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Jul 19, 2011, 02:00 PM
Registered User
I'm not sure how much extra cost goes into making these compared to the 70mm's, if you can avoid to obvious lure of upping the price because its bigger and keep them near your 70mm price then this could well be the best fan available,

congratulations!!
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Jul 19, 2011, 02:42 PM
My project: FAIREY DELTA 1
Erik v. Schaik's Avatar
Hi Gary,
I'm impressed with the power level of this fan!
You may serious reconsider the IGV concept for safety reasons. like this the rotor would always stay on the shaft.
These power levels are getting scary...
Jul 19, 2011, 03:20 PM
Registered User
SilentHunter's Avatar
Scary indeed... How is the rotor held on the shaft?

Sure is impressive.
Jul 19, 2011, 05:27 PM
efflux RC's Avatar
Quote:
Originally Posted by efflux RC
Guys,

Immedeiatley after reading Jim's suggestion last night (thanks Jim ) for a guard in front of the rotor, I contacted Mach about providing such a device, as a solution.

It's currently being addressed, and I'll keep ya posted.
Quote:
Originally Posted by Erik v. Schaik
Hi Gary,
I'm impressed with the power level of this fan!
You may serious reconsider the IGV concept for safety reasons. like this the rotor would always stay on the shaft.
These power levels are getting scary...

Hi Erik,
As you can see from my post above, There is nothing to reconsider.
The concern is being addressed, and we will present the solution shorlty.


.................................................. ........................................



SilentHunter,

The shaft adaptor is secured with a precision ground collet. (.0001" per side, runout max)

The rotor is secured with a hex nut, and a threaded spinner.
Latest blog entry: Updated blog May 2017
Jul 19, 2011, 06:26 PM
Pursuit of Happiness
Ron101's Avatar
Wow!
I missed this one, that is one impressive fan!
Crazy power

For safety I'd just forget the ground run up once I have my numbers at home and just taxi out and after the plane is past me drill the throttle

Would love to see a 120mm or a 80mm for Habus

very cool, love the sound too, it's almost turbine like

great work.... makes me want to come to big jolt
Jul 19, 2011, 07:12 PM
efflux RC's Avatar
Quote:
Originally Posted by Ron101
Wow!
I missed this one, that is one impressive fan!
Crazy power

For safety I'd just forget the ground run up once I have my numbers at home and just taxi out and after the plane is past me drill the throttle

Would love to see a 120mm or a 80mm for Habus

very cool, love the sound too, it's almost turbine like

great work.... makes me want to come to big jolt
Thanks Ron.
We have some DS-44 (85mm) coming for the Habu 32. (easy mod for the "can do" guys)

If you find yourself making it to the Big Jolt, come by our booth. We will have a 90mm ALL ALLOY EDF on display. It'd be a chance for us to meet as well.

Gary
Latest blog entry: Updated blog May 2017
Jul 19, 2011, 08:17 PM
fly like an EAGLE ;)
corsair nut's Avatar
look at it...skip that....lets put it in my T45 and fly it at big jolt
Jul 19, 2011, 08:51 PM
efflux RC's Avatar
Quote:
Originally Posted by corsair nut
look at it...skip that....lets put it in my T45 and fly it at big jolt
I'd love to Brent, but the last time we did something similar, (70mm in the Viperjejet at Cal jets) the thread was muddied up by someone who had to make a fuss about it in the threads.
Latest blog entry: Updated blog May 2017
Jul 19, 2011, 09:57 PM
deltas are cool
AIR SALLY's Avatar
well he's busy right now cause he flung some more mud
Jul 19, 2011, 10:22 PM
Registered User
Bigells's Avatar

Metal EDFs saftey by design and test


Some thoughts on addressing the safety issue of the metal EDFs:

Full size turbine engines are designed to address these particular failure conditions, which are, fan balde off and FWD bearing failure. If the rotor fails, a blade from the fan would usally separate from the hub. The fan case is designed to contain the blade and not let it pass through the case. The blade would be swallowed by the engine which then typically stops the engine quite quickly.

In the case of these metal EDF you can address these same issues in the design, to provide a higher level of safety. I realize that the design is done and it's into testing, so any suggestions may be to late.

The design of rotor attachment to the motor shaft should be such that if it fails, the rotor would be prevented from leaving the shroud either by a catcher mount, forward of the rotor or by having the rotor behind the electric motor.
In this case the rotor would be held from exiting the shroud by the motor and its mount. As an example, in model gas turbine engines, the centrifugal compressor (first one) is contained in the forward mount/case of the engine.


All the EDFs that I have seen, the attachment of the fans shaft to the motor is by a grub screw against the motor shaft. At these higher power levels this could be a point of failure. This could be better addressed by using a shear pin to attach the shaft to the rotor.

The rotor and the rotor shaft must be designed to withstand fatigue, crack growth and material creep from 38500 rpm over a specific period of time.

This is a brief high level overview of the design of the metal fans. The EDFs can be shown by design, analysis and test, to be safe for use in the hobby.
Last edited by Bigells; Jul 20, 2011 at 08:48 PM.
Jul 19, 2011, 10:44 PM
efflux RC's Avatar
Quote:
Originally Posted by AIR SALLY
well he's busy right now cause he flung some more mud
OOOh, I've seen it.
Latest blog entry: Updated blog May 2017
Jul 19, 2011, 10:48 PM
efflux RC's Avatar
[QUOTE=Bigells;18808863]
The design of rotor attachment to the motor shaft should be such that if it fails, the rotor would be prevented from leaving the shroud either by a catcher mount, forward of the rotor or ..............QUOTE]

Thanks for your comments Bigellis. a "catcher mount" as you describe it is in the design process.

Gary
Latest blog entry: Updated blog May 2017
Jul 19, 2011, 11:39 PM
Distributed Manufacturing
Quixksilver's Avatar
This is a master peace. The sound, oh the sweet sweet sound. I can't wait to own one in every EDF model I don't have yet

Keep up the good work, your really taking this part of the hobby to the leading edge of what can be done to date and then some.
Jul 20, 2011, 12:44 AM
Registered User
capt soap's Avatar
Sounds like I need to increase my life insurance, and buy one. Lee
Jul 20, 2011, 01:57 AM
deltas are cool
AIR SALLY's Avatar
great jet engine vids ....i wonder what they mean by a industrial engine???? what are they used for ? does any one have a clue. J-79's were awsome motors for sure.


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