Here is a list of all the postings Kiwi Bloke 1 has made in our forums. Click on a thread name to jump to the thread.
|Thread: Lathe design|
Thanks Michael, an interesting link, which I've skimmed (I'll read it fully over a suitable number of bedtimes...), but it doesn't seem to address saddle design. It does, however, illustrate how early machine designers thrashed around, trying this and that, probably without much science being involved.
John, no. An adjuster-screw-supported gib strip (as opposed to a taper gib or 'block-type' gib) will certainly wear more than a 'rigid' bearing face - and unevenly too - if only because it's flexible, and really only reacts forces around the adjustment screw locations. But you don't want the major guiding face to wear, do you? Neither do you want to have to continually adjust it. Also, the aim is to make the guiding face to be as rigid as possible, so it should not be the gib-strip side. You will see that cross-slides and top-slides are (always?) arranged 'correctly'.
I'm still puzzled by some early designers having made what seems to me to be a fundamental blunder. I expect that they had their reasons, but what were they?
Yes, in normal use, the forces the Cowells has to resist will be small, but we have a tendency to push the limits, don't we? Clearly, the Cowells seems to satisfy its users - it has an excellent reputation - so it must perform OK. It would, however, be easy to re-engineer the Cowells in accordance with current standard practice. It might allow it to perform better when pushed hard. Would it be an improvement?
My question is really about whether I've misunderstood the situation and the underlying principles of machine design.
Edited By Kiwi Bloke 1 on 13/05/2019 12:37:18
Many older inverted-dovetail bed lathes (EW, EXE, Portass, Grayson, and more) are arranged with the saddle's gib strip at the rear. This seems to have fallen out of favour, although I note that Cowell's still has the gib strip to the rear. Presumably, it's because it's a fossilized, ancient design.
Locating the gib strip to bear on the rear face of the bed's dovetail means that, apart from being difficult to access for adjustment, cutting loads are taken by the gib strip, not a rigid face. I assume this is why modern designs have moved the gib strip to the front. I see no reason why the Cowells lathe couldn't be made with the gib strip at the front of the saddle. Perhaps a re-design was just too much bother - or, perhaps there's a reason I've missed.
Does the location of the saddle's gib strip matter? Why the fashion for the 'wrong' location in the past?
|Thread: The Chocolate Fireguard as designed by Mercedes Benz|
I still don't understand where all the extra electricity is going to come from, nor how it will be distributed at the currents required for mass quick charging without rebuilding the entire grid.
Presumably, the internal resistance of the batteries is very, very low. This means that the entire stored energy could be dumped in no time flat - a massive flash-bang - far faster than a tankful of petrol could be converted into heat. Accidents or fault conditions could be interesting...
|Thread: EMCO Compact 5|
Hi William, I guess it all depends on what you mean by a 'good' lathe. My view, as an owner of one, and several other lathes, is that it's well made, but is very limited. It has a limited range of speeds, the slowest making screwcutting a bit frightening, and making turning large diameter ferrous pieces difficult. Also, the saddle and cross-slide are not particularly well-designed. Having said that, used within its limits, it can be accurate, and a pleasure to use. A lot of users are well pleased with them. I think that if you learn to turn with one, you will gain skills that stand you in good stead for when you get a more grown-up lathe. Sharp tools required!
You probably know they are no longer made. However, www.emcomachinetools.co.uk can provide some equipment and spares. www.emcoshop.at have a larger range of spares. You might consider the auto-longitudinal feed attachment.
Good luck. Enjoy!
|Thread: Bore micrometer|
Well, turn up a go, no-go plug gauge. Multiple steps, if you like. But a bore comparator is so much nicer - but pricey... Make sure it has all the anvil extension pieces!
It's certainly possible to do better than 0.001" with telescopic gauges, but fiddly. The bore comp's self-centring facility is a great bonus. You only need to wiggle it about in one plane, to get a minimum reading.
|Thread: The Chocolate Fireguard as designed by Mercedes Benz|
...and another thing... See, now you've got me started...
We have a new Honda Jazz. It's great, and one of the cheapest new cars in NZ. The control electrickery seems to marry the CVT and its torque converter together pretty well. I was fearful that they would'fight' each other. Gentle journeys can be done at 4.7 l/100km. It has an electronic fuel gauge.
We were about 30km from home, with a soon-to-expire, generous 40c-off per litre fuel voucher to use in our home town, but not where we were. The fuel gauge showed near-empty, with the warning annunciator lit, and the display showed the calculated range to be 20km. OK, into the nearby pumps for a $10 splash. Program the pump for $10 delivery, pull the trigger, and enter daydream mode. Back in the car, driving away, and the fuel gauge shows empty, etc., and still only 20km range. Back to the pumps. Not sure whether the pump automagically delivered $10-worth of fuel, or just fired blanks. Attendant assured me all was OK. Put in another $10's-worth, just to be sure (listened for the filling noises this time). Drove off. Gauge and range calculation unchanged.
The tank should now be about 1/4 full, but the electronics didn't know. Slowly, ever so slowly, we started generating petrol, as the gauge climbed up - to a stable reading about 20 km from the pumps. The range calculation resolutely stayed at 20 km. The journey was about 30 km. The thing had no shame.
Probably a good job it wasn't a life-or-death situation...
Progress. A couple of days ago, Mozilla 'forgot' to renew a certificate, so all (security) add-ons for the Firefox browser were disabled. Gmail has recently thrown a wobbly. Pilots fight and lose against airliners' safety-enhancing systems. Auto-piloting cars crash, for no apparent reason. Algorithms of Byzantine complexity make decisions too quickly for errors to be identified, and no-one understands what the hell is going on. The stock market has a 'blip'. Machine 'intelligence' learns by implementing heuristics it has 'learned' by processes no-one understands or can identify. Therefore no-one can tell whether the AI is correct or not, except by results - when it's inconveniently late for an error to be detected. And some of the mistakes are extraordinary. The prof. of security engineering (how's that for a concept?) at Cambridge won't touch internet banking.
It was nerve-wracking enough sitting in the passenger seat when junior was learning to drive. Luckily, instructions to go slowly were heeded. But how would it feel to be a passenger in an auto-piloting vehicle, with super-human reflexes, seeing all around itself, and making decisions far more quickly than the hapless, half-asleep and de-skilled human 'supervisor' possibly could, and speeding along, perhaps at speeds beyond the ability of any human driver, particularly in a complex environment. And yet the human is presumably expected to be able to take control as soon as (s)he senses that the AI has stuffed up. How relaxing to be a passenger!
And then there's the worrying problem of the AI's 'moral code'. Who gets sacrificed in certain accident situations (eg the owner, in a head-on smash, or the queue of people waiting at the bus stop, if the car swerves to avoid the head-on)? Will you be able to pay more to have a 'protect the owner at all costs' rule programmed in?
Since most garages seem incapable of sorting out existing misbehaving control systems, we can look forward to chaos when our electric vehicles have a slightly intermittent contact somewhere, or a bug that rarely manifests itself...
Progress? It's too easy to build complexity into software. Features are added 'because we can', and it doesn't cost much. But 'because we can' is not a good justification for doing something.
Rant over - for the moment.
|Thread: Bore micrometer|
You asked: 'Would it be less fiddly (better) or more fiddly to use a high quality telescopic bore gauge (eg Mitutoyo) with the aim of measuring down to 0.001"?'
Well, have you ever tried? Telescopic gauges need a bit of practice and a fine feel to get consistent readings, and, of course, are just transfer devices - the micrometer does the reading, so multiple error mechanisms. Certainly more fiddly. A decent bore comparator should indicate 0.0001" and can be set, as suggested, against a micrometer, slip gauges, etc. It will also directly indicate out-of-roundness and taper. Also need a bit of practice and finesse, but easier than a telescopic gauge (at least in my hands).
If you want a bore micrometer (of the three-leg variety) get a mortgage. If the bore is large enough, however, an internal micrometer is fine, and about as fiddly as a telescopic gauge, but at least reads directly.
|Thread: Oil, lubricating the lathe|
The reason why slideway oil (ISO 68 grade, eg Febis 68) is specified is because it's designed to minimize the 'stick-slip' phenomenon that will most likely occur with other oils, making accurate, fine adjustment of feeds a problem, particularly when gibs are adjusted to very little clearance (ie correctly). It is also 'sticky', so is good on the leadscrew, where it won't drip off so readily.
'Hydraulic' oils (eg Nuto 32) have good lubricating and anti-corrosion properties and are fine for plain headstock bearings. I believe that the detergents added to motor oils, to keep muck in suspension, allow water to be absorbed into the oil, which is not exactly a good anti-corrosion measure.
A bit of MS2 grease or 'assembly paste' works well on feedscrews, although beware of the ability of grease to carry swarf, etc. where it's not wanted.
|Thread: Loctite minefield|
There's a wealth of really good information only a couple of clicks away, at the manufacturer's website...
Loctite change the numbers of their products from time to time, so what follows reflects my stock, not what the latest numbers may be. Hopefully, they haven't changed.
222, 'Super Screw Lock', is suitable where the fasterer that has to be undone has a long thread engagement. The amount of torque needed to break the bond will be related to the area of thread that is bonded, so avoid high-strength products for screws (in most applications).
243 is a medium strength preparation, stronger than 222, and is suitable for nuts, or where there is short thread engagement if screws are used.
These two will probably take care of almost all needs.
609 is a high-strength retaining compound, and if used on fixings, will be awkward to undo, without heat.
If you think the plethora of Loctite's retaining compounds is a nightmare, don't even think about their range of sealants, etc.!
Hope this helps.
It's pronounced 'Ooooooooh'!
|Thread: 6" EME rotary table|
Nice rotary table! I don't think you'll be disappointed at all.
Elliott were a bit more than badge engineers. See **LINK**
Clearly a complex business arrangement. From what I've handled, seen and read, their equipment was no-nonsense, reliable and good quality, although not in the same league as some of the premium European, or better British manufacturers. Their products were a mixture of British-manufactured (by the companies they owned) and some imported gear, e.g. the Unimat, which they imported for a time.
I'm very happy with my Progress 2GS pillar drill (made in Peterborough). Spares were available in the late '90s or early 2000s from Gate, who appear to have picked up some of the pieces when the inevitable British Disease caused Elliott's demise.
|Thread: "Screwing" a car round a corner!|
Understeer, oversteer, total loss of control - all these things were possible in a Hillman Imp on crossplies. Luckily, it was usually fairly safe, because break-away occurred at such low speeds.
Fast-forward a bit. Lotus Seven Big Valve Twin-cam, with LSD. Not sure what the steering wheel was for - you steered it with the throttle.
And somewhat later, a Subaru Impreza turbo. I tried to unstick it on most trips out (it became a challenge, you see...), but, by the time it was sliding, it was going so damned fast that it was dangerous. But perhaps I had grown up.
|Thread: A visit to Manchester Sci and Eng Museum|
I went into the museum once, in the '80s. There was a cut-away Rolls-Royce Merlin. I stood before it in awe. So huge and complex, obviously with an enormous amount of hand finishing and fitting. How many man- (and woman-) hours went into making such magnificent things? Of course, I had seen cut-away drawings before, and had made the plastic kits of aeroplanes with these engines, but seeing the thing in the flesh, indeed inside the thing, was altogether different. Imagine the price, if one were manufactured today! And all for an average in-service life of ten hours, before the fighter pilot behind it was shot out of the sky. And they were made in their thousands. The war effort. So much effort; so much was given - by so many. The tears rolled down my face. I had to leave. I never went back.
|Thread: Moving to Australia - Moving Workshop Machines|
Good luck with your move. Don't sell anything - in fact fill all possible container space with gear bought at UK prices because it'll be more expensive at your destination, or will be oriental stuff of questionable quality. Research the market and make a bob or two. I wish I had...
We moved from UK to NZ in 2005. The workshop equipment filled a 20ft container. Everything possible was crated, the bases being 1in ply on spacers of sufficient height to allow a pallet truck underneath. OSB board walls. Machinery was bolted in and smaller items packed tightly into compartments. All bare metal was sprayed with anti-rust stuff. It was a lot of work. Ensure nothing can move or rub against anything else. Weeks of gentle movement at sea, and brutal treatment at the docks can do amazing things - there is no shortage of horror stories.
Everything was fully insured. Beware that some policies are void if the shipper does not unpack the lot. However, I was more worried by the ship going down, or the container being lost. Since the move, I have seen photos of stacks of containers falling off ships, being dropped by cranes, etc. Had I seen these before the move, I think I may have chickened out... Luckily, everything survived.
I was warned to beware the idiot bureaucrats whose sole purpose is to get in the way of common sense. Bio-security is taken seriously in NZ. The presence of a foreign fruit fly in Auckland recently made front-page news and caused panic, just like it did last time. I tried to research what hoops I was expected to jump through. Apparently, any timber used for packing, crating, etc. had to be 'treated' and 'certified'. What treatment and certification? By whom? No information. Then I found a document stating 'if treated timber is used...' (my emphasis). So did timber have to be treated? No-one could tell me. Containers were often fumigated with methyl bromide (IIRC), which sounded like it would do precision machinery a power of no good. I eventually found the 'phone number of an NZ inspector and asked for guidance. He said, in effect, that if nothing crawled out of the container when it was opened, it would be OK. Probably. Ah, the famous Kiwi 'She'll be right' approach in action. As I said, bio-security is taken seriously here.
When the other container of household posessions had to be cleared through customs, etc, I had to fill out a questionnaire including questions about whether anything was of plant or animal origin (complete with DIRE WARNINGS that it was prohibited!). "Er, what about wooden furniture, books and papers, cotton and woollen fabrics, leather shoes, etc." Look of puzzlement from bureaucrat. "Oh no, those don't count." That was one of many WTF moments. I lost 1 1/2 stone in the month of the move. Make sure you have an ample supply of stress pills.
|Thread: Page errors in 4610|
Hey, you guys are lucky! All the pages of my copy of 4610 are missing. Same with 4609. That's one of the joys of living on the far side of the world - subscription copies take an age to arrive...
And, of course, the delay is made worse by time getting here earlier...
|Thread: Windows Update (Again)|
Well folks, if you want to pay through the nose to be an enslaved drone in the Microsoft or Apple hive, go ahead, but if you want to be in control of your computer, enjoy reliability and better security, go for Linux or BSD and spend the money you'll save on beer.
|Thread: myford super 7 problem|
A bent leadscrew can do this (assuming the cut was with self-feed acting). Mount a sensitive clock on the saddle, bearing on a vertical or horizontal guiding face of the bed, turn the leadscrew, and watch for indication of horizontal or vertical movement of the saddle, in step with the leadscrew turning. Not an unknown Myford phenomenon.
|Thread: Meek screwcutting dog-clutch|
Graham; I've pm'd you.
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