Fans vs Berd-Air
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CPAP blowers are not always easy to get or inexpensive if you buy them, so I designed a printable blower that uses a motor from a HDD which most people can get for free. About $3 worth of filament and $5 for a BLDC motor driver via ebay and you can move a lot of air quietly. Printed centrifugal blower/compressor.
I haven't tested it pushing air through a small tube like the Berdair thing. Maybe I'll get a chance in the next couple days.
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@mrehorstdmd did you find a way to control to control the blower via a PWM input signal, or do you just PWM the input voltage?
I have some motors laying around, contemplating which controller I should use as I have a 24V PSU... -
The driver I'm using has a PWM input pin, but when I tested it on the printer I just PWM'd the power input to the driver. It would probably be better to use the PWM pin.
Of course, they don't provide any specs on the PWM input pin level. I would assume it is a 5V logic level input since there's some 5V parts and a regulator on the board. Maybe compatible with 3V?
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I was just wondering how your guys brushless pumps are going? I am looking at using either one of them or the berd air pumps. Since it looks like from the age of the posts that they have been running for a while, what are your preferences as to which is better? Have the brushless ones lasted being driven by pwm?
Kind Regards,
Sam -
@mrehorstdmd said in Fans vs Berd-Air:
Printed centrifugal blower/compressor.
Same question here.. any long-term experience updates?
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i found that
70% of berd-air noise is from pump air flow
30% is from the motorthere are simple solutions for both
Motor noise
use flex mount. for myself i made this one
there are other mounts with even vibration-canceling ones, but require more space. most simple solution (even no print needed) is to hang the motor on the rubber band
AND use 22500 Hz PWM frequency. as a bonus this trick also keeps pump motor cold
Pump airflow noise
use silencers my design makes it silent. very silent. it is a bit tricky to print, but once printed, you will be surprised -
@klcjr89 The flow rate in the data you posted is in H/L which I read as Hours per Litre. I'm assuming that's a typo and should be Litres/Hour. (Or does it really take >600 hours to shift one Litre of air
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ok, so this is an old post, but it seems to be the most popular on google and useful. Does anyone have any reports on how their berd air systems have held up over time? Have they been excellent or a waste of time? How is their reliability?
Does anyone have any followup data on the brushless aliexpress pump listed? It looks like the choice I am most tempted by at the moment.
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@Phaedrux said in Fans vs Berd-Air:
@c310 said in Fans vs Berd-Air:
my design
Link is broken.
Hey look the link is working now.
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@lael I just picked up a brushed system from the makerhive. Much cheaper than the brushless option. I might see if I can make the pump brushless at some point, but for now it's working great. I made my own air mount with some brass tube from Lowe's. Quieter and much easier to work with.
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@Surgikill I'm curious what size brass tubing you use? I've tried using small hobby brass tubing and even packing the tube with salt powder it would still collapse in on itself in bad ways when i'd try to bend it. I'd much rather use brass than aluminum since the brass would deform without tearing/ breaking as easy as the aluminum, and the akuminum gets more break prone after exlosure to hotend buuut i have not been able to shape it without issues.
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@lord-binky don't use salt, use electric wire. Put it in the tube, bend it and pull the wire. For example, iirc, K&S soft brass (something like 8121) tube is a perfect match for heater cartridge electric wire gauge.
Edit: yes heater cartridge cable perfect fit 8121 K&S soft brass tube
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@lord-binky said in Fans vs Berd-Air:
@Surgikill I'm curious what size brass tubing you use? I've tried using small hobby brass tubing and even packing the tube with salt powder it would still collapse in on itself in bad ways when i'd try to bend it. I'd much rather use brass than aluminum since the brass would deform without tearing/ breaking as easy as the aluminum, and the akuminum gets more break prone after exlosure to hotend buuut i have not been able to shape it without issues.
Invest in a small tube bender (min version of what plumbers use to bend pipes). Something like this https://www.amazon.co.uk/Tubing-Bender-Degrees-Manual-Bending/dp/B088H1MHWN/ref=sr_1_7?adgrpid=119993429162&dchild=1&gclid=Cj0KCQjwi7yCBhDJARIsAMWFScPk-xcgly9PRIz5mgxBPKlnamYT_OstJqT7pmfj1g5J3HHZ2Dz1Xs8aAohjEALw_wcB&hvadid=501516551233&hvdev=c&hvlocphy=9046150&hvnetw=g&hvqmt=e&hvrand=14776184315352084993&hvtargid=kwd-295847543910&hydadcr=1596_1935511&keywords=small+tube+bender&qid=1615808871&sr=8-7
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@lord-binky I didn't bend the tube. I just made jigs to drill it, then glued it into a tusk mount.
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Thanks, I'll try again with some of the cloth covered wire and see if that won't get stuck. I used jig's and spring tube benders which worked ok for the aluminum but that brass I tried before was just determined to fold in on itself.
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A wild suggestion ... try freezing some water in it and then do the spring tube bender thing. I have not tried that myself, just read about it.
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try tube bender https://www.thingiverse.com/thing:2869014
and my tube drilling mask https://www.thingiverse.com/thing:3608733
perhaps other berd-air useful parts :
Silencer https://www.thingiverse.com/thing:3429324
motor holder https://www.thingiverse.com/thing:3429374
