# G0704 Pneumatic draw bar and belt mod with pictures



## zaaephod (Feb 15, 2014)

The belt drive mod was based on the project in this thread: 

http://www.hobby-machinist.com/showthread.php/18468-Belt-Drive-Conversion-for-Grizzly-G0704?p=180536&posted=1#post180536

The pneumatic draw bar design is my own. Just push it down, rotate the spindle if needed, and hit the trigger. You'll notice I tend to go with the KISS method, keep it stupid simple. I also like to reuse scrap whenever I can, which often leads to odd looking builds. Sadly, I do not yet have a way to mill parts with nice radii, that's for another day.

Obviously, I need to clean up that wiring (along with the rest of the shop), I just got tired of taking the motor off over and over again. As it turns out, having a second mill would really have made this all easier.

The 3/8" butterfly impact came from a local hardware store for $27.
The mount it's in is part of an old dead pick and place machine.
The 20mm linear slide and bearing block were discarded from one of my machines, they were too worn for use there, but are just fine for this project.
The motor mount, and standoffs were cast in my home foundry, which I'm always proud of.

As you can see, the belt I got was thinner than I meant it to be, I'm waiting on the replacement, though even this little one is doing just fine. It turns out that a 6 corner 3/8" drive, 3/8" socket fits nice and tight on the square draw bar, though I may weld it, if it ever gets loose.

The last few pictures show the motor mounts I made, sand casting, and cleanup. I made two, one is thicker, I ended up using the thin one.


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