Help with 'Speedy' valve gear and other issues...

[suctionhose]

I had to throw my board in the tip due space and move on to 2D CAD. Not the same as scratching your head with a pencil is it?

[suctionhose]

a point to consider when castigating designers is they have to eat. Many hours go into the drafting for little return. The payback is casting sales. Hence, in my opinion, casting sets include many items that do not need to be cast and often are better made from bar stock anyway.
Point is commercially speaking a person in business has to decide when enough is enough, the market price has been reached and the product is for sale.
To refer again to LBSC Britannia; would the impact be as great if it came out a month late with a different throatplate?
In Australia, none of the famous UK designs designs are compliant (to my knowledge).Personalising your own boiler design is par for the course and part of the fun.
Of course go forward with eyes open. But do go forward and don't be put off by doomsdayers. If it was easy it would be boring!

[jma1009]

hi ross,

it isnt a point about castigating designers, its a valid point about warning newcomers of well known problems with certain published designs which in the case of SPEEDY are quite horrendous and fundamental. i dont think that any other published design has aroused so much criticism, plus efforts by others to correct LBSC's errors. unless you have a collection of ME's going back 60 plus years (my bookshelves are groaning under the weight) a newcomer wouldnt necessarily be aware of the pitfalls of the SPEEDY design as originally published.

there are plenty of excellent (sometimes overlooked) designs that dont have the mechanical and prototypical design faults that SPEEDY has!

cheers,
julian

[suctionhose]

OK! Get some sleep...

[ejparrott]

Nov 7, 2013 2:16:06 GMT jma1009 said:

hi ross,

it isnt a point about castigating designers, its a valid point about warning newcomers of well known problems with certain published designs which in the case of SPEEDY are quite horrendous and fundamental.
julian

Or like 'Lion', where as designed the reach rod goes straight through the side of the firebox.....

[Roger]

I really appreciate everyone taking the time to voice their valued opinion, it would be a boring world if we all agreed. What's caught me by surprise is the amount of customisation going on, but now I've spent more time with the drawings and interpreting them I can see why. A published design does indeed appear to be a starting point, including tripwires with errors. We ought to collectively come to a consensus on the blatant errors in drawings and make representations to Reeves to at least get those corrected. Most people don't have the tools that I have to spot these issues ahead of time.
I've spent many happy hours at one of Hagley's 'Drawing Engine', but it's not a place I want to revisit for anything other than the simplest of jobs. Dexterity in CAD comes through an awful lot of mistakes and frustration though, so please don't imagine it's plain sailing.
It takes a complete change of mindset to get the most from it. I've used SmartSketch, also known as Imagineer, for ten years or more as a stepping stone, but you don't get anywhere near as many benefits from that as you do from full 3D. That's because you still have to create the views, and modifications to the design mean that you have to re-imagine what that does to each of them. Solid modelling focuses on the model, not the drawing, and that's counter intuitive for most of us who have grown up in a 2D Engineering world. The joy of it is that you simply ask for what views you want, and the program creates them for you and keeps them in sync with the model. It's another world, but one that doesn't come cheaply. Most people would rather put their financial resources into something more physical and I can understand that. If you don't couple the output to a CAM module and then drive a CNC machine, the usefulness also is questionable. Put those elements together though and it's hard to beat.

But yes 'Suctionhose', I most certainly am spoiled but you only get out what you put in, and I've spent a fortune crafting my software and hardware environment to make it that way. Once you've got the kind of tools I have, you never want to go back to doing it the hard way. There's still plenty of hand finishing and old fashioned skill based work needed however much CNC and CAD you have, so don't imagine that those skills aren't required. Nothing has changed in that department.

So far nobody has suggested an answer to the question I posed though, and that is the minimum internal radius of any given flanged plate thickness. Can we get a consensus on that perhaps?

[jma1009]

3/32" rad is considered the minimum for 3/32" copper flanged plates in 5"g. you would need steel formers for this. i get 1/8" quite ok with wooden formers. hope that helps?

[suctionhose]

Appologies Striplar. My "spoilt" remark was not aimed at you or your drafting systems. 3D is used quite commonly these days. My son is 2nd yr Engineering - they gave him Solidworks and teach with it from day one.

I was really referring to the proliferation of people everywhere demanding perfection and complaining bitterly when someone hasn't given to them!

It must be the Era or the millennium or the Gen XY or Z but finding fault with everything seems to be the new wisdom. (Sit back down Julian - I know your intentions are for the best of reasons)

Before too much negative is said about the older designs and reputations are soiled for ever, some perspective is needed to put them in context. Others are suggesting that.

LBSC, Martin Evans, Don Young, Bassett Lowke, Henry Greenly, K N Harris are all heros in their own right for having the intestinal fortitude to uphold their views in public, in the face of criticism and at the risk of anothers peril. They were better men than me!

In my 11 models since age 16, I have followed advice from all of them and disagreed with all of them at one time or another. But without them where would I be? Thanks to the foundation of knowledge provided by the heros I have developed my "ways". I like to design my own mostly whilst remaining faithful to exterior scale so far as is reasonable. Some things I reckon I've got sorted. But then there's always someone doing better than my best effort!

In the computer age you pay a licence fee and you get updates. Then you pay more and get a new version of the same thing - with updates, patches, etc. People are learning to expect that in everything. Perspective: That's not how it was 50 years ago. The only way an old design will be updated or corrected is if someone with intimate knowledge of the design re vamps it and re issues it. Mostly people overcome the problems for themselves perhaps extended to a few friends and that's enough for them. Quite understandable.

Anyway, the good news is that today's technology is capable of capturing the experience of many and collecting it in one place. Alan Stepney's site is a great example and similar things are forming on other forum sites.

If Striplar captures the mods for Speedy in his 3D and makes it widely available then we won't be having this discussion again - that is if anybody agrees on the chosen mods...

Sorry for keeping you up last night Julian! You did tick me off the other day - a lot of thought went into that Procedure - more than you give credit!

As for flanging boiler plates, we say Rmin = 1Thickness. Not sure about steel formers - been there done that. I'm flanging 4mm copper over cheap plywood at the moment. Bloke at the club used chipboard for 3mm. As Julian said the rads might be more than 3mm. So they should be. The bigger the knuckle the less flat surface there is to stay (up to a point) .

My turn to sleep..
Ross

[Deleted]

Nov 7, 2013 1:25:21 GMT suctionhose said:

I had to throw my board in the tip due space and move on to 2D CAD. Not the same as scratching your head with a pencil is it?

------------------ 2b or not 2b ?? Aye there's the "rub".... What an awful mis-quote !!

[Deleted]

------------- try MDF board for a 1-off flanging former..Have a look at this}------ www.engineersedge.com/bend_allow_calc.htm ---------- and this>>>>>>> ronleigh.com/ivytech/_ref-ba.htm -----------

[Roger]

I wouldn't take anything personally anyway Ross, there's bound to be a diversity of opinion. I agree that we shouldn't expect perfection, but still selling uncorrected plans when it's well known that's the case is just wrong.
I certainly agree that those contributors you mention have made a wonderful contribution and their personalities added another dimension to that. I take my hat off to them for what they achieved with so little technology.

You're so right about the ongoing expenditure for software and I put it off for as long as possible and then argue the toss about the price and what I'm not getting for it. I justify it for my small business and it's an essential tool. I certainly couldn't contemplate doing some of the jobs it take on without it. If you're interested, I've just gone live with my first web site to show off my wares in the hope of drumming up a little more business, things are a little quiet at the moment.

Thanks to you both for your sheet metal bending information. It's just as I thought, yet another place where the plans are more of an artists impression of what the designer would have liked rather than how it has to be when you start bending metal. That wasn't another complaint was it? Oops!

[suctionhose]

Agreed it's "wrong" in principle. But even moving the cylinders by an 1/8 has ramifications to frame, smokebox, piston rod, valve rod, slide bars, etc etc. It's not as simple as scratching out a dimension and writing another in. But you know this already.
So I still cannot see the commercial means for document control and revisions to happen. Who would pay for it?

[jma1009]

hi ross,

LBSC, Greenly, and Martin Evans and laterly don young (when he finished as a draughtsman for J S Whites) all designed miniature locos as a living. Bassett Lowke never designed anything himself. if you set yourself up as a self proclaimed designer of miniature locos or are employed to do this job then surely it isnt unreasonable to expect them to do a good job?

that sets them apart from the 'amateur' loco designers. of these perhaps roy amesbury stands out amongst all others and who i have the greatest admiration for and have tried to copy his principles even to the extent of making one of his pressure gauges. in more recent times DAG Brown and Gordon Smith have made significant contributions in the field of injectors and safety valves, not forgetting Don Ashton to whom many of of us owe a considerable debt in the field of valve gears.

i am a great fan of LBSC. i have virtually all his 'words and music' and there is hardly anything he didnt have a go at. many of his loco designs are quite superb and he deserves full credit for them. his last published design (MABEL) is a wonderful loco, as was his first dear old AYESHA. anyone who can design a 2.5"g GWR KING was a genius! however the fact remains that anyone building PANSY, the inside cylindered stephensons valve gear MAID OF KENT, and the 5"g LION/TITFIELD THUNDERBOLT (despite a brilliant free steaming boiler design), and SPEEDY has some quite significant design errors to overcome which the newcomer and 'tyro' wont necessarily appreciate. hence those of us 'in the know' warning newcomers of the pitfalls. if that comes across as negative then so be it. anyone who spends lots of money on drawings and parts for a loco then valuable spare time making same that then wont work or wont fit together deserves a bit of help - so the advice is meant to be helpful rather than negative!

i agree with roger that given the historically well known problems with some designs, the commercial suppliers ought to do more to warn purchasers of their drawings and castings of the errors and update the drawings particularly boilers to comply with modern standards.

by the way LBSC wasnt the only person to make a few errors. don young's IMMINGHAM crank axle is another well known 'problem' as is his MARIE ESTELLE valve gear, and all of don's loco link stephensons valve gear designs exhibit the same errors as those in LBSC's designs. and as for martin evans the list is far too long to quote here! don would privately advise builders of improvements and modifications - much to his credit, plus he had total control of the drawing originals and would amend same when errors cropped up. i well remember keith wilson's DUKEDOG valvegear (i started one myself - anyone want a set of frames and wheel castings?!) when it transpired that the valve travel wasnt enough to work the valves and port faces as designed (similar to SPEEDY) plus there was very little room for the bogie to negociate even moderate curves. i dont think ive ever seen one of his ARIEL designs completed, though i had a set of frames and completed front bogie for same. ive a set of frames and completed cylinders machined out of meehanite and much else besides for don young's FISHBOURNE O2 till i realised the loco was designed to 1" scale instead of 1 1/16" scale! i'd driven many examples of the design and knew it was a cracking loco but just wasnt happy with the 'wrong' scale! if i was going to spend 5 years or so building the loco i wanted it to look right and be the right scale! on the other hand don young designed some wonderful locos and his LUCKY 7 was a brilliant loco that went like a rocket! best loco in miniature ive ever driven!

cheers,
julian

[Roger]

I'm now resigned to the fact that this is going to be a long haul to get to the bottom of all the issues, but that's the sort of challenge that's worth accepting. The boiler for Speedy is a nightmare to model because of drawing and dimensional errors. There's no room for fudged dimensions when you're using CAD, either the geometry and dimensions are right or it won't fit. You can't bend it and force it like you might get away with in practice. Still, I'll tease out where the errors are in the end and at least I know it will all fit when I do come to make it. I really feel for anyone who's invested so much energy an enthusiasm building something only to find that it would never be satisfactory. Thanks goodness for solid modelling.

The valve gear has proven to be quite a challenge to fit to Don Ashtons dimensions, but it's done now. The area around the expansion link is tricky because the lifting arm is so close to the back of it at half gear. I've compromised by trimming the end of the lifting arm, slightly reducing the front to back dimension of the expansion link and offsetting the whole link to the front while maintaining the radius to the pivot point. The dia block ends up with its pin slightly set to the rear.
Taking all of these measures together means that the geometry can be maintained without ghastly clearances having to be machined out of the parts that would clash. On the face of it, nothing looks different to Don Young's drawings but it's a different animal on closer inspection. I may not have cut any metal yet, and I may not for another year for all it matters. By the time I do, it will be an old friend and very familiar. It will be lovely to greet it in the flesh, so to speak.

[RGR 60130]

Good evening folks,

I think model engineers are their own worst enemy at times when it comes to reporting (or not reporting) errors in drawings.

The first question will be where to report them to and we have a couple of options. Either to the people selling the drawings or, on the internet, I'd suggest Alan Stepney's web site www.alanstepney.info/page6.html

Merely picking up the phone and telling the supplier of the drawings that the valve gear on such and such a locomotive is garbage or a stay is in the wrong position is not going to bring about the changes. I spoke to Blackgates about a few errors I'm finding in the Michael Breeze A1 drawings and the agreed way ahead is for me to list them, prove with my build that my corrections work, then draw out the details. Once Blackgates have that info they will issue the corrections with every set of drawings sold thereafter. Sorted.....

A number of locomotives have been discussed here in this thread and a quick look suggests that the details aren't all recorded on Alan's site. For those who are sitting on this useful info why not take an hour out and give others the benefit of what you know?

And finally; Yes, I did post the errors I've found when building Springbok!

Reg

[Deleted]

Relating back to STRIPLAR's last post I see an interesting parallel emerging here------ If you watch the film "I, Robot" (starring Will Smith and Bridget Moynahan)..there's a sequence where Will Smith's character is underwater and trying to save a young girl who is trapped in a sinking car.. A "Basic Model" robot jumps in and, despite Will Smith ordering it to ----" save the girl, save the girl", rescues him instead and lets her drown....As Will later remarks----" A human would instinctively have saved the girl, knowing that I've had my time...The robot, being merely a "Difference Engine" calculated the chances of rescuing me gave better odds... No soul, you see ??".........OK, a bit deep perhaps but those "Fudged dimensions" in the absolute world of CAD/CAM are the Engineers Tolerances and Allowances in this instance....Might I make a suggestion ??.. Consider having your boiler made professionally....This will give you both a lot more "Development time " with those tricky absolutes, plus you'll get a running engine approx 12 to 18 months earlier ??....... Just a thought..Other films to watch are}-- GATTACA, SOLARIS, and DARK STAR ( Discussing the meaning of life with a self-aware thermo-nuclear bomb is only part of the fun !!) . ps}--- That Bridget Moynahan is a cracker !!!.."Oh well" said Zebedee--"time for bed" !!

[suctionhose]

Good job! Accepting the inevitable comes first. Accepting responsibility to do something about is next! Waiting for someone else to sort it out never worked for me!

I know many people approach their modelling with the desire to make one piece at a time to the drawing and put it all together at the end. My working life has always about machinery; making, designing, adapting, recovering disasters. Believe me the errors etc we are talking about extend beyond model engineering to, well everything really.

First the design, then the prototype(s), then the redraw, then modifications to fix problems that show up later on... Good machinery is expensive because of the development costs.

While these standard ME designs are built repeatedly, each one is an individual. There is no mechanism to evolve the product. None should be expected.

Accept that and enjoy the opportunity to make you own contribution. You will be so much prouder of your achievement!

[suctionhose]

Nov 8, 2013 22:20:05 GMT @4930hagley said:

Relating back to STRIPLAR's last post I see an interesting parallel emerging here------ If you watch the film "I, Robot" (starring Will Smith and Bridget Moynahan)..there's a sequence where Will Smith's character is underwater and trying to save a young girl who is trapped in a sinking car.. A "Basic Model" robot jumps in and, despite Will Smith ordering it to ----" save the girl, save the girl", rescues him instead and lets her drown....As Will later remarks----" A human would instinctively have saved the girl, knowing that I've had my time...The robot, being merely a "Difference Engine" calculated the chances of rescuing me gave better odds... No soul, you see ??".........OK, a bit deep perhaps but those "Fudged dimensions" in the absolute world of CAD/CAM are the Engineers Tolerances and Allowances in this instance....Might I make a suggestion ??.. Consider having your boiler made professionally....This will give you both a lot more "Development time " with those tricky absolutes, plus you'll get a running engine approx 12 to 18 months earlier ??....... Just a thought..Other films to watch are}-- GATTACA, SOLARIS, and DARK STAR ( Discussing the meaning of life with a self-aware thermo-nuclear bomb is only part of the fun !!) . ps}--- That Bridget Moynahan is a cracker !!!.."Oh well" said Zebedee--"time for bed" !!

You are a complicated man Mister 4930!

[Roger]

I agree entirely but I think a Wiki based solution is a better option. The responsibility for hosting and backing up doesn't rest with a well meaning model engineer who won't always be with us. The ability for someone to post directly to a communal pool of information is much more powerful. I don't see any reason why each locomotive type can't have it's own comprehensive page.
It sounds like you've found a supplier willing to listen for your locomotive, but even then, valuable tips you could provide on the build won't easily find their way to other builders.

[suctionhose]

Now we're getting somewhere!