Jay needed a collet chuck for his lathe. The problem? He couldn’t get the Finance Director to sign off on his requistion for a new one. His wife is mean like that.
The other problem was that the commercially available ones were ER32 and Jay already owned ER25. If he couldn’t get the requisition signed off for the collet chuck, there was no WAY he would get it signed off for the chuck AND a new set of collets.
While at work, he poured a cup of coffee and it was so bad that he thought he could machine a collet chuck out of it!
(I’ve asked Jay to help me write this post because I have no idea what’s going on in most of these pictures. He doesn’t like my commentary, so if the rest of this post is not funny at all it’s not my problem ~ Management)
“At work I took a coffee cup, set it into a coffee can on a bed of sand and made a mold around it. It was poured and I let it cool. Then I cut two pieces out of it to check the machinability and to be able to use it with the four jaw chuck.
First thing that had to be done was to clamp it on the mill and face off the big end.
I wanted to make sure there wouldn’t be a big interrupted cut and to get a reasonably flat surface for indicating on the lathe.
Once in the lathe I started facing and turning the large diameter.
I used a center drill in preparation for a registration shoulder to bolt it directly to the lathe spindle.
Once I had the registration surface, and it fit well, I moved it back over to the mill. I then found center on the hole and drilled and tapped a bolt hole circle to fit the lathe spindle.
The small end was no longer needed on the casting, so I cut it off.
Now I could remove the four-jaw chuck from the spindle and bolt the casting directly to the spindle for the rest of the work.
I began turning and facing to remove the rough casting. Even though the casting was full of holes I knew they were just on the surface and would be machined off in the process.
I began boring out the center.
I had to bore it out to 3/4″. Then I used the compound and began machining the taper.
(Note from Management – He used the chicken head to do this. Back to Jay…)
The external threads were cut using single point on the lathe. They are metric threads cut on an Imperial lathe. Interesting to say the least.
(Note from Management – Darth Vader was NOT involved….)
After threading, contouring was the next step.
If you’re wondering, this is what five pounds of cast iron chips look like attached to a magnet.
Collet and nut installed. The run-out on the taper is .0005″. Good enough for my underground shop. Now it’s time to grab a dull beaver and start making more chips!