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Super 7s and power cross feed

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Glyn Davies27/06/2015 10:38:39
146 forum posts
56 photos

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

CotswoldsPhil27/06/2015 11:32:55
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196 forum posts
112 photos

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

KWIL27/06/2015 12:00:16
3681 forum posts
70 photos

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 Jenkins27/06/2015 12:29:35
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2376 forum posts
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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

KWIL27/06/2015 12:42:29
3681 forum posts
70 photos

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 India27/06/2015 12:48:20
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277 forum posts

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 Jenkins27/06/2015 13:19:58
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2376 forum posts
800 photos
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 Davies28/06/2015 13:41:45
146 forum posts
56 photos

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 Stevenson28/06/2015 13:56:39
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5068 forum posts
3 photos

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.

ega28/06/2015 14:15:08
2805 forum posts
219 photos

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?

speelwerk28/06/2015 14:22:04
464 forum posts
2 photos

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 Haine28/06/2015 15:57:27
5563 forum posts
322 photos

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 Wyatt28/06/2015 16:46:53
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19226 forum posts
749 photos
86 articles

> 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

KWIL28/06/2015 17:05:08
3681 forum posts
70 photos

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

JA28/06/2015 18:00:06
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1605 forum posts
83 photos

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 Wyatt28/06/2015 19:11:17
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19226 forum posts
749 photos
86 articles

> 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

KWIL29/06/2015 10:05:40
3681 forum posts
70 photos

Neil,

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

Mike Donnerstag26/09/2018 10:20:54
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231 forum posts
53 photos

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?

JohnF26/09/2018 10:47:35
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1243 forum posts
202 photos

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 Wilkes26/09/2018 11:27:41
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1613 forum posts
72 photos

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 smiley

H

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