Super 7s and power cross feed

[Glyn DaviesParticipant @glyndavies49417]

Just one question – why do Myford Super 7 lathes with power cross feed command about £2K more than those without it?

[Glyn DaviesParticipant @glyndavies49417]

[CotswoldsPhilParticipant @cotswoldsphil]

Hopefully, Collectors will stop paying inflated asking prices when the market peaks and they realise that there is no more money to be made. BTW it's not just PCF machines, just look at accessories and S/H spares prices.

I manage perfectly well without PCF on my basic machine for my hobby pursuits.

Regards

Phil

Edited By CotswoldsPhil on 27/06/2015 11:35:54

[KWILParticipant @kwil]

Demand and supply I am afraid.

Having PCF is a useful facility (I have it) but I would not pay +£2K just to get it.

[Roderick JenkinsParticipant @roderickjenkins93242]

You also need to factor in to your observations that power cross feed wasn't introduced until the mid 70s so PCF machines are newer than many on the market. And, by this time, I suspect that most machines were sold to hobbyists rather than schools, laboratories and jobbing workshops so possibly better looked after.

Sorry…. just been reading "Freakenomics" which is about how an in-depth analysis of data can lead to different conclusions from a more superficial look.

Cheers,

Rod

[KWILParticipant @kwil]

Rod

Does "Freakenomics" help to explain the strange values that show up on ME sites such as:-

" I cannot afford to buy a new drill because I am building a 7.25" guage loco", or "I cannot afford silver solder but will not admit I might have chosen the wrong hobby?"

 

Edited By KWIL on 27/06/2015 12:42:57

[Clive IndiaParticipant @cliveindia]

Agree with KWIL – a useful facility, but price quoted is inflated.

I think a decent Super 7 being offered at, say, £1.5k – £2k without PCF, you might have to pay an extra £250 with PCF . That is just how the market is.

It is always difficult to compare with and without since there is rarely a real indication of the overall condition.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by KWIL on 27/06/2015 12:42:29:

Rod

Does "Freakenomics" help to explain the strange values that show up on ME sites such as:-

" I cannot afford to buy a new drill because I am building a 7.25" guage loco", or "I cannot afford silver solder but will not admit I might have chosen the wrong hobby?"

I think it admits that we are on planet Earth, not Vulcan.

[Glyn DaviesParticipant @glyndavies49417]

Thanks for the replies – I hadn't thought that PCF ones are likely to be less worn as well and that accounts for their increased value.

[John Stevenson 1Participant @johnstevenson1]

I have always been curious why one would want power cross feed on a lathe that only has 3" travel ?

It's not exactly the great Antarctic Trek is it ?

In the past when we have mention CNC the purists have all fell out of the woodwork and said that it's not cricket and it's only a hobby and we should do it like it's always been done.

Then go one to buy PCF machines with DRO's , the mind boggles at the double standards.

[egaParticipant @ega]

GHT graduated to a PCF model and if I remember aright used to part off under power. An earlier ME contributor was Martin Cleeve who was of the same opinion as John Stevenson, although the latter is understating the Seven's cross slide movement.

Is there anything in the idea that the keyway in the PCF leadscrew has a "tapping" effect on the half nuts?

[speelwerkParticipant @speelwerk]

One of the first things I was learned when placed behind a lathe was how to move the slides manual in a evenly motion, for that you do not need power cross feed. It is the same as all those extras you can have on cars like rain sensors, airco, etc., nice to have but not essential. Niko.

[John HaineParticipant @johnhaine32865]

A long time ago I read an autobiography of Geoffrey de Havilland, he of the aircraft company fame. He recounts how, as an apprentice, he had to make a mating nut and bolt out of a couple of chunks of steel using hacksaw, files, cold chisel and hammer. That's the way to do it! Lathes, what a luxury!

Speaking personally, when I bought my New S7 PCF was an essential, having spent too many hours getting cramped fingers taking facing cuts on things like faceplates. And yes, it was very useful for all kinds of things including parting. Now the lathe runs off CNC so PXF is inherent. One of the reasons PXF is so expensive on a Myford is that they never modernised, a little electric motor would have some the job better than the complicated mechanical arrangement they used. Likewise, you could always buy a non PXF machine and add an electric drive.

[Neil WyattModerator @neilwyatt]

> One of the reasons PXF is so expensive on a Myford is that they never modernised, a little electric motor would have some the job better than the complicated mechanical arrangement they used.

One thing I've noticed is that the second hand values is very strongly linked to teh original cost. So an expensive option adds a lot to the resale value.

Very different to cars, where you can usually get a top-spec for little more than a base model once it is five or six years old.

Neil

[KWILParticipant @kwil]

Neil

That is because the second hand car market is rigged using the so called pricing guides. Someone decrees that a new car shall loose value to say 65% after three years etc.

The premium price cars have a good wheeze, they charge +20% say above what there new car is really worth and then you get it back 3 years later as a "higher residual" Sir, on our brand! Free loan of that added sum to the manufacturer for the 3 years!

With our toys we use them until they drop before we buy another. We buy tools that we can afford, not just to say "my car is a ****"    In any case I did not get a Company Lathe as part of a job deal!

Edited By KWIL on 28/06/2015 17:07:58

[JAParticipant @ja]

Myford lathes and their PCF models command high second hand prices because of demand. I guess Colchester and Harrison lathes are a bit like second hand cars and sell for a lot less than their new price. As for Chinese lathes I am not aware of a second hand market. Is it because they are so cheap to start off with? Do they wear so well that they don't need to be replaced? Are second hand Myfords really good value compared with Colchesters and Harrisons? More and more questions.

As for me I have a Big Bore PCF Myford and see no reason to change.

JA

[Neil WyattModerator @neilwyatt]

> As for Chinese lathes I am not aware of a second hand market.

I'm aware that very few mini-lathes go second hand compared to the number sold (did Ketan say half a million from SEIG alone?)

here's one theory: A large proportion are sold to younger people in the last 20 years, who are mostly still active in their workshops, and it's not a big enough investment that they feel the need to sell sell it if it's rarely used. Even if you don't use a lathe much, it's a brilliant 'get out of jail free' tool when that one awkward job comes up.

Not many folk have the space or the money to have a harrison or a colchester sitting in a corner 'just in case'.

I coluld be completely wrong, of course.

Neil

[KWILParticipant @kwil]

Neil,

I must be fortunate then as I have Myford PCF Super 7 and a Harrison M300 available!!

[Mike DonnerstagParticipant @mikedonnerstag]

In a previous post on this thread there was a question of interest to me that wasn’t subsequently answered. I quote:

 

Is there anything in the idea that the keyway in the PCF leadscrew has a "tapping" effect on the half nuts?

[JohnFParticipant @johnf59703]

Is there anything in the idea that the keyway in the PCF leadscrew has a "tapping" effect on the half nuts?

Mike and EGA, I purchased my S7 with PCF new about 1977 and its been in use almost every day since then, there is no apparent wear on the cross slide feed at all and minimum backlash so I would deduce this is a fallacy with no substance.

John

[Harry WilkesParticipant @harrywilkes58467]

Oh I love to see these high prices for the Myford S7, I suggested to my Daughter to ask around a £1000-1200 for mine when I go it came with a load of 'tooling' to which I have added so now I'll be telling her £3000-3500

H

[egaParticipant @ega]

JohnF

Glad to hear that your PCF S7 has served you so well.

My own 60s non-PCF machine is on its second cross slide feedscrew and nut. I replaced both but I believe the thinking was that the relatively cheap die cast nuts could be changed without necessarily replacing the screw.

[John HaineParticipant @johnhaine32865]

My S7 big-bore with PXF had a hardened steel nut and I think a larger diameter screw than the standard. This might well be because the usual mazac nut wore quite quickly under the rigours of power feed. Certainly for example when parting off under power the force on the tool is likely to be much larger than under manual feed. I don't know whether the keyway on the screw would act as a tap as well, but another reason for having a hardened nut.

Now I have replaced the standard screw and nut with a ballscrew.

[not done it yetParticipant @notdoneityet]

The lathe with PCF, that Myford stopped marketing in the early 70s, still only sell for plus or minus £500. Far better value for money, IMO.

[Howard LewisParticipant @howardlewis46836]

I had always wanted a Myford lathe, an finally got a ML7.

Just before retiring I looked to replace it with a Super 7 Sigma with the bigger bore mandrel, and the Norton box. Was not available with PCF. It would have been nice to support home industries, but the cost could not be justified, for a hobby.

For a quarter of the price of the Myford, with chucks, steadies etc, I got a larger, more rigid, Far Eastern machine, with Power Feeds, all the extras, and hardened bedways. The vendor fitted a VFD before delivery, and all for a quarter of the cost of the S7 Sigma that I originally lusted after.

Still delivering what i want after fifteen years. Wish that my skills could do justice to it.

I bought a Mill/Drill because, in my view my secondhand ML7 was not sufficiently rigid with a Rodney Milling attachment on it.

Myfords are nice, but overpriced, in my view.

Where did I leave my tin hat and suit of armour?

Howard

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