst this was curing I did take the opportunity to have a side step for a couple of days  :D .....


Two cranks for a slowly progressing pair of 5cc diesels - more on that perhaps a bit later


'Thatsit frum tha ol shid taday'

Regards - Ol Tug


PS I think I should point out I did this in reverse to how it's described - with the success of the testing in boiling water I felt there was no need to do the same with the copper pipe parts.

 


"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 sco

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Re: Tug's Corliss Tandem Compound Project
« Reply #148 on: February 06, 2018, 11:13:12 AM »
Nice bit of test work there Tug!

If you tell me the pipe diameter and the length of engagement in the elbow I'll work out what shear stress you've tested it to.

Simon.
Ars longa, vita brevis.

Offline Jasonb

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Re: Tug's Corliss Tandem Compound Project
« Reply #149 on: February 06, 2018, 12:39:42 PM »
Thanks for posting the results of your tests Ramon, all useful info for those of us whole like to do our own thing rather than limit our choice to available castings