About the filter

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16

I am almost at the point with the filter to fabricate my own. As said above I don’t imagine its much more then pre filter Hepa and carbon.

Only thing I need to know is what cfm is needed as well as if there is over rev protection on the gf fans. As the fan I plan on useing is a 8inch 790cfm (0-10v or pwm speed control) so I know if I pull 800cfm off a gf fan only turning 200cfm the vacuum from my fan will spin the gf fan faster and that will generate back feed power into the gf and maybe let the smoke out. I have to assume they put protection in for this as they must have expected people to have booster fans. But as my fan is speed controlled all I need to know is cfm requirement so I can just tune my fan.

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17

I agree, this is a very important thing for us to know. @dan?

18

the problem with doing this is that you also need to run tests on the composition of the outflow. laser combustion / ablation produces dozens if not hundreds of compounds, many of which are toxic, carcinogenic, and often odorless, or nearly.

as for the over rev this has been covered on the forums; they were using a 3rd party filter on the ones at bamf; if you search you can probably find what they used.

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19

Purex was the brand name, no mention of model number.

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20

yes but someone explicitly noted the CFM it was pulling, which is my point; that lets you know that at least that much pull is fine

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21

Found a thread that mentions it…

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22

cheers thanks! i was definitely feeling too lazy to find it :slight_smile:

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23

Looks like the 200i is 88cfm.

http://www.kluzinternational.com/wp-content/uploads/2016/10/200i_400i.pdf

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24

this is the post i was thinking of

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25

Sorry wasn’t clear . I would still vent out side it would be to cut the noise way way down and the visual smoke and the smell… To avoid a 50$ per day condo fine

26

ah cheers, totally fine to do that then :smiley:

you may find this useful if you haven’t already seen it

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27

The filter combines a HEPA particulate filter with activated carbon.

It’s in the software todo hopper.

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28

Sadly, I don’t think it’s a software issue. There has to be special circuitry to avoid damage.

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29

Unless the existing hardware allows for software that can detect incoming current from the fan and disconnect it from the circuit… ie: the same switching that turns the fan on can also turn it off.

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30

correct you could use a bunch of different hardware methods to handle this but software wont fix it

something like a diode so its uni direction current or a trip and dump sensor if there is over volting… and this is what will happen with any booster fan on exhaust even for the people with extended runs that need to add a booster never mind diy filters etc…

@dan CFM that GF peaks at ?

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31

Yes, this is my understanding. Back EMF suppression diodes are needed.

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32

I would assume that they have a speed sensor on the fan since it adjusts speeds for the job and for cooling purposes. So easy enough to regulate I would think

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@dan posted this:

34

Thanks for that 200 cfm is easy to accomplish also easy to over drive. The canfilters I was looking at have a min eating of 210. They are the filters used in auto body shop and paint houses etcs.

35

what about this one? @karaelena @mpipes
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