Amateurs

Donald (Wittman, not Mitchell),

 

Regarding your comment that there is often only one way to do something.

 

The late Tubal Cain said in one of his writings something along the lines of "that there is never a wrong way to do something in engineering". Sorry, I cannot easily find the reference, nor can I remember it exactly so you will just have to take it as Gospel. Anyway, I take it that this means that as long as the eventual result performs its purpose adequately, then that will be satisfactory.

 

In case you don't know, Tubal Cain, or T. D. Walshaw to give him his correct name, was a highly skilled engineer and author of a number of books aimed at the amateur. He was, in his time, also a diesel engine designer and there are at least two books written by him on this subject.

 

I rather think that he knew what he was talking about. And I for one, as a very humble and low level self-teaching the hard way amateur, am extremely grateful for his writings. As I am for the kind help that has been given to me in this forum. Comments such as yours do not help.

 

Regards,

 

Peter G. Shaw

There is rarely only "one correct way". With your example of turning a taper, in what way is turning it with a taper attachment inferior to turning it with an offset tailstock? Is it not true that either can produce a satisfatory result, and that each has advantages and disadvantages? Depending on the circumstances, one method may be preferred to another for purely local reasons, such as whether or not a taper turning attachment is available. If it is, it is likely to save time on setup. (and reset) But of course many amateurs do not happen to posess one, and it may not be worth obtaining one for a limited number of items. I happen to be a professional myself, but in telecommunications, another of our members is a surgeon, while yet another is a lawyer. So we at least know that there is nothing magical about being a professional. (Actually it carries a professional obligation to admit your ignorance where necessary)

 

Terry can be annoying at times, but you are not exactly winning yourself any friends with your own attitude. I don't know how much experience you have with written rather than spoken communication, but it would seem to me that you have a bit to learn about how to avoid offending and annoying people. Since the whole point of making a post is presumably to communicate with people, it would seem counterproductive to switch off a large portion of the possible audience before they have read anything you might have to say. Some of what you will see here is advice from people who have used the technique they describe, some is not, but is for instance a suggestion of what they would try based on their own experience and equipment. You can usually tell which is which, especially if you have followed things for a bit. Most of us are willing to consider other approaches, we are here to learn. Indeed, there would be little point in reading the posts if there was not the hope of learning something.

 

Finally "model engineering", whatever that actually is, is not actually the same as industrial production engineering or even toolroom engineering, even if the particular part to be made might be extremely similar. In the production case, where large numbers of identical parts are likely to be wanted, it is a case of tooling up with the ideal equipment to do the job, or farming it out to someone who specialises in that sort of thing. In the toolroom case, it might be closer to the amateur situation, except that the machines available are likely to be of a wider variety and to a higher standard than the amateur can afford. Also the amateur undertakes a far wider range of work than is usual for any one worker in industry, he or she will do his own pattern making, in some cses the moulding and casting, then the machining and fitting, the boiler making, the painting, the woodworking.....und so weiter. In lieu of having the right equipment, the amateur will often pay in time, for instance by doing by handwork what industry would do on a specialised machine. Whether or not the standard reached is as high as might be reached under top professional conditions is immaterial, since the whole point is to have the pleasure of doing it oneself. And of course quite often the standard is such that the professionals can't beleive the equipment it was done on.

Hi There

I made some parts for the RAF Nimrod.

They were all done on a CNC mill. Everything was surfaced all over, nothing was flat,

There were no drawings, just a computer model.

 

I assume they took a part from a thirty year old Nimrod, put it into a computer measuring machine and made the model.

I doubt the original Nimrods were machined on CNC machines.

I said at the time that we were making brand new Nimrods that were 30 years old.

 

Perhaps that is why they destroyed them with JCBs?

 

The funny thing was, one of the components I spent about 4 weeks of nights on, when I came in one night the day shift chap said the bottom of these components was not flat so he had skimmed them. Four weeks work down the pan.

 

regards David

 

 

Well I'd like to congratualte Donald on bringing the site alive I though it was dead on its feat, the number of post it was getting.

 

I don't agree with the sentiment of his post we all have to learn, and as a time served toolmaker I'm still learning about this hobby, its all about getting the best out of your Kit even if it is cheep Chinese stuff.

 

Stew

Hi There

I misposted.

What I should have said was we would never employ a toolmaker on production work as he would take 5 times as long as a production man to do the same amount of work.

regards David

 

Hi donald, you talk of Chinese machinery as if you know all of it, you don't. 20 odd years ago I went looking for a lathe, I looked at Myford, then the price. Ithen looked at a Taiwanese lathe quite a bit bigger, and a class above the Myford in the oppinion of an engineering friend, price one third. I'll admit that setting up a 300kg lathe on my own was a struggle compared to the Myford would have been. Perhaps the Chinese send all their c***p to UK, I have no qualifcations in engineering, I am registered as a nurse.

Show us some of your model engineering examples, you must have some good stuff.

Ian S C

John Stevenson,

If you read my post I said MORSE TAPER not a steep taper like your photo.

I have never had a problem finding a centre lathe job although I am equally at ease with CNC. as for bulls**t well you would know more about that than me.

I only joined the forum yesterday and have been constantly bombarded with flak.

If that's what you get for speaking your mind then bring it on.

by the way your not Chinese are you?

Donald.

If you want a peek at what amateurs can do then I go here from time to time, it's an aussie site.

 

 

...amateur being a very broad term...personally speaking, from looking around that place, I aspire to become an amateur.

Thanks, Stewart and Ian,

I am not a model engineer. It certainly looks like I have put the ball up on the slates people on here seem to have a problem understanding that I am not

trying to belittle model engineers but I must be missing some point here. And for another poster YES I am familiar with the work of Ms Hill, that is my point I could not imagine her giving out crap advice could you? unlike many others, not just here but on other forums.

I have certainly no need to ask advice from any forum but if I myself was asked then I would certainly give the best I could [even if it did mean causing the fur to fly]

Regards,

Donald.

PS to the other Donald, it's Wittman

Mr. D Wittman;- it must be good to know everything, and never need to ask advice. I was an apprentice eng. many years ago, then a design draughtsman. My chinese lathe is pretty good, but I am constantly having to invent non standard m/cing methods, and asking questions, often on this forum. When designing it is as well to keep in mind how it will be made, and if necessary, redesign so it can be made with what you've got. My postings often finish the thread, I hope this one does.

Posted by Donald Wittman on 24/03/2011 10:25:05:

 

 

Nice sidestep

 

John S. Who's not Chinese

Hi Donald,

I am beginning to think that you are not the to$$er that I first took you to be, I am coming around to the thought that you are merely being a mischievous little imp. I find it hard to believe that someone with such a limited attitude, as you profess to have, was found to be useful in industry.

Logically then, you must be taking the p*ss at our expense, this is unfair and unjustified. An amateur has many more skills than a production turner could dream off and if he works to tighter tolerances, than a professional, it is because he can. In industry tolerances are sloppy to make sure that the part fits with another one made by some other bored clock watcher. Also, as we know precision takes more time than hammer and bodge'm methods. An amateur should not be compared with a production turner but more should be compared to, say, a Master Gunsmith, where every part he makes is custom made and hand finished to the highest level of fit and finish. The difference is hand-crafted against production line, "London Best" versus cheap Russian, or for car version, Rolls v. Mini. Or at least when "Rolls" meant something.

 

If there is only one way to do a job, that way must be the most efficient way. As for your example of Morse taper turning, in industry the most efficient, and might even in fact be the only way, would be CNC. Off setting the tailstock way is far too slow. Taper turning attachment comes second best to CNC, but let us not forget the Skiving tool.

 

To take you up on the dual DTI device on another forum, if it the one I am thinking of, I believe the chap to be a very competent and experienced machinist, I seem to recall he is former RR but I could be wrong. He is always looking for a better way to do things than the way he was taught. If you regard your teachers to be infallible, you are heading down the path to fanaticism, just look where it got us with suicide bombers. Open your eyes and try to take in advice for more experienced, yes even amateurs, you don't have to slavishly follow but you might just learn something! Unless of course you are the Imp in the first paragraph, in which case just sit back and continue your laughing fit.

 

To paraphrase an old saying "those that can do, those that can't complain" Prove me wrong!

chriStephens

Posted by chris stephens on 24/03/2011 12:07:54:

 

 

It actually "If you can do it, then do it, if you can't do it, then throw chalk at it "

 

John S.

 

Donald -

 

If you are "equally at ease with CNC" then I'm sure you will be aware that commercial tooling with Morse tapers (or any other tapers for that matter) are not machined by offsetting the tailstock these days, and have not been manufactured that way for many years. So if the only "proper" way to machine a MT is by ofsetting the tailstock, I presume you must believe the manufacturers have all got it wrong moving to CNC & should immediately revert to using manual machines with offset tailstocks?

 

You don't have an ancestor by the name of Ludd by any chance?

 

Regards,

Tony

Mr Wittman,

 

I am happy to describe myself as an amateur, I took up model engineering when I retired, having wanted to do it for decades, having been a mere clerical worker.

I bought a second-hand Unimat 3, which appears to be capable of much more accurate work than I can produce on it, with my self-taught skills.

I can't afford a new Myford, and I haven't the space for one anyway, so I am contemplating buying a Chinese Mini-Lathe which should last me until I die, plus a similar milling machine. I expect to have loads of fun with them, making rattly little models whilst improving my machining skills over the years.

I have received nothing but help and understanding from my fellow forum users, plus a good-natured attitude, and the same from the members of the model engineering club I joined, despite my often silly questions.

 

I will never achieve the standards of fine engineering that I see all the time, but I am willing to learn, and that is the crux of the matter.

 

Regards

Geoff Theasby

 

 

 

 

 

 

 

 

 

 

Well God bless the Chinese - and I never thought to hear myself say that.

 

I have a Myford - its a lovely machine, but it is quite small. For the cost of a darned good second hand Myford I was able to buy a 6x36 Harrison chinese copy, and a big (by modelling standards) Warco mill. So where before I would have been forced into making 2" traction engines or 5" locos, now I can build 3 and 4" engines for a fraction of the capital cost of such a set up say 7-10 years ago.

 

The chinamen have limitations, that I accept, - they are not professional grade production equipment. However they are both very accurate, and will see me out .

 

Sure when I win the lottery it will be a brand new Harrison and a brand new Bridgeport too, and the 3 phase to run them.

 

But until then the Chinese have transformed model engineering for all of us. With their lathes, mills and good enough tooling.

Hi All,

 

The last MT3 taper I made was by using Harold Halls method of offsetting the top slide and using that to cut the taper. I had to move the cross slide on each cut as I could only get about 2/3 sf the necessary movement of the toolpost.

 

It didn't really take very long to do on my old Boxford. When thought it finished I applied engineers blue and tested it in the Milling Machine spindle. I had to use the drawbar and a tap from a copper hammer to remove it and most of the blue was gone, indicating a good fit. In fact I tested it using a 12mm nd mill side cutting steel with drawbar slightly loose and there was not problem with it coming loose. It's a real pain to know that I now have to go and make a new MT3 because I didn't use the correct method. Doh!

 

When I finally moved into engineering design I was always told that it was the end product that mattered, not the path to get there. Now I know better, thanks Donald.

________________________________________________________________

Hi John,

 

I may be annoying, and sometimes I set out to be controversial to raise debate, but at least I'm, often positive and helpful as many of the members know. If I can offer advice and help I always offer, otherwise I shut up and read. By the way Geoff I wasn't trying to be rude to you on an earlier post it was just my clumsy way of trying to say something and was not aimed at you personally, if it caused any offence I apologise.

 

Best regards,

 

Terry

Hi All,

 

Is it just me or is it possible that Mr Wittman (what a misnomer) can hand out unwarranted, vitriolic and unnecessary criticism, but can't take it. What does he expect after the rubbish he wrote in his initial posting?

 

As secveral of us have asked, show us some of your work please Mr Wittman.

 

Best regards

 

T

Hi Terry,

Would it be very very childish and immature to put an extra "T" at the beginning of his name?

chriStephens