South Bend 9 10k Cross feed nut adjustment

[intrepid]

I'm assembling a 10k I bought some time ago that was partially apart. Currently working on the saddle and cross slide. From the unclear drawings I have been able to locate there is a pin and set screw to adjust the cross feed nut. There is a pin in the side of the nut that I cannot get out and was thinking of drilling it out. Does it go all the way into the screw from the top? It seems it does because I cannot remove the top screw. I thought this screw was only for oiling the cross feed screw. This nut seems tight on the CF screw and hoping to salvage it and reuse. I can make a new pin from CR steel but need to know the length and end tapers.

 

[jcp]

It's been a long time since I've seen one of those types of nuts but I think that you can thread the slotted screw down into the nut and it pushes the pin out the side. I vaguely remember the screw has a pointed tip and the pin a bevel that work together to hold the nut tight in the cross slide.

 

[JPar]

It's been a long time since I've seen one of those types of nuts but I think that you can thread the slotted screw down into the nut and it pushes the pin out the side. I vaguely remember the screw has a pointed tip and the pin a bevel that work together to hold the nut tight in the cross slide.

Yes, I think that's correct. I had mine apart last year and that's what I remember. From what I recall, the screw is (or should be) removable. Once it's out, you can push the pin out from the inside. I have a book out in the shop with more information. I'll get it tomorrow and have a look to be sure.
John

 

[intrepid]

SO, if I am understanding correctly, the screw on the top is holding the pin? I thought the screw on top was an oiling port and the pin on the side was held in place with a set screw from the side of the cross slide. But after looking at it again I see the pin is in alignment with the cross feed screw so now I think I am starting to understand. The pin is wedged or tapered on the inside end and the screw must be pointed? The screw pushes the pin out to hold the nut into place?
In any event the screw is as tight as the pin so one of them will need to be drilled out.

 

[JPar]

SO, if I am understanding correctly, the screw on the top is holding the pin? I thought the screw on top was an oiling port and the pin on the side was held in place with a set screw from the side of the cross slide. But after looking at it again I see the pin is in alignment with the cross feed screw so now I think I am starting to understand. The pin is wedged or tapered on the inside end and the screw must be pointed? The screw pushes the pin out to hold the nut into place?
In any event the screw is as tight as the pin so one of them will need to be drilled out.

The screw doesn't hold the pin. Both the screw and the pin are pointed on the inside ends. When the screw is turned in, it bears on the pin and pushes it out because both pieces are tapered on the ends.
I would consider drilling only as a last resort. Have you tried a little heat? Brass and steel have different coefficients of thermal expansion, so heat may help loosen things up.

 

[JPar]

Take a look at the picture in post #20 of this thread:
https://www.hobby-machinist.com/threads/south-bend-9-cross-slide.82928/page-2

 

[intrepid]

Thanks John. I was early this morning before you posted your great information and link. I used my heat gun on the nutand within a minute or so I could see a liquid appearing the pin and screw. At first I thought maybe someone applied lock- tight. After a few more minutes I was able to remove the screw using a lot of force. The pic seemed to be galled into place. Using a drift I was able to move it further in the nut. At this point I could not force it out for fear of damaging the internal threads. A little more heat and then some light leverage with a drift I was able to get it moving back and force and finally out. After cleaning things up pin would not go back into the hole. The pin measured 0.250 so using a hand reamer I cleaned the hole and oiled things up. Everything is back together and working great. Thanks again John and others for the help.

 

[JPar]

That's great news.
John