Steam engines

[sandy_ACS]

Hi Eddy....The questions I have to ask in return are: - 'HOW MANY DO YOU WANT TO PURCHASE?' and 'DO YOU WANT SINGLE OR TRIPLE EXPANSION SIR ?'
sandy

Just the one for now - but if the fleet increases, who knows? :-)

Wouldn't a triple expansion be absolutely gorgeous! I'd certainly sell a kidney or two to purchase one! Even a single expansion would be almost as nice!

As a few people on here know, I have plans for the Glen Sannox at 1:48 scale (thanks to Walter Snowdon) which gives a model of about 67" length, and a 3 cylinder diagonal engine would just be delightful if I could find one!

But as it's almost certainly a none starter from a commercial point of view I'll probably just have to keep dreaming :-(

Hi Eddy,

Just thought I would check in, whilst having my lunch....the Waverly has gone now....He He.

Yes, a triple expansion would indeed be something special, but, as you say, not really a practical commercial proposition, at least not for mass production.
And it would be difficult, although not impossible, to arrange for the required vaccuum pump in the exhaust system and also the R/C control for starting the thing. On the puffer (VIC 32), which has a 2 cylinder double expansion engine) a system of bypass valves are built in to the start loop to give a whiff of high pressure steam to both cylinders to get over the dead spots.

A three cylinder single expansion engine would be an easier option and although possibly not for mass production, I am open to most of the usual forms of bribery for a possible one off.

Not to keen on kidney's though, How about a liver and 3 legs?

Keep dreaming. :wink:  sandy

[sandy_ACS]

Hi Pd's,

Ok Tony Iwill keep the info to hand, you never know!!!

Anyhow guys, Ive cracked the OZ silver soldering thing...simple really..just mix Vegimite with the Amber Necter in equal proportions and apply as flux...then use the solder stick the other way round and...bingo.
Now that only leaves the problem of the assembly fixtures being the wrong way up......Perhaps Derek won't notice the burner being at the top, with the funnel sticking out the bottom...especially if I tell him it's a special IRISH STEALTH version...LOW smoke emissions...Well the ship is PS Decoy!!    :wink:  :wink:

As for markings on the boiler Derek...No problem....won't make any more steam than normal but hey.....How about I add the entire works of James Joyce, or at least 'Finnigan's Wake'...that should give the officials a few problems to decipher.

Keep happy     .

Sandy

[derekwarner_decoy]

Hi PD's - Sandy - just knowing the boiler is part IRISH brings a warm feeling to my heart and NO I am not selling that [anyway it's probably part pickeled :?:   ]

One point,   could the relief valve bet set at the ACS standard 3 Bar please - Derek

[derekwarner_decoy]

Hi PD’s – had the pleasure of five hours in the workshop this Saturday morning & the preliminary result [everything below the green engine base] is the supporting structure called the [ENTABALATURE] for the JMC3H engine  
   
For rigidity, I will plan to add a  horizontal stiffener just under the crank shaft, athwart ships to the hull frames on either side to eliminate the natural torque or twisting associated with simple D/A steam engines – Derek  
“””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””””  
   
   
   

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[Eddy Matthews]

A nicely done job Derek....

Is the frame mounted into the model as you've shown it in the photo?  I assume it's so the engine lines up with the paddleshaft? Or is the engine fitted vertically with the cylinders at the bottom?

If my first suggestion is correct, what about the weight with the engine mounted so high, and it's effect on the models stability?

[derekwarner_decoy]

Hi PD's & first please let me correct yesterdays blunder   - the JMC3H is a single acting twin cylinder engine with reversing gear - she is not D/A as the Australian owner stated - only explanation is the extra  solderig flux fumes must cause the mind to distort things

Thanks Eddie - the Irish answer to your questions would be no, yes & possibly I don't understand the last question so I had better clarify

1) the cylinder axis will be horizontal & on near deck level
2) I have taken a leaf from othe PD's about keeping components modular
so the plan is to have the steam regulator & servo with the reversing servo under the engine frame with the lubricator at engine level for access, but by disconnecting three steam lines & two servo cable sets I can remove the whole box & dice out in one lift
3) the crank shaft is AFT with a chain drive FWD to the paddle wheel axis
4) I understand your point about top heavy, but even with the vertical boiler & engine placement, Decoy will still need approx 3kg of additional lead shot in the bildge

Talking about boilers!! - Sandy from ACS interrupted his Saturday afternoon game of CROQUETTE on the green overlooking the Clyde + six pints @ the local   to pen an e-mail to me asking if I knew the British Official number for PS Decoy, as he thought it appropriate the model boiler ACS are producing bears the same stamping and certificate number - unbelievable  and - Derek

[Eddy Matthews]

Thanks for the reply Derek, even though I didn't explain things very well (it's difficult sometimes putting things into pure text!), you've managed to answer all my questions!

Once you have the rest of the gear from Sandy it will be time to start saving for the bottle of champagne ready for the official launch! I for one cannot wait to see PS Decoy on the water!

[derekwarner_decoy]

Hi PD's & here is a question for Stuart [Badger] of the Reliant fame

 :lol: - not sure Stuart if you have kept up with the latest postings, but I have swallowed the anchor & purchased a 3 CC horizontal steam engine & a boiler package

 :?: my question to you is could you tell [us/me & the PD's] a little more on the chain reduction [sprockets & chain on the Olde Trafford] as installed

thanks & regards Derek

[derekwarner_decoy]

Hi PD's - Steam reversing gear :?:  :?:  - whilst I understand the geometry involved with the Stephensons/Stevensons reversing gear linkage to 'reverse the rotation of my engine', I am at a loss to understand the best way to actuate it via R/C servo- I considered posting a translated to French question to the manufacturer, but reflected that I may as well eat garlic snails & the like [slugs] as get a resonse  :  :  :  :

In the reversing gear triangle or quadrant, the relationship between the length of chord to arc appears as 22mm : 18 mm on my JMC3H or a ratio of 1.222:1 [as best measured on a Sunday afternoon after Church & a few 's]

I could install a compound adjustment [two X turn buckles] in the servo linkage to accurately position the reversing quadrant centers & also limit the movement to 18 mm +zero to -zero, but this seems crazy & could place a full load on the servo if the + to - signal drifted :?:  :?:  :?:

I there any way to get like a flip/flop servo action which would allow the reversing gear to be sent to the desired position then relax the Tx left stick to return to central neutral without the Stevensons reversing gear linkage moving :idea:  :idea:

I'am realising that driving/piloting/manovering a steam engined vessel is a little different to an electric powered vessel as with this steam version both FWD & REVERSE will require the Tx stick pushed in the same direction - any comments greatly appreciated - Derek

[sandy_ACS]

Hi PD's - Steam reversing gear :?:  :?:  - whilst I understand the geometry involved with the Stephensons/Stevensons reversing gear linkage to 'reverse the rotation of my engine', I am at a loss to understand the best way to actuate it via R/C servo- I considered posting a translated to French question to the manufacturer, but reflected that I may as well eat garlic snails & the like [slugs] as get a resonse  :  :  :  :

In the reversing gear triangle or quadrant, the relationship between the length of chord to arc appears as 22mm : 18 mm on my JMC3H or a ratio of 1.222:1 [as best measured on a Sunday afternoon after Church & a few 's]

I could install a compound adjustment [two X turn buckles] in the servo linkage to accurately position the reversing quadrant centers & also limit the movement to 18 mm +zero to -zero, but this seems crazy & could place a full load on the servo if the + to - signal drifted :?:  :?:  :?:

I there any way to get like a flip/flop servo action which would allow the reversing gear to be sent to the desired position then relax the Tx left stick to return to central neutral without the Stevensons reversing gear linkage moving :idea:  :idea:

I'am realising that driving/piloting/manovering a steam engined vessel is a little different to an electric powered vessel as with this steam version both FWD & REVERSE will require the Tx stick pushed in the same direction - any comments greatly appreciated - Derek

 :post  :hmmm

Hi PD's...Oh the joys of Stephensons reversing gear.....first things first Derek...I would suggest that you use a spare, fully proportional, channel to effect your reversing gear installation...this will allow you to exploit one of the better features...Namely 'NOTCHING UP' which, if you didn't already know, is the term used for adjusting the valve timing between fully open position (maximum valve travel, at the outer end of the quadrant) and the mid-gear position (centre of the quadrant, where the only movement of the valve should be to cover the lap and lead for the valve)

Once your engine is up to speed, and with model running in the water, you can 'NOTCH UP' the forward (or reverse, if that's the way you are going) to a position closer to the centre of the quadrant; this will change the cut off point ( the point in the valve travel where the steam port closes) and the engine will continue to run using the expansion of the steam already in the cylinder to complete its stroke. This will reduce the amount of steam used overall. Model steam Locomotives, and full size engines (including marine engines) for that matter, use this for the same reasons.

A couple of things to note, when setting up your installation.

1.     When setting the travel for the 'Full forward' and 'Full reverse' positions of the quadrant, be sure that you do not go to far....the sliding die block in the quadrant (the one connected to the valve spindle) should not be allowed to go to the full extreme of the quadrant arc....so set for about 95% of available travel....this will allow for any 'DIE SLIP' which is common on Stephensons gear and will not allow the gear to go to far, posibly jamming the die.

2.    For servo operation...and to take care of any signal deviation...it is a good plan to fit the valve gear pushrod with a device called a servo saver...See attached sketch...these are reasonably easily made...but I believe a similar item is now available from most good model shops.
I know of no method which can perform a flip=flop action for you to be able to return the stick to the centre...this would automatically alter the servo pulse width and, even of you could arrange it mechanically...you would then get major conflict in your receiver decoder...which would be trying to bring the servo back to centre.

Finally...it might pay you to use a servo with metal gears, rather than the plastic ones.

Hope this is of some help.


BTW....it's no good using an ICBM to try flying here...we have an excellent  AWAX early warning system here in the UK (we call it EARWAX).
So you will just get a Polaris up your........ vee hav vays of keeping you out...... :nose      :music

Have fun.

Sandy

[derekwarner_decoy]

Hi PD's & thanks Sandy for your comments re the Stephensons reversing link - this evening I have penned a note to the Contact Officer for a 4" gauge model steam rail group in Wollongong NSW

So I propose to leave this posting open & will get back when I have spoken to somone from that group - Derek

[derekwarner_decoy]

Hi PD’s & look what turned up today – the boiler kit – absolutely superb Sandy & thankyou!  
   
One or two or the more astute PD’s will realize that my basic line Drawing [dated 30/10/2000] of PS Decoy behind the model is shown on its voyage going down toward the equator, where as you will note that I have built the model facing the equator – well makes sense to me anyway  
   
Another point is all of the other bits & pieces that ACS have manufactured as shown on the STDB side near where the paddle box will be will actually reside down stairs & under the engine piped up with little bits of bent copper tube etc so will not be all that visible in YEARS to come – yes my good wife Karina suggests they could build another Sydney harbor bridge in less time that it will take me to finish Decoy!!  
   
PS Decoy was described as being a HOTBOX of an engine room, so I will use a little extra building license & not enclose the lower or upper walls above the engine, the boiler room on the real PS Decoy was open on three sides so the intention is to maximize the viewing angles of both engine & boiler  
   
Interestingly, the parcel had been open by Customs between Scotland & OZ, as the base of the box parcel had different colored tape & a little sticker confirming an Australian Customs inspection had been performed  
   
Sandy – all of the items on the manifest Invoice were received in perfect order, but the intended stick of high temperature COMSOL solder has vanished – I am not sure if you keep up with Australian politics, but none other than Phillip Ruddock MP is responsible for Customs & Excise so I have penned a e-mail communication to his office demanding a Royal Commission into the investigation of my missing stick of COMSOL HT solder - Derek  
         
 
 

 
 
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[Khephre]

Now that's really a pretty picture Derek. For all his sporran twiddling and emoticon overload that Sandy chappie's no slouch at what he does!

You must feel like a proud new dad all over again! I can't wait to see Decoy all plumbed up and steaming.

well done gents
Tony

[kiwimodeller]

Will you have it ready for the weekend Derek :?:      :?:

[derekwarner_decoy]

Hi PD's

Tony - thanks for the comment but the real credit goes between the respective manufacturers "JMC & ACS" & I am pleased with the early end result & on the strength of seeing the new equipment loosely placed in Decoys hull I have rewarded myself with a   or two & spent the next two hours considering best location/alignment & placement of the bits & pieces

KiWi Modeler - I will guarantee a finish before "A" weekend, but cannot guarantee which one that will be :?:  :?:  :?:  :?: - Derek