Here is a list of all the postings Nigel Graham 2 has made in our forums. Click on a thread name to jump to the thread.
|Thread: Screw cutting advice ml7|
I have somewhat similar problems on my ML7 with engaging the half-nuts, and if it doesn't engage neatly I kock it straight out of wherever it has stopped and try the next number or iteration.
It is just possible to clean and lubicate the mechanism fairly well without removing the apron, by taking the lever off and operating pins out. The lower half-nut can then be winkled out downwards. I washed the remaining innards with liberal squirts of WD-40 (which is not a lubricant), wiping what I could with a small brush and paper towels from under the apron; then lubricated the lot liberally with oil. It helped but I still have that trip effect so will examine the indicator alignment as suggested above - for which thank you.
I note suggestions to "re-align" the leadscrew. Any axial adjustment will simply take up end-float on the screw itself, and although that might help, it disguises the real mis-alignment.
Instead the half-nuts are adjusted by a small screw with lock-nut on the end faces of the apron.Not the lead-screw.
If you think about it the relative position along the machine of the saddle and screw is not important so adjusting the lead-screw will merely kick the saddle down the road, to paraphrase...
What matters is the mutual alignment of the two half-nuts, then the alignment of the indicator marks so they agree with the half-nuts and the screw.
On mine the stud holding the cam to the apron was working loose in the apron thread, and that won't help matters, by introducing a lot of slop.
|Thread: What Did You Do Today 2021|
I suppose someone had to say it, Kiwi......
I wish I could share your optimism but the whole concept just does not stack up as the green types and politicians imagine.
However many charging points they install there will always be queues at busy times; and what happens if the connector is incompatible with your car, or the chargers are out of action and you may be a long way from the nearest alternative assuming you know where it is? A parallel argument applies to availability of petrol or diesel of course, but their ranges are more reliably longer.
The ranges seem suspect, as if calculated or test-track conditions, not real driving in a hilly country in busy traffic in bad Winter weather.
The cost of the electricity in future is a huge unknown; even more so if /when subject to tax and/or the payments are via enforced "smart"-phones with their contracts and hidden middle-men fees. And variable signal coverage.
The new costs are not likely to fall to "affordable" levels; and if second-hand ones are cheap it's because their very costly batteries are dying.
Well, I reckon motoring will go back to the 1910s when it was the preserve of those who could afford the proliferating battery-powered cars of the time.
If you can't join that exclusive car-owning club, how are you going to take your latest creation to the major model-enegineering show or rally? Assuming they exist of course thanks to it being no bad thing that most of us have to stay local apart from the annual trip Pwllheli or Fylde, so the attendances and exhibit lists at major events are uneconomically too small.
Indeed I foresee a time when huge swathes of the country's culture and leisure will die off , and what's left will be severely limited in choice and heavily constrained, as people become unable to go anywhere in large numbers, or to take anything anywhere, any significant distance from home. Replacing frenetic dashing to social and cultural events, clubs etc, with the more stressful isolation, sense of loss and monotony. Nothing man-made in this world comes for nowt, and electric cars come with a lot of owt.
|Thread: Milling machine in the (wood floored) workshop|
I solved the same problem in my previous home by cutting four recta ngular holes in the floor, cementing small brick plinths to the underlying concrete a few inches below the shed floor, and putting a thick PVC pad as damp-proof / levelling layer between the milling-machine's angle-iron bench and the bricks.
|Thread: Stone moving machine|
Whether the Druids ever used Stonehenge, they did not build it.
More seriously, the stone actually used may have been hauled from no more than a few miles away. If I knew the reference I would give it but a geologist who has studied this recently pointed out that although the source was Wales, the rocks used in the building were "erratics"; moved far from home on an ice sheet that crept across Ireland and Wales to about as far as Wiltshire. More of the same rock is still there, where it was deposited by the melting ice.
(During the Last Glacial Maximum, Southern England was exposed Arctic Tundra, and ice-sheets rather than glaciers was the main ice cover extending down to about the Severn - Thames line.)
Would seem a classic example of three sets of experts - here professional archaelogists, geologists and engineers - not talking to each other then journalists reporting the first not knowing the rest exist!
What all the speculations on how ancient people moved umpteen-ton blocks fail to spot is the nature of the ground. The usual assumption in those "reconstruction" paintings, is tree-trunk rollers, which is probably correct; but that alone would be insufficient on almost all ground because the logs would partially sink. I suggest that they may have laid more tree-trunks longitudinally, as a sort of road-way.
As for raising them upright, one theory holds they would have levered and packed, levered and packed... I wonder if they used some form of rough derrick, or lashed an upright at least as long as the slab to its foot end, and applied the pull over that.
(I have used similar, with a scaffold-pole and rope, to recover a milling-machine that fell over into a bramble bush when we were trying to load it onto a trailer, and the ramp collapsed.)
|Thread: Universal thread cutting|
Interesting point, Chris.
Perhaps it's too easy to think the more complicated the solution the more efficient the result; or that the solution even needs to be complicated; and I have seen others and been caught out myself by this tendency.
I suppose the main advantage of a gearbox is the ability to switch from screw-cutting to plain turning and back rapidly - I have a gearbox for my ML7 but am yet to fit it - but the chart in the change-wheel cover does give the wheels for several standard metric threads just from the ordinary change-wheel set. My Harrison L5 lathe manual gives similar combinations, but I think I have a 127T wheel for it anyway, and it has a narrow-range 3-speed shaft gearbox that extends the change-wheel sums.
It's probably worth looking at the intended work. Brian may wish to make long, very highly accurate threads so does need very close matching.
For most of us though I suspect most of our screw-cutting is over short lengths, less than 10 turns, and to ordinary accuracy standards; not long threads and still less, high-precision lead-screws. For those two, rare, instances it is usually simpler and not very expensive to copy industry and base the components on stock studding / lead-screw rod and nuts.
Consequently I spent a few lunch-breaks at work calculating by spread-sheet change-wheel combinations for odd-numbered and metric pitches on a simpler lathe than a Myford, with a 1/8" lead-screw and smaller change-wheel range; and was surprised how close many came within sensible tolerances. Having done that, all I then need is to print a copy for ready use! No need to search for prime-numbered wheels (though I did buy a 63T wheel), electronics,stepper-motors and the like.
By all means build an NC lathe as its own project but I am wary of going Long Way where the Short Way reaches the same point just as properly, with less overall cost and effort.
I have been there - making the thing far too complicated for its own good, then spotting how I could have done it and wondering why I threw so much extra time, steel and electricity at it. It's a matter of balance, but efficiency and quality count, not complexity!
|Thread: What Did You Do Today 2021|
"Door opening training"... Ah, in this case the fatality was due to door closing.
Blow me, when I opened the workshop door this afternoon, there was a frog sitting on the floor immediately inside, staring up at me! They aren't easy to pick up without risking injuring them, so I chivvied it to hop gently outside and into a safe area. It had most likely crept in when I previously had the door open.
I did once have a genuine door-opening near-miss. It was at work, or at least on work duty, and I should probably have reported it. Driving somewhere on a work trip, I stopped at a service-area. It was a windy day, and as I opened the door to resume the journey a gust of wind caught it, jerked it out of my grip and rammed the very corner against my forehead. Half an inch lower and it would probably have had my eye out.
|Thread: "footprint" of Dore Westbury|
I've mounted my machine at an angle to to the wall, and partially covered the corner at machine stand height. This gives a cubby-hole for things not needed in a hurry, and more usefully a compact tool shelf.
|Thread: Self-Lock threads|
Oh yes, been there!
The risk may be reduced where other factors of the design allow, by using different grades of the steel against each other.
|Thread: Change Wheel Programme from MEW|
Intriguing! I didn't know BASIC, in one form or another, is still used.
My initiation to "confusers" was in a scientific establishment that used locally-written BASIC programmes to run electronic test-equipment. Many of the instruments were made by Hewlett-Packard, which published its own version of the language allowing expressing the operation settings as simple character strings.
In later years the scientists for whom I worked, started using LabView instead for that purpose.
However my work had taught me MS 'Excel' to a moderate level, hence I produced charts for various threads on machines like my EW 2.5" lathe with its 8TPI lead-screw and change-wheels from 25 to 65 (I think) X 5.
It was thus easy though a bit laborious to juggle the wheels in the table to obtain least errors for odd-number inch, BA and metric pitches, with the error calculated and displayed for 1 turn and 10 turns. This is for cutting short threads - studs, piston-rod ends, steam-fittings and the like - not long control screws.
Probably, someone with advanced speadsheet skills could make it do the juggling automatically. Nevertheless I have the tables, allowing prints for laminating so I don't have to run the computer every time.
The main points are:
1. Determining and closing the accuracy limit by number of turns. It is surprising how close I could calculate many standard but non-octal threads with the limited wheel range; within fair tolerance. I accept finish-profiling by die a slighly shallow-cut thread anyway, though for these threads the modest pitch correction brings slight thread-thinning with accumulating error. Hence 10 turns as the likely practical maximum, enough anyway for most applications.
2. Producing a printed table of pitch / tpi, wheels and error; for laminating for ready reference.
I used a similar approach to create a feed-length table for the Denbigh H4 horizontal mill I am in the throes of putting back into use. This has a 6 tpi longitudinal screw (0.167" pitch), of all strange things, and it's anyone's guess what the dial markings mean! I suppose most horizontal milling is through-cutting, or to lengths that are not very critical.
I had already used the EW lathe to cut a metric, non-standard thread listed in none of the reference-books, with no die available, to fit a keg CO2 cartridge for a special purpose, so knew the possibilities. The thread was probably designed for commercial exclusivity; but might now be in one of the ISO-M Fine ranges.
|Thread: What Did You Do Today 2021|
Had a Feeling Bad incident...
I've accidentally killed one of my garden frogs!
Lying on the floor, head through the worshop door and under the front of my steam-wagon where I was re-fitting the front axle after a modification, I noticed something on the bottom of the door jamb, about 18 inches from my face.
It took me a few moments to identify it as a small frog.
Post-mortem showed cause of death to be traumatic conversion from isometric to orthogonal body shape. Inquest concluded it had been there, unseen by me, when I'd turned the workshop lights off and closed the door late last night, trapping the animal against the jamb.
Scooped it up with the 17mm spanner I had in hand, put it under a nearby bush, and reflected that I must be more careful on completing late-night engineering sessions, but at least it would have been an instant death.
RIP, little amphibian.
|Thread: Hydrogen home heating|
To think the UK used to be among the world's leaders in developing nuclear power-generation, though I think it did suffer a big blow when France stopped funding a partnership in this.
I listened to an edition of Any Questions some weeks ago now when the matter of coal-mining came up, and it was clear that none of the panel had a clue why coal is still necessary in making "steel" (iron, actually). I recall learning it in school geography lessons - and at quite a young age, too.
The alternative reducing agent being investigated is hydrogen, but what of course its proponents seem to gloss over are the sources of the gas, and the method of heating the ore to the appropriate temperature.
|Thread: Lathe DRO|
I have fitted and do sometimes use a leadscrew-handwheel on my Myford lathe, using the adjacent corner of the bed as a pointer, but that does give the screw and half-nuts a hard life. So as a general rule, I combine the carriage feed and compound.
Cut most of the length with the saddle travel, then (assuming it is actually set parallel) lock the saddle and trim the little bit with the top-slide. Or if working on the end of bar-stock, over-cut the length slightly and face it to length.
If I am cutting a short diameter within the range of the top-slide I sometimes use that to create the first step as a guide; then the saddle for the remaining cuts very slightly short, leaving a tiny but visible witness step, then the top-slide again just to finish to size.
I don't use dogmatic approaches, but go by which I think the best option for the particular task.
I have fitted a Machine-DRO 3-axis system to my Myford mill; but not to either the Myford or Harrison lathes. I have looked at the idea but it seems to put a lot of vulnerable bits where they ought not go, and anyway possibly get in the way.
I don't like this x,y,z nomenclature though. It makes sense on a mill, and does correspond to geometry (Y does not go "to the sky" in maths, map-reading or CAD; but is horizontal, towards the far edge or North; so should be that for a lathe cross-slide).
It's OK on the read-out itself when you are using it and accustomed to it: X long travel, Y cross-travel, Z vertical; but when writing describing machining operations, I prefer and use the proper machine terms.
On guards, I have to confess my lathes don't have such things, other than a crude plywood tool-tray that shelters the inverter screwed to the cabinet below the headstock, on the ML7. The electricals on the Harrison are well out of the way: the motor on a frame above the headstock, the inverter and controls on the wall above the tail end. Even so, I think I ought fit guards to both machines, if not interlocked, at least controlling the swarf, and on the L5 me due to the clutch lever position. A mass of steel string grabbed by a big, fast-spinning chuck is not nice...
|Thread: Re-making a centre hole in a small crackshaft|
I would suggest using the lathe is the eaiser option because to use the milling-nachine as you suggest, may mean having to set tthe shaft etc in the "corner" off the table.
I have done that for one or two awkward tasks, and it is not easy!
You mark the cra nk end as having weard bands but are there bands between them on which you can place the DTI? I am thinking of being better to set the steady at the chuck end then slide along to the support point.
That of course assumes a constant diameter but I see the outer end both steps down and appears to have a groove extending from the key-way, and which might create problems for the steady unless it is much narrower than the steady's contact areas. I think if you can mount the steady right by the step you might be OK with very careful machining, but as John suggests, putting a bush on the shaft would be better.
Obviously you can't face that end back more than enough to just clean it up, but I would try using a small knife tool to ease the damaged area of the centre-drilling down enough to give re-drilling it a better chance of concentricity. It doesn't look as if the shaft is especially hard there so HSS tools ought cut it.
Incidentally you learn something new every day here! I have never previously heard of a "spring dog" yet lo and bohld, there is one, on the drawing of the lathe set-up. As the "words and music" bear out, it holds the work back onto the live centre, since the outer end is not constrained axially.
|Thread: WHAT IS IT ?|
A possibility. There were still some odd threads around in the early-1900s, perhaps more in horology than other branches of engineering.
Another suggestion I have... clutching at straws, or dropped stitches. Something textile?. Setting pattern- (e.g. lace-) weaving looms or special knitting-machines, maybe?
No good. Short of someone coming on here and saying, "Oh, my Grandad used one of them every day for [ ... ] " , we may have to start asking specialist trades or museums selected by intelligent guess, if they recognise it.
You never know, there may even be modern electronic ISO-Metric equivalents in use as we type!
|Thread: electronic cylinder indication|
A very interesting project.
The one point I might suggest with respect if you've not done this, it to place a water-block between the sensor and the cylinder, as on the boiler pressure-gauge, to protect the transducer from hot steam.
|Thread: Bureaucracy with a tinge of Madness|
I am afraid you are missing the point. You seem to mean that if you want to use a computer or indeed 'phone on-line, you need a deep knowledge of programming, well beyond the basics of simply using the thing.
The only defence we have against such attackers is careful use and installing reputable anti-virus software; not trying to learn computer langauges we may have no opportunity to be taught, or would find too difficult. Some, including me, would be faced by both obstacles.
|Thread: dirty clutch trick|
Well, something like this is used on horticultural machines more powerful than an ML7 motor, and provided it does not unduly wear the pulleys, as you say a belt is a lot cheaper than a motor.
|Thread: Lapping a cylinder with dowel + paste|
I'd split it with a fine-bladed saw, and use the same tool to cut the wedge. That part of the operation does not need great accuracy.
More to the point ensure you keep the lap moving, and as axially as you can.
Recently I carried out the opposite, externally lapping the end diameters of a shaft, with an aluminium lap turned to a close sliding fit on the shaft and in a die-holder. I cut the split in the lap with just a hacksaw, with a touch of a file along the cut edges to remove the burrs..
|Thread: Bureaucracy with a tinge of Madness|
I for one find that rather offensive.
Falling for a scam out of naivety, or momentary lapse of concentration, is one thing; but not all of us deeply understand computer languages and operating-systems, nor should we need to.
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