In article <***@rcgroups.com>, DR_G <***@rcgroups.com>
writes
Post by DR_GHello again.
Well, I’ve gone and done it. I bought the lathe last night, and got it
home at midnight. Attached photos show the main bits. Not shown is the
tray, home made stand and a couple of drawers which contained a set of
Britool & King Dick spanners etc.
Superb people to deal with, but the circumstances leading to the sale
were absolutely tragic. I had very mixed feelings when removing it from
the previous owner’s workshop, watched by his son in law and grandson.
The gentleman’s wife showed me some of the superb work done by her late
husband using the lathe, and I felt totally inadequate knowing that it
will be many, many years, if ever, that I will be able to turn out such
work. Even though I really want a lathe, in this case I would gladly go
without, if it would change the circumstances of its sale. Silly
thoughts maybe, but at least it is going to a good home rather than
some dealer.
The lathe was initially advertised on EBay (#320094482656), but after a
couple of calls, it was agreed I could view it and have first refusal.
The specified starting bid was £600 (no bids). If anyone is interested
in what I ended up paying, contact me offline. It’s just that it
somehow doesn’t seem right to broadcast it over the internet after
private negotiations with some very sound people. I’d say I paid a very
fair price for something that is after all a fairly unknown quantity.
The price negotiations were done with a friend of the gentleman’s
family who is a skilled model engineer himself, so knows the value of
these things.
This morning, first thing was to ‘phone Myford with the serial number
(K 74315). The build date was, as correctly guessed here, 1966. January
to be more precise. After reading the manual, and some offline advice on
modern equivalents, I also located a local supplier of HYDEX 32
Hydraulic oil, and SLIDEX CGLP 68 slideway lubricant (I got 5 litres of
each for £20). This is from a manufacturer called Petro-Canada.
The molybdenum disulphide greases are quite good for lubricating the
cross slide and top slide.
Post by DR_GThe belts are a bit tatty, so I tried to get from BSL, but I’m a bit
confused. The manual doesn’t give widths or depths, just an inner
length. The motor belt is a smaller section than the other one (the
adjustable one), which seems a better fit to me. BSL can only supply
the right length belts in the smaller section (which seems a bit too
small to me) though. Any ideas? The belt tension lever actually touches
the clutch lever when fully tensioned, which also suggests something is
wrong with the belt spec. somewhere.
I have also bought a new sealed push on / push off switch to replace
the suicidally wired original.
Good idea; I have been using my S7 for 20+ years with the archaic
circuit breaker it came with, but I should have replaced it years ago.
(In fact I am just about to do so, with a proper Myford NVR/overload
protected push button starter.)
Post by DR_GI think it will be good lathe – as I said I don’t have much lathe
experience, but with all your help I at least established a few things
1. There is a bit of wear in the bed. It tightens slightly at the
tailstock end, but is still ‘hand-crankable’ all the way along. I did a
micrometer check along the distance too, but couldn’t find much
difference in thickness to be honest. The ways are not rusty at all, in
fact they are incredibly bright. Some of the accessories are a bit rusty
though, and one of the chucks is discoloured. The photograph made it
look worse.
If the tightening is not causing a problem I would be inclined to leave
it alone. If it is, a light stoning of the rear bearing surface might
help, failing which a bed regrind would be required - there are several
companies offering this service.
Post by DR_G2. The saddle crank feels a bit loose and sloppy. It is however secured
tightly to its shaft. Maybe needs a new Oilite bush?
Do you mean the handwheel which moves the saddle along the bed, or the
handle which moves the cross-slide? If the latter, I would check the
fitting of the gib strips. To do this, you must remove the handle and
feedscrew, and adjust the gib bearing screws so that moving the slide by
hand is reasonably free and silky, but with no trace of side-to-side
slop. Then replace the feedscrew - you must screw it all the way in
before replacing the screws which hold the feed nut bracket, otherwise
it might be slightly misaligned.
If you mean the wheel which moves the saddle along the bed, then mine
has a little play, both lateral and rotational - not much, a mm or so
and a few degrees. I have never thought this significant, it is just a
rack and pinion for rapid movement of the saddle; when turning to length
I always use the leadscrew handwheel for advancing the saddle. Good to
see your ML7 has one, they are not standard on this, but are on the
Super 7. (BTW, am I the only person who cannot understand why most other
lathes do not have this as standard? I could not live with a lathe which
didn't have one, traversing under power is all very well, but if you
want to turn up to a shoulder, hand control is the only thing precise
enough.)
Post by DR_G3. The motor is very quiet and smooth, and the clutch is like silk.
Excellent.
Post by DR_G4. Due to the amount of swarf around, I daren’t remove the main bearing
caps. I did however top up the oilers and run the lathe for about 20
minutes. I listened to the caps with a screwdriver and they were quiet
and cool. I tried the bar in the chuck and wobble test, and couldn’t
detect any play.
Ditto.
Post by DR_G5. The pulley trunnions on the countershaft had an occasional ‘knock’
when listening through a screwdriver. Sounded almost like a pulley or
belt was catching something. As mentioned above, I’m not sure the belts
are right.
Pass - the countershaft arrangement of the ML7 is quite different from
that on my S7, so I am not familiar with it.
Post by DR_G6. The leadscrew seems loose to me. When the half nut is engaged there
is some initial vertical play. When engaged it runs smoothly enough
though. Comments?
Hm, my leadscrew is pretty rock-solid in the vertical direction when
engaged. However, handsome is as handsome does, and if it ain't broke
...
Post by DR_GI eventually plucked up enough courage to machine a piece of bar, and
measured the diameters at each end, but I wasn’t thinking clearly
enough at that point to make any rational judgement of the results (not
used a lathe of any type for about 10 years, never mind someone else’s
unfamiliar one, with their immediate family watching). I think I just
said something like ‘Hmmmm. Good’.
Well, even if you had some difference in the turned diameters at each
end of the bar, it could well have been caused by the lathe bed being
bolted down slightly out of true. Even a brand new high-spec lathe will
turn taper if bolted down on the skew. In fact, one of the most
important things you will need to do when you get the lathe home is to
bolt it down very carefully, with shims under the feet (or better, some
proper jacking blocks - they are commonly available on eBay) checking
the bed alignment as you go. There are numerous books and articles on
how to do this. A few "tenths" per foot would be the standard to aim
for.
Post by DR_GI have decided to give it a partial strip down and through clean and
lube. I will not be painting it, with the exception of the tray, which
is chipped and also the wrong colour. Maybe the region between the bed
ways will get a coat too, since it is a yellow primer colour.
It does look a little "cosmetically challenged", though this will not
affect performance in any way. The yellow colour in the bed gap is
standard though, goodness knows why.
Post by DR_GAny comments at all on how to proceed from here would be very much
appreciated.
Buy the George Thomas books. IMO, these are by some margin the best
handbooks I have found for the home engineer. The format is not, as you
might expect, arranged by technique, but consists primarily of a large
collection of tools and lathe enhancements, but in every case the
important techniques are described and discussed. If you work through
the books and make eve a quarter of the things in there, you will (a)
have a much more versatile kit, and (b) be a much more accomplished
machinist!
FYI, Hemingway Kits supply castings and materials for many of the items.
Neil Hemingway was a close friend of GHT, and worked closely with him on
these, and though the business has now been sold on (twice?) I am
pleased to see that it still seems to uphold the same standards. I
visited Neil at his home several times to buy kits back in the early
90s, nice chap. Anyone know if he is still around?
Post by DR_G|Filename: P1000329.JPG |
|Download: http://www.rcgroups.com/forums/attachment.php?attachmentid=1231307 |
+-------------------------------------------------------------------+
Out of action for maintenance.
David
--
David Littlewood
