by Rando » Fri Nov 24, 2017 11:39 am
CyberBiker:
Maybe a blast-gate style "valve" can lower the amount of air pulled? Technically, a side-hole or open Y in the vacuum tube will also shunt some of the pressure. If you put the blast gate in that side vent, you could adjust the pressure in the main tube without restricting the main tube's cross-section. The closer the shunt valve is to the final end, the more of the main extraction tube length will be having the higher air volume, improving material clearance of the tube while also reducing intake flow rate at the material removal opening
I do the opposite, working in aluminum, I need a chip-blower. In that case, I use the Loc-Line series of lines, valves, manifolds, nozzles, etc., and I use the valves to adjust the amount of air from each nozzle.
And failing that, maybe the cheapest solution is to get a much smaller shop-vac. I use the $49 small plastic ones, since running during a multi-hour CNC run isn't what most shop vacs are happy doing. Among the ones I have, the smaller ones are quieter, also a bonus for long runs. That way, if the motor/bearings die, it will at least be a low-cost thing and only stop that one function, not the whole shop. For recycling purposes, to have a "clean" waste stream, I use separate vacuums for aluminum chips and then anything else. That way my aluminum chips don't have contaminants in recycling. In the 2.5 years I 've been running, only one of the little units died, and that was due to a hole in the filter that let metal chips in to the motor. D'oh!
You can also get around the too-heavy issue of the larger tubing by suspending it from the ceiling on a spring that takes like 90+% of the weight of the haging tubes. I do that with my two air tubes, my mister, the spindle power and coolant: they're all suspended from the ceiling now, with almost no weight on the gantry or the z-axis carriage. Picture below:
Regards,
Thom