Hobbyking Zulu - Page 10 - RC Groups
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Oct 14, 2017, 01:28 AM
Registered User
jo2lo's Avatar
Finally (like FINALLY! since I bought this back in Nov2015) I've got my Zulu together, new Corona 22gm servos and balanced per Heady's 85mm CoG. That required a huge amount of Pb in the nose. I have to admit to being a bit nervous putting what the forum appears to consider a dodgy composite plane in the air when I'm still planting foamies on occassions.
Sloping on Wednesday 18th on the Port Hills in Christchurch NZ. Will see what wind direction and speed is before the launch. Hope to have some vid soon. Fingers crossed.
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Oct 14, 2017, 09:23 AM
Reap the wild wind
headlessagain's Avatar
A mate has copied the wing and fuse and is making one out of balsa. He did check the c of g against an online tool and found it spot on at 85mm. The need for lead in the nose isn't unexpected when you consider it can be E-powered.
I very happy with the way mines flys. No nasty habits and can be flown quite slowly as you may have seen from some of my landing approaches where I'm tacking across the slope backside bleeding off height.
Andy
Apr 16, 2018, 03:48 PM
Registered User

CG on this bird


Flew my composite Zulu again, and really liked it. I am at around 97mm CG, and that is flirting with a crash: if I am not careful it will pitch up and with my corrections get into a really bad oscillation (not on video). But it can be avoided with smooth flying. At least it does not undercut in a dive, but you have to be careful not to get into an oscillation.

I can see heady's Zulu flying really nice at a CG of 85, so this is probably the starting point. However, the usual way to set up planks for performance is to move CG back as far as possible, in order to have the least reflex - and fly it just on the brink of being hard to control. That requires slop-free linkages and servo trains, and small throws. As I have written here, my Zulu with the 97mm CG has the elevons 2mm BELOW the airfoil line as indicated in the center and the wingtips. Strange. Also, those elevons are huge (deep), nothing I have seen on performance planks, so that may be a contributing factor.
Anyway, it flies fine, mine is pretty light at 650g and is not well suited for stronger winds.
heady, what is your AUW, it seems to penetrate quite nicely? thx

Zulu composite sloping Stetten evening 14apr2018 1 (4 min 20 sec)
Apr 16, 2018, 04:34 PM
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headlessagain's Avatar
I can't answer the c of g question at the moment as mine is in bits! Bodged landing in iffy winds resulted in the ply tongue, where all the electronics are mounted, breaking off at the bulkhead. I made a realyy good job of glueing that in so it's going to be a right pain to remove without damaging the thin fuselage.
I might trim down some copper pipe foam lagging as it's a good fit in the fuselage. I'll just cut out aperatures for the pack and RX and make the power connections via the access hatch underneath the wing. The nose can then stay taped on
Yours looked to fly very well at the c of g. If it's overly sensitive to elevator inputs it would benefit from adding some nose weight. From memory both my elevons were either neutral or slightly down as well. They are large compared with other flying wings but you have to remember that it's a progression of the earlier EPP, then EPO Zulu. The latter one even has linked le drooperons control surfaces
Andy
Apr 16, 2018, 04:51 PM
Registered User
sorry to hear about your landing mishap! the fuse is very fragile, I dread the repairs which will follow a less-than-perfect landing, so far I have been lucky

not sure those huge elevons are a good idea in terms of performance, and I will shorten those slightly on one of my EPO Zulus (I am a plane hoarder, and bouht 3 kits), however my impression is that the EPO Zulu (sans drooperons, i.e., taped on) flies better than the composite Zulu
Apr 17, 2018, 01:29 AM
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headlessagain's Avatar
The fuselage was actually undamaged but my solution for installing the battery and rx's didn't fair so well. I should have used better quality ply for the vertical equipment plate or at least beefed up the joint with a thicker curved piece so as not to create a stress joint.
I only bought my Zulu as it was on sale and agree that if it hadn't the EPO version would have been a far better option


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