DIY Vacuum Fixtures

[Boyan Silyavski]

here is the video where i show the details of the vacuum system, if you are ready to bear with my gibberish for 5 min

[Boyan Silyavski]

Hi,
one more video. The final result. Using the vacuum station with the aforementioned vacuum fixture. That saves me a couple of operations when fabricating the top and bottom of the small musical instruments i make. Avoiding tabs, cutting the tabs, sanding the tabs, sanding the shape. The pull is incredible, i can not move it with all my force.

The video is a timelapse of the 15 min process. The cutting is done using 3 flute 1/4" carbide at 17k rpm and 90IPM. I tried full length cut and no problem with that as the fixture is strong and the machine is rigid, but fire starts inside the dust, so no additional 5min savings for now. Maybe time for a new dust shoe and a bigger cutter.


So all cost me not so much, looks nice and is useful to the point that i see starting to use vacuum fixtures for anything i make. Made from cheap wood, it saves additional operations. As far as i see it the key being here is make properly specific vacuum fixture to maximise pull, universal table will be nice, but specific fixtures are simply perfect and easy to make.

[Boyan Silyavski]

Some follow up after 2 weeks of 8h per day continuous use.


All works like a charm. Super strong holding force when fixture designed with laws of physics in mind, meaning as big as possible vacuum suction cap area.



But:

Somewhere hidden in the vacuum pump manual is that - When in continuous use oil heats, goes out of pump and travels from exhaust out!!! Discovered that the hard way. Good that i always monitor first time setups. So there is a need of another expensive device that separates and recycles the oil. Or in exhaust there is a spring valve that makes back pressure of 1-2 bars to pump. Remove that and all is cured. But smoke starts then. Dangerous for health smoke.

"No way" i though. More money? The solution - after the exhaust, either you have it or you don't, a pipe must be fitted, vertical for at least 50cm .Oil goes up and when stopped goes down. That ventilates gases far away from your workshop. I left the backpressure valve so i don't produce a lot of smoke. Without this it becomes impossible in workshop after a couple of minutes.Anyways i was wearing a gas mask / for the fine dust. Care should be taken for dust or humidity not to enter back as it sucks all when cooled. When pipe long enough that's not a problem. Plus i bent it at the roof downwards so rain stays out of it

After trial and error i discovered that 35-40Hz from VFD /when 50 is max, remember its a 3 phase / works best so pump makes fast enough negative pressure, no need of valves and pressure switches to control in case of too much vacuum and at same time pump is cool to the touch. That keeps it from consuming oil also.
I think that's the best discovery i have made so far and i think that the pump in this mode will need no repair soon even if working nonstop.


Here is how little smoke it makes now with this setup. No windows or neighbours near, dont worry.