Here is a list of all the postings chris stephens has made in our forums. Click on a thread name to jump to the thread.
|Thread: Elf n Safety police|
Yet again I'm glad I'm getting old and don't have many years left, reading the above and seeing the way H&S regulated paranoia and society in general are going I'm glad I wont be around to see how it all works out, not for the better I suspect, correction, know.
|Thread: D bit query|
Hi Mike, I see you have got the shape now but reading your reply to my note, I would have put it as mill to less than half diameter not greater.
I think you will find the idea of having greater than half Dia is to stop the tool bit chattering, or otherwise moving about, and therefore cutting a larger hole than itself. If for instance the flat is less than half thickness it could move about as the cutting edge is less than its diameter. If the D is greater than half, the cutting edge is also less than Dia but it now has support.
The better shape would be to have only a quarter or third section removed, which would give far better support, and this is indeed one of the commercial shapes for gun drill and the like.
Hi Mike, that D bit looks about right but you really should hone the cutting edge after heat treatment as the heating tends to blunt sharp corners. Oh and it wants to be slightly thicker than half thickness by a few %.
|Thread: HSS Lathe Tool Angles for Small Lathes|
Of course you can but, and it is a big but, they have to be the right ones. To a lot of newbies a carbide insert is just a carbide insert, without realising that there are a myriad of different types often with very specific purposes. Anybody buying a load of industry surplus tips hoping they have solved all their problems is surely in for a disappointment.
Buying tips from, say, JB you are pretty certain to get the right purpose you have asked for, but if you ever look in an insert catalogue looking for tips, watch your step as you have entered a minefield. The general majority of tips are for industry, where the money is, not with the penny pinching old farts, sorry, cost conscious old farts, in model engineering (myself included)
|Thread: Lathe design not keeping up|
Hi John and Neil,
Where's the thumbs up button, I want to press it.
|Thread: Salvage Squad|
That must be an adult, their children seem to have even less and ours are rapidly following suit.
I remember when one of the "experts" on that show screwcut a thread for a gate valve, couldn't stop laughing all evening, makes me smile even now at the thought.
If you want to know about shafts, props and the fitting of same, take a look at Keith Fenner's YouTube playlist on "Marine Propulsion" at www.youtube.com/user/KEF791/playlists. His attention to detail impresses me and I don't impress easily being an old cynic.
|Thread: 25 Years of Model Engineers' Workshop|
One would hope that it will be available from the usual sources, WHS, as well as from the publishers. I am really quite interested in the article on Dill grinding, see the second link.
|Thread: Todays update from Bodgers Lodge|
Hi JA, so you are one of our former customers, glad that some still remember the old shop. From memory we only had problems with BMW valve head dropping on the 450/650 range, my own 75/5 has 150+Kmiles and the heads have never been off. You might remember the bike as the one parked out front on Ladbroke Grove.
|Thread: Flycutting - need help total noob.|
Hi Vic, I must admit I am in two minds about which looks better, but i always try to file away machining marks so it makes little difference in the end one way or the other.
Another very good video on fly cutter tool grinding is my mate the other Tom, Tom Lipton at Oxtool
I can heartily recommend his grind, although i do do it slightly differently myself but that is because I don;t have a standard design flycutter.
As for cross hatching, it is a sign that your mill is set up right not a flaw.
|Thread: understanding screwcutting|
One of the best threading primers on Youtube is "Toms Techniques" (youtube.com/user/Figbash3) "thread cutting on the lathe" in his playlist. Some of the others on YT are, at best, awful and a waste of time to watch but I doubt you will go far wrong if you follow Tom's advice, even if some say he is doing it all wrong because that is not how they were taught. His way is logical and it works and that is all that matters.
|Thread: Special bolts for when you make a mistake|
Excellent, now we have found the award for the JohnS Challenge
|Thread: A new class for MEX|
What ho Sir John,
An excellent and welcome idea, but no more than is expected from a real tool user who has and uses his little grey cells to great effect,. If there is a minor problemette with the idea it would be that seeing a lovely bit if shiny metal innovation on a table, even when accompanied with a description, says absolutely nothing to the average stick-in-the-mud old fogey about its use. Granted there a few who will see and understand straight away, but to many the only way to show an innovation's benefit (if no benefit it would be a solution in search of a problem) would be to see it in use. Speaking from experience of demonstrating at shows, taking for example a tangential tool holder, many paid absolutely no interest in it till it was shown to work and work well, then they got interested and asked for plans and info. Perhaps any bit of innovation should be accompanied with a you-tube type video, instead of a paper description, to show the the great unthinking masses (T firmly in C) its use.
As for the presentation cup/award for the JohnS Challenge, why not have a competition for the design. Oh maybe not, you would need a cup for that design and then a design for that etc etc.
chriStephens, (also a John Stephens' son )
|Thread: Forgotten engineering techniques|
Hi Robert, all is not lost because, so far, I have not found the need for one.
I do realise that machining all over is the only true way to make one but I figured that the fork stanchion would be a wizard way of getting the parallel bit done for no effort, especially as it was literally lying around on the floor. I could easily file the ends true, after all it is only a few microns that need to come off. Or, I could hold one end trued in the four jaw and the other trued in the tailstock. I will make a dedicated squareness checker first, instead of relying on a lash up, before bothering either way to remove any measuring inaccuracy.
Thanks for your comment
Hi Les, My four jaw must be far worse than I thought/hoped, I checked the cylinder square using standard methods and you are right it is miles out, I read a total lean of 1 thou in four inches, read on both ends equally. Still for this amateur bodger that will have to do till I resurrect the surface grinder.
Hi Les, I could be wrong but if you have reasonable faith in your chuck jaws you should be within home tolerance requirements. If looking for NASA standards, well, what are you doing looking at an amateur's forum.
Given a little time I shall test it for true squareness, but so far it checks out against a new M&W square(?).
Hi Guys, with this talk of cylinder squares I thought I would make one, well in truth I saw a short length of sawn off motorbicycle fork tube on the floor of the engineerium, just before sliding on it for those who might wonder, and then thought of making a square.
For those on a budget, motorbicycle fork tubes should make good squares being reasonable quality steel and hard chromed. My bit was 33mm diameter and 4 inches long, if you are offended by mixed units, deal with it! I trued it up in the four jaw to within a couple of tenths and took very fine cuts till each end was clean and then de-burred, et voila, a cylinder square. Fork tubes are thrown away at motorbicycle repairers all the time, even if bent (the fork tube not the repairer, although come to think of it.....) there will still be a long enough straight bit to make a couple of squares. Gone are the days when they would be straightened, is that H&S or just more profit in new or,to bring it back to title of this section, a forgotten art?
Now of course I will have to think of a use for it, having survived all these years without.
|Thread: Vertical Shear Lathe Tooling|
Hi Jon, Take all the issues you like, the smiley face shows I was poking fun and not meant to be taken too seriously.
With regard to Mr Pete, I wont call him Tubal Cain as it is disrespectful to our one, I did in my first post say you could learn basics from him. That is a sort of praise from me, dogma though has no place once you have learnt how to be safe in a workshop, as it stifles ingenuity and progress.
As for the colonists over the pond, one only has to look at their obesity rates if you want evidence of fantasy being brought to a conclusion by the undertaker. The fantasy is that there are no consequences to their life style choices. I still have great regard for the few Yanks I like to call friends, by the way they are the ones with a sense of humour. even if they will have avoidable health problems as the years go by.
PS never take anything i say too seriously, as I never do.
Hi Pgk Pgk, I thought that was what I wrote, school children.
Edit, on further thought, from my limited experience of Americans they seem not to grow out of childhood, and its fantasies, till the undertaker comes a-calling and reality finally kicks in. Got to love them all the same, as I'm waiting my second childhood, still being in the first.
Edited By chris stephens on 06/01/2015 17:44:40
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