9 x 20 half nut problem

[Downunder Bob]

Heres the thread inside the handle after burning out the broken tap then running the intermediate tap through.
View attachment 282873

Then bolted in place
View attachment 282874

Looks like a pretty good reovery

Look forward to a beer Bob.

Me too,.

 

[Downunder Bob]

Cut the keyway in the handle by grinding a carbide (horrible) small boring tool thinner and used the saddle handle to gently cut away the slot.
I used the same process of lowering the tool holder after every pass.
View attachment 282665
To stop the chuck rotating I locked it with my indexing system.
View attachment 282666
I have got to get my act together and clean, polish and blue all my made tools in a forlorn attempt at beating the humidity rust bug.

Charles, have you tried Inox MX3 will stop the rust.

 

[savarin]

Charles, have you tried Inox MX3 will stop the rust.

Which one Bob? I've just looked on line and there are a variety of Inox MX3 products.

 

[Downunder Bob]

Which one Bob? I've just looked on line and there are a variety of Inox MX3 products.

It's called Inox MX3 lubricant, and comes in different container sizes so suit yourself, a spray can is convenient but expensive, a small hand squirt bottle, a 5l container and bigger, you don't need the FG grade unless your working on food machinery.

All the other products like MX2, MX4, MX5 etc are for a variety of uses they are pretty self explanatory on the website. The little hand squirt bottle is a convenient way to try it. Ive been using the 5L bottle now for some time and have a few small squirt bottles around the shop. I use it for protecting metal that is stored outside, especially freshly cut, and or welded. I even give a light spray onto a new roll of MIG wire when I fit it into machine.

Also all my hand tools, also use it as a cutting fluid on lathe, drill press and band saw. It's very good on difficult metals like SS and Al, I don't have a corrosion problem even though shop has evap air con.

 

[savarin]

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.

Flipped it and faced again

I kept it as large as I could just in case.
then turned the fixing spigot.

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.

 

[Downunder Bob]

Waste not want not, still as creative as ever.

 

[dkwflight]

Hi
I thought the threads on the lead screw were pretty sharp on my lathe. I ran a triangl file in the threads as the lead screw turned. This de burred thand softened the edges nicely.
I may have to try the brush idea.
I tried making a cover for the screw nut it did not work too well.
The best thing I did was to make a shelf to catch the chips mounted on the screwa the hold the traveling rest.

 

[Downunder Bob]

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.
View attachment 283343
Flipped it and faced again
View attachment 283344
I kept it as large as I could just in case.
then turned the fixing spigot.
View attachment 283345
Drilled and tapped then filed to fit the gap in the saddle casting
View attachment 283346
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.
View attachment 283342
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.

Love the look of that vernier on the dial, Real cool, and as we all know, cool beats practical all the time.

 

[dkwflight]

I replaced the OEM potmetal half nuts with a set from Grizzly. They seem to work fine except I cannot thread under power using the threading dial. I get multiple tool paths being very careful to get the dial in the exact right/ the same engagement place.
I find an issue with the gearing that makes it mandatory to keep the half nuts engaged.
Problems with the lead screw. I find you have to move the carriage as far to the right as possible with the right side bearing loose engage the half nuts. Then tighten the cap screws.
If you cannot get the lead screw in the right position you may have to enlarge the mounting holes in the bearing as I did.

You also have to de burr the lead screw. I ran a triangle file in the thread grooves under power and also with a stone clean up the key way. This improved the half nut operation.

 

[dkwflight]

This pic shows the tool paths I got while power threading. most of the blue is gone