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Old Dec 26, 2012, 12:28 AM
I don't like your altitude
Stupot46's Avatar
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Here's one someone made earlier! That last pic reminded me of it.
Phenomenal work.
Stuart
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Old Dec 26, 2012, 09:54 PM
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United States, FL, North Port
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Well i didn't do much today... I've got one of the EDF units dynamically balanced, and installed all of the blind nuts for the landing gear and bolted them back into place..

Anyone have any good idea's for ensuring the EDF unit is installed correctly so its Center line will exit at the center of the exhaust exit opening?

The only thing I can think of, is taking a piece of PVC pipe and modifying it so it will fit around the motor can and having it long enough to extend to the exit opening and go through a hole
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Old Dec 26, 2012, 09:55 PM
Life begins at transition
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Not really needed. The air will bend as required - it's the exhaust itself you need to worry about.
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Old Dec 27, 2012, 05:14 PM
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I mount a laser pointer to the back of the motor . The magnents will hold it to the motor can , and put a target on a template the size of the exhaust outlet on the rear of the jet and adjust the edf unit accordingly.
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Old Dec 28, 2012, 03:44 PM
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Alrighty, today was the day of Inlet ring modding and installation..

Thanks to paul (tempest) I got the 2nd inlet ring i needed. Its a little bit different than what i've got, but i'm not waiting!

first up I needed to figure out a way of getting the motor shaft Center-line aligned with the center of the inlet and exhaust. Poking through the shop, i found a piece of 1 1/2" wing tube socket that was the exact same diameter as the motor. So the socket was squared up and taped to the back of the EDF unit and motor:


Then a 80mm diameter foam template was cut out with the center drilled out to 1/8". This will be used to make the tailpipe's as well. This was then placed on one exhaust exit flange and put into the correct position (I centered it with the mark 1 eye-ball). Then the 1/8" center-hole was drilled into the center section:


Then a ply template was cut to allow this center hole position to be transferred to the other side. And the 1/8" center hole drilled into the center section:


Then using a 1 1/2" Forstner bit, a hole was drilled for a 1 1/2" wing tube.. keep reading! It will make sense soon!


Then a wing tube was slid into the 1 1/2" hole. And the EDF unit with the wing tube socket put into position inside the wing. The wing tube was then pushed into the center section and into the wing tube socket. Once these were joined, the EDF unit was placed into the inlet, the inlet ring attached to the EDF unit, and then the inlet ring tack-glued with CA to the center section:




As you can see in the above photo's, the inlet ring becomes part of the center section and gives a nice smooth transition into the EDF unit. The wing tube socket and wing tube act as the alignment device to make sure the EDF unit's thrust line will exit out of the center of the 80MM cutout in the back, when it gets cut out.

After the inlet rings were tack glued into place, and the wing tube socket and tube removed from the motor can, you can look in the hole at the exhaust and see this:



A near perfect thrust line alignment!

Then the inlet ring to center section seam was taped over and a mixture of epoxy and cotton flock put around this seam on the inside of the center section. The inlet ring is part of the mounting system.



And then I spent about 2 hours Dynamically balancing one of the EDF units.
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Old Dec 28, 2012, 05:19 PM
2014 EDF JET JAM We be Jamming
Kevin Cox's Avatar
St. Louis Intl, Missouri, United States
Joined Jan 1997
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Nice!!!
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Old Dec 28, 2012, 05:30 PM
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Unbelievable! Incredible work.
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Old Dec 28, 2012, 05:49 PM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
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Very nice.Necessity the mother of invention.
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Old Dec 28, 2012, 07:17 PM
Pro Horder
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upland CA
Joined Dec 2004
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Nice work. If you look from the front into the duct does the rear of the fues cut up into the eflux area? not sure if you get what I mean ..On mine the tail section is very much in to the exhaust flow...So I cut the resess to go farther back and not be in the way of air flow
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Old Dec 28, 2012, 07:20 PM
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Quote:
Originally Posted by turbonut View Post
Nice work. If you look from the front into the duct does the rear of the fues cut up into the eflux area? not sure if you get what I mean ..On mine the tail section is very much in to the exhaust flow...So I cut the resess to go farther back and not be in the way of air flow
At first i was like "huh?" But now i understand!

Actually, i havent cut out the full size exhaust hole yet, but i dont think the rear end of recess/fuse transition interferes with the efflux column.
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Old Dec 28, 2012, 08:05 PM
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Looks great . Seems almost like you used my Idea about a rolled up cardboard tube to align the fan units ,Or maybe great minds think alike ..
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Old Dec 28, 2012, 09:57 PM
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Well, as is typical for me lately, my luck has gone to Hell. If anyone has a spare ChangeSun 12 bladed 90mm rotor (or an entire fan unit, i don't care), let me know. The rotor got jammed onto the adapter on my 2nd fan unit during balancing and in the process of removed the rotor, one of the blades busted... Sooo now i'm one fan unit short.
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Old Dec 29, 2012, 02:39 AM
ich bauen groß modell flugzeug
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Just buy some spare blades off of hobbyking (can't post a link because im on my phone)
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Old Dec 29, 2012, 07:20 AM
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Quote:
Originally Posted by Keenan smith View Post
Just buy some spare blades off of hobbyking (can't post a link because im on my phone)
Those blades as supposedly weaker than the blade from another company. If it comes down to it, i'll order a new rotor from HK, but after this one had a blade snap just by tightening up the bolt, come tax time I'll probably end up going with a pair of Jet-Fan 90's
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Old Dec 29, 2012, 08:03 PM
Life begins at transition
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Joined May 2007
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You can weigh them. I can't remember the numbers, but the CS12 thread has a lot of discussion about the weak rotors.

Given your ability to pop out a mould in about 3.8seconds, could you just cast a quicky and make some carbon blades?
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