Quote Originally Posted by irving2008 View Post
There was an extensive thread on CNCZone on this for a CNC milling machine... using a compressed air ram to eject the tool into the holder and some form of locking mechanism to pick the tool up. Not sure its a simple home build exercise tho....

yea i saw that one ..problem is - its getting a bit complicated (there's a fella on youtube thats built one -- its real slow)- looking more towards something like those quick change posi -bit holder options ! I did find a thread on cnc-zone (don't ask me to find it again!! I can't --I've tried) but it wasn't suitable for anything over 10 000 rpm..... Lee its for a mill ...I got an idea of using the same type of tool changer as what you find on a lathe toolpost ( you know the wedge / dovetail variety).

I do have an idea for one one but its going to be a bugger of a build .... imagine for a sec a normal tool holder ...looking at it from the top view --theres a wedge shape mounted ontop --about 10 - 12 mm wide tappering down to about 5mm ..... from the front (pointy end facing you ) the two longest sides will be dovetailed ....and the pointy end sloped downward with a small circular pocket milled into the top about 5mm deep.

the spindle would have the other side (female) with a springloaded ''drawbar'' of sorts -- more of a ''pushbar''...so as the pointy end of the toolholder slides into the wide open end of the spindle ..at a point the ''pushbar'' drops into the pocket milled out ontop of the toolholder and locks the entire thing into position! .....to release --the ''pushbar'' is lifted by pulling the outer sleeve up ... i do have the alignment figured out --but thats for next --times short and i got to move ...

too da looo