Member postings for Hopper

No wonder. 20mm tooling is massive for a lathe that size. Ship's crankshaft machining stuff. I'd be tempted to use 12mm and fit four in more easily.

I see now there are Laser Welders being advertised. Such flawless beads of perfect weld they are laying. Wonder if that is too good to be true too?

Thanks guys. Interesting and informative. Obviously i should have paid more attention to my steam tables at school. The lower latent heat at higher temperatures is quite counterintuitive.

So would we say, then, that steam provides more power to an engine than air because of the greater amount of sensible heat in the steam that can be converted into work? And I suppose if the air was the same temperature as the steam, steam would still create more power because steam has a greater specific heat than air?

Interestingly, quite a few texts and papers seem to state as an assumption that latent heat in steam provides power in engines/turbines but none really go into specifics of how. Perhaps what they are referring to is the use made at the end of the cycle in the condenser where the latent heat is removed by contact with cooling water tubes, thus creating the vacuum "for free" that allows the last of the work to be extracted from the steam at the LP end of the turbine?

Sorry, I thought you had made the hole and were now asking about the outside.

Yes books can be hard going. But using a lathe is harder. So well worth the effort to sit around and browse a few of the former in order to make the latter easier.

No it is not common to remove the cross slide because then you have nothing to mount the tool on and no way of controlling its depth of cut. But needs must and you could remove it for clearance if you needed to move the carriage under the large chuck so you could bring the tailstock up closer, if it would fit.

Edited By Hopper on 18/06/2023 11:31:49

Edited By Hopper on 18/06/2023 11:33:06

Myford lathes use a lot of Mazak (same as Zamak) on peripheral parts such as the motorising unit frame and H frame, belt guards, gear guards, leadscrew brackets, cross slide end bracket and the awful little ML7 cross and top slide dials. But not any of the main moving parts, thank goodness.

I think its main component is zinc, with lesser amounts of aluminum and copper. Never seen it used as a bearing. Always seems to be a brass or bronze sleeve in it, eg Myford leadscrew mounting brackets.

Julian, have you tried tracking down the author of the quoted book, Leighton Smart? He is most likely a local person in the area. Maybe through the Artie Moore Amtr Radio Assc? Or the online whitepages?

PS : A quick Google of his name and and "radio wireless" reveals he was a contributor to Practical Wireless magazine in the 1990s. He gave his contact details then as

Leighton Smart GWOLBI, (GWOLBI is his radio call sign)

33 Nant Gwyn,
Trelewis, Mid Glamorgan, Wales
CF46 6DB. Tel: (014431411459.
a

If he is still around after all these years, he might divulge his sources for the booklet he authored.

PDFs of his column are posted on WWW. worldradiohistory.com but there seems to be no mention on that site of Artie Moore. Perhaps he was  bigger figure in Mid Glamorgan than in the overall history of world radio.

Edited By Hopper on 18/06/2023 11:14:44

If you look at Jason's pic, the three-jaw chuck is holding the job by the round hole in the middle. But you need to have the reverse jaws for your 3-jaw to do this.

Otherwise, you could put a piece of round bar in the chuck, turn a step down on the end to fit in the hole in your plate, then drill and tap a hole in the middle and use a bolt and large flat washer to hold the job in place. Known as a stub mandrel or arbor.

You will save some grief by hacksawing the corners off your square before machining it round.

And please do follow Oldiron's link above and download the book. Life will be so much easier if you know the basic terminology and procedures. It is a great old book and still relevant to day. Turning is turning.

Edited By Hopper on 18/06/2023 10:54:01

I have had the same experience of being ignored, even after repeated replies including my email address in the text, as well as the type the system generates. I thought maybe they just did not want to mail to Australia, but like you would have appreciated at least a "booger off" in reply.

On the other hand I have had wonderful response to a couple of small wanted ads I have posted, with members bending over backwards to help me out. So the enthusiast spirit is still alive and well -- just not universal!

Which book was published in 2006 by the Arthur Moore Amateur Radio Society and is 8 pages long.

Sounds like Leighton Smart is/was a society member. I wonder if the book includes sources? Or is it based on local oral history? There is a copy in the British Library at St Pancras but I am unable to access it from here.

Yes filthy work. I worked around a couple of coal fired boilers and did not miss the glamour when I left. Wait until you have to climb down into the ash pit to retrieve and repair the chain-grate stoker (a metal chain conveyor belt) that has broken and fallen into the pit. No thanks. Then with the loco guys, there was all that shovelling. They would have been fit.

Edited By Hopper on 17/06/2023 11:01:10

As I obstinately stick with my four way because as in the "lost" video thread I find it quicker and easier than a QC to use, I have considered a Lammas 3-way. But when I discovered you need a left had and right hand version to change between things like a turning tool and a boring bar etc, I stuck with the faithful 4 way.

As I said in the "lost" thread, I have machined the Myford 4 way so a standard 10mm indexable tool fits straight in with no shim needed. Then if I use 3/8 HSS tooling I know it needs one of my standard thickness shims under it, plus another if the point has been ground a bit low. Flipping a toolbit upside down on the bench and sliding a shim or two under the tip soon tells exactly how many are needed. But as I use the same tools over and over I know which ones need how many shims. And tend to store the bits with their shims with them ready to use.

I have also machined a couple bits of 10mm key steel into an L cross section just right to hold a piece of 1/4" HSS at centre height. Very handy as the smaller bits are quicker to grind and cheaper.

But for the most part, using standard 10mm insert tooling, no shimming needed.

Plus I like the fact that the 4 way cuts tool overhang down to the absolute minimum.

Video unapproved by the authorities re advertising issues in the past apparently.

Other stories on the net have Artie cycling (one-legged, on his homemade counter-balanced bicycle) to the local police station to raise the alarm, only to be told to go back to bed and behave himself.

None of the many other stories about it on the net cite sources either, including the BBC and several newspapers etc. Local legend adopted and promoted by the museum that houses his stuff perhaps? Bit like the Wright Brothers and their allegedly not-quite-first planes at the Smithsonian?

Edited By Hopper on 17/06/2023 10:41:21

I wondered about that too. But assumed it was a trick of the light. If not, then yes, something definitely to be addressed.

Using mostly **GT carbide insert tooling these days, I rarely find a need for cutting oil. Only time I use anything is for screwcutting with HSS tools and then I use whatever is in the oil can for the lathe bearings, usually 20/50 engine oil. For tapping and die-ing threads I use Trefolex compound.c

I've given up using oil on milling cutters. Just seems to stick the swarf to them and clog things up.

Edited By Hopper on 17/06/2023 09:19:01

Same here. Licensed to run steam boilers on three continents. In industry you always vent the air out of the boiler as it warms up from cold. Air in the steam is corrosive, both in the boiler, the steam pipework, process machinery and the condensate return pipework. So you get rid of it ASAP. A lot of money gets spent on chemicals to help remove air from water and steam throughout the cycle, and on de-aerators to physically remove air from feedwater. So venting the air out of a cold boiler drum as it warms up is important.

Steam locomotives were a relatively primitive piece of equipment, often run on relatively untreated water, without a condenser or condensate return, so they probably did not worry about it quite as much. Just let it go up the stack or out the cylinder drain cocks and called it good.

On model engines it probably matters even less.

Some of the latent heat goes up the stack, or into the condenser water, but not all, I vaguely recall from tech college about 50 years ago, involving things like enthalpy and entropy and adiabatic expansion in the Carnot/Rankine cycle. In a nutshell, I vaguely recall, the latent heat of steam entering the cylinder at say 100PSI is greater than the latent heat of the expanded exhaust steam at say 5PSI. That heat energy has to go somewhere. IE becomes mechanical energy by expanding the steam as the pressure drops as the piston descends the cylinder. This is because as the pressure of the steam in the cylinder drops as the piston descends, the steam is actually superheated, ie the temperature is above the boiling point at that pressure. So that superheat energy is given up as mechanical energy. Adding a condenser lowers the exhaust pressure and temperature, allowing extraction of more latent heat energy before the steam exits the engine/turbine. There is also the factor of partial condensation and then revaporisation of steam as it hits cooler cylinder walls, releasing and reabsorbing latent heat. But my recollection may be completely wrong after 50 years.

Either way, whether it is sensible heat or latent heat, the heat energy contained in steam is greater than in compressed air and will do more work. In practice what you would get in a loco boiler firing up from cold would be an unholy mixture of very wet steam and air and probably would not make much noticeable difference as after the first few strokes of the piston the air would be all or mostly gone and you would be running on steam already.

One thing I do remember from tech college is that the thermodynamics of the deceptively simple steam engine is surprisingly complex, thanks to the thermal properties of water/steam. That is why steam is used rather than compressed or heated air.

Edited By Hopper on 17/06/2023 05:48:17

You might try polishing the taper you cut with some emery paper and oil to get a smooth finish, then check your reading. If it is still good, you could drill and ream a dowel hole through the topslide and cross slide for future use with no set up time needed. Just drop the dowel pin in and go.

Dementia rate is increasing, for reasons they can't work out. In particular, young onset dementia is increasing alarmingly.  Not unusual to see people in their 50s and now even 40s diagnosed today. Something to do with our modern lifestyle but so far nobody knows what.

Yes there are many different forms and Alzheimers is just one of several dozen. From what I have seen being involved in the local dementia support group, it seems to affect everyone differently and at different speeds of progression. Which makes it very hard to deal with because you just never know what will happen next.

Edited By Hopper on 17/06/2023 01:10:59

Yes it would do. Steam inherently contains more energy than compressed air at the same pressure because the steam contains the latent heat used to convert the water from liquid to gas (steam) form in the boiler. That latent heat is then available to convert into kinetic energy (power) as it is expanded through the engine.

Edited By Hopper on 17/06/2023 00:33:53