Hey guys, you might have followed my build along in another thread, here is the resulting video:
Spoiler: I bought a side-channel blower which is going to arrive in a few days I hope (will have nearly the same specs as my Miele Vaccum, but will not break down as fast). I also tried it with 18mm MDF that I only planed down on one side and it also worked well. Further tests later. 
One of the challenges of using a vacuum cleaner for this sort of work is that they rely on exhausting the air around the motor to keep things cool. When the vacuum is blocked, things heat up in a hurry. You may want to add an additional “cooling air” source around the motor.
That’s the problem with a vaccum.
If you have an air compressor you could also use that cheap and wonderfull device that create huge depression and is exactly made for that vaccum table use case :
https://a.aliexpress.com/_ExCQVor
Most modern shop vacs have their own motor cooling fan.
Those vacuum generators do work decently, but often require a fair sized compressor to work. Also the generator needs to be big enough to handle the worst leak, and they use the same amount of energy regardless of the amount of leaking. So not as simple as proper pump.
I didn’t know this… makes me appreciate how much more efficient older vacuums were in that regard, hehe.
they weren’t. They were pulling dirt and crap right through the motor. Newer vacs use the same motor, the cooling fan is outside the vac airflow so it’s not filling the motor full of dirt.
Ditto on all your reasons! We had a few machines that used them. They worked well at first, then multiple issues with leaks, both on air supply and vacuum lines. All have been removed.
Intriguing. Does a vacuum hose leak more often than a pressurized one?
If you don’t use a vacuum pump but a side channel blower like I do (or a shop vac) it is never a “real” vacuum. Should be called “Suction Table”… The blower and Vac need the air to cool and work. If there was no airflow, the vacuum would stop to work.
The “failure mode” I experenced was that the plastic (nylon?) brush holders in the shop-vac motor got hot enough to deform and the brushes stopped making contact with the commutator.
Hi All,
So @Tokoloshe and @ttraband,
Philipp is 100% correct regarding a suction table vs and vacuum table. Also about 90% correct around the vac motors
So it turns out we sell whole home vacuum systems and we repair them, i don’t deal in that area, and although I had seen them on the wall I had not put 2 & 2 together.
SO after having a chat to the guy that does that, here is what I learnt.
There are general 3 types of motors.
This is what they call a “bypass” motor as the dust is not drawn through the motor, this unit would be much better for a suction table. This is the motor that i plan to use as its like 4hp. The air to cool the unit is drawn separatly, this means it will last longer BEFORE over heating.
then we have two other cheaper designs, that are called FLOW THROUGH motors as the air from teh vacuum force flows through the motor.
So my idea to use them was to mount a BYPASS unit into a box and as i am using a PAULK table (basically a really big torsion box with open sides and a grid of 20mm holes spaced in a 96mm grid on the surface.) i could use that box holding the motor and slide it into the space under my table and locate it using the 20mm holes in my table, and use one of the holes for the suction area. (see my build tread for more info on the table.)
After doing the reading here, it seems hard piping is the best idea, but that would negate the idea of using the one table for multiple things, OLNY in my case, but technically you could do the same thing and just add the vac motor directly to the hard pipe.
So, for me, using a suction table and the MDF properties, plus the fact these motor a MUCH larger than the average VAC, i am hoping for a good result.
And I just got giving a second hand Central Vac unit as my dust collection unit. COOL!
now to make a cyclonic seperator to save the money on bags!
