PTS Flowbench Forum

So they look like shop vac motors. They are different than the motor type found in most of our benches. Or at least mine were. Can you show us a pic of the motors with the outlets?
Thanks. I used to run 8 shop vac motors myself and were not that efficient.

I installed the one out of my shop vac and went backwards! so I removed it...
Guess I'll have to order more of the Lamb motors...

I have 3 separate circuits running the 6 motors, no leaks, and they only pull 33.5" wc max with the valves closed...
Am I missing something????

S2Z wrote: Am I missing something????

No, but the guys who have the knowledge are - the spec of the motors. If not a pic, do you have the spec sheet or part number?

S2Z wrote:I installed the one out of my shop vac and went backwards! so I removed it...
Guess I'll have to order more of the Lamb motors...

I have 3 separate circuits running the 6 motors, no leaks, and they only pull 33.5" wc max with the valves closed...
Am I missing something????

I think my 4 motor bench pull a lot more then that, with the bench sealed off..............
But , that's really not whats impotent.

I think the motor spec at 28 to 44" would be more accurate. as that's the working inch of water that most if these bench's work off of.

You can get a vac motor that pulls 100 inch of water but will only flow vary few cfm at 28"
and then you can find a vac motor that will flow 80 cfm..........at 2 inch of water.

when you can get the cross hairs of then two motor to lined up at 28-44 inch, you got a grate vac motor.

And the 3d equation is aprage.........You could probably get a vac motor to pull 100 cfm at 28".......but it would cost to much to buy$$$$, electrical bill, and probably won't fit in you bench.

You have something seriously wrong, do not waist any more money or time on motors, even the cheapest motors will pull over 80” closed off. If you have 6 amtek motors running WFO and are only pulling 33” I would look under the bench to see if it is still there? You are not either telling us the whole story or you have a design flaw or you have a great big leak.

Post some pictures of your setup, BTW the Harbor Freight controllers are good to like 15 amps, if you are testing with no air flow (Free spinning) you will not be draw the current that full flow will.


Rick

Simple flow bench math says 1 Amtek motor equals 2 sets of Bruce’s Plans, DIY is supposed to help us learn and save us money! Food for thought.

I would like to second what Rick has said as I have been 2 other routes for flow benches and have found Bruce's plas the best so far.

Also a question, did you paint the inside of you bench to seal it and then seal all the joints with silicone or some other sealer?

John

and once again, it would be nice to find that thread that had the bubble escaping the bench board/panels.


One more note: are you counting both side of the U Tube? That one threw me for a loop, for the longest time.

If you are reading 33" of water on only one side, this i wrong. You have to read both side aka 66 " of water..................

Oh Man are you kidding ME???? Total BOTH sides of the U-Tube Manometer?

I've been only reading the side that raises under vacuum...
After all this, I've got some really, really good news!


I've completed a total rebuild / rethink of my bench: (Sorry, no Pics)
Got rid of the side mount vacuum source plenum: (Eliminates the "S" bend)
Directly below the MAF is a 4" to 3" reducer directly connecting the MAF to a 4" manifold.
I now have 4 motors running in parallel, (2 pairs of the motors are mounted 180 degrees from each other).
I encased these housings with a 6 inch PVC drain cap and attached a 1 1/2" pipe to each of the housings, which the inlet for an additional motor attaches to. So 4 motors in parallel, with 4 motors stacked in series.
Made rubber gaskets using the stage housing and a dowel, so the rubber gasket now seals against the motors.
Checked each motor output, cleaned the 1st stage housing of RTV, all motors if given the chance will suck the fluid out of top of the manomer(greater than 90" wc)
I used 3 long wood screws to pull the motor housings to the manifold. (no longer relying upon RTV to hold the motors.)
Trimmed each motor 1 1/2" inlet connection flush to the inside of the 4" manifold.
Mounted the manometer to the LH side of the bench to easily read.
CHecked, and rechecked for leaks, NONE!
Now with all the motors running 3/4 to 7/8 WFO, will suck the fluid out of the top of the manometer!
(RATS, its a pain to keep re-filling)...
I building and testing check valves now...
More on that later...

Oh Man are you kidding ME???? Total BOTH sides of the U-Tube Manometer?

LOL yes,

figure should start to come around now!

If you didn't paint your inside of you bench, you are loosing vacuum/ pressure.

Here you go I found it on the old forum.