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Hi guys,
Vacuum again ;o)
Would you like please to look to this pump specs, and let me know what you think.
http://www.vabs.co.nz/side-channel-b...06-02kw1p.html
FPZ SCL 15DH two stage side channel blower
0.55kW 230V single phase 50Hz electric motor
Displacement 50 m3/hr
Pressure to +30 kPa
Vacuum to -27.5 kPa
That would be close with 3.988537788 PSI......
If you already have done the vacuum table, would you use a pump like this ?
P (1) Δp (2) Q (3)
kW mbar psig m3/h cfm
COMPRESSOR
A 50 Hz - 2900 rpm
0.37 50 0.72 90 53
0.55 150 2.17 70 41
0.75 250 3.62 52 31
1.1 350 5.07 35 23
1.5 400 5.80 26 15
B 60 Hz - 3500 rpm
0.9 225 3.26 84 49
1.3 350 5.07 64 38
1.75 450 6.52 46 27
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For who would may be interested to know.
My initial question to this post was related to the motors, and Brady help me to figure out how things are there, thank you very much again for that help.
Then my next problem , was related to how square is the table, because I could se on large rectangles a 2mm difference on the diagonals.
Long story short, initially I can not figure out from where came that error, ant I learn to live with that ….basically can not be seen , but I know is there …
Until I make a “next step” , and I have done a plaque using a V-bit cutter , on that process I have notices the “Z” axis is having a little movements in some directions , I could see it just watching the V-bit cutting , Stop, and checked all again , and I have found the “Z” car having a bit of movements because I have not tide properly the down eccentric bearings . Tide the bearings to remove any movement , start again , the movement disappear , redone the large rectangle test and the diagonals are now equal ;o)
Thanks to everybody for giving his input, and help me to fix this problems.
I am still having the vacuum a project to be done, and a opinion about the pump what is above would be very appreciated ;o)
Cheers DAN
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Dan,
The pump listed above has the following specifications:
8.12 inches of Mercury
29.4 cubic feet per minute (CFM)
0.74 horsepower
This is a small pump - and is not worth buying for your CNC. You can put together a very affordable and useful vacuum hold down system ($150 or so) by using a Lighthouse Brand vacuum motor and a BradyVac vacuum plenum from a single sheet of ultralight MDF or Trupan.
Several years ago I shared my vacuum research with this forum The 9-15 - Open Source Vacuum Project with the idea that others would take my research and make it into something a bit more polished. Gary Campbell did a fantastic job with his Black Box Vacuum Source as did many others. It is hard to beat the Lighthouse motors for getting into the vacuum game. Several people use these on a production basis, but they really are not designed with the same duty cycle in mind as a bonafide vacuum pump, that operates at a much lower RPM with much tighter tolerances.
Take some time to check out the links above and do some more searching on this forum to give you some ideas and examples of what others have done. Also, check the For Sale & Wanted section since good pumps suitable for CNC machining pop up for sale from time to time, like this one.
-B
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Hi Brady,
Thanks again for your fast answer, I have already a read on this projects, and I will have a bit more.
The problem is I am here down under in Gordonton New Zealand , and if you guys have difficulties sourcing stuff …do not ask us ;o)
I would like to go for something like this “Lighthouse Brand” vacuum motors for the price, the challenge is to find them here if I can.
What would be something what will work ? if I take this like “reference “ where I should be , to be okay ? (on the budget … I can find here “Becky” but I can not afford in this stage ;o( )
8.12 inches of Mercury =? To be okay
29.4 cubic feet per minute (CFM) =?
0.74 horsepower =?
Thanks again , and for the “ramping” article good stuff ;o)
Cheers DAN
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So if I can find something close with 190CFM ..that would be a good start ?
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Dan,
2 Specs are the most important:
CFM range between 90-200 (higher number = more airflow)
Suction range between 8-12 Hg" (higher number = more suction)
Find what you can locally...and you may be able to get a Fein Turbo III vacuum near you. It does something like 125 CFM & 8.2Hg" - but they are pricey & you would want multiple ones. I've used one for years...it's more important HOW you use the vacuum you have than the vacuum you have itself.
-B
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Thank you very much for you answer, I will have a look around, and once I find something what I think will work I will try to ask again your opinion. ;o)
Cheers DAN