Here is an old mini lathe model 1679 that I purchased 28 years ago. In my ownership of this lathe I made a ton of parts, lawnmower parts, truck parts, mill parts, gun stuff, etc.
One problem I found with this machine was in single point threading. The machine RPMS are just too fast and I can't control the stop points when generating threads. Here was my solution. I made this almost out of the gate, and it fixed it up nicely!
I found an old tire off of a small tractor in the shed. This will be used as a manual chuck drive. I added a shaft that slides into the spindle bore and placed it into that old tire. I put a roll pin thru the shaft as a drive key. I cut a slot on the outside of the spindle bore shaft. When this is all assembled I can simply rotate the chuck to form my threads without the fear of not stopping where I what it to stop, thus avoiding damaging my threading operation and ruining my job.
The pictures will help you understand what I'm trying to describe.
The other modification was I added a quick change tool post. This can be seen in the last picture. I needed to mill the cross slide down .300 so the center height of about .552 would be maintained. That was an easy modification to do. Then I bored a hole underneath so I could bolt the new quick change tool holder in place. I used a long Allen bolt and I pinned the head from underneath to keep it from turning. So when I tighten the bolt it stays tight ( from underneath).
I then milled the extra bit away from the bolt head so the table could be reassembled.
Well, I hope I gave ideas to someone who is just starting out by seeing modifications from other peoples machines!
One problem I found with this machine was in single point threading. The machine RPMS are just too fast and I can't control the stop points when generating threads. Here was my solution. I made this almost out of the gate, and it fixed it up nicely!
I found an old tire off of a small tractor in the shed. This will be used as a manual chuck drive. I added a shaft that slides into the spindle bore and placed it into that old tire. I put a roll pin thru the shaft as a drive key. I cut a slot on the outside of the spindle bore shaft. When this is all assembled I can simply rotate the chuck to form my threads without the fear of not stopping where I what it to stop, thus avoiding damaging my threading operation and ruining my job.
The pictures will help you understand what I'm trying to describe.
The other modification was I added a quick change tool post. This can be seen in the last picture. I needed to mill the cross slide down .300 so the center height of about .552 would be maintained. That was an easy modification to do. Then I bored a hole underneath so I could bolt the new quick change tool holder in place. I used a long Allen bolt and I pinned the head from underneath to keep it from turning. So when I tighten the bolt it stays tight ( from underneath).
I then milled the extra bit away from the bolt head so the table could be reassembled.
Well, I hope I gave ideas to someone who is just starting out by seeing modifications from other peoples machines!
