3D printed 400mm EDF project

[SkyersJet]

Hi thanks, it looks exactly like the cutaway in the blue diagram. It's just a simple single speed gearbox.

[sprocati]

Very nice project.
Could you provide information about the BLDC motor?
Who manufacturer it?
Which ESC have you used?

Regards

[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

[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

[nicobie]

Nice.

Can't wait to see the test results.

[BalorNG]

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]

These blades are actually PLA.

[SkyersJet]

Can people see the video? I just see a blank.

[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?

[fechter]

I could see the video too. At least it held together this time. Which one gave the most thrust?

[SkyersJet]

Hmm must be my browser.

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

[SkyersJet]

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

[SkyersJet]

PDF with more data and theory:
http://www.skyersjet.org/resources/(web ... ciency.pdf

[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

[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.

[SkyersJet]

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

[nicobie]

Is that strain gauge reading lbs.? If so 161 lbs is great!

[SkyersJet]

17.2 kg

[nicobie]

That's still respectable! I was having trouble believing it could pull 161 lbs.