HK DH VAMPIRE 70mm EDF - Build Log - Page 7 - RC Groups
Thread Tools
Aug 28, 2012, 12:34 AM
Registered User
Peter this it my first venture into rc limited experience is with coax helicopters like big lama and micro ones like bell 47 medivac... I did contact someone from the Bendigo rc club at Marong and to be honest they didn't seem too keen on having "cheap foam EPO's" buzzing around their airfield... kept talking about quaility of planes and Rx's ..

Im at Quarry Hill which is 5mins from G Sq...well anywhere in Bendigo is 5mins from

I have no problems anyone flying my plane so long as they either have flown one (HK Vampire)..or have had heaps of flying experience. Just to see my mods actually work would be a big plus for me..Send me a pvt message and We can talk more.
Sign up now
to remove ads between posts
Aug 28, 2012, 12:39 AM
Registered User
If you do relocate the main landing gear just be careful with your cutting as the wing does get pretty thin.. (see my pic's in previous pages)Thats probably why they(Durafly) chose to build them the way they did..Im not complaining..just making comment as cost and quality dictate how they made it. My satisfaction is making things better at minimal cost..I still havnt worked out how to operate outboard doors but Im sure someone out there will know. and hopefully post their ideas.
Aug 28, 2012, 01:01 AM
Registered User
Yeah, for sure it is easier and more viable to do the landing gear the 'wrong' way. So I don't see any issue in what they chose for that. Some things chosen at times can be 'that was a lame copout', but others are plainly valid. (more often copouts though! hehe)

I haven't measured thickness of the wing there but it might need very narrow wheels, and/or could need even a total cutout right through the wing, but with a plate then put into the top side, just so that is the thinnest possible - because leaving a thin layer of foam would not cope.
But I will see what I come up with when I look into that.

hehe, Clubs and foamies..... often they are a bit behind the times. Many of the larger (eg 1.4m or more) foamies are as good, or better, than any of their 'real' models. The few I went to over the last year, people are just starting to appreciate foam and I saw/heard lots of "Oh that is so well done.... they are getting to be decent planes", sort of things. Eventually they will all end up thinking that way! LOL. Well..... at least a large percentage and then foamies will be fully accepted as equals(?).
And even the Vampire, at the smaller 1100mm size area, is a great example of how good foamies can be!

Then... "improve" them yourself even more (Hey!! That is aero-modelling!!) and see what they think then!! eg flaps, CS10 sound, decent reliable LG, and the 'linear stable' flight of more weight (rather than the overly light 'toy flight' otherwise). Not that I am out to impress them, but it will just be the result of anyone recognising a good plane - no matter what it is made from.
Aug 28, 2012, 04:27 AM
Registered User
I have trial fitted the Durafly wheels into bent 3mm coathanger "rod" and they do fit and I did not go through to the other side. I will be "glassing" the rest of the plane so that should also beef up the wings too.. I have noticed that the full size wheels do look a lot thinner and I have been scanning heaps of locations to see if anyone has any 50mm wheels thinner than the stock ones but so far found nothing scale looking.
Aug 28, 2012, 09:28 AM
Registered User
What diameter are the wheels thanks. Hmm, maybe I got them with the kit anyway....
And otehrwise, what size do you think they should be?
I see HobbyKing has a new range of wheels that look somewhat ok.
Many sizes available, and good reports from most reviews.

Oh, I found them..... forget they give them in the kit too....
3mm wire, bah.
But they sort of look nice enough. probably longer than I want them. I will make it LOW like the real one - FOD risk etc doesn't bother me.
Hand-launch... or cricket pitch take-off.....

Last edited by PeterVRC; Aug 28, 2012 at 09:35 AM.
Aug 29, 2012, 09:39 AM
Registered User
The landing gear addition is under way.
Much like Agediffer's idea. Which was lucky I saw that, as I never had even noted the LG runs the 'wrong way' on the stock Vampire!! Thanks!

First was to cut out the retract mount position, to have the Main Gear LG leg a bit outwards of the boom centreline - much like the real Vampire. I wanted to stay as inwards as possible, to keep the retracted wheel as inwards as possible too, but you also want a bit of scale effort, plus a wider main gear stance.

I also wanted a very low stance - like the real Vampire. So that meant cutting down the supplied stock legs, and the alloy covers they give. 15mm off the alloy parts, and then you just set the wire leg to have 11mm coming out from that - because that is what you need going into the retract. (10mm to 11mm).

It clears the underbody by approx 40mm. So that is nice and low.. not bad compared to scale. I am not fussed over FOD issues.... I have a good "runway" to use.

For the legs to be able to run along the retract motor housing, the alloy covers had to be filed flat on the side that meets the motor. Plus also have a slight taper to the top. Once I am ready I will use Red Loctite to lock the alloy covers onto the LG.

Laying the retracted assembly on the wing, I traced and cut out the wheel bay.
Finding the stock plywood plate along that way!! It was hidden under the decal! And I thought they weren't even in the wing already, DOH. So I hacked that out and will fill it all in with foam.

The wing is quiote thick still at this wheel bay point. The whole wheel can fit in completely flush!! That surprised me, and was a nice thing. And there is something like 8mm to 10mm of foam still above the wheel to the top of the wing! So all in all.... it worked out great! I might even set the wheels a bit deeper into the wing. I will be adding the LG leg cover plates, and I will toss up on the outer wing gear doors, which I could easily enough hinge off the wheel bay 'ends'.

I have to make up the ply retract mounts.... mine are longer, but narrower than the stock ones, so I won't be using theirs. Well, I don't intend to.... but might use theirs along with some of my own plate....

Aug 29, 2012, 07:23 PM
Registered User
Looking good there.I havnt cut my legs yet..I just used the trusty 3mm coathanger for trial fits.Being bendy you can trial various combinations before hacking into the stock ones.
Remember that the outer gear door is flat..I made same mistake and cut a circle...Still havnt decided myself how to attach door and make it work without servos...Elastic and metal rods seem to the go looking at other forums/posts
Aug 29, 2012, 07:57 PM
Registered User
Closing the outer doors most likely with a spring hinge, and the wheel itself pushes an 'L' arm that closes the outer door.
Last edited by PeterVRC; Aug 30, 2012 at 10:28 AM.
Aug 30, 2012, 10:39 AM
Registered User
I started the nose gear retract tonight.
I decided to cut out some of the stock foam, and mount a retract plate higher up in the fuselage. This is because I will use the mounting plate at the 'top' of the retract (not the bottom as per stock) because you need to do it this way to use pushrod steering. PULL_PULL WIRE SUCKS!!! LOL
It also means a far far stronger retract mounting system - it will pretty well never break!

The steering servo will go at the very rear of the gear bay - just above my Turnigy strap, in a ply servo tray I will fit there. A fair amount of the foam bay "cover" will still be used to minimise the opening left for the gear retraction. Plus some bay cover will be on the gear leg (as per the real Vampire). Once I get it operating, I will check for the option to have operating bay doors - but only if it can be run via the gear retraction driving those too. The same for the main gear wing doors.

The "alloy covers" of all gear legs have an issue.... they are still to 'wide' on the retract motor side. So they all need to be filed flat, right down to the gear leg itself!! eg You will just see the wire leg as filing down to the inside 'hole' is reached. That will still all look fine, it just means a fair bit more filing to do!

The main gear mounts are all done, so the area needs some 'foam filling'. And also some Dremel Drum Sanding of the wheel bays to smooth them off, and fit the wheel comfortably.

With retracts, I will also have to move to an 8 channel RX. All 6 are used now already (2 for flaps). And it will need 1 more for retracts, and 1 more for steering.

Aug 30, 2012, 10:41 PM
Registered User
Going well there....lots of foam and dried out epoxy...just what i like to see..One question..How do you mount screws from top with nose obstructing. i just made longer rails and mounted as per stock. I am making front landing gear doors and will post pix soon when all in place..
Aug 31, 2012, 01:01 AM
Registered User
The retract is still screwed from below. Some of the pics didn't have the plate on the retract yet, hehe.
That is because that one is an old 'nylon trunion' retract I just used to measure etc.

The mounting plate bridges from the new 'box' frame up front, across onto the bottom of the battery tray. And seeing the battery tray is mounted within the fuselage halves, it is all a very strong assembly.
If this bites the dust via the front retract, the nose will probably snap off!! LOL
Same for the main gear too I guess......

I actually have some pretty short oleos I could probably use, to gain suspension. I will check if they are actually short enough. Probably fine for the mains, but not short enough for the nose.

If it was planned BEFORE joining the fuselage upper and lower, the nose gear could be made to have the forward nose gear rake AND still retract fully. I am pretty sure.
But too late now....
Aug 31, 2012, 06:41 AM
Registered User

trial fit..nose gear doors

Just finished trial fit of nose gear doors..Some ideas taken from other Vampire/Venom builds..Still to decide on best way to close large door without having to use servo.. String used at the moment..Front door works well with spring.

I'm not sure about having steering front wheel..Someone may know if working rudders will provide enough force to turn plane.
Aug 31, 2012, 10:47 AM
Registered User
Hmmm, I don; think rudders alone will do it. They will once it gets to a higher speed, but you will need steering before that almost for sure always.

I have done most of mine... coming next post....
Aug 31, 2012, 11:05 AM
Registered User
I completed all the retract mountings. Put in the foam pieces to complete/fill the wheel well areas. I ran the wirings to the three way (main, main, nose) join before the RX.

I still have to cover the main gear retract unit areas. I will do that with either balsa sheet (eg 1/8th"), or foam (unlikely), or even hard card (2mm). So it will all be flush as per the wing was there prior. Then foam pieces to replace the boom 'starts'.

The nose gear has an MG-14 metal gear servo, mounted in a ply plate down the rear of the nose gear bay. I have to find/make the steering arm, slider rod, slider, pushrod stuff for the steering. I will do that tomorrow.
Plus I need to file the extra from the alloy strut 'covers' so they will allow the retract to close fully when they are on.

The stance came out exactly what I wanted. Phew.... though I did measure it to a fair degree of accuracy - just not overly large effort as I probably should have. A few degrees of AoA.
To take off it will just go faster and faster, with no elevator use until it rises off into 'flight' on its own accord!

Total weight, with a 5S 3300mAh 30C battery is 1420g. Pretty much what it weighed with the 4000mAH 20C, but no landing gear. So the 4000 will take it to around 1.5Kg.
It still feels fine weight-wise all ready to fly.

If it is a nice day tomorrow I will just go an hand-launch it again, for flight/weight testing. But I can't wait to get the LG going!! This is going to be AWESOME with the flaps!! Landings should be beautiful to watch!
Take-offs.... yeah, they should be really nice too.... needing to get to flight speed to fly, and the nice extra weight making that all "a plane that actually has mass and inertia" - and will be clearly visible.
I almost don't want to hand-launch it ever again!

Aug 31, 2012, 11:07 AM
Registered User
Oh, and I now need 8 channels to run everything. So I have to change the RX.....

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion HK DH VAMPIRE 70mm EDF mackone Electric Ducted Fan Jet Talk 11231 Nov 21, 2017 05:41 PM
Build Log whalleyB0Y's First Build (HK F22 Raptor Twin 70mm EDF) WhalleyB0Y Electric Ducted Fan Jet Talk 364 Dec 12, 2013 12:14 PM
Sold NIB Durafly(HK) 70mm Vampire MK6 W/Electric retracts OCLightning Aircraft - Electric - Jets (FS/W) 7 Apr 27, 2012 09:39 PM