Mellor lathe.

[God mode restorations]

Can you explain what you scrape these too, is it to each other or to some flat surface? Ive only really scraped flat using a surface plate, or bearings

Over a period of time and use the compound and cross slide start to wear .this causes a lot of problems when turning. I use a surface plate and camel back straight edges to bring both parts back in alignment . also with scraping you get little islands and this helps oil distribution between the two surfaces. One it's done the operation of the cross slide and compound slide are very smooth. Definitely worth doing on any old machinery . hope I have explained it.

 

[addjunkie]

Think I understand, initially I did wonder if you used a pair of parrallels on the sufrace olate to blue both sides of the cross slide parts at the same time.

 

[dobbslc]

Really does look like a dark art that scraping business!

 

[God mode restorations]

Think I understand, initially I did wonder if you used a pair of parrallels on the sufrace olate to blue both sides of the cross slide parts at the same time.

I do a side at a time on the bottom part of the compound slide. I do the top part on the surface plate . If it rocks when it's assembled then you know that one side is out. I check this with a dti on the surface plate . Pete can explain it in a lot more detail.

 

[addjunkie]

I do a side at a time on the bottom part of the compound slide. I do the top part on the surface plate . If it rocks when it's assembled then you know that one side is out. I check this with a dti on the surface plate . Pete can explain it in a lot more detail.

Im waiting for the video, want to see the flull scraping action in the flesh!

 

[God mode restorations]

Im waiting for the video, want to see the flull scraping action in the flesh!

One day I might. I am still a beginner addjunkie. I know the basics and enough to do my own machinery. There is so much more to it.

 

[addjunkie]

Really does look like a dark art that scraping business!

Its a dark art alright, I remember doing big marine engine bearing shells about 500mm diameter, in blistering heat and humidity, with a hangover. Ewarding also when it works afterwards

 

[Pete.]

Basically you want the ways flat and co-planar. It's a lot easier to achieve with modern cross-slides because they are long but the shorter old type make it more of a trial.

What I do for a cross-slide is scrape both of the flat underside ways on the slide by spotting on the surface plate. I survey the slideways on the saddle (that the cross-slide run on) and if they are not too worn I scrape them using a small straight edge to get the ways flat and using the already-scraped cross-slide ways to check they are running level with each other. It's very easy to spot a low corner, you just put the slide on and tap the four corners. Any which have a gap will clack.