Tight Cross sSide

[Alan]

When I was operating the cross slide on my ML7 it got tighter as I wound it outwards. I stripped it down, cleaned and regreased, I adjusted the Gib screws but it was still tight. I noticed that the Gib strips (there were two of them)were held in place by two screws each, each is countersunk below the CS surface, by slackening them off solved the problem, however I do not know whether this was correct because I assumed these screws should be tight however if i tighten them the Cross slide again goes tight when wound out. ?

[weldsol]

I'm sure that when I had my old ML7 there was only one gib strip and that it was located by one of the adjusting screws into a dimple in the strip.
I cannot remember seeing any countersunk screws.
It may be if your strip is anchored at both ends it is bowing when the screws are pulled up tight ??

Paul

[Noddy]

Have you just got this lathe?

It should only have 1 gib running the full length of the cross slide.

With the 2 gibs, assuming you don't have sharp edges biting into the male dovetail on the Saddle and If you've adjusted the screws to give free travel but without any slop, and the cross slide goes tight when you get to the less used end...,

It sounds like you could have a worn cross slide too

This could (would probably) also be matched by wear on the saddle, take the cross slide off, give the flats which the bottom of the cross slide runs on and the dovetail on the slide a really good clean and see if:
1) there is a slight lip at the head end of where the slide runs on the saddle
2) any evidence of slight out of straightness on the dovetail (if you can see it, it is severe).

There are lots of discussions on other boards about re scraping:
www.practicalmachinist.com/vb/showthread.php?t=146913

but best idea is give Myford a ring for advice.

Keith

[kingsteam9]

CM,

Just a quick thought but are the csk screws you're referring to fitted in the edge of the crosslide or down through the top? if through the top then it sounds like you've got a Super 7 slide fitted not the standard 7 type. The S7 slide was fitted with two gib blocks which might be what you're looking at. If you look at Tony Griffith's site 'lathes.co.uk' and his section on the Myfords you'll read more about it. If my guess is right a phone call to Myfords, and a chat to one of their knowledgeable team will put you right on how to set up/adjust the slide quicker than any other way.

regards

Robin

[Alan]

Hi Robin
It is a Super 7 I have, I believe it is a 1993 machine The two gib blocks are secured down through the cross slide each with two cs screws although I have no slide play, if tighten down these screws the cross slide tightens up, although it can still be turned in and out.

[Noddy]

I thought we were dealing with a broken gib on an ML7.

Ok, you want only the slightest of drag on operating the cross slide, any more and you aren't gaining anything much (the main load in use is taken by the front way on the cross slide, not by the gib), but you will accelerate wear, as you squeeze the oil film out and force metal on metal sliding.

[kingsteam9]

cm

Ok, if it's an S7 then back to my original advice - speak to Myfords. I've got a funny feeling that if there's no side adjsutment then there should be some shims between the tops of the gib blocks and underside of the slide to give the required adjustment - could be wrong because I haven't dealt with an S7 for several years.

My experience of Myfords - the staff that is - is that they are unendingly helpful with enquiries like this. The last time I rang them I spoke to a chap in spares dept about our club's newly acquired very old S7 and he questioned me about the belt cover design, then as soon as I described it he could tell me exactly how old the machine was (45yrs +), tell me exactly what I needed, then told me he'd spent a fair part of his early working life actually building that type of machine and knew them inside out etc. Not many companies left like that now where you can get that sort of service and knowledge.

Robin

[ravensworth2674]

Super7's have a nasty habit of getting a bent cross slide. Run a straight edge over it before you start the gib business.