Simplex or Super Simplex

[greasemonkey]

Hi John
Did all my boiler with easy flo 2 and didnt have any problems with joints melting.

Andy

[SteveW]

ChrisV,

Re 'Locomotion': bore is 7/8" stroke 3" and wheel diameter is 6-3/32".

I understand that the dimensions of the grate/tube area determine the amount of heat/heat transfer to generate an amount of steam. This steam is then consumed at a rate determined by the swept volume(s), number of strokes, steam pressure and cross sectional area of the steam transfer system (in and out of the cylinder(s)). It is possible to push more steam through the system than can usefully be used and you just get louder chuffs up the chimney.

Surely the more area provided by the piston then the more push a given amount of pressure will provide. The pressure being that fraction of boiler pressure allowed by the regulator. In the case of 'Locomotion' the only variable is the regulator setting.

I can see that sustained speed needs amounts of steam which is a function of fire & grate/tube area while the amount pull available is pressure, bore and stroke over wheel diameter. My max pressure is 80psi and stroke and wheels are fixed. This leaves me with cylinder diameter that's got to provide the pull to move me.

What am I missing?

[greasemonkey]

Hi Steve
A diet? ;D ;D Your right, force = pressure xarea so the only way to increase the pullig power is either to increase the pressure or increase the area of your cylinders. To change anything else would involve a fairly major rebuild.

cheers

Andy

[Chris Kelland]

Hi Ron,

Any chance you can give me an idea what was in Martin Evans' ME article from April 1987 titled 'Improvements to Simplex'

I thought I had all the articles on Simplex, but I missed that one.

Chris.

[ron]

Chris
Send me your e-mail address via the board messaging system and I'll send you a copy, there's about 4 pages including drawings.
Ron

[spurley]

Hi Ron

For info. I had a look at a Model Engineer magazine index; the issues with the Simplex serial in are:
Vol 133: issues 3319, 3324, 3326, 3329 & 3332
Vol 134: issues 3336, 3340, 3342, 3344, 3346, 3348, 3351, 3353 3357 & 3359
Vol 135 issue 3373 Boiler test.

Super Simplex

Vol 162: issues 3846, 3847, 3848, 3849, 3850, 3851 & 3852.

Hope this may help you with your search for 'enlightenment' it certainly has guided me!

Cheers

Brian

[Jo]

As someone who is building the super simplex, I must first admit to being biased.

The only real difference in the castings is the chimney and the dome to allow for the larger diameter boiler. As for machining the simplex castings for the larger bore of the super: Forget it! There is not enough metal I have had to line my cylinders and the bore is back to the same as the original design.

But I would advise any potential builders of either engine to not waste money on those useless cast motion brackets and build from scratch: Much easier.

I decided to redesign my boiler with crown stays.....

Note: the brake blocks hit the rear cylinder covers where they have been located on the Super. Is it the same on the original?

Jo

[baggo]

Hi Jo,

I've just checked the cylinder castings that came with my collection of bits. They've already been bored out to 1.5" leaving a wall thickness between flanges/ribs of just over 7/32"so mine would stand the extra 1/16" diameter I think. The finish on the bores leaves a lot to be desired so I'm going to have to skim them anyway. Probably your castings came from a different supplier who was a bit tighter with the metal!

The original Simplex didn't have brakes detailed and it was left to the individual builder to fit them if wanted. This highlights the problems that can occur when drawing out a design that you are not actually building or have not built before doing the drawings. It's left to the people who are actually building it to find any cock-ups! (sounds like Microsoft software ;D)

The original Simplex did not have cylinder drain cocks either which I would have thought was a pretty essential item on a 5" gauge loco, especially one with low superheat.

I will stick to the original basic design as I already have the frames cut out and ready for assembly (I'm looking for a fairly quick build) but I will try and incorporate some of the Super ideas if I can.

It looks as though there are quite a few Simplex/Super Simplexes either being built or are going to be built so perhaps the subject ought to have it's own section?

John

[ron]

Hi Jo
Thanks for the info, who did you get your castings from? and John have you any idea who was the original supplier of yours.
I think I'm going to do the boiler first, that's the major expense and the area I know least about but I can get experienced help with it, once it's made the rest of the work is more familiar ground.
Ron

[baggo]

Hi Ron,

Unfortunately I don't know who the original supplier was, the only identifying marks on the cylinders (cast iron) are what appears to be '5008'. I would hazard a guess that the boiler kit probably came from Reeves so maybe the castings did as well.

John

[greasemonkey]

Hi Ron
I modified my boiler from the original design for ease of manufacture and saftey if you want details then let me know.

Andy

[Jo]

Hi John,

Maybe that is the difference my cylinders are gunmetal (now with cast iron liners).

As for where my castings came from they were a box of goodies at a club auction at a price any model engineer would have been proud of (the buyer that is ;D). The super specific castings came from Blackgates.

Nearly forgot another change on the super castings: the saddle is different due to the new boiler diameter! And the original simplex door looks silly on the larger diameter boiler.
-------------
Andy: You should have come to bits and pieces: I brought along my redesigned boiler back last January. As for the redesign of the boiler: I added four rows of seven crown stays. But you need to make sure that they do not get in the way of the blower tube etc..

Jo

[greasemonkey]

Hi Jo
My boiler passed hydraulic back in Feburary and is now ready for steam test, but Ive got slightly distracted by Dougal and some fiddely but intresting fabrication work for the 9F hope to post some piccies soon. With the ready availability of laser cutting these days it is often easier to fabricate than machine castings, in the same way I had the brass platework CNC profiled and all rivet holes put in to speed the job up a bit.

Andy

[Chris Kelland]

Hi All,

It certainly looks as if Simplex's, old and new are very popular. I thought I was one of very few who think they are a good loco. How wrong you can be. I am rebuilding yet another one, this time for the club (City of Oxford).

Interesting about the cylinder castings, in the intro to the Super Simplex, Martin Evans sounds a bit 'iffy', saying 'I expect the existing cylinders will be suitable for boring out'. Sounds as if he did not actually try!

I would be quite happy to use the standard Simplex cylinder dimensions, These give plenty of power but it is the boiler that occasionally runs out of breath.

I like the idea of a separate section for the Simplex.


Chris K.

[ron]

Well I've gone and ordered a boiler kit from Reeves, nobody else seems too keen to take my money.
I'm going to build the original version and add cylinder drains and brakes [even though brakes are for cissies ;D], I actually prefer the look of the original version, but I suppose it's the old saying beauty's in the eye of the beholder, hope I haven't made the wrong decision.
I also agree with previous posters about a Simplex section on here, I'm going to need all the help I can get ;D

Ron

[jones]

Hey everyone,

I've settled on the Super Simplex but I think I may not bore out the cylinders to the larger bore, just to ere on the safe side (castings are expensive!). I will have the plans sometime next month, as I am planning on scanning the ME articles at my local club. A Simplex section sounds like a GREAT idea! I also think I will need help with some parts, as I am quite a "newbie" at this machining thing [insert smiley here]. This topic has been invaluable in helping me reach a decision. Thank you everyone for all input.

Andrew Barber

[mattm]

Hi all,
I have just found the site and am enjoying reading through the posts.
I am looking at building the super simplex to run on my local club track with a view to building a circle track eventually around my garden.

Can anyone assist me with locating a copy of the articles featured in ME magazine for both the building of simplex and also the modifications for the super simplex?

I would also be intersted in purchasing a copy of the book if anyone has a copy they are no longer using.
I have heard a few stories about the quality of the drawings supplied from various supliers and was wondering if anyone had heard the same? and if so are any suppliers considered better or are they all the same?

Thanks for all your help and look forward to talking more frequently

Matt( from australia)

[ron]

Hi Matt, welcome to the forum, if you PM me your e-mail address I'll send you a copy of the Super Simplex articles.
You're best bet for the book is Ebay, though depending on your luck at the time the price can vary considerably. The book isn't really all that good it's just the original ME articles in a collection with some poor quality photos, so don't pay over the odds for it.
The modern drawings aren't great but if a bit of care and common sense is applied they're OK, I'm not a very experienced model engineer and I haven't had any great problems building Simplex using them.
Ron

[mattm]

Thanks ron
I emailed baggo yesterday and he sent me a copy of the articles this morning(my time)
After starting to read the articles i dont think im going to worry about the book, unless one comes up reasonably priced.
I am thinking about building the super simplex but leaving the cylinders the original size( simplex) rather than the bigger super simplex size. From what i hear the simplex was a pretty good puller and the inclusion of the super simplex larger boiler should make it a little steam hungry.

I am not an experienced model engineer, but have a fair amount of experience elsewhere. Been a fitter and turner for 17 years and now studying mechanical engineering degree part time while working. I have been thinking about redrawing some of the drawings in the articles with autocad to make them a bit clearer for use in the workshop if i cant find an acceptable copy of the plans in Australia. I think the 150 - 200 dollars being asked for the plans over here is a bit expensive if they are not really good quality.

Matt

[baggo]

Hi Matt,

I would recommend producing a set of full size drawings if you can as there may well be errors in the original articles which would (may) have been corrected in the later drawings. At least if you draw everything out first you can check that all the bits will fit together!

I am about halfway through a set of CAD drawings for Simplex but they probably won't be of much help to you for the Super.

John