super 7 cross slide adjustment

[Bob LambParticipant @boblamb44747]

[Bob LambParticipant @boblamb44747]

I am having problems with the friction dial behind the cross slide handle. (Super 7 manual cross feed)   There seems to be some backlash which allows the dial to bind against the cross slide bracket  and the dial simply stays put while the handle is turned – not much use really.    If I simply turn the handle when it is not cutting all is well.  However if I pull the cross slide back towards me and turn the handle there is a small gap between the friction dial and the bracket which closes up and means the dial doesn’t turn with the handle.   

I have discovered the small collar underneath the bracket which I tried to adjust but I am not quite sure how I should go about adjusting it.  Or has something worn and I need a new something?     Any suggestions as to how to solve this would be really welcome.

Thanks in advance,

Bob

[John HaineParticipant @johnhaine32865]

I’ve had exactly this problem on a new S7…solved by removing the graduated collar and gently lapping the back edge that binds on a diamond plate.

[Bob LambParticipant @boblamb44747]

Hi John – thanks for the reply.    I talked to the nice man from Myford and it seems likely that I have some wear on the shoulder where the leadscrew goes through the casting.   I am sure that wasn’t the problem with your nice new S7!   One solution is a new leadscrew and nut and the other, as suggested by you, is to take a few thou off the back of the dial and stop it binding.  That is what I am going to try first – ( as approved I think by Myford!)

One good thing that has come of this is that I looked for AND FOUND the original maintenance and parts list that came with the lathe 35?? years ago!  The diagram there  hopefully shows where the problem is.

 

Thanks again – Bob

[Bob LambParticipant @boblamb44747]

I’ve now taken off the cross slide leadscrew and casting and indeed there is wear on the shoulder and the casting so I will try a shim washer and see if it works.

[KWILParticipant @kwil]

Faced with a similar problem some time ago I modified the bracket, fitted a new shorter bearing with needle thrust  washers on each side, result smooth and free from future wear.

[NJHParticipant @njh]

Whilst this specifies ML7 is it also applicable to S7?

 

http://www.arceurotrade.co.uk/projects.aspx

 

 

 

[Bob LambParticipant @boblamb44747]

Thanks KWIL and NJH – the shim washer seems to have worked but I prefer the idea of the needle thrust washers – I’ll call arceuro tomorrow and see what thy say.

Bob 

[KWILParticipant @kwil]

NJH and Bob, That is similar to what I did some time ago to my Myfords but I think it it is rather different with the S7 because the size/method of the adjusting “nut” which is behind the bracket. The diameter of the leadscrew is also larger. With careful sizing you can have totally enclosed thrust bearings to keep the dross out.  They work a treat, I have them on all leadscrews, I can recommend fitting needle thrust bearings to the main leadscrew on the thrust bracket at the right hand front end of the bed.

[NJHParticipant @njh]

Thanks Kwil

 This sounds like a useful mod – I will add it to my list!

The trouble is of course, as I’m sure you know,  there are so many good ideas one picks up that cause diversion from model making! I have lots of projects “in progress” but I’ve concluded that , in the end, what I enjoy is the process of making “stuff”. As one friend said recently about a model project  “nice but what do you use it for ?” – I guess nice is good enough!

 

Regards

 

Norman

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