Stripped Half Nuts

[savarin]

And here it is in place
in the off position

And engaged. Way much better to handle that the original lever.

The two c/sunk screws are temps till the grub screws arrive.

 

[savarin]

Just a quick update on the half nuts.
With the handle in the engaged position the half nuts clamp onto the lead-screw with absolutely no backlash unlike previously.
If I disengage the lead-screw drive and engage the half nuts the saddle is solid with zero movement which I found out doing a series of heavy interrupted facing cuts on a 100mm x 19mm face. No more hanging on to the traversing handle like grim death to keep it in position.
Singly point thread cutting test in the next few days as I build the qctp plinth.

 

[Bill Gruby]

Maybe you can't see or feel it Charles but there has to be some backlash no matter how little. Absolute Backlash and the screw will NOT turn in the nut.

"Billy G"

 

[savarin]

Point taken Bill, I'l re-phrase it to "So little that I cant feel it."
Compared to what was there before its like chalk and cheese.

 

[Bill Gruby]

Just messin with ya Charles. I know what you said. For the benefit of the super new guys, zero backlash in a screw thread means all surfaces are engaged or touching. When this happens there will be no movement at all. We can get super close to zero but can never get there if we wish things to move.

"Billy G"

 

[RCWorks]

Well I am glad I saw this thread... My lathe is low hours but I use it more and more... I just called up and ordered a set of half nuts for mine before they are imposable to get.

My machine is still being sold online and in the store and they first told me that they were not available, yet they still sell my lathe with up to a 2 year warranty. With that I asked for management and managed to place an order for mine for $13.99.

I am looking at selling mine to go to a bigger machine, but if things keep the way they are I may just convert the 8x12 to CMC and buy a good 10 inch.

But thanks for the thread, you may have just saved me some grief down the road. The day I install that new one will be the day I sell that lathe.

 

[xman_charl]

made up some half nuts years ago, still working good

Charl

 

[Mark_f]

I'm glad that worked out. I would have got a block of bronze and made new nuts by machining a nut and splitting it. I figure if someone made it .... So can I .