(03-23-2014, 07:55 PM)PixMan Wrote: I took the nut out of the chuck thinking it would run down the whole thread, not so. I had to put it back in and take another thousandth or two. That's a pain in the butt!
I hesitate to say this Ken but, nyah, nyah, I told you so.
03-24-2014, 07:26 PM (This post was last modified: 03-25-2014, 07:27 AM by PixMan.)
Still not sure why it did that because there really doesn't seem to be ANY taper in the screw.
If you've ever made mating Acme screws you would know just how oddly they fit together. The tiniest change in pitch diameter or thread form can be the difference between binding up, smooth fit or just plain wonky fit. The nut now sails from end to end on the screw and there's no measureable difference in clearance anywhere.
Nice job on the nut Ken (and the tool). It looks like you got a good grade of bronze for machining.
Another easy way to reacquire a thread is to run the tool into the bore with it retracted and stop the spindle with the lead screw engaged. Then you can sort of feel your way into the thread using the compound and cross slide to get close and finish up under power (cross slide till it touches and compound to depth). It's definitely easier on coarse threads than fine ones.
What's left to do with the screw is to turn the 20mm diameter and M12x1.75 thread, them mill keyways and drill a hole through it. Look for Darren's print in the Milling Machine section under Kondia rebuild thread.
The hole through the key slot confuses me. I cannot see a function for it other than to knock the key out should it get stuck. There are other shafts with key slots on this mill that don't have a through hole, so it is not a consistent feature.
Darren is it possible that under a previous ownership, whatever it is that is now held by the keyway was once pinned to the shaft?
Is it a straight key or a woodruff? Maybe the hole was to pin the straight key?
03-25-2014, 10:29 AM (This post was last modified: 03-25-2014, 10:31 AM by PixMan.)
Attached the prints he sent me. You can see the 3.5mm hole going through the shaft for no readily apparent reason other than to perhaps make it weaker.
If anything could use that hole as a knockout, it should be that blind 5mm pin hole!
Steve - I'm currently in Europe at a meeting, so I cannot refer to the original Kondia drawings. However, I don't believe that the shaft has been modified.
I've been wanting to make a two-in-one wrench for my QCTP for some time. I managed to slip it into the lineup after work today.
The main nut on the tool post is different than the one for the four-way tool post, so using sockets makes the most sense. I started with a pair of drive adapters for 3/8" and 1/2" drive. I turned a short piece of steel with bosses on the ends to fit the inside parts of the adapters.
I welded the adapters to the centre piece and drilled and tapped it for a threaded handle I had kicking around.
From this ...
To this.
Mike
If you can't get one, make one.
Hawkeye, proud to be a member of MetalworkingFun Forum since Jan 2013.