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Re: 3D printed 400mm EDF project

Posted: Aug 04 2021 4:52pm
by SkyersJet
Hi thanks, it looks exactly like the cutaway in the blue diagram. It's just a simple single speed gearbox.

Re: 3D printed 400mm EDF project

Posted: Sep 02 2021 7:03am
by sprocati
Very nice project.
Could you provide information about the BLDC motor?
Who manufacturer it?
Which ESC have you used?

Regards

Re: 3D printed 400mm EDF project

Posted: Oct 12 2021 5:14pm
by SkyersJet
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

Re: 3D printed 400mm EDF project

Posted: Oct 12 2021 5:18pm
by SkyersJet
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

Re: 3D printed 400mm EDF project

Posted: Oct 12 2021 8:41pm
by nicobie
Nice.

Can't wait to see the test results.

Re: 3D printed 400mm EDF project

Posted: Oct 21 2021 2:54am
by BalorNG
SkyersJet wrote:
Oct 12 2021 5:18pm
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).

Re: 3D printed 400mm EDF project

Posted: Dec 05 2021 8:40am
by SkyersJet
These blades are actually PLA.


Re: 3D printed 400mm EDF project

Posted: Dec 05 2021 8:41am
by SkyersJet
Can people see the video? I just see a blank.

Re: 3D printed 400mm EDF project

Posted: Dec 05 2021 8:52am
by SlowCo
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?

Re: 3D printed 400mm EDF project

Posted: Dec 05 2021 11:39am
by fechter
I could see the video too. At least it held together this time. Which one gave the most thrust?

Re: 3D printed 400mm EDF project

Posted: Dec 05 2021 3:49pm
by SkyersJet
Hmm must be my browser.

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

Re: 3D printed 400mm EDF project

Posted: Dec 12 2021 3:53pm
by SkyersJet


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

Re: 3D printed 400mm EDF project

Posted: Jan 30 2022 5:14pm
by SkyersJet

Re: 3D printed 400mm EDF project

Posted: Feb 22 2022 4:37am
by mechhead
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

Re: 3D printed 400mm EDF project

Posted: Feb 26 2022 2:53pm
by SkyersJet
I tried angled fins, it was a flop https://twitter.com/SkyersJet/status/14 ... 0553483269

If you mean an outrunner the problem is torque, not power hence the gearbox.

Re: 3D printed 400mm EDF project

Posted: Feb 27 2022 5:11pm
by SkyersJet

I blame the heavy steel ring on the duct for this. The test trolley has got to go as well, too wobbly.

Re: 3D printed 400mm EDF project

Posted: Feb 27 2022 7:24pm
by nicobie
Is that strain gauge reading lbs.? If so 161 lbs is great!

Re: 3D printed 400mm EDF project

Posted: Feb 27 2022 8:21pm
by SkyersJet
17.2 kg

Re: 3D printed 400mm EDF project

Posted: Feb 27 2022 8:46pm
by nicobie
That's still respectable! I was having trouble believing it could pull 161 lbs. 8)