Fixing Cross Slide Backlash on my South Bend 11
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- čas přidán 27. 09. 2020
- Making a new nut for my cross slide to address the excessive backlash. I'll also address the problem with a screw that obstructs the compound angle while cutting internal threads. My South Bend is a 1931 model and I'll be updating the cross slide nut and screw to make it more like newer South Bend lathes.
must be the fall for backlash removal
Had backlash also. So, tapped thread in a 50mm block of propylene. Finished it off to fit, still had a little backlash. Heated it up a little, squeezed it in a vice, now tight. Cheap, easy and as I am 80, won't have problem again. Try it.
I'm curious as to why you swing your compound towards the back. Why not just rotate the compound to the left of the cross-slide? Then your handwheel for the compound would still be towards the front of your lathe when cutting internal threads. With the compound rotated towards the back, the tailstock is going the be in the way and you have to put your hand behind the work piece. Maybe I'm missing something, but I think that you create an issue as a consequence of a bad technique.
If you want to take up all the backlash in the nut split the nut .250 in perpendicular from the back side and add a couple grub screws just cut it about 3/4 way through so when you tighten them it will spread the threads and take the lash out . Thats the way i did my old Clausing lathe and it worked great
You keep at this you will have a better than new lathe. I am surprised you chose brass. I thought TQ100 hot plate would have been a beter choice. It is highly machinable with great wear resistance. Brass is slippery enough but I suppose the wear has to happen somewhere eh. Either wear the screw or wear the fitting. You made a better choice my friend. You sure solved the backlash and now time will tell all on your material choice. I am thinking your on the money my friend. Hmm, I was always taught to work cast iron dry with min rake on the tools. Same speeds and feeds as stainless. Great results my friend.
Hey Winky! A good way to avoid issues while drilling brass and bronze, is to use a oil stone and stone a little negative rake on the face of the cutting edge of the drill bit. It won't take much and sure makes life easier. Use a little cutting fluid while drilling and you can control the drill bit easily. I used to keep a full set of negative rake drills, taps, and counter- bores for bronze, along with a full set of bottoming drill bits and taps. Thanks for the video as always!
Play/ backlash is inherent in any normal thread. With a conventional lathe, the play is always moved to one side so it's never a problem. CNC is a whole different ball game although the same principles apply. A really useful feature is a locking mechanism on any slide not in use for the operation at hand. If you don't have it invest time there. We have a Colchester Triumph 2000 lathe at work which I found has a very nicely executed locking mechanism for the compound, also the saddle can be locked. I have yet to locate the cross slide lock.
Lots of people making them. I did so as well a few years ago but made mine out of MDS infused nylon instead of brass. It is easy to machine and works great! This material has a lubrication factor built right in. It will outwear teflon in extreme conditions 100 to 1. Also you can drill a pilot hole all the way through a brass one, then drill a hole all the way through the bolt and use this to directly oil the screw.
Nice job. I recommend that you drill a hole in a screw that you made and a small hole through the nut that you made so that you can oil that nut and you will get a lot more life out of it. That's the way it's done on a standard cross slide from south Bend.
I'm just a hobby machinist so maybe finding center with your six-inch steel rule is commonplace for others. But not for me! I know you didn't explain the process you were using to get center as it wasn't really any of the point of the video, but thanks for leaving it in.
Just love when you get excited when things work out perfectly. Learning lots from you, Thanks!
Excellent video and you have a way of explaining things so that when you're done it all just makes sense. Thank you for that.
Thanks for inviting us into your shop .It was very enjoyable!
A great improvement to the cross slide. I learn a lot from your videos. I like the why you explain the problem, how you will fix it, then demonstrate the fix.
Fun to watch you work. Excellent shop project. I need to pay more attention to tuning up my machines. Well done. 😎 -Mark
That was a top-class job. Really good.
Great job ! That is a big improvement in my book , ENJOYED
Great Job on the project. Fixed 2 problems at the same time!
Good work. Extremely practical!
Absolute genius! Believe it or not, I have actually used my lathe with both of the screws removed, takes a bit of planning but it can be done. Desperation and necessity breed interesting solutions.