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Feb 09, 2020, 08:12 PM
Watch out for that planet....
Shane McMillan's Avatar
Looks good fuzz, and sounds good too.

I found if I shook my head at the right frequency, the video smoothed out.

Shane.
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Feb 09, 2020, 08:23 PM
Big gov never Works
St. Martin's Avatar
Thread OP
HiYa' Shane! Ha..I just tried that..it works!

Fuzz
Feb 10, 2020, 02:55 PM
Aka Magical Moonstone
balticS2's Avatar
I just assumed one of those tubes of Ambroid was leaking.

Who else would have that stuff in their stash?
Feb 10, 2020, 03:28 PM
Big gov never Works
St. Martin's Avatar
Thread OP
Ha..none left in tubes. I emtied the old tubes in a jar and thinned it with lacquer thinner. Works better than Balsa-Rite or Stix-It. Still smells like my basement as a boy. Funny, I always wanted to break out my guitar and play Sky Pilot!(Eric Burdon & the animals). Same happened with the Aero-Gloss..
Feb 15, 2020, 11:01 AM
Big gov never Works
St. Martin's Avatar
Thread OP
For the past week, due to the floral holiday(Valentines), I have not felt much like construction, on the Jungmann. When I get like this, I like to tinker. Of course, not like that King Tinker'r Bill, but pretty aggressive for myself. I went through all my fan parts boxes, and decided to make up a mongrel fan for a stick jet. That led to another 3:30AM this morning.

The first fan is really an odd one. I started off with a Velocity WM-400 MkII. This fan is a IGV(intake guide vanes) fan(pusher) vs the conventional OGV(outlet guide vanes) fan (tractor). Ran it at 1200W with the original 4b rotor. Taking the fan apart, I studied the shroud. No reason why it might work well in a tractor configuration, with a different rotor and smaller motor. With 4 stators, I needed to find an odd blade count rotor. Originally, one of the few fans I had with an even/even, blade/stator count, that worked great. But, I need to get it lighter for a stick jet. Original configuration, in stock form, ARC 48mmL motor, it was 201g. The new configuration is 142g

With the ARC long motor(2850Kv) it required a minimum of 5s-3000. The new motor is an ARC 28-37-2 @ 3750Kv. Needs only a 3s-2200. The rotor is a great find. I have 3 of them. They are a chinese WeMo 5b copies, non-glass filled. And no static balancing required, just clocking the spinner. I have no idea of the watts. I would not run it up full power holding it in my hand for clocking. But it had very good static thrust and efflux with a intake lip and original 56mm exhaust. More than enough for a stick jet. (hint...)

Now the second fan, was created, after looking at the original jet in this thread. The warbirdkits, A4 Skyhawk. It use a 64mm 5b Free Wing, that never really made me happy. Weight of this fan is 96g. Having a 64mm FW 11b/7 stator fan, I got a few ideas. I hate outrunners for EDF. Hard to get perfectly clocked, unless they come that way. The weight of the FW 3300Kv outrunner is 88g. An HET 3W inrunner is 75g. 18g savings and better efficiency and balance. But, it will not fit in the same place as the outrunner. Too large.

Back into the junk box's, found a 4 stator 70mm chinese fan. And with some 1/64 ply, I made a new shroud at 64mm, to fit the FW 11b rotor. So, assembled I am saving 20g over the FW. But, 12g more than the original 5b FW. Small increase for better power/efficiency. Well see, I'm sure it will be much better on 3s, than the original. The stators are curing in the shroud for a few hours.

The ply shroud had to be fashioned with a radius lip to match the original, and still be a drop in. Now the HET 3W is kind of a mongrel motor. These motors are 3000Kv, or at least supposed to be. This one is an odd ball.. I figured the Kv @ 3400 a few years ago. This will allow the same 3s-1500-3s-2200 batt.

Long post..eh? Be back later..

Fuzz
Feb 16, 2020, 08:33 AM
Big gov never Works
St. Martin's Avatar
Thread OP
Well, the FW mongrel fan, did not fair too well... This fan gave me issues when I tried to use it in the RBC F-100. Just could not get it to run smooth. So I purchased another that was better, but still not as well as I am accustomed. I was hoping going to an inrunner would help things, but not. One thing for sure, on the same batt/esc the stock FW was loading at 22A on 3s. With the change to a more aggressive stator pitch of the 4 stator, the rotor actually got more efficient! As evident by the now 27A load. It really puts out the static and efflux, but a horrible noise. No amount of clocking can get it smooth as I prefer, but better than the stock outrunner. Think I need to experiment with another rotor.

Fuzz
Feb 16, 2020, 08:41 AM
Or current resident
glewis's Avatar
Love the old Zippo! Wore out a few of those myself.
Feb 16, 2020, 01:56 PM
Big gov never Works
St. Martin's Avatar
Thread OP
Yea, thats an old one, Glenn. Brass showing through, music wire hinge pin. Still works. Zippo will not send me a new case. I have to send the whole lighter, minus the fill and flint. They will send it back new. That was 15yrs ago when the hinge broke. It was about 5yrs old then!

Fuzz
Feb 16, 2020, 03:24 PM
Or current resident
glewis's Avatar
I sent a number of them back for refurb. They come back good as new, except the finish. They weld on a new hinge and stick in new innards and done. Had a couple that I wore out 3 times!
Feb 17, 2020, 08:48 PM
Or current resident
glewis's Avatar
While digging for my missing velcro stash, I ran across this fan I completely forgot about. 70mm looks pretty big. Is this thing any good and what size model would it be suited for?
Feb 18, 2020, 01:24 AM
Big gov never Works
St. Martin's Avatar
Thread OP
I had one of those fans, Glenn. Given to me years ago, with a you guessed it, out runner. The fan was an odd ball for lipo requirement. More likeable with roundy cells, because of the Kv. 4s was too much, 3s not enough. It has a 60a esc for a reason. The rotor is a high load. It does run well in a restricted ducting. And it is a whiney fan. The reason for the whine is: one blade passes a stator at one time. This is good. But, because the blades are such wide chord, it is a horrible whine. Similar to the HET (4b) and WM400(4b). And, because there is no movable spinner, the ability to "clock" the spinner to smooth out the balance dynamically, it is horrible sounding.(this increases the whine)

Out runners are highly inefficient for EDF, when compared to inrunners. And the higher the Kv, the worse they are. The only benefit, is the ability to balance the outrunner dynamically, using a piece of wire. I can walk you through the procedure, if Your unfamiliar.

I did cut the rotor down to 65mm, along with the stators to 66mm. Then used a 1/64 ply laminate (2) shroud. Then used the wire method to dynamically balance the out runner. The fan performed pretty well. Load was down about 25% and it had very high efflux using a 52mm exhaust. I used it in a Wattage MiG-15, and it literally flew the wings off on 4s. And it sounded pretty nice with the stock cheater. Had a throaty jet sound in positive manuvers.

But, it could have been a fluke. Not sure if I could do it again. The fan, cut down, is still a heavier system fan. Unless used in a large stick type frame. The exhaust could be run at 54mm, or 90% FSA approx, to favor static thrust. So, the fan has some flexability in use, when reduced in size. I think it was a design effort to mimic the Shubeler fans, with little good points copied.

The same Bell A4 at 200%, as in this thread, may work well, if the fan is reduced. Or even the F-4E enlarged to fit. If you want, I can attempt to cut it down and remake to 65mm. But, no guarantee's. This type of fan is hit and miss, without that separate spinner. But, it will only cost shipping and some 1/64th ply to find out.

Fuzz


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