Oh boy, I did it again! PRAZI SD400.

[twhite]

This is a friggin disaster....

Heres some music while youre waiting for me to unfuck myself.

If anyone knows what movie the GTO and Gasser scenes were from PLMK.

Two lane blacktop with Dennis Wilson as the Mechanic James Taylor as The Driver. Loved that movie.


Cutting oil is my blood.

 

[RaisedByWolves]

Kinda took a fork in the road here as I had two projects that needed the 4 jaw chuck and figured Id knock them both out while I had the 4 jaw on the lathe.


First one was adding a radial and thrust bearing to the tailstock. If you are watching the other SD400 thread you have probably skip ahead to the oiler modification below as much of this is repetitive.


I wont go into great detail here, so basically I bored a hole .0005 larger than the radial bearing and made it a snug fit.

Then I bored a pocket for the thrust bearing. The blue portion in the back wall of the bearing pocket and you can just make out the step between the two bores if you look close, its kinda blurry.

With that done I test fit everything and found it all to work well. I stacked up the bearings on the quill screw shaft and assembled the whole works and function checked. It was at this point I realized I was not done, there is no provision from the factory to oil the quill screw bearing and no way to get oil to the bearings I just added.

Taking inspiration from the SD300 lathe I decided to install a small set screw to provide an oiling port.


Looking at it from the inside.

And all put back together. That makes for one less step to do. If you look at the tailstock back plate you can just make out the set screw for oiling.












And now for the 2nd job using the 4 jaw, modifying the oilers.

I looked all over to find some small oilers to provide a simple way of oiling the rear bed way on these machines and couldn't find what I wanted, so I bought the next closest thing and modified them.


I needed to fit this .750 tall oiler:







Into this .750 space on the back of the saddle. The red line represents the rear way and there is actually about an inch of room to the top of the cross slide ways, but I wanted to mount the oiler higher so I could angle the hole with a slight downward slope, hence the need to make the oilers as compact as possible. The red dot denotes the approximate location. It looks offset, but it is actually centered on the length of that way.











So into the 4 jaw they went. I had a hard time indicating these as their pressure cast zamak and nothing is round or square to anything I could find on earth.

I tried indicating the outside, but even where the flange for the cap retainer rides was wildly out of round.









So I settled on indicating the bore.









Even that wasn't great, but I was able to get it within .002 radially and axially (I think) and figured that was good enough.



Then I turned off the old spigot and flange.







Took off the peak of one of the hex shape of the body to lend some extra room.







Then turned a new spigot and retaining groove.







Perfect!







I then assembled it all back together. Better than the day it was made and .225 shorter than it was.









With that excursion completed Ill get back to the apron gear train and get closer to final assembly.

 

[Pevehouse]

Kinda took a fork in the road here as I had two projects that needed the 4 jaw chuck and figured Id knock them both out while I had the 4 jaw on the lathe.


First one was adding a radial and thrust bearing to the tailstock. If you are watching the other SD400 thread you have probably skip ahead to the oiler modification below as much of this is repetitive.


I wont go into great detail here, so basically I bored a hole .0005 larger than the radial bearing and made it a snug fit.

Then I bored a pocket for the thrust bearing. The blue portion in the back wall of the bearing pocket and you can just make out the step between the two bores if you look close, its kinda blurry.

With that done I test fit everything and found it all to work well. I stacked up the bearings on the quill screw shaft and assembled the whole works and function checked. It was at this point I realized I was not done, there is no provision from the factory to oil the quill screw bearing and no way to get oil to the bearings I just added.

Taking inspiration from the SD300 lathe I decided to install a small set screw to provide an oiling port.


Looking at it from the inside.

And all put back together. That makes for one less step to do. If you look at the tailstock back plate you can just make out the set screw for oiling.






View attachment 505707





And now for the 2nd job using the 4 jaw, modifying the oilers.

I looked all over to find some small oilers to provide a simple way of oiling the rear bed way on these machines and couldn't find what I wanted, so I bought the next closest thing and modified them.


I needed to fit this .750 tall oiler:



View attachment 505709



Into this .750 space on the back of the saddle. The red line represents the rear way and there is actually about an inch of room to the top of the cross slide ways, but I wanted to mount the oiler higher so I could angle the hole with a slight downward slope, hence the need to make the oilers as compact as possible. The red dot denotes the approximate location. It looks offset, but it is actually centered on the length of that way.





View attachment 505721





So into the 4 jaw they went. I had a hard time indicating these as their pressure cast zamak and nothing is round or square to anything I could find on earth.

I tried indicating the outside, but even where the flange for the cap retainer rides was wildly out of round.


View attachment 505710






So I settled on indicating the bore.




View attachment 505716




Even that wasn't great, but I was able to get it within .002 radially and axially (I think) and figured that was good enough.



Then I turned off the old spigot and flange.



View attachment 505711



Took off the peak of one of the hex shape of the body to lend some extra room.



View attachment 505712



Then turned a new spigot and retaining groove.



View attachment 505714



Perfect!




View attachment 505713


I then assembled it all back together. Better than the day it was made and .225 shorter than it was.




View attachment 505715




With that excursion completed Ill get back to the apron gear train and get closer to final assembly.

I love to watch the way you work. Your an amazing machinist sir