Super 7 questions

[IgnatzParticipant @ignatz]

Just acquired a Myford Super 7 to replace the rather careworn ML-10 I had been using.

The Super 7 dates back to '96, but appears to be in fairly good shape for all those years. It doesn't have a quick change gear box, but does have power cross feed… and it came with all sorts of tooling.

Anyway, as a first time Super 7 owner I've just a few questions if anybody can help…

(1) I've run a few test cuts, entirely by hand feed, with the gear train to the lead screw disengaged. What I've noticed is that there appears to be a subtle noise that comes from the toggle link that connects the main spindle to the drive pulley stack.

The toggle engages as it should and the lathe cuts cleanly for all that, but I sense that there is a slight backwards-forwards rotating motion of the spindle that makes itself known as a subtle click-clack when I change the amount of feed applied to the cutting tool.

There is obviously a wee bit of play in the connection between the toggle link and the bull gear. This play (in a rotational sense) is equal to perhaps a third of a tooth width.

What I'm wondering:

• Is this normal for a Super 7?
• Is there anything I might do to damp down this noise/motion?
• Does this indicate wear in other areas that should be investigated?

This little bit of noise is annoying, but for all that, the lathe appears to cut as it should, without any undue play or runout.

(2) I need to purchase some screws for mounting bits of this and that, but have no way to identify the correct threading required.

I have a copy of the Super 7 Operation Installation and Maintenance handbook, but it provides no information regarding the particular bolts/screws that I need.

So, perhaps someone can tell me what screw/bolt threads are appropriate for the following locations as indicated in the following photos:

[IgnatzParticipant @ignatz]

[Nigel BennettParticipant @nigelbennett69913]

Bolt Hole A is for a screwcutting dial indicator. Hole B is for a travelling steady. and holes C are for the screwcutting gearbox. Google the above for photos of them. If you're going to be doing any screwcutting you'll need the indicator.

Yes, there is generally a little play in the toggle link. It shouldn't be of concern.

Hope that helps!

[Mark BarronParticipant @markbarron78673]

I can't comment on the thread sizes, however I have the same noise problem from my S7 (same model as yours but made in 1999). The only way I've managed to reduce the noise is a small blob of grease where the half-circle of the toggle locates into the gear.

Hope this helps.

[Frank GorseParticipant @frankgorse]

On mine A and B are 1/4BSF,can’t help with the others I’m afraid

[Ramon WilsonParticipant @ramonwilson3]

Mines the same model but older (1979) – don't ever recall any noise from where you suggest so can't help you there but as far as I'm aware all threads are BSF

Looks like you have a very tidy and clean workshop there – impressive wiring conduits but personally I wouldn't have the off hand grinder so close to any machine ways if there's an option to have it elsewhere. It's not the grinding dust sitting around the base of the grinder but the carborundum fine dust that floats over a wider area to be concerned about.

Tug

[Rod RenshawParticipant @rodrenshaw28584]

My Super 7 is about the same age as Tug's and all the holes indicated on your photo are 1/4" BSF on my lathe.

Rod

[J HancockParticipant @jhancock95746]

Don't know if the ML10 had it but look for the device that locks the headstock spindle to stop it turning when

fitting/removing the chuck.

[J HancockParticipant @jhancock95746]

Don't know if the ML10 had it but look for the device that locks the headstock spindle to stop it turning when

fitting/removing the chuck.

[Martin KyteParticipant @martinkyte99762]

Regarding the Backgear Toggle high speeds tend to throw the lever outwards allowing it to touch the headstock casting every revolution if the detent is not crisp in action. See the following link

**LINK**

Items 4, 81, 82 and 7. Either the detent dimple gets worn or the spring is not strong enough. It's annoying but not fatal. I did manage to fix mine on the old Myford. The new one is OK thus far.

regards Martin

[John PurdyParticipant @johnpurdy78347]

Ignatz

I just checked my Super 7 (1976) and, although I have never been aware of it, there is some play in the bull wheel, about .010" at the periphery of the gear. As far as the threads go, as stated above, "A" is for the thread dial indicator ( on mine a 1/4 BSF stud and nut), "B" is 1/4 BSF for the traveling steady, and "C" for fixing the quick change gearbox (on mine this is M6x1.0).

John

[DMBParticipant @dmb]

Ignatz,

My MLS7 is older and grey like its owner! (1971) It has BSF threads all rounds except some locations that call for something smaller than 1/4"BSF, where 2BA has been used. The leadscrew brackets, felt wiper brackets on the left hand side of the saddle, retaining screws on the ends of the changewheel spindles and there could be more.

Grope around behind the left hand mandrel bearing and you will find the locking pin.

Hope you have many happy hours using it.

John

Edited By DMB on 13/10/2021 19:50:50

[Fowlers FuryParticipant @fowlersfury]

Sorry for two unsolicited comments in addition to suggesting you have a good looking Super7B there.

(1) What size bolts are employed to hold down the lathe onto the raising blocks? From your photo it appears there are small dome nuts which I'd suggest are maybe inadequate to ensure it's secured level for prolonged use. The S7 bed will flex more than your previous ML10 and truly accurate levelling is really important.

(2) If you have the original "V" belt driving from countershaft (i.e. a solid, continuous belt) then replacing it with a multi-link belt (e.g. Brammer) will not only make for a smoother running & cutting S7 but will also reduce that "subtle noise" you hear.

Is that a "zero-able" dial on the carriage hand wheel? Why?

[bernard towersParticipant @bernardtowers37738]

Fowler’s fury, it’s for length machining

[noel shelleyParticipant @noelshelley55608]

Many would query the wisdom of the use of link belt on the myford lathes ! Bolts are 1/4" BSF I have bolts in lenghts from 3/4" to 4" if you need them. Spindle lock is hidden behind the change wheel guard, took me 10 years to find mine. Good luck, Noel

[Barnabas TaylorParticipant @barnabastaylor89961]

Posted by Fowlers Fury on 13/10/2021 20:59:15:

t with a multi-link belt (e.g. Brammer) will not only make for a smoother running & cutting S7 but will also reduce that "subtle noise" you hear.

I would second the fitting of new belts! I recently fitted some Fenner(?) link belts and it made my lathe absolutely amazing, compared to how it was before. Suddenly I was getting unheard of power transmission, the vibration I used to get at high speeds was gone and the lathe is so much quieter now. Get some good belts, you will not be disappointed!

[Adrian 2Participant @adrian2]

I agree about the grinder being close to the lathe, perhaps it just lives there out of the way and gets used elsewhere .

I always try and do any grinding outside and never in the machine workshop .

Adrian.

[Rod RenshawParticipant @rodrenshaw28584]

Reading through the posts it seems Myford may have changed the screws that secure the gearbox from !/4 " BSF to M6 at some point. OP might be best to check his machine.

Rod

[egaParticipant @ega]

That looks like a very nice machine.

I think that what you call the toggle link is the back gear key in Myford speak. Mine certainly has some rotational play but I can't say it's a problem in practice. An associated point is the importance of lubricating the spindle via the nipple in the pulley.

I believe that Myfords did use some metric fasteners in later production, an example being the big-headed cap screws securing the saddle to the apron.

[IgnatzParticipant @ignatz]

First of all let me thank every one of you for the informative feedback.

After spending a number of hours this afternoon giving the lathe a closer inspection I can say the following:

Yes, there is that little bit of play in the backgear toggle, but like I said it doesn’t seem to affect anything and if it really bugs me in the future I can always add in that gob of heavy grease (thank you Mark Barron) or else jam in a piece of toothpick to (?) take up the play. That backgear toggle works very crisply and I suspect its spring is plenty strong enough to prevent it from spinning outwards at high(er) speeds. Thank you Martin for suggesting that I should check it out.

After cleaning some old, accumulated swarf from out of those three holes and testing with some drill shanks I am fairly satisfied that all are threaded the same… which Rod Renshaw indicates as being ¼” BSF. On the strength of that I’ll order those screws and (gently) try them out for size.

Fowler’s suggestion of replacing the standard V-belts with segmented link-belts sounds interesting. If one were to do so the following questions come to mind…

• Which size segmented belt is correct for the Super 7?
• Does one change just the belt running from the jack shaft to the lathe or the motor belt as well?
• Does running a segmented belt in reverse cause problems in practice? Here I’m referencing the need to run the motor both forward and reverse for threading.

Anyway, I’m going to hold off for the moment as the standard V-belts appear to be in very good condition. Truth to tell, I ran a few test cuts today and the machine is already so much quieter relative to the old ML-10 that I’m not sure I even need extra sound/vibration dampening. Perhaps time and use will change my opinion on that one.

And now some other observations…

About that "zero-able" dial on the carriage hand wheel, I haven’t a clue as to why one of the previous owners put that there. It can be used for measured cuts, but my own preference would be the hand wheel at the end of the leadscrew which gives much more control.

I’ll have to take a closer look at whatever size of bolts are used for securing the lathe to the table. I had a (very) brief look at them while we disassembled and reassembled everything for the move from the seller’s place to mine. They appeared to be of sufficient size for purpose, but I would agree that ‘as large as possible’ is probably best here.

I took the time to put a dial test indicator on the spindle. My indicator has a precision of 0.01 mm ( 0.00039” ) and the needle didn’t move at all when I measured for runout on the outside of the spindle register behind the threading. Same result when measuring inside the spindle taper… the needle didn’t budge.

Amongst the tooling that came with the lathe was a set of Myford collets that fit in the spindle taper. I chucked up a new 10mm milling cutter and put the dial test indicator on its shank. The needle on my dial test indicator merely “breathed”. Naturally, I’m quite chuffed with these results.

Oh and, yes, now that I have such a nice lathe it is probably time to move that grinder to some other location… just to be safe. Of course, I tend to do some angle grinding work as well as a touch of woodworking and such in my garage so a really good cover for the lathe is also on the “must obtain” list.

[Martin KyteParticipant @martinkyte99762]

Posted by Ignatz on 14/10/2021 15:54:41:

About that "zero-able" dial on the carriage hand wheel, I haven’t a clue as to why one of the previous owners put that there. It can be used for measured cuts, but my own preference would be the hand wheel at the end of the leadscrew which gives much more control.

I have one of those too. Mine is a Graham Meek special bought at a show about 10 years ago. I believe some more were manufactured after that initial batch. It is actually better to use than the handwheel. It's faster perfectly accurate to 1' or so, you can set to zero and you don't have the pain of counting in batches of 0.125" per revolution. Use it and enjoy it.

I made Grahams tailstock micrometer for my Myford too, that one counts in sensible numbers too.

regards Martin

Edited By Martin Kyte on 14/10/2021 16:13:56

Edited By Martin Kyte on 14/10/2021 16:15:05

[Speedy Builder5Participant @speedybuilder5]

Mmm Ramon – are you allowed to take a spur off of a spur ?? Ridiculous really as the spur could have been to a 4 gang socket, BUT I agree, nice clean wiring installation.

Bob

[Fowlers FuryParticipant @fowlersfury]

No doubt you'll receive a variety of answers to your queries !

• Which size segmented belt is correct for the Super 7?
  It appears there are no 'hard & fast rules'. I've seen on the (new) Myford stand that their belts are much thinner i.e less thick, than the Fenner or Brammer belts. I went with the thicker belt & it's hard to provide you with a dimension given its nature. However you might get some idea from this:-

  

  Advantages? # smoother running & no pattern when light turning due to orig solid belt joint running over pulleys. # can be fitted without removing the mandrel & disturbing bearings.
  Disadvantages? # provokes bad language when trying to remove a link # they stretch (mine needs 1 link removing after about 5 years – a job that is regularly put off) # they don't "bed down" into the pulleys as well as the 'solid' belt when taking a deep cut meaning they can slip when old. That's not necessarily a bad thing.

• Does one change just the belt running from the jack shaft to the lathe or the motor belt as well?
  Only ever used it between countershaft & mandrel.
• Does running a segmented belt in reverse cause problems in practice? Here I’m referencing the need to run the motor both forward and reverse for threading.
  Never experienced that, even when being forced to cut with lathe in reverse BUT work in collet not of course in chuck or on faceplate !

  Anyway, I’m going to hold off for the moment as the standard V-belts appear to be in very good condition. Truth to tell, I ran a few test cuts today and the machine is already so much quieter relative to the old ML-10 that I’m not sure I even need extra sound/vibration dampening.
  It's at high speed that you'd notice the benefits compared with the original hard belt.

[IgnatzParticipant @ignatz]

Point taken about the high speed. Couldn't run the old ML-10 fast enough for that to be an issue.

I'll take some time in the next day or two to check what this new lathe does at high speed.

[John PurdyParticipant @johnpurdy78347]

Ignatz

You say you checked the holes with some drill shanks. Be aware the core diameter of 1/4 BSF and M6x1.0 are almost the same so your hole "C" may be either.

John

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