Author Topic: worn out half nuts  (Read 1745 times)

savarin

Re: worn out half nuts
« Reply #30 on: December 18, 2018, 05:52:37 AM »
And then that bloody shed gremlin got into the act.
I started to make the actual handle for the cross slide in stainless.I was rather happy with the result that took me about 4 hours to almost finish.
I turned the end down leaving a length thinking I was being clever so it could be reversed in the chuck and a 6mm hole drilled and tapped in then parted off to finish.
Nice and easy , no problems, yeah right.
Tapping under hand pressure only,  plenty of cutting oil, by hand very gently and BANG! it bloody snapped.
I am so glad I made that eroder but how to hold the unusual shape.
I drilled a 9mm hole through a block of wood then a 14mm hole 3/4s through then a 5/8" for the fat end.
This keeps the handle vertical and tomotow I will finish burning through the tap (I hope)



woodchucker

Re: worn out half nuts
« Reply #31 on: December 18, 2018, 08:49:27 AM »

I am so glad I made that eroder but how to hold the unusual shape.
I drilled a 9mm hole through a block of wood then a 14mm hole 3/4s through then a 5/8" for the fat end.
This keeps the handle vertical and tomotow I will finish burning through the tap (I hope)


You made an EDM machine? Super. good luck with getting the tap drilled out.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

chips and more

Re: worn out half nuts
« Reply #32 on: December 18, 2018, 08:54:24 AM »
Your “Yankee Ingenuity” will always amaze me!

savarin

Re: worn out half nuts
« Reply #33 on: December 20, 2018, 06:56:31 AM »
Done. I replaced the usual brass electrode with a tungsten rod from the tig set.
This was well worthwhile and burnt faster with less reduction of the electrode.
The internal thread was after the burn out, picked out a couple of little bits of the tap thread then ran the intermediate tap through.
Looks like I missed all the cut threads with the electrode.
And the handle in place.
And yes, the little black dots are inclusions or porosity in the cast aluminium disk.

savarin

Re: worn out half nuts
« Reply #34 on: December 26, 2018, 04:15:10 AM »
Todays job was making a new cross slide nut from some brass sponge as a test.
I will eventually do this in bronze and hopefully solid metal not a spongy mess. Chopped a chunk from some failed casting and faced it off.
then turned the fixing spigot, gee, look at all that porosity.
Drilled and tapped then filed to fit the gap in the saddle casting.
With such a long thread it is very smooth and not much side play.
 I need to add a couple of shims on the top of the boss as if I tighten the fixing screw very tight the movement becomes stiffer. 
All bolted up and a nice smooth movement with extended travel both fore and aft.
 When the M10x1 die arrives I will cut the shaft 12 mm shorter and use two M10x1 locknuts to fix the handle.
 Compared to the original its now  joy to use.

4GSR

Re: worn out half nuts
« Reply #35 on: December 26, 2018, 07:07:20 AM »
That's a cool modification you made there. Most of the smaller Asian made lathes have that problem of not enough travel on the cross side.

savarin

Re: worn out half nuts
« Reply #36 on: December 26, 2018, 07:58:23 PM »
Thanks Ken, I got the idea from various people who have done a similar mod.
I just had to think a bit how I could do the same without a mill.

chips and more

Re: worn out half nuts
« Reply #37 on: December 27, 2018, 09:28:51 AM »
Great job…as always! I think that porosity is a really good thing. All those little holes will retain oil. I wonder if there is a way to soak that nut in oil and make it kinda like Oilite? Maybe in a vacuum? I’ll bet, if you tried to make that spongy stuff on purpose, you would have a hard time doing it…LOL...Dave
« Last Edit: December 27, 2018, 09:33:07 AM by chips and more »

PJB

Re: worn out half nuts
« Reply #38 on: December 27, 2018, 01:33:02 PM »
Nice work...Kinda makes you appreciate why mfg’s all gouge $$ you on replacement nuts.   
I want what yooz gots