You're welcome! Hope it helps.

Thanks! Glad it helped.

The springs pushing the blades/vanes out against the edge of the chambers would close the gap. I don't know how much of the blades could be worn away before the pump would stop working entirely.

Mine eventually had this problem too. I attributed it to a failed starter capacitor or switch. I got a refund and bought a new one.

ime when it does that, try turning it off and on again, kick it, or hit it with a rubber mallet. sometimes it just need a good whack to get going. we're not dealing with high quality parts here - I think it just doesn't always have the power to overcome the friction on a cold start to get going. The metal shavings building up inside over time probably don't help.

Yup, my box, manual and nameplate all disagreed on the specifics too. I don't actually know the specs of mine for certain. I'm happy with the performance though!

I can't find a good frame in the video to show it, but I recall a small hole in the first stage that leads to under the surface level of the oil sump that allows a small amount of oil to seep in and be carried through. That little plastic bit at 6:00 is just to fill the key in that shaft, as far as I can tell.

@@tjhowse that little plastic at the small hole is the oil pump that circulates fresh oil through the vanes, its actually a very small vane itself.

I never did get to the bottom of the problem with this pump. A few weeks after this video the motor burned out. I got a refund and bought a slightly larger version that has worked perfectly well. It still gets hot, but doesn't cut out from overheating. I'd imagine you'd get quickly diminishing returns by adding further stages. It wouldn't pump down any faster, and the quality of the vacuum would be limited by factors other than the number of stages. Getting deeper vacuums would be done with a turbomolecular pump, since at these low pressures air molecules act more like balls ping-ponging around inside the volume rather than a gas.

i mean if i pour oil through oil port or exhaust port they are going within same place?

Yep! They both lead to the same sump.

It's pretty simple inside. There's a centrifugal starter switch and capacitor and an overtemp cutoff switch.

@@tjhowse ok tkanks , I just have one that has had the case broken and some wires were disconnected, trying to figure out where the wires go