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View Full Version : Made some new feedscrew nuts for my mill/drill



Mike W
05-10-2004, 03:06 PM
New ones were $45 each so I made a new and improved version. :)

http://img36.photobucket.com/albums/v110/tek798/Mill/?action=view&current=Lower_nut_1.jpg

Paychk
05-10-2004, 05:47 PM
Too cool, I like how you adjust the upper nut, that is a slick solution to taking the slack out. :cool2:

fla jim
05-10-2004, 05:56 PM
Thats excellent work Mike. Did you do the cuts with a slitting saw?Show us some pictures of your shop.

one_rod
05-10-2004, 06:02 PM
That is a nice piece of work. I'm guessing the split nut is bronze, and the locating pin at the top.
The rest of the assembly? Looks like ally. casting from the photos. Did you do that yourself?
The spring loaded setscrews, are they backlash control?
Can't quite figure it out from the photos.

Forgive the dumb questions but I am reconditioning an old miller with worn out lead screw nuts and am looking for good advice.

Mike W
05-10-2004, 11:27 PM
My slitting saw was my ultra precise hacksaw. :o

The mill was out of commission so all I had was the lathe and the bandsaw. The part that holds the nut is steel. I cut it out on the bandsaw and bored it on the lathe.

The two balls go in holes on the sides. Then you screw in the allen head screws. They have a taper on the end to push on the balls. I used a set screw to contact a dimple on the nut to keep it from turning. I can adjust the backlash with a long extension holding a 3/8 socket with an allen key in it.

I can take out all the backlash but then the handles are too hard to turn so I set them to .010 to .015 of backlash.

This whole project is a result of burrs on the lower feed screw which ate up the nut. Check yours if you haven't yet. :D

one_rod
05-11-2004, 06:03 PM
Mike,

Yes I get the idea now. Thanks for the info.
The nuts on my machine are just bronze castings, bored and threaded. No means of take-up on them at all. That will change when I make the new ones.
The machine is in bits at the moment and it will go back together clean but the screws are very exposed so I may make some kind of shields to keep the swarf off them.

Once again thanks for the advice.

rusted
05-12-2004, 04:56 PM
Showoff :D I'm jealous, I need one of those things someday.

Every day I work on my house or in the shop, I think of more and more things I could make. A mill and lathe just puts you there.

Mike W
05-13-2004, 03:58 AM
Yeah, but it is a disease. I am looking for a bigger lathe now. :D

HWooldridge
05-13-2004, 04:29 PM
Just a note: Some mills (Bridgeport designs) allow you to turn the nuts around. Since the drive force with a two nut design is all on one side, swapping end for end lets you employ the unused side of the thread. I also agree with your comment on backlash. You must have a little bit or the damn thing won't turn. I have purchased at scrap prices and rebuilt a few Bridgeports rather than see them get melted and sent to China.