Hi Ray,

I have recently finished a refurb on a Myford S7, this model was manufactured in 1964 and I believe is a mk2 version.

See forum posts 'Myford Super 7 for £395 at SRS'

I did extensive work on the saddle & apron, luckily the rack & pinon were in good order but after repairing the bed and saddle the fitting of the apron to the saddle was now lower than previously, and the right thickness shims had to be fitted at the interface of these two components to put the pinion in correct mesh with the rack.

I don't know what you mean by 'bushing' .. my interpretation is that a bush is a cylindrical collar but may mean something else to others. If both the rack & pinion are worn I can't see any way out of it but replacement of these parts however if the two are not in close contact it can feel as if they are worn and with some adustment of apron to saddle can be put back to a working situation, probably if worn there will be some backlash but I should imagine there would always have been an amount of backlash present even in the new item.

This was the apron prior to cleaning up the shim should ideally fit along the edge facing.

As Dave has mentioned a picture of the rack & pinion would give a better idea of the problem.

rgds..Bob.

I agree with Neil, there no shims to adjust the height of the saddle, the only shims used are for the saddle strip.

One of restrictions on regrinding the bed is the rack. Myford use to say 10 thou, as this is the amount of movement the rack can be moved up to re engage with the pinion. Remember regrinding the bed involves repositioning both rack & Leadscrew.

PS I had all these questions rebuilding a S7 many years ago but was fortunate to live not to far away from Myford so use to go to buy parts then go into the workshop and ask the fitters "how do you do this then", they were always very accommodating.

I can also recall asking how old is my lathe, and this gentlemen went of upstairs in the fitters shop came back with a notebook with every machine serial no date and who originally bought it recorded. I wish i knew where that book is now

A bit of play on the gear on the rack is not a real issue. Normally on a S7 you use the lead screw hand wheel while cutting.

I have a 1958, Mk1 head stock, MK2 clutch and yes there is some play in the rack feed, not an issue. Sometimes I will use teh carriage hand wheel to advance the carriage when machining. The play does not matter as you are moving the carriage by gentle pressure.

I will improve rack feed slack at some point but it does not impact performance.

Of more importance was

1 fix bed wear – bed grind

2. replaced clutch bearings and headstock bearing, did tapper roller bearing conversion

3. adjusting the lather to turn parallel

Peter