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        Discussion Durafly Vampire 70mm

#1 bmiller Oct 08, 2012 07:23 PM

Durafly Vampire 70mm
 
Ordered from hobbyking Saturday Oct 6, Email and shipping looks like its in their LA distribution hub in nearby Lakewood! We'll see if it arrives Tuesday!
Was inspired watching Hung fly his 90mm 'glass version last week. It flys extremely well. That one is $1000 bucks for the bare airframe so this little foam guy comes completely built only needing an rx and 3S 2650. Plan is a few flights all stock then put my 4S 3200 wemo megaEDF setup in it. over 800W should be plenty. Reading some threads on it, I'll have to add a carbon spar in each boom as they flex badly. Probably swap all electronics out for decent quality stuff.

#2 porcia83 Oct 09, 2012 08:14 PM

Fly it stock
 
No mods needed on this one, try it with stock stuff first. I would suggest cutting a little slot right behind the wheel well to open up some air for the ESC cooling, but that's not even really needed. I flew mine to death in the middle of summer and never more than some mild warmth from the esc.

This will haul around nicely on a 4S 2200 battery. It can fit a 3000 too, but it's not really worth the weight. 2650 isn't to bad. The flex isn't to bad either so the rods might not be needed, and it's a tad tail heavy anyway. I recently donked mine landed in a hard crosswind and loosened up the front gear. If any mod should be done its for a rudder, it's hard to bring her in without one in a crosswind.

I have a second one in box ready to paint up. I suppose a nice HET set up would make it scream all the more, but it's really a bulky fat body with chunky wings so not sure how much faster this could go, or needs to go.

Have fun with yours, it's a great plane, even more so considering what you get for the money.

#3 bmiller Oct 09, 2012 09:52 PM

Thanks for the info! Still waiting for it to arrive but meanwhile my airfield F-14 showed up!
Rereading your post, a 4S pack won't smoke the electrics? That'd be a perfect hopup with no hassles.

#4 porcia83 Oct 10, 2012 06:55 AM

The plane is set up for 4S batteries, 2700kv motor and 45amp speed control. 3S won't really work, don't ask how I know :eek:

#5 bmiller Oct 10, 2012 09:08 PM

Ahh I see my mistake. I mixed up the 3s vs 4S setup with the F-14.:o
Thanks for the heads up!:)
Still no plane yet, must be coming from seattle....

#6 bmiller Oct 11, 2012 11:48 PM

Arrived undamaged today! Very nice. Gotta dig up an rx and check if my old 4S 2650s are ok.:)

#7 bmiller Oct 13, 2012 04:44 AM

All done! ready for maiden tomorrow.
Ran fan up and it was noisy with vibrations, removed rotor, balanced, reinstalled but it now rubbed against the shroud badly. Had to pull the whole fan out which was a pain with all the glue they used to hold it in place. Got it out eventually and was able to center the rotor. Reinstalled , ran it up and its pretty smooth thru the entire rpm range.

#8 bmiller Oct 13, 2012 09:36 PM

Nice flyer! Two flights 1st w/ 4s3200s CG at 305mm, decent power w/quick takeoff, noticed it dives with power, climbs power off. Other than that it was very stable and glides forever. Landed very slow and easy.
2nd flt 4s2200 CG 310mm, short takeoff roll, a good thing on my dirt runway.
Dive with full power very pronounced with the lighter pack, Checked the stall high up, right wing dropped half turn recovery, Extremely slow speed needed to stall it, this jet is very forgiving! Landing is a non-event, retracts worked well, Both flights 4min, even the 2200 was barely warm. Fan sounded good, glad I balanced it. Next is adding a thrust tube for alittle more speed but it's mostly so I can add a shim to change the thrust angle.
Also going to chamfer the trailing edges, made a big difference on my F-100 so we'll see if it works on this one too. The slicker shape needed less power to fly and sharpened handling as well.

#9 bmiller Oct 16, 2012 04:06 AM

Cut up a plastic cup at the field for an exit duct experiment. little bit smaller exit size than stock then stuck a 5mm shim under it to change the thrust angle. Much better
Didn't notice any speed increase though.
Did a couple tailslides for fun, no problem with this jet!

#10 bmiller Oct 22, 2012 01:40 AM

More flights today, all sorts of silly aerobatics and trying to see how slow it can go inverted. Major fun!
Settled on stock CG 311mm, elevators flat and no ballooning.
Need to look at fan alignment, no one else seems to have my diving under power issue (which the shim cured) I must've screwed the alignment up when I yanked the fan to balance the rotor then literally slapped the unit back in place.

#11 bmiller Jul 12, 2013 02:33 AM

It's now mid july 2013, probably 40 flights on it with zero problems. Read some people have issues w/ the retracts but mine still work perfect. The smaller exit cone does make it faster, Another guy just maidened his stocker and mine is significantly faster. We swapped batteries and his pack is actually more powerful so the difference is down to the exit cone and my balanced rotor. Anyhow the Vampire is still a lot of fun and its easy to land on the mains and carry the front wheel down the runway which impresses the onlookers enough that they think I'm a better pilot then I really am!LOL:p


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