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

[Roger]

And I'm still looking for the CNC magic wand that some people imagine these machines come with.

[jma1009]

i nearly dropped my hacksaw and scriber on my foot after reading paul's post! must finish the latest packet of 'honey cheerios' cereal so i can do some more drawings! then back to the hacksaw and file making STEPNEY's tool box that fits behind the bunker. not a DRO or CAD in sight here! friend jim scott has spent hours and hours beautifully riveting up his own 5"g terrier cab. i would like to see a computerised machine that could do the same with the same degree of precision and display the same excellent old fashioned skills that are often required in miniature loco building and take up so much time if done properly! and give the same level of satisfaction in a job superbly done!
cutting the stuff to size (or buying ready made parts) is nothing compared to the time and skill required to properly put the bits together!
cheers,
julian

[Jim Scott]

Julian, Paul's observations make a lot of sense to me, just make sure you have your safety shoes on next time you log on..!

All engineering is (or should be) a process of continuous improvement and the modern CAD/CAM processes reflect this; it certainly shouldn't be decried. Of course things can still be done the old ways, as dictated by available equipment and the ability to use it. I know you have limited facilities, as have I.

As for riveting, its just another engineering procedure which, as it happens, I find quite satisfying to do. However, Paul's comment re masochism and Life being too short is hard to argue against. Make no mistake, riveting could be duplicated perfectly by modern equipment and programming - but why would you want to?

Jim S

[suctionhose]

I'm 97% with Julian this time! (allowing 3% concession for my DRO on mill)

Is a model a statement of "modernity" or a "personal achievement"

I still think the latter...

[pault]

Hi Julian/Suctionhose
Can I assume that you both still fit riveted boilers to locos you build, after all they are traditional, have a much longer life and are cheaper to build than a silver soldered one. Oh they are easier to fix in some ways as well. Clearly neither of you would use a pocket calculator or spreadsheet to work anything out you would obviously use a pen ink and paper for all calculations. Obviously you would use no PTFE, silicon rubber sealant, loctite, o-rings etc. Obviously you would use callipers, not vernier or digital, with standards, no micrometers for measuring work.
My point is that we all have a level of technology/techniques that we are happy/comfortable with, as long as they work for us that’s all that matters none of us are wrong none of us are right
Regards
Paul

[bhk]

Nov 14, 2013 21:48:58 GMT suctionhose said:

I'm 97% with Julian this time! (allowing 3% concession for my DRO on mill)

Is a model a statement of "modernity" or a "personal achievement"

I still think the latter...

But this still refers to the idea that CNC work is unskilled, building a model regardless of manual machining or the use of CNC to produce the parts is still a great "personal achievement"

I can and do machine (building my current engine) manually to a high standard, I use to make my living from it. but I also can (don't presently as don't have the machinery) program and operate CNC machinery, they both have there pro cons and both require a high degree of skill, neither is less involved.

I think the only people who can present a fair argument in this case are those that can do both, everyone one else (no offence meant) is commenting on pure stipulation and there perceived ideas.

I recently read a website of a chap who had bought a Tomahawk CNC mill, he had never owned or been trained in operating machinery before but had this idea that it must be easy, he then went on to talk about melting cutters and pulling jobs out the vice and how this was the machines fault and not what you see on those youtube videos that make it look easy, it's easy as the guy making the video is skilled.

[Roger]

I guess we all have our own idea about where to use skill and where not to. I'm just pondering over a drawing of a set of side steps that have four rivets holding each one in place. There are several to do and it would be good to get it really neat....

So do I mark each one out, centre pop them, bend them by hand and then drill them?
Do I make a little former on the mill to bend them round and add the rivet holes so I can spot them through?
Do I CNC rout them out with the holes in the flat and then fold them round a former?

The fact is, there's no right answer, but surely it's better to have the choice of all three?
For the record, I'll make a former on the CNC and add the rivet holes to that as a drill jig. The biggest source of error and uncertainty is in the folding, so that's my choice. I could mark them out by hand and make a pretty good job of it, but with all the will in the world, it won't be as accurate. I'll probably rout the blanks for the steps too. Making one is fun, making six is tedious.
I'll CNC rout the backplate and drill all of the rivet holes to the drawing dimensions too so there's no need to fiddle around with toolmakers clamps to get it in the right place. It will take a fair bit of careful tidying up by hand, but that's something the machine can't do and I can. It's all about playing to the strengths of each workshop tool whether that's a file, hammer or a CNC mill.

I agree with Suctionhose about a model being a personal achievement. I'm not about to introduce my CNC mill and CAD package to someone and say "look what my tools have made" anymore than if I'd hewn every part out of solid with a hacksaw and file. There's absolutely no difference in my opinion.

[jma1009]

something like this?

[suctionhose]

bhk
You must know by now that I don't disagree with you!

My own value system, with which no one else need agree, differentiates the two skills concluding that creation directly by one's own hand is the greater achievement.

Digital technology, a knowledge and skill in it's own right, is designed to remove the human element. That's what makes it so powerful and dependable.

But Model Engineering is an Art form as well as Engineering. In much the same way an Original painting is more highly prized than a Reproduction, in my eyes, technology inserts itself between the creator and the creation. The directness is lost to a large extent.

That separation provides a buffer with the ability to erase a mistake, like recording a performance vs performing live.

I admire Victorian Engineering because things were made by people, using machines yes, but machines that responded to people not programs.

Would love to go on and on but have an appointment now.

Great thread!

Ross

[terry1956]

Hi all.at the moment I am rebuilding my speedy. At the moment it as all been taken apart.the globe valves became a nightmare for me.the reason for this was that they had been made none standard.the options I have are to remake the valves, or buy off the peg ones.i went for off the peg, only to find that the way the valves fitted into the boiler by using bushes screwed into the backhead.i found that the bushe fittings had rusted badly and also needed replacement. The work started to build up.at the moment I am trying to work out the best way to replace the bushes. This would mean removing the old screw fittings from the backhead. Anyone have a good way of removing the old screws, there is not a lot remaining above the surface.i can, t redrill new screw positions due to the position of the valves when fitted. As to the drawings, how snyone can make anything worthwhile from these beats me, I found them next to useless.

[jma1009]

rusty boiler fittings? oh dear!

[Deleted]

----------- oh gawd, here we go again !!--------

[Deleted]

[quote Making one is fun, making six is tedious..[/quote]------ EXACTLY !!!The R&D part is the interesting and "Skill-challenging" bit, the resulting production run is ideal for modern technology to cope with....thus freeing you up for more R&D time........makes sense to me......Which is precisely the way I have approached designing and building No.111.) I'm a regular customer of Model Engineers Laser for example, but only after I'm happy with all aspects of the item concerned via proof testing, dummy building, etc)............In actual fact I generally agree with the spirit contained within the whole of that particular posting but chose that part as it encapsulates the whole ethos, I think.........

[jma1009]

[Deleted]

AH !!-------- TWO NIGHT OWLS THEN ??

[jma1009]

alan,
i always enjoy your posts and are a breath of fresh air sometimes! not sure all of mine do the same!
cheers,
julian

[Deleted]

We're two sides of the same coin, old son !!!----------keep 'em coming !!

[jma1009]

paul,

you throw the cat amongst the pigeons! it was the last line of your previous post that i dropped my hacksaw and scriber! the rest of it i agreed with!

yes, i do regularly use a scientific pocket calculator! no, i dont build riveted boilers as you well know! silver soldered throughout!

i only use PTFE to make washers and some very fiddly bits on small scale boiler fittings ala roy amesbury. i have pen and ink and paper to hand!

loctite yes, spreadsheets decidedly no, silicon sealant no (i think - though my old favourite red hermatite has been replaced by something that might be some sort of copper silicon sealant that's quite expensive). vernier and micrometer yes - cant remember the last time i used calipers. 'O' rings sometimes.

does that make me a 'luddite' or semi-luddite?

what a thread!!

did someone mention the inside of cereal packets?!

cheers,
julian

[Deleted]

With apologies to Shakespeare}-------HAMLET:
To be imperial, or not to be: that is the question:
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune,(by selling a loco or two---)
Or to take arms against a sea of troubles,(the metric mob)
And by opposing end them? To die: to sleep;
No more; and by a sleep to say we end
The heart-ache and the thousand natural shocks
That flesh is heir to, 'tis a consummation
Devoutly to be wish'd. To die, to sleep;
To sleep: perchance to dream: ay, there's the rub;

[jma1009]

im impresssed! a bit of culture, wot!
stratford is a lovely GWR station!