Super 7 questions

[IgnatzParticipant @ignatz]

John, thanks for the tip.

I've got loads of M6 screws so I'll gently try one for fit.

[IgnatzParticipant @ignatz]

John, … Once again my thanks for your tip.

I tried out an M6 x 1.0 and, yes, it seems to fit in every one of those holes (!)

Went looking on line and found that those two threads ( 1/4 BSF & M6x1.0 ) are very roughly similar although they have different thread angles (55° vs 60&deg. Also, the M6 isn't a 'perfect' fit and the 1/4 BSF's are probably a safer bet for anything that will take heavy strain.

[IgnatzParticipant @ignatz]

Fowler,

… I tried running that lathe at the higher and highest speeds. Definitely a bit more vibration and I can see where a segmented belt might be of some use. Time will tell if this is something I will choose to invest in.

During these brief high speed tests I noticed a pronounced 'squeal' when switching on the motor… ultimately to figure out that the motor drive belt is a bit slack when placed in the high speed position. It seems to have a correct tension in the low speed position, but I could be wrong.

Does this indicate that a replacement motor drive belt is required?

[KWILParticipant @kwil]

An "easy test" for belt tension, Grasp belt midway between pulleys using thumb and first finger. Can you just twist the belt 90 degrees, if so.OK

As an aside, I can run my S7 at top speed without vibration being an issue. Yes it's a standard belt.!

[IgnatzParticipant @ignatz]

Kwil,

… thanks for the info. I twisted the belt as you suggested and it went quite a bit further… about 135 degrees.

Actually, the belt looks pretty good, just maybe a bit too slack.

Where is the adjustment for the tension of the motor belt located?

[Michael Brett 1Participant @michaelbrett1]

Two grub screws with lock nuts that rest on top of the shaft that holds the belt tension lever.

Mike

[IgnatzParticipant @ignatz]

Michael, … Are you referring to the two screws that I have indicated in this exploded diagram?

[John PurdyParticipant @johnpurdy78347]

Ignatz

I just checked and while a M6 screw will screw into a 1/4 BSF threaded hole (sloppily), a 1/4 BSF screw will not go into a M6 threaded hole, it's too large a diameter. So your hole "C" may be either. When I screw a M6 screw into hole"C" it's a nice snug but not tight fit whereas into a 1/4 BSF nut it's a very loose rattling fit.

John

[John PurdyParticipant @johnpurdy78347]

Ignatz

Just thought, the studs holding the change wheels to the quadrant are 1/4 BSF. You could use one of them to check the hole sizes, as I said, if it won't go in will be M6.

John

[Michael Brett 1Participant @michaelbrett1]

Ignatz

Yes , you use the screws you highlighted to adjust belt tension.

Mike

[IgnatzParticipant @ignatz]

John, … great suggestion to use the change gear retaining studs to check the hole threading. It turns out that the holes at 'C' for mounting a quick change gearbox are indeed M6. The others are 1/4 BSF.

Michael, … I fiddled with the tensioning screws (indicated in blue below), but ultimately had to drop the motor a bit (shaft indicated in green below) as well to get the motor belt and counter-shaft belt tensions to balance.

In the process of testing it out I discovered that the counter-shaft bushing at the clutch control arm end ( #125 indicated in yellow ) must be pretty worn since the associated oil cup (mounted at red dot) empties out in mere minutes… or sooner.

Obviously, until I take the time to disassemble the counter-shaft/clutch assembly I won't know if I just need a replacement Oilite bushing or both that and a replacement counter-shaft.

[KWILParticipant @kwil]

Micheal, as Ignatz has pointed out the green bolt and nuts are for the motor belt adjustment, the blue ones are strictly for the layshaft pulley (106) to spindle belt tension.

NOTE You should all be aware that in Manual S.723N dated 8/73 the Quick Change Gearbox mounting screws are given as 1/4"BSF x 3/4 (Large Head) and in Manual S723W dated 11/84 they are given as M6 x1.0 x 16mm Capscrew.

When the actual production change over was made I am not aware

[KWILParticipant @kwil]

I have now found the changeover points:-

Headstock hold down, changed to M8 x1.25 and Gearbox and apron to M6 x 1 from machines ML7 K125240 and Super 7 SK124461. Ref Ian Bradley

[John HaineParticipant @johnhaine32865]

Regarding the link belts question, the original S7 uses I think "A" section but the big bore "Z" section which are actually smaller in width. Important to get the right ones, A section link belts on Z section pulleys slip. There are also link belts with links moulded from flexible plastic without reinforcement – I bought one of those from RDG and it was quite unsuitable, stretched like anything and slipped badly. Finished up with a Gates red belt made of some sort of fibre sections bought from RS.

[IgnatzParticipant @ignatz]

Haven't had the time to tear into the counter-shaft assembly to assess the damage at that leaky bushing, might be a few days until I have a free moment to do so…

…but, I've a few questions about that ahead of time.

1. If I'm replacing that worn bushing (#125) should I also replace the bushing at the other end of the shaft (#126… I'm not seeing any unusual oil loss at that end.)
2. How much wear is considered normal on the end of the counter-shaft?
3. If the counter-shaft is worn are there ways to save it? Polish the end? Turn it down?
4. What is the normal running clearance between the shaft and the Oilite bushing?
5. I'm certain that I'm not the first to encounter this sort of problem. Can anyone point me at any posts on the forum or perhaps online videos that present the proper way to handle this repair?

Any extra hints or tips gratefully accepted.

[John PurdyParticipant @johnpurdy78347]

Kwil

That info on the changeover to metric screws agrees with what I have with my lathe. It was bought 22 Sep 77 in central Canada and has Serial #SK127323. The manual that came with it, S.723Q (no date) shows the metric screws in the parts list. The old Myford site showed serial#s SK115830 – SK 129944 were manufactured between 1974 – 1976. ( not sure were it came from but I also have a note that #SK122657 was made Jun 75 and #SK136311 was made Nov 77). So based on that I suspect mine was made mid to late "76.

John

[Fowlers FuryParticipant @fowlersfury]

Re: Ignatz & oil loss from countershaft:-

Unless you feel some compelling, desperate need to dismantle & replace the bush then I doubt there is any great requirement to do so. AFAIK, those oiling cups on the counter-shaft of S7s lose oil at a prodigious rate.(it's almost worth collecting and recycling !).
I just top up prior to use and live with it – been that way for many years on my S7. The oiling cup on the front bearing of the mandrel doesn't lose oil at anything like that rate and remains full for long periods.
I do though always oil the nipple on the other end of the countershaft. For that it's worth investing in a genuine Reilang oil can with the appropriate female end as the Myford oiler is notoriously cr*p. The Reilang is not cheap but saves a great deal of annoyance as the oil goes through the nipple and not all over the lathe.

[ChrisLHParticipant @chrislh]

Somebody mentioned recently that interposing a piece of cloth between nipple and Myford gun improves the sealing . It works, after 50 years of oiling everything but the bearings I can now do the job properly.

[Martin KyteParticipant @martinkyte99762]

As the countershaft bushes are sintered oilite type you would expect them to absorb the oil at a fast rate. They can only hold a certain amount, The rest will dribble out. I wouldn't fuss over them too much.

You talk about a squeel when turning on. Although you said this regarding the motor the usual source of this especially at higher speend is a dry clutch. Just a drop of oil between the cone and the pully will illiminate this.

regards Martin

[IgnatzParticipant @ignatz]

Fowler & Martin, … I doubled checked the oil usage at the right hand side of the counter shaft bearing once more. With the motor belt at on the low speed pulleys the oil tends to remain in the joint ( and the oil cup ) as once would hope. When the motor belt is placed on the high speed pullets then the oil starts weeping away from that right hand shaft bushing at an amazing rate… empties the oil cup in less than twenty or thirty seconds.

I know that the Oilite bushings being porous retain oil within, but should I be concerned at this great rate of oil loss?

A related question: If the oil loss is this fast when using the high speed range, how long would you estimate that I could safely run the counter shaft at high speed before needing to give it another shot of oil?

About the squeal – that was entirely due to the motor belt being too slack. The squeal came from the pulley slipping within the belt during high speed start-up. Once the belt was properly tightened the squeal disappeared.

Chris, … great suggestion about using that little piece of cloth between oil gun and nipple. The oil gun now seals properly when applied to the nipples….

… of course, the silly oil gun still leaks all over the place from its own seals so that my hands probably get more oil than the lathe.

[Fowlers FuryParticipant @fowlersfury]

I can't offer any useful advice re "……but should I be concerned at this great rate of oil loss? A related question: If the oil loss is this fast when using the high speed range, how long would you estimate that I could safely run the counter shaft at high speed before needing to give it another shot of oil?"
It is very seldom that I've had need to run the S7 by switching to the "high speed" pulleys from motor to countershaft in the 20+ years since it was new. But as before ~ those oil cups on the countershaft do empty fast.
(I've equipped the S7 with a VFD etc – an excellent investment – I can now run the lathe at a fast enough rpm for 95% of jobs by leaving the belt on the "slower speed" pulleys).
No doubt it'd bring a sharp intake of breath from the experts but a few times, I've added some molybdenum disulphfide oil to the cups.
I wouldn't get too neurotic about oil loss; IMHO it's more important to keep topping up with the correct oil !

[BazParticipant @baz89810]

My countershaft oil cups empty as fast as I fill them, I now use chainsaw oil in them hoping that being thicker it may stay in the bearing a bit longer. The oiler on the headstock front bearing seems to last about a day before it empties, I have no idea if this correct or not, it would be nice to know how often others have to lubricate the spindle.

[Martin KyteParticipant @martinkyte99762]

Just because the oil cup is empty doesn't mean the bearing is not lubricated. So long as the bearing is loaded with oil it will self lubricate for a very long time. I did have a hunt around on the web for some data and the best I can come up with is re oil every 1000 hours or anually. For my Super 7 I add a few drops of oil to the cups every month or so and I suspect most of that goes to waste by finding its way back out again as the bushes are saturated already. Essentially if the bearing shows no sign of running hot it must be sufficiently lubricated. As an aside I would have said that chainsaw oil was far too sticky to work well with sintered bearings. I'm no bearing expert so maybe someone would like to comment further.

regards Martin

[DalboyParticipant @dalboy]

Not sure if the super 7 is anything like the system I have on one of my woodturning lathes which is a record cl3 and has a tapered bearing on the spindle output side the other end has a sealed bearing.

This lathe has a small oil cup the type with the little sprung lid I find that three drops of oil everyday(if I use it for a days turning) is all it needs. I have only ever had to adjust this bearing twice in the 12 years I have owned it, any more than three drops at any turning session ends up with oil being thrown out. The cup does not hold any oil as soon as I turn it on it uses it.

I do check the bearing play once a month and clean it down after every session of turning which allows a quick inspection picking up any faults quickly.

I intend to carry this on with my metal working lathe and mill as I do with all the machines in the workshop

[Fowlers FuryParticipant @fowlersfury]

As with many issues/queries raised ~ they have been covered on here before. I'd recommend to "Ignatz" that it's worth looking at this thread of 8 years ago:-
**LINK**

Other useful info can be found by searching on "Esso Nutto"

Shortly after acquiring my new S7B, there was a rumbling noise from around the 1ph motor. Myfords sent out a guy to inspect & rectify. He left me with a 1 litre bottle of Esso Nutto and advised that I always use that for lubrication. (He also left me with 1 litre of Shell Ensis and said to apply regularly to all bare metal surfaces of the lathe. Words of wisdom because there's never been a trace of surface rust since).
Like Martin K above – I'm no bearing expert but I'd support his doubts about chainsaw oil [and his other comments]. When I use such oil in my chainsaw, it leaves a very sticky residue.

I think the consensus re. oil loss is "it ain't broke so don't fix it".

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