Here is another shop built tool I thought might be of interested and the build process:
The Cathead Fixture.
Inspired by Jerry Keefer and Dave Berryhill to strive for the best, most accurate work possible I decided to take on this little project. While the project itself is fairly simple cleaning up the mess- not so much!
The cathead is a fixture used support and center a part to be machined that can not be held adequately by the machine alone using the usual holding methods, Chuck, etc.
In my case this cathead is going to be used to hold 1911 barrels, primarily for cutting length and re-crowning.
Her are a few pictures of the process of making my cathead fixture.
I started with a 3” round billet then drilled and bored it to accommodate the 1911 barrel dimensions:
Next off to the mill to locate, drill and tap the adjusting screw holes:
Each hole was located drilled and chamfered, the tap was started with the mill to ensure a straight shot then finished by hand:
When the fixture body was complete I modified the eight adjustment screws with a brass contact tip to reduce the chance of marring the barrel. I will most likely be using small aluminum pads for the screws to rotate on but in case that isn’t needed or possible the brass is a good fall back.
The end of the screws were faced off and drilled to accept the brass then the brass rod was turned down to the large dimension and each tip cut down to an interference fit in the screws. Sorry I didn’t get pics of the tip making process just of the finishes product:
That’s it, a simple project, although time consuming... especially the boring-boring!
Hear she is:
OH! The mess, You really create a large quantity of chips/swarf when boring a solid bar out to almost 1.6”! I would have preferred if the surplus metals place would have had some heavy walled aluminum tubing... But I guess I was lucky to find a section of bar stock just the right size.
This was a fun project... except the mess!
Now I need to get hold of a range rod so I can indicate the axis of the bore for those perfectly square crowns!
Hear’s a link to how Dave uses his Cathead:
http://www.1911pro.com/forum/viewtopic.php?f=23&t=118