I had been wanting to put together a vacuum chuck for a while but am too cheap to shell out the money for a commercial system. My idea was to keep it under $100 and use stuff I had in the shop.
On New Years Day Harbor Freight had a 25% off coupon so I couldn't pass up their single stage vacuum pump for $89 minus 25% is $67 including a free flashlight!!!.
Next step was to figure out the adapter. Watching YouTube, it looked like most DIY systems used lamp rod and 3/8 ID bearings. I had the lamp rod but not the bearings. What I did have was lots of skateboard bearings. I used to own an online skateboard shop and that is about all I have left. The problem was how to get the lamp rod to mate to the bearings since the ID of the skateboard bearings are 8mm.
Solution: Air Hose quick connects
So I mated the quick connect to the lamp rod by tapping the internal side of the threaded end and screwing it on the lamp rod.
What isn't shown is that I turned off the hump on the small end so the bearing will ride on the larger shoulder. and the fitting epoxied into the bearing
Now how to mate that to the vacuum hose. Again YouTube had a few ideas. I was watching Earl's Small segment shop and he built one out of wood and as I was watching it became really clear that I had many of these in my shop already. They are called skateboard wheels! So now I had a way to mate the spinning lamp rod with the stationary vacuum hose. I turned another air fitting the same as the the first one and epoxied it in the bearing. I then used a couple fitting adapters to mate it to the vacuum hose.
Now I could get vacuum to the head stock. I needed a chuck. Well, YouTube again. First attempt was a PVC based chuck ala Carl Jacobson and Stephan Ogle. I couldn't get that one to hold vacuum. So I went with MDF and that worked.
Switched it on and got a nice round bowl and plugged it in and was pulling just under 25 inches of Mercury. It was strong enough that I could pull it off. I was thrilled. For a total cash outlay of $67 for the pump and $8 for a pack of the fun foam and my time I have a fully functioning vacuum chuck.
But...
My wife walked into the shop and said why is it so foggy in here? I hadn't noticed in my excitement that the pump was putting out what I thought was smoke as it pulled the vacuum. After some more YouTube I found out it was oil mist and not that great to breath. Again it seamed like there were commercial solutions that cost more than the pump. So did some more searching and found a few ideas, and yes I could use stuff in my shop.
Solution:
A piece of threaded PVC hot glued through the lid of a plastic peanut butter jar. The jar is filled with scotch bright pad and and old t-shirt with holes in the top for exhaust. This seamed to do the trick.
I am thrilled with the outcome but not sure about the long term durability. I guess we will see.