Advice on a new lathe

[johnhindleParticipant @johnhindle]

Hi, I am new to the hobby and just in the process of buying my first lathe. It is a Myford super 7 with quick change gearbox, and has been converted to 415v with an alpak induction motor. I am very hesitant to buy it as it has been removed from a fitters shop and cannot be tested on site due to no 3 phase supply being available. Are there any views on whether this is a bad idea? The price is very sensible. Is there a unit I can buy to test it on site? And what checks should I be carrying out aside from the motor working? Many thanks for any help

[bernard towersParticipant @bernardtowers37738]

Firstly take someone with you who knows what they are looking at.

[duncan webster 1Participant @duncanwebster1]

Join your nearest ME club and see if there is some knowledgeable person who will advise. Motor is the least of the potential probems, bed, saddle and main bearings wear is what to look out for

Of course if it’s cheap enough you could just buy it, if  no good sell it on, but thats a pain.

[noel shelleyParticipant @noelshelley55608]

Where abouts are you John ? If you can borrow a transwave converter of the right size it can be run, it’s a good motor. Noel.

[johnhindleParticipant @johnhindle]

<p style=”text-align: center;”>Thanks Noel, I’m in Leeds. I think I just need someone who knows to check it over</p>

[BazyleParticipant @bazyle]

The motor is a fairly trivial part of the equation and single phase Myford motors are around for <£100 but an ex industrial machine is going to have had a harder life than an ex hobby machine.

[Howard LewisParticipant @howardlewis46836]

Certainly have someone knowledgeable check it out, mechanically.

It sounds like a good spec.

It may have been worked hard and long, and, consequently worn, unless the “fitters shop” was a toolroom, where it might have only been intermottently.

If you have to get a new motor for it, would the budget runs to a VFD?

If not, single phase motors are available, secondhand or new.

I have no experience of them,  but Clark motors, from Machine Mart do not sound to be suitable as replacements, judged by comments on this Forum.

Howard

 

[egaParticipant @ega]

A secondary but significant consideration is the included accessories; a machine from a professional setting may well come with valuable tooling.

[Grindstone CowboyParticipant @grindstonecowboy]

I have an ML7 that a previous owner had fitted with a Clarke motor from Machine Mart (still has the label attached) and it seems fine, so it can be done. Looks like the mounting plate had to have a slight modification, though (holes elongated), so not a direct drop-in replacement.

Rob

[jaCK HobsonParticipant @jackhobson50760]

Difficult. I got a cheap, old S7 10ish years ago for £500. It is worn and it has taken me time to learn how to use it to accomodate its wear. In the end it was a good buy as it can turn out stuff and I learnt a lot.

If you know nothing about lathes there there is a lot that could be wrong. A lot of those wrong things might be easy fixes. A lot might be difficult to fix. As already said, motor would be the least of my concern.

I would test it by operating all the slide ways to limits of travel and see if they get stiff at any point. I would also grab bits of lathe and apply force to see if I can feel any play at different sample point of travel. Also the headstock bearing – does it spin freely and is there any play. Are all the backgear teeth in good condition – no missing or chipped teeth.

Also, is it a 7B with power cross feed – nice to have!

Ideally you want to see no visible signs of wear, nice paint, no ‘play’, and free moving spindle and slideways – myfords can be silky smooth. If there is play or signs of wear then it takes more experience to know if it is significant or not.

My guess is that an OK S7 with gearbox goes between £1500 to £3500… If you get one for less then well worth considering. If in the £1500+ price bracket then take a look at what you can get from Warco or Amadeal.

Im no expert though.

[Howard LewisParticipant @howardlewis46836]

Jack,

A skilled operator can produce good work on an old machine. A novice is more likely to produce scrap on a new machine; until they acquires skills.

A former colleague produced excellent work, far far better than mine, on a century old lathe!

We all have / had to learn!

Becoming familiar with a machine allows the user to expand its range of operation, beyond what they first thought.

Forty years ago, when I first got a lathe, I never expected be screwcutting or making special purpose ER25 collets.

If my advice is worth anything; become familiar with the machine and what it can do.  The latter will grow as familiarity increases. But only change one thing at a time, so what produces the effect is clear, before moving on to something else.

Howard

[Dave HalfordParticipant @davehalford22513]

Hi John,

For me, if it has been recently painted it would drop the value by £200, it’s true you can’t polish a tu!d but some people do paint them. Has it been removed by someone from the fitters shop? Otherwise it’s a re-sale and may have had parts swapped into it from other Myford models.

Check how much lost motion is in the handles for the top slide, tailstock and cross slide, 10 thou you can live with 20 thou will need parts to fix.

Use fact that you can’t run it as a negative and wobble a bit to get the price down further.

Jack Hobson’s advice above is sound.

Good Luck.

 

[Howard LewisParticipant @howardlewis46836]

Caveat emptor!

Shiny paint would mean that the machine needed a really close examination.

Unscrupulous folk imagine that repainting equals refurbishment. This might just deflect potenrial buyers away from the wear!

As already said, take someone with you who knows what to look for and check.

A slightly dirty, oily, machine might be actually be in better condition that a shiny one!

Really, you need to hear it running (there could be one or more broken gears, which could be rotated to hide the damaged /missing tooth) Unwisely, some folk unscrew a stuck chuck by engaging back gear without freeing the bull wheel, to lock the spindle while great forces are applied to the chuck to unscrew it. Often this results in one or more damaged gears. So check very carefully.

It might be O K , but check very carefully. ( I know someone who bought what appeared to be an excellent machine. When delivered, the toolpost had been used to cover a large piece broken out of the cross slide! And he had problems getting his money back)

Do any other items come with the lathe ( a 4 jaw independent chuck, as well a 3 jaw self centering, any extra gears, vertical slide for instance, or cutting tools, drill chucks)?

Try to find out more about where the machine came from, and how it was used. An ex Tool Room machine may have been in industry but seen occasional use, compared to larger machines around it; or it could have been the principal machine and worked hard, day in and day out.

If it turns out to be a bad ‘un, you might be better looking at a new far eastern machine from a reputable supplier, for the same money.  And it would come with a warranty and probably some technical back up, should you need it.

Howard

 

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