Aluminum casting projects

HI
In a past post interest was shown for casting aluminum.
Reil Burner (Oxide00 Project #2)
And a project “The Dividing Head” by David Gingery. Well I built one many years ago and just finished a project that I needed to cut gears for. I developed a foot pedal that could be used on a tig welder or motor speed control. Here is a youtube video showing 2 foot pedal I built the last using the gears.
http://www.youtube.com/watch?v=283PgFZbHAA The small gear is a 16 tooth (.817) diameter and the large one is a segment of a 120 tooth gear. I cut a disk of ¼” aluminum (5.454”) with a center hole of 1.125”. This disk would make a 120 tooth gear but I needed only 20 teeth. The disk was cut into pie shaped pieces welded to a thicker (.750”) 1.125” disk with a 3/8” center hole. This was used to cut the 20 tooth gear section shown in the video.
Attached are pictures of the dividing head that I made.

Have fun
Tom

Thanks Tom,

You just showed me why I need an AC Tig. I knew I wanted one, I just couldn't quite see why, but now I know. ;)

Thurmond

those look really nice. What method did you use to cut the teeth? How did you get the correct play in the gear mesh or did that not matter since it wont run high speed or for a long time at once?

HI Jason
I used a handmade cutter in a milling machine and a dividing head shown in the last pictures. For this application this worked just fine. If I wanted production gears I would use an involute gear cutter. The process of cutting gears is not that hard. There are formulas that give you the info needed like size of gear blank and how deep to cut the teeth (actually the space between the teeth). David Gingery has a series of book on how to make many things your-self.
http://www.lindsaybks.com/dgjp/index.html
And for aluminum casting
http://www.backyardmetalcasting.com/forums/
Or google the topic of your choice.
Great fun. If you want more info just post it.
Have fun
Tom