Small Lathe T(r)ek – The Next Generation.

[mgnbukParticipant @mgnbuk]

I don't think it is fair to compare Cowells to Myford or hobby lahes generally.

The price comparison was to highlight the cost of producing a manual lathe in the UK, Robert, not a reflection on the build quality or capabilities of the Cowells machine.Their current price list shows a 90ME lathe costs £4128 inc Vat, which isn't to far off the costs of a new basic S7 from Myfords. What ever way you look at it, that is a lot of money for a small lathe, however capable it may be, yet I doubt that Cowells are getting rich selling tham at that price. It would be interesting to find out how many new machines current Myfords & Cowells produce per year – I doubt that the market for either is large.

As you say, providing adequate guarding is a minefield. I doubt that a safety line in front of a lathe would be adequate – not going to absorb the energy of an ejected workpiece or broken tool & safely contain the ejected object.

Nigel B.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Simon Collier on 30/04/2023 03:28:13:

All mechanical lathes will still be functional in 50 years assuming reasonable storage. Indeed two of my lathes are more than 50 years old. The circuit boards on my 6” lathe’s DRO, plus both main and control boards on my SX3 mill drill, all have failed, with replacements very expensive. Just now the digital Z axis readout on the SX3 has failed. A not cheap digital calliper failed. So you can see why I would not go near an all electronic lathe.

A faulty analysis I fear!

How long lathes last in storage in neither here nor there. It's how long they last in action that matters, and that's measured in hours, not years, let alone decades. Bearings, slide-ways, gears, and worms all wear out.

Hobby lathes have long lives because they don't cut much metal by machine tool standards – their running hours are low and the average work load is light. Hobby lathes are damaged by clumsy operators and poor maintenance rather than persistent hard work.

When electronics are protected from the environment and operated with specification they are highly reliable. All my cars have gone for scrap with their electronics in full working order. The problem has always been high-cost mechanical issues, tending to occur together after about 12 years or 100,000 miles. The cause was me using them on the road rather than storing them in them in a garage!

It is true that electronics are sensitive to abuse – damp does them no good at all! And cheap electronics have low headroom compared with industrial equivalents. I keep this in mind and don't push my machines too hard, allowing the motors and electronics time to cool off. Short sessions of moderate cuts, avoiding merciless deep hacking.

Dave

[Robert Atkinson 2Participant @robertatkinson2]

Posted by mgnbuk on 30/04/2023 11:50:18:

I don't think it is fair to compare Cowells to Myford or hobby lahes generally.

The price comparison was to highlight the cost of producing a manual lathe in the UK, Robert, not a reflection on the build quality or capabilities of the Cowells machine.Their current price list shows a 90ME lathe costs £4128 inc Vat, which isn't to far off the costs of a new basic S7 from Myfords. What ever way you look at it, that is a lot of money for a small lathe, however capable it may be, yet I doubt that Cowells are getting rich selling tham at that price. It would be interesting to find out how many new machines current Myfords & Cowells produce per year – I doubt that the market for either is large.

As you say, providing adequate guarding is a minefield. I doubt that a safety line in front of a lathe would be adequate – not going to absorb the energy of an ejected workpiece or broken tool & safely contain the ejected object.

Nigel B.

Ejected tool or workpiece is not CNC machine specific. Are you saying all lathes should be fully enclosed?
I accept that a crash is more likely with a CNC machine but it can happen with any. There is also plenty of video evedence that the enclosures on modern industrial CNC machines will not contain an ejected tool or workpiece

A safety line allows the operator to stop rgardless of their position. It can also stop the machine if the operator is pulled in. Most modern safety standards accept that the cost of reducing risk below a certian level is not reasonable.

Robert

[mgnbukParticipant @mgnbuk]

Ejected tool or workpiece is not CNC machine specific. Are you saying all lathes should be fully enclosed?

Perhaps re-read the specific example I quoted in my original post WRT issues that would require addressing to put a UK manufactured small ELS or CNC equpped lathe on the market.

When I was involved in such things, the company sub-contracted guard manufacture to guarding specialists for the design of guards – mainly on larger vertical borers. Containmnet of ejected parts was a consideration – it didn't matter if the guard was not fit to use after such a containment. Cincinatti quoted the design criteria for the containment capabilities of their guards in the manuals for the Sabre range of VMCs dating form the mid-80s.

This discussion is largely irrelevant to the original thrust of my initial post, which was intended as a "reality check" fo those suggesting that "all" current Myford need to do to enjoy widespread sales amongst UK hobbyists is to re-design the S7 to use a VFD and ELS / basic CNC to be able to sell a "better" UK made machine cheaper than the current basic S7. It isn't going to happen !

Nigel B.

[JasonBModerator @jasonb]

As this "ideal" hobby lathe won't be getting used in a work enviroment I expect many purchasers will disable and safety features, just look at how many do away with the chuck guard on a lathe or milling machine now. I don't see the current Wabeco, Sherline, Sieg Tormach etc CNC machines currently on sale having anything special in the way of guards so why would this lathe need them?

I would have said 95% of Cowells sales are to hobby users not professionals, more likely to find an old Myford in a workshop than a cowells

As for life of an imported lathe then compared to a £13,000 Myford I may as well bin my Warco and just get another one if it goes wrong I'd still be well in pocket, don't think what comes off the Myford would be 10 times better than what I can do on the Warco that cost 1/10th the price.

Edited By JasonB on 30/04/2023 13:21:18

[JellyParticipant @jelly]

Posted by JasonB on 30/04/2023 13:18:12:

As this "ideal" hobby lathe won't be getting used in a work enviroment I expect many purchasers will disable and safety features, just look at how many do away with the chuck guard on a lathe or milling machine now. I don't see the current Wabeco, Sherline, Sieg Tormach etc CNC machines currently on sale having anything special in the way of guards so why would this lathe need them?

I doesn't really matter where you think it's going to be used, the legislation doesn't differentiate, if you place a machine or machine element onto the market (by offering for sale, using commercially or in some circumstances giving away), and it was first placed onto the market after 29th December 2009, then the requirements of the Supply of Machinery (Safety) Regulations 2008 apply.

In complying with them the person placing them onto the market must prepare a technical file and undertake an internal conformity assessment which justifies that they are in compliance with the regulations, then affix a UKCA and/or UKNI marking; if it involves using interlocks or safety relays other than those supplied as partly completed machinery with their own UKCA mark, then it's an Annex VI qualifying item, and the technical file would need to be assessed by an approved third party.

Failure to do so, or making a faulty conformity assessment (deliberately or otherwise) is unlikely to have immediate consequences, but it doesn't seem like a good gamble to take given you're up against the:

• Financial liability of trading standards being able to seize and destroy your goods at any time if non-compliance is highlighted, and/or
• Legal liability in the event a user is injured and HSE determines its down to a preventable cause linked to the machinery you supplied, and/or
• Threat of a prison sentence up to two years and an unlimited fine.

Even if you sell to a user in a non-commercial setting (predominantly home, technically certain other non-profit organisations but it's a grey area) knowing they intend to defeat the safety systems you install without committing a crime under the 1974 Act or PUWER98.

The question comes down to whether you believe you can genuinely justify omitting a type of guarding from your design based on a risk assessment showing that that particular risk is ALARP.

[JellyParticipant @jelly]

In any case, I've been able to source some high-precision bearings cheap (local supplier overstocked an unusual size some years ago and let the matched set go for £75), and think I will definitely be having a bash at building a one-off prototype based on a Boxford lathe bed.

Starting with the hard bit by making a very high speed spindle, (which will probably need outside input for dynamic balancing) it's not the first one I've done in this speed range, but it is an order of magnitude bigger.

If I can make a go of that part, then all the remaining elements will only be hard.

​

As to whether the end result could be commercially viable, I think I set out a fairly clear path which could lead to viability in part by pursuing a fundamentally different business model to previous machine-tool builders in the "Worth It?" Thread,

Without doing some prototyping, who knows if it's even possible to achieve the level of simplifications I think would be needed to make that work.

[Kiwi BlokeParticipant @kiwibloke62605]

Interesting discussion. However, it's a discussion about solutions and wish-lists, before the problem has been defined. What will be manufactured is what will sell. Are we specifying the ideal lathe, the beginner's lathe, the affordable lathe, the best value, the best quality, one on which you can mill, swing huge diameter flywheels, what?

I don't suppose Myford (MkII) or Cowells sell many machines. Each serves a rather odd niche market, which seems satisfied with machines that are essentially 1930s solutions to the amateur user's requirements. In those days, the lathe may have been the only powered machine in the workshop, so versatility was paramount. Myford certainly achieved that, especially with its range of accessories.

Interestingly, Myford bought out, and closed Raglan, which made rather better lathes, and a milling machine. Perhaps these didn't sell as readily, I don't know. But Myford was cheaper and more versatile. Also, decades ago, a purchaser was much more likely to have received at least rudimentary workshop training, at school.

Now, however, imported machine tools cost a much smaller proportion of earnings, and amateurs' workshops often contain multiple machine tools. Sadly, as is evident from some postings on this forum, inexperienced and poorly-informed folk will happily spend a lot of money on machines, yet have little idea of how to equip and operate them. Their requirements are different from typical purchasers of decades ago, and they influence the market. The market is less discerning and less well-informed. Today's kids want a machine on which they push buttons and out comes a finished item. Will the 'screen generation' want manual machines?

Much as I hate to say it, I think Myford and Cowells have had their day. Leave them to the shrinking niche they occupy. They are terribly old-fashioned, but will never be fundamentally updated. Comparing current mass-production to them isn't very helpful.

So, what's on my wish list? I suppose the machine will be made in the Orient – pity, but it seems there's little realistic alternative. However the Orient can make stuff to any level of quality that can be paid for. So, number one on my list is for quality of design and manufacture to be improved – considerably. Number two is for the machine to be modular, so it can be added to, as requirements change and funds allow. I'm nervous about the long-term reliability of electronics, so keep it as 'mechanical' as possible. For amateur use, belt-moving to change speed isn't too bad, is it? The KISS principle is pretty sensible, at least in the home 'shop. And then all(?) the other suggestions, already made, can be considered – but as add-ons.

[noel shelleyParticipant @noelshelley55608]

Like Kiwi, KISS, so belt drive ! The number of issues with vari speed that come up on here, be it DC or VFD would rule them out. A better standard of finish ! And the one thing Myford got right, a huge array of ready to fit on accesories, often the mounting holes were already there. I don't want to have to spend weeks making the tool to do the job, I want to get the job done ! I bought my Myford in 1971, it has never let me down, even when overloaded, and has not cost me a penny more than the £200 I paid, it even has the original belt on it ! I have no problem with oriental manufacture, though I wonder how long a lathe set up with the capstan arrangement( if one was made) would last ? Noel

[JellyParticipant @jelly]

Posted by noel shelley on 03/05/2023 13:34:20:

Like Kiwi, KISS, so belt drive ! The number of issues with vari speed that come up on here, be it DC or VFD would rule them out.

I would tend to disagree that it's the wrong way to go.

It's both mechanically simpler and simpler to manufacture, so would be the number 1 way to maintain price competitiveness whilst maintaining high standards of fit and finish.

Most of the issues we see with DC-Brushless and VFD's on here tend to come from three sources:

• Proprietary controllers which have been heavily value engineered.
• Poor documentation.
• User Retrofits.

By using COTS (commercial off the shelf) parts from reputable suppliers, and properly documenting the implementation with complete circuit diagrams and control logic schema as part of the manual, much of that pain can be avoided.

Using a Mitsubishi drive might be double the price of an unbranded one, but it would still represent a major cost saving over all the additional casting and machining needed to provide a speed range even close to that via pulleys or gears.

Similarly, using a Melsec HMI (Human Machine Interface) panel rather than a custom PCB adds cost, but makes it both more reliable and more maintainable, you also have a much greater level of adaptability if we're thinking about accessories for a modern CNC age.

Just flash the HMI and Controller with new software and it can upgrade the capabilities of the machine to use additional accessories.

[Nick WheelerParticipant @nickwheeler]

Posted by Kiwi Bloke on 03/05/2023 12:05:57:

Now, however, imported machine tools cost a much smaller proportion of earnings, and amateurs' workshops often contain multiple machine tools. Sadly, as is evident from some postings on this forum, inexperienced and poorly-informed folk will happily spend a lot of money on machines, yet have little idea of how to equip and operate them. Their requirements are different from typical purchasers of decades ago, and they influence the market. The market is less discerning and less well-informed. Today's kids want a machine on which they push buttons and out comes a finished item. Will the 'screen generation' want manual machines?

So, what's on my wish list? I suppose the machine will be made in the Orient – pity, but it seems there's little realistic alternative. However the Orient can make stuff to any level of quality that can be paid for. So, number one on my list is for quality of design and manufacture to be improved – considerably. Number two is for the machine to be modular, so it can be added to, as requirements change and funds allow. I'm nervous about the long-term reliability of electronics, so keep it as 'mechanical' as possible. For amateur use, belt-moving to change speed isn't too bad, is it? The KISS principle is pretty sensible, at least in the home 'shop. And then all(?) the other suggestions, already made, can be considered – but as add-ons.

Why limit that to todays kids? I'm 53, and would much prefer to push a button and get a finished, or at least usable part. The machines are only tools, how they work isn't actually important. Unfortunately, standing in front of manual machines twiddling knobs and levers is the only practical way of getting the work done. Bigger machines are the obvious improvement, simply to reduce the amount of time taken.

There is no way I would buy a new lathe, mill, pillar drill or pretty much any machine tool that wasn't variable speed.

[JasonBModerator @jasonb]

I don't see many commercial CNC lathes having problems with their variable speed setups. Certainly never seen one have to stop and have it's belt changed at the same time the tooling is changed and they can alter the speed during a cut as diameter changes to keep a constant cutting speed

As Jelly says most of the electrical problems we get here are either due to building down to a price, not wanting to pay much or worn out old equipment. We see less problems with the VFD/motor combos from Newton and the likes but they do cost more than direct imports.

Just belts is going to need some big pulleys and or counter shafts if you are going to get a decent speed range particularly to make use of carbide, I'm assuming as you just want belts that means no backgear. Myself I like my variable speed and if I had to choose would rather go back to a geared head like my Emco rather than belts.

[JellyParticipant @jelly]

Posted by JasonB on 03/05/2023 18:29:41:

I don't see many commercial CNC lathes having problems with their variable speed setups. Certainly never seen one have to stop and have it's belt changed at the same time the tooling is changed and they can alter the speed during a cut as diameter changes to keep a constant cutting speed

As Jelly says most of the electrical problems we get here are either due to building down to a price, not wanting to pay much or worn out old equipment. We see less problems with the VFD/motor combos from Newton and the likes but they do cost more than direct imports.

Just belts is going to need some big pulleys and or counter shafts if you are going to get a decent speed range particularly to make use of carbide, I'm assuming as you just want belts that means no backgear. Myself I like my variable speed and if I had to choose would rather go back to a geared head like my Emco rather than belts.

There's probably a place for belt shifting to move between speed ranges of you want to have maximum versatility, I am envisioning three pulleys giving 60-600, 300-3000, 1500-15000 (I know some people like glacially slow speeds for screwcutting but I normally run between 120-200 and don't have too much trouble, 60 seems reasonable, plus with ELS by default it wouldn't really matter).

My geared head lathe has change gears in the drivetrain for that purpose, albeit with not quite as dramatic a range of speeds and it works quite well as you're rarely going to find a job that needs 28RPM and 3200RPM on the same workpiece, it is however a pain to take the cover off and switch out oily gears so belts seem more civilized for the purpose.

[Author]

Posts