Member postings for Kiwi Bloke

You're not the only one.

Feel better now? Of course not, because, deep down, you know it will only get worse. Welcome to the club...

It's with some trepidation that I offer an opinion that differs from Graham Meek's. I believe that it is possible, preferable, even, to adjust the 'slider' and gib clearances with the head and column in situ.

The crucial thing is to ensure that the head can fall under its own weight. The feedscrew should never be trying to push the head downwards. The adjustments should be done in the order Graham specifies, with the feedscrew removed. The head isn't that heavy, and can be slid up and down the column without too much effort, and still with good feel, the process being helped by being able to stand behind the machine, at a suitable height (on a stool, for example). Ensure there's a block of wood, etc. between the table and the head, in case you lose grip!

Anxiety about x-axis inaccuracy can be investigated by 'clocking' possible rotation around the column, and attending to the gib adjustment.

It's not the most rigid design, so I believe that the adjustments need to be as tight as possible, to the point where the head is only just free to move under gravity's influence. It's for that reason, and for convenience, that I suggest doing this with the head and column in situ. Lock the head to the column whenever possible when cutting. Some folk have improved the clamping arrangement. I just use my impressive strength...

Edited By Kiwi Bloke on 30/06/2022 11:01:35

Terrific posts! Keep 'em coming!

Is it noteworthy that many of the hybrids place fuel tank and battery adjacent to each other? Risk multiplication?

Original nut is, I believe, a zinc alloy, Mazak/Zamak, etc. 7075 has been mentioned as a nut material. Honest question: is this a wise choice? In the back of my mind, a small voice is saying that the stuff is abrasive, and wears cutting tools quickly. Quite likely mistaken, though.

I really don't know what to make of these rather underhand advertising videos. Perhaps what's not said is more significant than what is said.

I wonder what will become of the shelf-loads of beds, countershaft brackets, and all the other very obviously used major components? When 'reconditioned' is mentioned, I expect the major components of a machine to be kept together: will these be? Perhaps they will be fettled and made to look like new. They will be a little under-size, according to original specifications. Does that matter? Well-aged castings are no bad thing, and if machined well should be just fine - possibly better than original production. Will these components form the basis of a 'newly manufactured' - and priced - machine?

The leadscrew shown in one of the videos looked cut, not rolled. There is/was a leadscrew manufacturer in Halifax, that produced leadscrews by 'thread whirling'. Is the work-hardened surface of a rolled thread significantly better? The bed and slideway finishes seem to be milled, not ground or scraped. If accurate, how much does this matter?

All things change. Myford lathes are dinosaurs. I suppose it's lucky someone has done a 'Jurassic Park' for the Myford name and products. The new factory is rather different from the Beeston works, where one could also see the MG12 cylindrical grinders being made. Hand scraping was a crucial part of manufacture of those, and there was a most sophisticated grinding machine producing the spindles. The S7 tapered bronze spindle bearing was hand scraped too.

I suppose it all comes down to quality control. It must be easier to monitor subbed-out QC if it's just down the road, as opposed to somewhere in China. I hope to see the new factory's metrology lab in a video...

When I went round the Beeston factory and saw the re-badged Taiwanese milling machines, having just seen a beautiful 280 lathe, apparently neglected in a store-room, I knew the end must be near.

Edited By Kiwi Bloke on 29/06/2022 11:29:37

What's this got to do with model engineering? No, I'm not a miserable old killjoy. It's one of the joys of this forum that wildly off-topic posts pop up quite often. They're usually fascinating, and the breadth of knowledge shown by contributors is amazing and humbling. Keep it up!

A S7 in good condition should do better than that! Ignore comments that it doesn't matter. The thing is built to perform better, and it should. That's what matters.

It's not clear whether this runout appears when the spindle is effectively in isolation, or only when it is being acted upon by the machine's drive train. If you haven't already done so, I suggest that the spindle drive belt is slackened, and the spindle bearing set-up procedure is gone through. Then, begin the hunt starting with the isolated spindle, then add components of the drive train, one by one, measure, rinse and repeat...

Also, I'm not clear whether you're measuring runout, where there's no 'slop', or free movement that appears on alternate rotations. The rear bearing ball set will indeed orbit at half spindle speed.

You have measured runout when back-gear is engaged. Is there a little backlash in the back-gear train? If it's too tight, any eccentricity of a gear may cause radial forces on the spindle. Turn by hand and check.

From 20-year-old memories, and thus suspect, I think that the metal hub, to which the gear is dowelled and fixed with screws, has its major diameter as the radial locating face for the gear. The hub fits quite tightly into the recess formed by the remnant of the 'upstand' on the face of the gear. The gear face inside and outside this 'upstand' have been faced down, thinning the clamping face and also the teeth (hope that makes sense). What looks like a retaining ring is the result of the 'upstand' having de-laminated.

The tooth width is small enough, I'm sure, to allow the gear to be cut without proper helical form, so the job isn't too bad...

It's an helical spur gear, just to make life more complicated. However, as Graham Meek has demonstrated with his FB-2 gears, the proper helical form can sometimes be ignored, with the gear being cut with the cutter fed at an appropriate angle to the gear's axis of rotation. Of course, those with universal dividing heads and a universal mill needn't worry. It could also be 3-D printed?  [ Long way of saying that a DIY replacement isn't impossible...]

Edited By Kiwi Bloke on 20/06/2022 22:20:08

Derrick, Gate Machinery took over the Progress name, and offered support for the products. About 20 years ago, a very helpful chap at Gate (who was a friend of a friend, and will have retired years ago) provided me with a new Tufnol gear for my 2GS (same as yours, but floor-standing). The original gears were a dark grey plastic material, not fabric-reinforced, and tended to swell in the oil. Perhaps there are still a few, lurking in a dark corner, somewhere, although the web site makes no mention of machines of this age. Sorry I can't be more helpful.

**LINK**

Good luck!

Relatively expensive insurance has some benefits (but not to you careful and blameless drivers). Here in primitive NZ, insurance is not compulsory, so young lads career around in high-performance cars, which may - or may not - have scraped through the MOT-equivalent examination, which is feeble in comparison to the MOT. Darwinism removes a few, but the remainder are a danger to all, and a noisy annoyance. Driving standards here are dire.

The device pictured above is an oriental knock-off of the American Blake Co-ax indicator, which was priced at $267 in 2006. I daren't look up its current price! Blake claim centring to within two 'tenths' (imperial), but I don't trust mine to better than just under a thou. Compared to a lever-type indicator on a fixture in the spindle, it's a rather more complex mechanism, necessitated by the nice feature of having the dial assembly not rotating with the spindle. The complexity must be paid for in accuracy and repeatability, and wear. A simple 'indicator on a stick' can be as sensitive as the indicator (one tenth indicators are common enough, if expensive), and there's nothing twixt workpiece and indicator to add error. However, the Blake is often quicker and more convenient to use - provided there's enough headroom. An indicator on a stick is more versatile. Of course, this assumes the 'stick' is satisfactory. Look through Stefan Gotteswinter's videos to see his in action in many and varied applications.

Edited By Kiwi Bloke on 15/06/2022 11:45:44

Correction to my previous post. Immersion is addressed. It's also given as a way of discharging the battery!

Here's a link to one of the manuals I mentioned. For dead-pan humour, it would be hard to beat. Just put yourself in the driver's seat...

**LINK**

No operational problems here. However, a couple of my posts got 'lost'. Such a pity: one was my best post ever, erudite, educational and entertaining, full of wit, wisdom and whimsy; quite unlike my usual sarcastic and curmudgeonly drivel. Now lost to the world - I can't possibly repeat it. Oh well, that's progress...

I'm another fan of link belts - at least for the primary belt (motor to countershaft). Its possibly reduced torque transmission capability isn't a problem here. The increased damping of the link belt dramatically smoothed the drive. The original belt (in fine condition) thrummed annoyingly, with the vibration being easily felt by a hand on the headstock. Changing belt tension (within reasonable limits) didn't stop it, but the link belt did. Beware low-quality link-belts, of unknown provenance, however!

Well, technology may be moving towards less dangerous battery chemistry, but there have been many documented cases of apparently spontaneous ignition of current tech. batteries, perhaps the most ironic being that which caused a ship, loaded with expensive vehicles, to sink recently. All that water with which to extinguish a fire, but not that sort of fire... And now, manufacturers advise that these vehicles are not garaged.

If you want to scare yourself - or have a laugh, if you're twisted, like me - search for the instruction manual for first responders, issued by Hyundai. Tesla's manuals are rather coy, and leave a lot unsaid. With perhaps 400V DC around the vehicle, and a crashed vehicle likely still to be 'active' (ie will drive off or move if accelerator accidently depressed), with no indication to those unfamiliar with such vehicles, the dangers should be obvious. So the manuals explain how to find relevant fuses, how to cut (in two places) power cables, how to wait until capacitors have discharged, and so on and so on. I don't think that immersion in water is addressed.

Does anyone know the depth of water that can be driven through by an EV? With floor-level batteries, even fording a small stream could be a worry.

Let's hope that when there's a crash, in the back of beyond, the Good Samaritan, anxious to extract the incapacitated occupant(s) from the burning vehicle (without wishing to watch their immolation or exsanguination, whilst the emergency services arrive) has a library of type-specific manuals to hand, and the stipulated PPE, and the time to read them and don them, before attempting to provide aid.

Thorium decays by emitting alpha particles. These cause intense ionization, which will damage cellular DNA, but do not penetrate skin to a significant depth, unlike gamma rays, so just handling the electrodes is not risky. Inhalation of the dust liberated by grinding is different and is risky, because the lungs' lining isn't protected by relatively thick skin. It is regarded as a known problem, so precautions shpuld now be taken, but it can't be a high-probability risk, given the large number of people exposed to the dust, and the few cases of consequent lung cancer. These days, I think there is little need to use thoriated tungstens.

Hi Gray. Inspired and inspiring! When I saw your post announcing your intention to down-size, and to concentrate on the Compact 5, I was tempted to ask facetiously whether we would be seeing a full screw-cutting gearbox, with leadscrew single dog clutch for it. I didn't because downsizing decisions are too often the result of adverse circumstances, and I certainly didn't wish to be insensitive. However, it seems you're well on the way to elevating this machine from near-toy level to Serious Machine status, so perhaps the question is now part-answered... I'm sure we're all going to be fascinated by developments.

It seems to me that the Compact 5 has serious design defects, predisposing it to problems resulting from wear, that warrant attention, perhaps before embarking on complicated enhancements - well, that's true of my machine, at least. Have you any interest in re-engineering the cross-slide feed 'nut', which, on earlier machines, is cut directly into the saddle, and is neither adjustable nor replaceable? Also, will we see leadscrew half-nuts and saddle handwheel feed, as (IIRC) hinted at in a previous post?

Edited By Kiwi Bloke on 16/05/2022 06:57:43

It's about time someone mentioned the apocryphal newspaper headline for the report of an escapee from the local asylum who sexually assaulted a woman in a laundry, then ran away.

'Nut screws washer and bolts'.