Myford bearing spacer

Did you check for end float on the spindle before you adjusted the front nose (bronze) bearing.?

As Nigel says, the scribed line is only valid if the replacement bearings are the same as the originals fitted at the factory.

Hi Rob,

I've clocked longitudinal movement to less than 0.01mm, when running the oil film builds nicely and like I say there is no deflection under side load and no heat build during high speed running so I'm happy to say they're set correctly.

Took a while to get there though!

Nigel B,

How do you put too much oil in an open bearing ?

You can't of course however once the bearings are in place in the headstock the adjusting rings effectively partially enclose the bearings allowing excess oil to be retained within the bearings. Eventually any excess oil will find it way out of the bearings meanwhile the excess oil can make the headstock noisy at higher speeds. I don't know why and I would be very interested to learn if others have experienced similarly.

Eric,

I was tempted to ask Nigel if he had used a thicker grade of oil during assembly, so it didn't all run out, but didn't because

I do enough teaching Granny to suck eggs anyway

He wouldn't be that silly

When I did the belt replacement on the mandrel of my ML7R last year I had the rattling noise (I call it 'burbling' coming from the thrust bearings. This was certainly down to excess oil & although I guessed it would go away eventually it was so annoying I instead elected to remove the mandrel again & clean the bearings using a cleaning spray in-situ. I then used a small amount of good quality grease in each bearing - a blob about the size of a fingertip, not more. Everything settled down & ran smoothly Now I only very sparingly put oil into the thrust bearings & I have removed the almost useless grease or oil nipple & simply fitted a 2BA knurled screw in its place so I can see that I'm just putting in one or two drops.

I also decided to oil the bearings in my Fobco Star bench drill only to experience the same burbling sound, although in that case it went fairly quickly as excess oil seems to drain away better on the drill, presumably due to the spindle being vertical.

Seeing as winter appears to have arrived, I dug my way into the garage today to find the winter tyres for the car. With that chore out of the way, I had a play with the S7.

As the machine has been stood a while & was very cold, I started slow & ran it through the speeds over 10 mins or so. Then, while running (quietly) at 1020 rpm, I pumped oil into the rear bearings until it flooded out. Absolutely no change in noise level as the oil went in (and came out !) or over the next 10 mins or so running.

I live around 3 miles from Millers Oils head office & buy my oil from their trade counter. I use "Millway 3" - a 46 viscosity slideway oil - for all the oiling points except the screwcutting gearbox, which gets a 68 viscosity slideway oil.

Nigel B

Whilst on this subject, I am in the process of changing my 1966 S7 spindle bearings. I have not stripped the current bearings out yet to get the sizes of the Hoffman bearings to replace. I have been advised that the present bearing details are Angular Contact 7205 BEP size 52x25x15 mm, I am expecting that the bearings currently installed, due to the age of my S7, to be of imperial classification, if so how would the proposed new bearings fit correctly? Any advice from our brethren would be appreciated.

Hi Terry, I wasn't aware there were different sizes, I bought direct from Myford and was supplied FAG x-life 7205-B.

My machine is 1974.

Cheers

Edited By Nick Taylor 2 on 14/01/2017 19:11:11

There are not any different sizes and they are metric 52mm OD

Still unable to find out if my Myford S7, circa 1966, spindle bearing specified as of Hoffman manufacture was or is imperial or metric dimensions. Current replacements 7205 BEP,52x25x15mm may fit OK if Myford had gone metric at the time of manufacture or even Hoffman only supplied in metric form. If imperial sizes were fitted I may have to make mods to the lathe to accommodate the metric range. Please help.

Why don't you ring Myfords and ask.

Martin

Terry.

Have a look at this extract from the official "Nottingham Myford" parts list for all Super 7's.. No mention of change in headstock rear bearing alteration so undoubtedly metric bearings have always been specified.

The correct bearing is , as you have been advised 7205 BEP from SKF or other reputable maker. I bought a matched pair from Lathe Parts at a very reasonable price made by SKF in Austria.

Don't fash yourself about why Myford chose a Metric size bearing as they were probably the best overall dimensions for the headstock design. Hoffman , later RHP were the premier UK bearing supplier in the 1950s together with SKF who had 2 large manufacturing plants in Luton. My wife worked as SKF Luton for several years and was able to get me a substantial staff discount on bearings.

Popular Spare Parts For Pre-Power Feed Super 7,

Power Feed Super 7 and ML7R Lathes

History:

The Super 7 lathe, was introduced in April 1953 to compliment the already, very successful ML7 lathe. Whilst virtually identical in capacity, the Super 7 incorporated a number of features within its standard specification that made it a truly outstanding machine, these were:-

A spindle, supported in a taper bronze front bearing and a pair of angular contact ball races at the rear, which for its size gives outstanding performance, this coupled to 14 spindle speeds give an excellent and progressive speed range of 27-2105r.p.m. Over 40 years later there are many machines being marketed as screwcutting lathes, which have bottom speeds of 200 r.p.m. or so. This is just too fast for screwcutting. Other features are backgear engagement by lever, a countershaft clutch unit, a larger cross slide with block type gibs, a fully swivelling topslide, resettable friction dials on both cross and topslides, a self ejecting tailstock and a leadscrew handwheel. Over the years there have been a great number of modifications made to the original design as part of our continual policy of planned improvement. The major additions and changes are as follows:-

The first quick change gearbox became available in 1955. The gearbox used soft gears and the leadscrew drive was on the right hand side of the gearbox. In 1956, hardened gears were fitted to the gearbox.

In December 1956 the gearbox design was completely revised and from box No. QC 2501 the leadscrew passed through the gearbox and the drive was taken from the left hand side.

In June 1958 from machine No. SK 8128 the expanding sleeve clutch mechanism was changed to the current cone clutch. The change involved redesigned motor and headstock belt guards.

Customers are asked to note that we regret we are no longer able to supply spares for the early gearbox and clutch units.

In May 1959, from machine No. SK 9167 the drip feed lubrication to the headstock was replaced with a wick feed system.

In August 1972 from machine No. SK 108891B the broad guide bed and saddle were introduced in preparation for the launch of power cross feed models in March 1974 from machine No. SK 115830.

In February 1975 from machine No. SK 120965 swing head oilite bushes were ground on the outside diameter.

In June 1975 from machine No. SK 122657 the bronze cross slide feed nut on power cross feed models was changed to hardened steel unit.

In December 1975 from machine No. SK 126004 the power cross slide feedscrew was modified requiring a larger counter bore in the corresponding micrometer dial.

In November 1977 from machine No. SK 136311 the power cross feed apron was redesigned incorporating an adjustable cam for the leadscrew half nuts.

In April 1977 from machine No. SK 142981 the colour of machines was changed from grey to green.

Today over 40 years after it was first launched we are continuing to improve the Super 7. Apart from those items previously stated we can supply almost every spare part for these lathes.

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