Wednesday, May 27, 2015

Lathe project

Some video and pictures from the latest project, an Atlas 10D 246 vertical drive lathe restoration. 

These guys have been awesome help so far: the mailing list has an extremely deep knowledge of these old tools and is eager to share information an dideas.

The ways determine accuracy of the lathe. The ways are the metal parts where the carriage moves toward and away from the jaws of the jaws of the chuck, which holds the spinning material. Older lathes wear here first and lose accuracy. Here I am trying to measure for problems.

On overall picture of the project in pieces.

The first real problem. A carriage gear is missing a tooth and the gear case is broken into three pieces. Unfortunately the case is an injection molded alloy metal with a very low melting point so welding or brazing are out of the question. The metal itself is an interesting mix of aluminum, zinc, magnesium, and copper called Zamak. 

 The gear will have to be pressed off the shaft, I have a new one on the way. Still researching how to best fix the case. That may take a while to think through. 

Update: Last night I presented this broken part to the CAMS club monthly meeting. I mean actual presentation. I stood in front of the group and described the project, it was a fun impromptu public speaking opportunity. The group discussion about the project was informative and I think I have several good approaches to this project.  

There were plenty of ideas about how to fix the broken part. I think I'm going to try alumaweld aluminum rods to do the repair. I picked some up today at harbor freight, 15$ for a ten pack, along with a cheap butane torch. While in Home Depot I also noticed that they had aluminum welding rods, so I picked some of those up $3.69 for a pack of three. I'll have to experiment to see which works better.

At the end of the meeting, one of the club members who was following my project on the mailing list pulled me aside and presented me with some better chucks for the lathe and sold them to me at a great price. The original three jaw chuck is in the picture to the right. The two chucks to the left are a better three jaw and an independant 4 jaw that I purchased at the CAMS meeting.

Update: Today, my new gear arrived in the mail. I spent a few minutes taking things apart and getting them ready for alumaweld. After some light heating with a small butane torch, the gear was easily tapped off of the shaft. 

I've since cleaned the oil/grease off of these, but neglected to take a picture. I'll post more after I attempt the weld.

Update: Weld failed. I heated the part slightly too much. Without any warning or indication it transformed from a part to a thousand little molten balls of metal skittering across my work bench. It wasn't that important anyway since the lathe is somewhat usable without it. I have plans to fabricate a new part from scratch, I can infer the dimensions from my sketches and the bolt holes on the lathe apron.