Mk1 Super 7 – What colours ?

[Dave HalfordParticipant @davehalford22513]

Posted by Peter Sansom on 29/11/2018 12:40:21:

The photos show the colours. I know it needs general painting. The Super 7 on the Headstock Belt cover was also picked out in cream, but all that paint has flaked off.

That colour was known as Straw, anyone who worked on telephones in the 60s / 70/s would have seen equipment racks painted in it.

[Chris TriceParticipant @christrice43267]

This might prove useful. https://www.youtube.com/watch?v=XVdM1ZI3hEQ

[Dave WhippParticipant @davewhipp44543]

Thanks for the video link – yes, that will come in handy – thanks.

Light Straw. Yes, I work for BT and there's still plenty of ironwork painted that colour in the exchanges. Maybe that is what my "custard yellow" was intended to replicate ?

However, colour wise, I've settled on Grey & red.

Re. the bearings, yes, will get SKF ones, Hopefully should last me out. Ta.

As for the saddle to bed clearance, Ive gone over it with my 2 thou feeler gauge and I can't get it in anywhere so pretty chuffed about that. There's the odd place I can just about squeeze the 1.5 thou feeler in (the thinnest I have)

I have given up on trying to extract the brass oil dripper tube from the headstock – it is indeed very tight and if I force it more something is going to break. I will attempt to make a replacement plastic "thimble" from nylon bar and slot it at the back to go around the tube, like you say. I am tempted to make it a fraction longer and put an O ring under the bezel. I will have to wait till the lathe is up & running first, so I'll just put some tape over the hole in the meantime.

The thimble has (as far as I can measure) a 22mm X 0.7mm thread. Does that sound right for a Myford of that era – I would have expected imperial measurements ? Or am I measuring badly ?

If so, should I be able to cut such a fine thread on my S7 when I get it running ? I'm a complete newbie to threadcutting though I have watched a fair few youtube videos on the subject.

Dave.

[Peter SansomParticipant @petersansom44767]

Could be 36tpi, if you have a QC Gearbox that is a standard thread and more likely to be used in the 6 years that this initial style of headstock was built. The thimble is an odd size as 21.9mm OD, so could be 22mm. What is the bore in the headstock for the oil thimble?

Remember that the Idea is not to fill the sight glass, but rather to have a steady drip of a good quality Hydraulic oil. Myford recommend ISO 32, but I have always run ISO 46 as it as felt to be better in warmer areas such as Australia. Also at the time easy access to that oil as where I was working used large quantities for steam turbine lubrication.

[Dave WhippParticipant @davewhipp44543]

Hole in the casting measures 22.1mm or .87 inches.

I don't have the gearbox on my lathe, but I do have plenty of gears. Will have to work that one out later I suppose.

The thread is so fine I could just put a slight taper on, and push the bezel over the plastic with some sealant on it but I'd like to make a proper job of it really. I will have a look at my thread gauge and see if 36 tpi seems a better match than 0.7mm

I have just bought a 5L can of 32 hydraulic oil so should be OK for a while there.

Cold & damp in the UK at the moment – I don't need to worry about the oil being too thin !

Dave.

[Peter SansomParticipant @petersansom44767]

The pitch for .7m is .0278" and for 36TPI .0276", a difference of .0.78%. Cut which ever you have the change gears for.

[Dave WhippParticipant @davewhipp44543]

Thanks Peter.

[DMRParticipant @dmr]

Dave,

I am entering this conversation without reading it all so just three points:-

1) The yellow down the middle of the bed depicted an unhardened bed. A hardened bed was painted red.

2) A wide gauge saddle will not work on your early bed. The leadscrew claspnut will not line-up.

3) The Brass tube on the drip-feed is a push fit, straight sided arrangement. You need a good BSF bolt (1/4 BSF I think) that will screw in the length of the thread so as to have a fair chance of not stripping it. Set up a lever arrangement to the back side of the oil well and pull straight up; it gives way very suddenly – frightening!

As to your cracked white back piece. Once you have it out, assuming it has not been bodge-glued in before, apply some Araldite or similar to the cleaned-up outside of the crack and that will do the job. I just run a bit of oil via the tap at start of session and that works fine. The sightglass was never meant to be filled, so no need for an oil-tight fit.

Dennis

[Dave WhippParticipant @davewhipp44543]

Many thanks Dennis.

1- Very interesting to know the history. My bright yellow had been sloppily painted on top by the guy who was selling it. I wire brushed it all down as it looked terrible, there was traces of cream / light straw paint underneath the several layers that were there though. Today I painted the inside of the bed red, so that was a nice easy way to harden my bed without even realising

2 – I found that out the hard way and have modified the wide saddle – it now lines up and works well.

3 – I gave up on removing the tube – I was getting very near to thread stripping time with the amount of force I was applying and decided to leave it be before something broke and ended up giving me an even bigger headache. The plastic thimble was loose and a section of the threaded edge had cracked and a chunk was missing, so I have pulled out the plastic remnants and will make a new one from some white nylon, and slot the back so it goes in over the tube.

Thanks – Dave.

[Peter SansomParticipant @petersansom44767]

Have a look at this YouTube video on the Headstock oiler

https://www.youtube.com/watch?v=F9KU-liSGNk

[egaParticipant @ega]

Posted by Peter Sansom on 14/12/2018 12:30:20:

Have a look at this YouTube video on the Headstock oiler

https://www.youtube.com/watch?v=F9KU-liSGNk

Thanks for the link. I think I now understand why the Mk 2 Super Seven is thought by some to be inferior in this area.

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