Member postings for Jelly

So I had a response to this, but it goes so far off topic that I've forked it into another thread.

(The quoting function does not seem to like pasting between threads however.)

Forked from the "Worth It" thread.

Posted by Robert Atkinson 2 on 28/04/2023 15:57:42:

Jelly said:

"... For me there's a real gap in the market for Myford to undertake some meaningful product development to offer a lathe the size and quality of the Super-7, but refreshed with the features of the 254, and geared to offer speeds appropriate to modern tooling on the size of parts you'd expect to use a 3.5" centre height lathe for; that would actually differentiate them from the competition from abroad. "

I could not agree more. They have the name to charge a premium price. It would be so good if they re-engineered it keeping the style but integrating (not scabbing adding on) a 3 phase motor and VFD, deleting the clutch (not needed with VFD), camloc chuck (with adaptor for the old threaded kit), primatic bed etc. Options could be DRO (again properly engineered into the design), ELS (instead of gearbox) and powered cross-slide (possibly leading to CNC).
I recon they would make money on a bit of investment and possibly set the standard for the next generation of small lathes.

Robert.

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It's funny you should say that...

I currently have a stack of lathe beds in the workshop which were originally destined to become the ways for my Horizontal Boring Mill project... Having now filled both the space and niche it would have occupied with a very large turret mill, I've been mulling over what to do with them.

Attempting to develop something that fills the niche described would be an interesting project on a par with the HBM, although I doubt I'd be in a position to commercialise it past the stock of beds I have.

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I broadly agree with your list of requirements, but if I put a manufacturing hat on it potentially makes more sense for some of the options to be default features.

I suspect that for serial or volume production offering an ELS would actually be far cheaper than a proper screw-cutting gearbox these days, similarly electronically powered cross-feed is going to be cheaper than the machining time for feed-shafts and gearbox.

That would then allow the DRO to operate from the encoders on the servos (an idea I'm not mad about, but would save a lot of cost, separate linear encoders would be an easy add-on though) and enable an almost "plug-and-play" conversion to CNC with a dedicated kit of ball-screws and controller.

It also occurs to me that in a CNC scenario the quintessential Myford accessory, the vertical slide, would actually take on a whole new dimension in that sort of scenario, equipped with a servo-drive one need only add a 40mm standard powered spindle mount, it turns the lathe into a tiny Mill-Turn​.

The requirement I have in my head as most challenging would be to engineer a headstock which could truly provide a range of speeds allowing hobbyists to take full advantage of modern tooling, which would probably require a max speed of 10,000-15,000 rpm (assuming it's optimised for a minimum workpiece in the region of 1/4" to 10mm, and non-ferrous materials).

Assuming that for drilling, out-of-balance turning and the like, a more normal range of speeds would also be desired, that probably requires either a specially specified Inverter-Duty Motor suitable for very high frequencies, or a permanently tensioned flat-belt system, the former being perfectly reasonable for volume production, but rather pricy for the first prototypes, and the latter adding the kind of complexity more associated with Schaublin, Monarch, Holbrook, and Hardinge than with a Myford.

15,000 RPM also requires a lot more of the bearings, although if you're completely eliminating belt-changes there's more leaway to provide for that, it also pretty much demands a collet-chuck as a default option, and possibly an interlock to prevent using a 3/4 Jaw at full speed (it's scary enough swinging a 10" steel-body 4-jaw at 3,200 rpm, let alone a 6" one at 15,000!).

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Any opinions on the future development trajectory of the small lathe welcome.

I would be inclined to suggest that you start out by getting one of the inexpensive diamond "sharpening stone" sets (available widely on the internet for around €10-€30) which you can use to work the edges by hand (either with the "stone" secured on the bench and the tool hand-held like a wood chisel, or the tool in a vice and the "stone" handheld like a slipstone or scythe-stone).

That will both allow you to dip your toe in the water to see if the results are good enough to justify investing in a proper wheel, and because most come as a set of 3-4 grits, give you an opportunity to compare to see what works best to help you pick a wheel that suits your uses best.

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Carbide doesn't necessarily benefit all that much from an extremely sharp edge, for exactly the reasons Ady1 describes, but it can benefit a lot from a really smooth surface finish on the surfaces that intersect to create the edge, which helps to reduce the tool-pressure more than you'd think.

On one or two occasions I have used diamond laps/hones/stones of a comparatively fine grit to polish up the points behind the cutting edge on a tool, then taken one or two strokes with the very lightest pressure to just slightly dull the knife-sharp edge created, which is something my grandfather taught me.to do, and results in a ground tool which very closely mirrors the design approach used for modern insertable tooling.

I have a real soft-spot for Super-7's, its the lathe I first got to use on a regular basis, I made a variety of really interesting and challenging parts with it, and they are generally a really well made machine which is a joy to use.

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But, unless both space and robustness were both at a massive premium, I wouldn't buy one new or used.

Even then a used Boxford, Smart & Brown, or South Bend would be more attractive, and you'd need to be going into the purchase knowing you were planning to really push the limits of the machine to warrant going for one of those options over a modern mini lathe.

The price premium is impossible to justify when you consider that the functionality on offer is significantly behind other manufacturers, and they're not particularly well equipped to make use of all the modern advances in tooling (although few mini lathes are either in fairness to Myford).

When I was still using the Myford regularly I had bouts running various "full-size" lathes and it was obvious that the core functionality all those lathes shared like a screw-cutting gearbox, lever controlled gears (or variable speed) and sliding/surfacing feeds all made things just so much nicer.

They may not have been as ergonomic or nicely finished as the Myford (although the Lang and DSG put them to shame), but I was rewarded with the joy of getting parts made quickly without fuss or stress, rather than the "joy" of how smoothly the compound slide ball-handle moved perfectly in my hand a zillion times as I painstakingly bored out a taper in stainless steel 0.005" at a time.

Given the choice between a Warco with power-feed and a gearbox, or a Myford without I would go for the Warco every single time.

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IMO, the best lathe purchasing strategy is to set a budget, establish what size of parts you'll be working on and then go search out the most heavily built and feature rich one that has the speed range you will want for your size of parts, and is practical for you to have in the workshop, that will fit your budget.

If you have a concrete floor and good access that's likely to be a small "full-size" lathe either in good used condition or new from the far-east, if you're more constrained for space or in a smaller workshop it's most likely to be a new mini-lathe or if you're lucky enough to run across one a nice condition Boxford or South Bend.

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For me there's a real gap in the market for Myford to undertake some meaningful product development to offer a lathe the size and quality of the Super-7, but refreshed with the features of the 254, and geared to offer speeds appropriate to modern tooling on the size of parts you'd expect to use a 3.5" centre height lathe for; that would actually differentiate them from the competition from abroad.

You also have Terex-Pegson in Coalville and Red Rhino in Grantham manufacturing plant for mining, quarrying and demolition, and Hitachi's european manufacturing centre between Durham and Sunderland.

It's a myth that the UK doesn't make things anymore, we just make very expensive niche stuff and export it, then export most of the profits too!

You can use either a lofted extrusion or a profile swept along a path, with the twist sub-option enabled to achieve the same result in Solid Edge.

In either case, you would put the twist in from the start, not make the part then twist it.

No, but that's pretty normal for a DRO kit.

You can only have that behaviour with absolute position scales (like Mitutoyo Series 539 AT[###]), and a compatible Readout/Counter unit...

Which are really quite pricey compared to the incremental scales used by every clone of the very widespread Sino DRO (of which Vevor is one) and most of the standard options from other manufacturers (including Newall, Easson, Acurite, m-dro and others).

Finally completed testing the 3 phase wiring in my workshop after moving everything around.

I now have the Phase Converter going into an Inlet on the side of the distribution board, which goes to a 30ma RCD, then to individual MCB's for each radial circuit for a socket.

I could regret it if I find that I want to use anything with inverter drives in the future, but otherwise was the cheapest way to achieve compliance with the 18th edition and is substantially safer than having trailing leads on the floor to the RPC, it also future proofs things if I want to use a genset rather than the converter down the road.

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Followed up by beginning to strip down the big welder for a proper overhaul, before it was time to head out.

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Then rounded the day off by attending a Panel Discussion organised by the Joint Professional Engineering Institutions Committee: Does Decarbonisation mean Deindustrialisation for the Sheffield City Region", which far from being doom and gloom actually highlighted:

• the significant number of good jobs and apprenticeships being created as a result of manufacturing demand created by new green technologies,
• the huge investments being made by all three of the remaining steel mills in the city in low/zero carbon steelmaking technology,
• a joint project with EDF to build a 300MW green hydrogen plant to supply high volumes of gas for industrial use to all three steelmakers and several large forging companies which has now completed a feasibility study and initial trials,
• a project to establish a consortium of several companies to form an integrated manufacturing supply chain for small modular reactors feeding an assembly plant utilising the Davy-Markham manufacturing site which is currently stood idle, they have the financing to build 3 GE-Hitachi BWRX-300, but are waiting for the customer to get government approval for the proposed location the reactors would be going to.

All very cool stuff.

Induction motors are so widely available that your best option is to determine what frame size and mounting you need, then google to find the cheapest supplier of motors in that size and an appropriate power rating.

Unhelpfully your data-plate doesn't give the frame size and style, but you can easily determine the size by measurement and comparison with a chart (unhelpfully there are two standards IEC and NEMA) and the mount type by inspection (Downloadable reference here).

The "Type CO² 71 34" marking might be trying to say: "A face mounted motor (NEMA C-Mount), frame size 71 (an IEC size), with a 34mm long shaft", but if so is mixing it's standards, and should be marked IEC71 B14 (which would have a 14mm diameter, 30mm long shaft as standard).

Edited By Jelly on 24/04/2023 19:46:01

Looking at the chips it looks like one of the ferritic or martensitic stainless steels which fall into machinability class P, the neutral rake on the tool will definitely be helping with getting it to short-chip too which will do no harm.

I have found that kind of stainless to be similar to medium carbon steels when turning but perhaps a bit less forgiving if you don't maintain an even feed, crucially it doesn't do the built up edge behaviour that you get with the Austensic and Duplex grades which really stresses the cutting edge.

Edited By Jelly on 24/04/2023 16:12:56

That has turned out very nice indeed!

I take it the polishing process also softened the edges of the pattern enough to make it comfortable in the hand without removing the nice "crisp arrises" which give it visual appeal.

So I woke up early this morning and decided to be productive, by 7 am I had cleared two workbenches of clutter, swept up, and figured out how to adjust the split nut on the new mill to take up backlash (it's down to 4 thou from 9.5, I can get zero backlash but it makes it unpleasantly stiff, may have to replace/remake the nuts/leadscrew if I want it to be any better)...

At which point I decided to do another of those I'd been putting off for ages, and move the 24"×24" cast iron surface plate up onto the welding bench (it was declared uneconomic to rescrape by several surface plate companies, but it's still more than good enough for fab work)... By the time I was fully committed, it became apparent that it would be a very difficult lift to say the least, (given that now I remember I did weigh it and it's 142kg), I think my shoulders will forgive me eventually but it's not going to be today.

Sorted out some 14mm×22mm M12 T-Nuts, allowing me to mount the vice on the new mill and cut the first chips, very happy with that, performance is if anything better than expected.

However, in the process I did manage to snap the handle which tensions the belt in the head, which appeared to have been cracking from a stress riser in the threads for years and chose today to let go, less happy about that.

However, I was able to come up with a novel method of broken bolt removal, if you drill two 3mm holes in a broken M12 stud, you can then use an impact driver to put two self tapping screws in the holes and wind it out with a mole-grip.

The handle had enough length to just cut an additional section of threads with a die and reinsert it, so it's a happy ending... Although I might re-make it at some point as you do feel the loss of leverage a bit when tensioning the belts.

It did occur to me that if he'd taken that tone with my favourite second-hand tooling supplier, he'd have been subjected to a tongue lashing in a mixture of Urdu and "De-Dar" and/or escorted to the door by the proprietor's nephew.

However, applying common-sense, I strongly suspect Paul was polite (if audibly frustrated) when speaking to the supplier and is now here to vent his frustration in a more appropriate way because it's really got his goat.

You're not wrong in some regards, but at the same time the information is all out there.

The issue is that without some initial formational knowledge or a mentor to bounce things off its very difficult to know what you need to research.

To steal the Donald Rumsfeld quote:

"There are known knowns. These are things we know that we know.

There are known unknowns. That is to say, there are things that we know we don't know.

But there are also unknown unknowns. There are things we don't know we don't know."

You will continue to run up against "unknown unknowns" the whole time you're engaged in engineering, but it will become less challenging as time goes on to deal with them because you'll have a deeper pool of existing knowledge and experience to work with, and more experience "solutioning" an unexpected problem as it arises.

It's also far easier if you're discussing it with others to hash out the best approach, because whilst a bit trite sounding "Engineering is a Team Sport" is a very accurate little aphorism.

No one person can possibly have a complete understanding of the subject because it's an unimaginably vast body of knowledge, so co-operation and exchange of ideas is key.

From a practical point of view, what's stopping you from mounting the backplate on the spindle nose and using the lathe to turn the required recess/spigot to fit your chuck?

It will result in the most accurate fit you're going to get in terms of run out, and is not particularly complex turning.

Sure, as a novice on a lathe that's new to you, it may take a couple of attempts to get it right, but that's fine, backplates are thick and the locating features on them need only be quite shallow, so if it goes wrong and ends up loose the first time, you can face off the mistake and try again without too much drama.

Edited By Jelly on 21/04/2023 14:30:43

I think you have confirmed my suspicions there.

It works and is far more convenient than dials (especially with the dials being in inches but all my tooling and edge finders being metric) so no rush to replace it, but I think replacement is probably warranted.

Still seems a bit of a shame to scrap it, I wonder if there's any vintage electronics bods who would find it an interesting addition to their collection.

I guess the question now is if sine wave to TTL convertors are cheaper than new 500mm and 1600mm 2μm scales.

Edited By Jelly on 20/04/2023 21:42:52

Has anyone come across or used one of these before.

I am struggling a bit with working out the functionality beyond the basic readout function (which itself has some foibles, like not being able to change the value of the existing position information when you switch between inch and mm), and preset system.

To their credit Heidenhain does have the manual for this 33+ year old DRO on their website, but the description of how to use the memofix system is pretty obtuse to say the least.

Given that it's a product of West Germany it is throughly before my time, but it occurs to me that quite a few forumites may well have experience from using these dating back to when they were still state of the art.

There's a distinct temptation to just swap it for a modern DRO, but it seems a shame whilst it still works.

With it being Heidenhain (and old) it uses sine-wave scales, it would mean new low-profile scales or sine-wave to TTL conversion boxes, neither of which would be be cheap (or buying a compatible counter unit from Newall, Mititoyo or Heidenhain for more than I paid for the mill itself!).

If I find it workable I will most likely just get a cheap single axis Sino DRO to add z-axis, (possibly using a summing interface and scales on both knee and quill).

Edited By Jelly on 20/04/2023 19:14:18

The feed pressure required is going to be really very substantial, and I would expect it to kick back viciously if you let the pressure up for a second, with a metal workpiece that's likely to be much more dangerous than a woodworking table saw.

If you go this route I would strongly advise you have a chain or hydraulic feed which moves a very rigid work clamp, although I would still consider it a lot riskier than an equivalent bandsaw.

That's the reason why (excepting some truly gargantuan slab-saws in steel mills) every cold-saw with a rotating blade moves the saw head through thecwork in a very rigidly fixed path, and bandsaws are the defacto standard for metal cutting if the workpiece is the moving element.

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You can buy bandsaw "Bandwheels" as spares for an existing design, or purchase the tyres for a given dimension and fit them to wooden or fabricated wheels.

If I was fabricating one I would get a disk of steel cut (or cut it on the plasma cutter) and use a ring-roller to make the OD out of steel strip (doesn't need to be hugely thick, (1mm would do if it's not too wide) you could probably tack weld and hammer form it round the disk too.

The bigger the wheels the greater the cutting capacity you can have, and the wider the blade you can tension (which improves straight line accuracy), as the minimum wheel size increases proportional to how wide and thick the blade is.

I agree with Clive, it's definitely a workshop made machine.

It looks like it's been built using some components from a Myford "Euro-Ten", which might be how the Myford name got attached to it, but it's easily ¾ home built parts.

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If it's a reasonable price and will get you going now I wouldn't turn it down just because it's home built, but don't pay top dollar top euro for it.

It looks to have an eccentric (in both sense of the words) mechanism to provide screw cutting feeds, which you would likely need to work out for yourself as I've never seen anything like it; or replace it with a banjo for change gears.

Thanks!

I'll post up how I got on in "What did you do today? 2025" I guess (though I am hoping it will be a mite quicker than that).

Had fun completing a question about my knowledge of other engineering disciplines, topping off my relevant experience with a list of additional qualifications from "UKCA Machinery Safety Compliance Assessment" to "BS 4872 and BS EN 9606 coded welder"...

I hesitate to think what the assessor will make of a "professional engineer" having vocational qualifications, hopefully it's someone from an Ops background who will get the value of having experience on the tools rather than a Designer or Academic who has lofty ideals of what engineers should be.