3D printed 400mm EDF project

SkyersJet

10 mW
Joined
May 11, 2021
Messages
23
Hi thanks, it looks exactly like the cutaway in the blue diagram. It's just a simple single speed gearbox.
 

sprocati

1 µW
Joined
Sep 2, 2021
Messages
1
Very nice project.
Could you provide information about the BLDC motor?
Who manufacturer it?
Which ESC have you used?

Regards
 

SkyersJet

10 mW
Joined
May 11, 2021
Messages
23
Thanks. It's a TP 5870 inrunner. I am running it with a Hobbywing 14s ESC. I previously used a Castle Edge HV 12s ESC
 

SkyersJet

10 mW
Joined
May 11, 2021
Messages
23
New Prototype

  • Wider shaft to prevent flexing
    Drive shaft secured at both ends to prevent vibration
    Washout added to blades
    Duct lengthened to allow air to accelerate
    Thinner walls and shorter screws to save weight
    Narrower gearbox to not obstruct air
    Stators are now aerofoil sections
    Nylon blades
 

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BalorNG

10 kW
Joined
Nov 10, 2019
Messages
513
SkyersJet said:
New Prototype

  • Wider shaft to prevent flexing
    Drive shaft secured at both ends to prevent vibration
    Washout added to blades
    Duct lengthened to allow air to accelerate
    Thinner walls and shorter screws to save weight
    Narrower gearbox to not obstruct air
    Stators are now aerofoil sections
    Nylon blades

Seriously impressive project, might as well use it to propel a bike :)
But unless your nylon is higly CF/GF-filled, it is not that much stiffer than petg in my experience, so you'll still have problems with blades contacting the shroud at high RPMs I suspect. They might *survive* it though, but this is still not very nice...
Using CF/GF filled filament (not nessesarily nylon, CF petg works well according to my tests, to promote epoxy adhesion) and carefully gluing strips of uni CF to stiffen the construction over it will work, but balancing it would be a nightmare (I think it was already suggested).
 

SkyersJet

10 mW
Joined
May 11, 2021
Messages
23
These blades are actually PLA.

[youtube]EXOGdaD66-g[/youtube]
 

SlowCo

1 MW
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Jan 5, 2015
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2,283
Location
The Netherlands
Yes I can see/view the video.
Did you also have a thrust measurement in place (suitcase weighting scale) to see the amount and difference in thrust?
 

fechter

Administrator
Staff member
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Dec 31, 2006
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16,254
Location
California Bay Area, USA
I could see the video too. At least it held together this time. Which one gave the most thrust?
 

SkyersJet

10 mW
Joined
May 11, 2021
Messages
23
Hmm must be my browser.

circular intake gave 5.7kg @1492W and the elliptical one gave 5.8kg @1439W
 

SkyersJet

10 mW
Joined
May 11, 2021
Messages
23
[youtube]3IVCCHnLBxg[/YouTube]

I think I might consider switching to direct drive. The gearbox is still vibrating too much.
 

mechhead

10 W
Joined
Mar 10, 2017
Messages
89
Location
adelaide south australia
Hi, nice work.

you are likely loosing a lot of thrust because your diffuser thrust straightening fins are not angled and are likely in a stall. you might study pictures of ones off actual aircraft. the air coming out the back of the fan is turning about the aixs and this needs to be caught with angled fins that cancel the rotational moment of the airstream, a lot of the thrust is made by streightening the flow with angled stator blades that also have an optimal spiral twist to them and the duct nozzle is non parallel in most ducted fans also to enhance thrust .

keep up the experiments you may also like to try a pancake style drone motor that is made for the slower rpm of the big fan instead of a lossy gearbox an 80 or100mm dia one can be had inthe same power level as the motor your using
 

SkyersJet

10 mW
Joined
May 11, 2021
Messages
23
[youtube]wbeCjJO5vHw[/YouTube]
I blame the heavy steel ring on the duct for this. The test trolley has got to go as well, too wobbly.
 
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