Viper Jet 70MM - Printable Version
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Viper Jet 70MM - samste - 10-06-2011
Viper Pics
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15534
Customed Mounted Edf into Viper
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17221
Bench Tested Install 1000watts, 1.5 kg Static Thrust, 47 Amps, 6s lipo setup
(No Adjustments Done Yet with Tweaking of Timing)
Steve
RE: Viper Jet 70MM - paulj - 10-06-2011
Steve is that photo showing the edf in it's final position in the fuselage?
Looks a long way from intake tube.
RE: Viper Jet 70MM - samste - 10-06-2011
(10-06-2011, 07:27 PM)paulj Wrote: Steve is that photo showing the edf in it's final position in the fuselage?
Looks a long way from intake tube.
Yes Paul, Edf has been Fixed in its position, I am going to Install ducting to inlet and seal up but in reality i don't think it will make any difference in performance.
Steve
RE: Viper Jet 70MM - paulj - 11-06-2011
I think it will make a big difference.
If you left it as is the fan would not be as efficient, at least
that is what my research has showed up reading other edf discussions
on rcgroups etc.
RE: Viper Jet 70MM - ~KevJ~ - 11-06-2011
i agree with dad on that one steve, it will still definately fly without issue but i think it would affect your vertical and top speed abit. in its favour tho is that fact that it already comes with a rounded off intake lip which will help settle the air into the hoursing alittle.. bear in mind i guess we are not talking about the difference between working or not working - only between working well and working at its best.
anyway steve i cant wait to see her down the field when is it looking like maidening??
RE: Viper Jet 70MM - samste - 11-06-2011
Your Right paul and Kev, Sealed Up Edf Inlet and She's smoking Hot Now.
Need to Really get Started On Getting Wings On so It Doesn't look Like a Rocket
And Finish off Playin Around with Led's which i leave in as a permanent Feature.9 led's with surround painted black and installed outside intake but in fuselage so not to effect edf outake.
Steve
RE: Viper Jet 70MM - gbanger - 11-06-2011
You know what would really sick Steve, if you had a few red LEDS around the exhaust that are on all the time as well as a few more yellow or white ones that are staggered between the red ones that run off the throttle input that would give the impression of afterburner on throttle up and that would look seriously cool.
RE: Viper Jet 70MM - samste - 11-06-2011
(11-06-2011, 05:07 PM)gbanger Wrote: You know what would really sick Steve, if you had a few red LEDS around the exhaust that are on all the time as well as a few more yellow or white ones that are staggered between the red ones that run off the throttle input that would give the impression of afterburner on throttle up and that would look seriously cool.
I know It Looks Pretty Cool Though With the Red Led's on permanently, Kizza would know how to get the Yellow or white Led's to flicker with Throttle.
RE: Viper Jet 70MM - ~KevJ~ - 11-06-2011
sweet ride steve cant wait to see her man.
RE: Viper Jet 70MM - paulj - 11-06-2011
Nice steve.
I will be doing something similar with the leds on my L39.
Are you planning on maiden this weekend?
RE: Viper Jet 70MM - samste - 11-06-2011
(11-06-2011, 06:08 PM)paulj Wrote: Nice steve.
I will be doing something similar with the leds on my L39.
Are you planning on maiden this weekend?
I was hoping Too but Too much to do , Now That I'm finished With My Edf Led Setup, But I Think Its going To take a While Getting all the Wings servos tail servo rods and the rest of Electrics Etc all Fitted on.
FINAL SETUP BELOW
Connected Led's Positive and negative to Main Brushless esc Blue and Red to get it To work Nicely on Throttle Curve
RE: Viper Jet 70MM - kizza42 - 11-06-2011
Steve, get a brushed speed controller and run the led's through that. That will dim the led's on low throttle and glow brighter on full throttle. Then all you need is a mini water tank to spray atomised water out the back for the full effect.
RE: Viper Jet 70MM - smuzz - 11-06-2011
The brushed ESC is a very clever solution KV - full marks!
RE: Viper Jet 70MM - Claudius - 13-09-2011
Anyone tempted by the new, 90mm bigger brother? (suspect a bit out of my league speed-wise just now... but it helps to have aspirations
)http://www.hobbyking.com/hobbyking/store/__15536__ViperJet_Fiberglass_90mm_EDF_1250mm_ARF.html
![[Image: viper90-15536.jpg]](http://www.hobbyking.com/hobbyking/store/catalog/viper90-15536.jpg)
RE: Viper Jet 70MM - ~KevJ~ - 13-09-2011
oh yes im very temtped
i almost pulled the trigger last night but i stopped myself because i have jets coming out my eyeballs and i really want to buy a 3d style plane like gary's suhkoi or jasons extra.. grr your making it hard for me to forget about this damn viper.. aahhhhhh
jks
RE: Viper Jet 70MM - gbanger - 13-09-2011
Im thinking about putting my Seb Art Katana on the market Kev.
Ive got to many aerobatic 3D aircraft and have just ordered a Seb Art Sukhoi 140 that should be arriving in a few weeks to upgrade the mighty Sukhoi 50 and need to make space for said project.
If your thinking about buying a good 3D aircraft you wont find a better starter than the Katana.
I might sell the Sukhoi 50 but that will be expensive because it has got some pretty specy JR gear in it.
The Katana has a Hacker 50- 14 425 kv 1250 watt motor running a 16 x 8 APC prop with a Turnigy 85 amp swichable ESC and Turnigy 959 coreless digital metal gear 12 kg servos that kick arse, communication is through a Spectrum AR 6200.
If your interested let me know.. I will make the price very respectable, will even throw in a 6S 5000 25C battery so you can bind'n'fly.
I have even done an structural upgrade on the landing gear mounting point so it can handle the odd landing that is a little on the hard side.
Over to you or anyone else who is thinking about upgrading to a Seb Art (don't need to say much else)
Gazz
RE: Viper Jet 70MM - Raptorfly - 13-09-2011
(13-09-2011, 01:56 PM)Claudius Wrote: Anyone tempted by the new, 90mm bigger brother? (suspect a bit out of my league speed-wise just now... but it helps to have aspirations
http://www.hobbyking.com/hobbyking/store/__15536__ViperJet_Fiberglass_90mm_EDF_1250mm_ARF.html
Buy, Build and fly later when you are ready and the only way is to push your limits. I'm waiting for the 90mm Hawke coming to HK soon.
RE: Viper Jet 70MM - ~KevJ~ - 13-09-2011
(13-09-2011, 07:22 PM)gbanger Wrote: Im thinking about putting my Seb Art Katana on the market Kev.
Ive got to many aerobatic 3D aircraft and have just ordered a Seb Art Sukhoi 140 that should be arriving in a few weeks to upgrade the mighty Sukhoi 50 and need to make space for said project.
If your thinking about buying a good 3D aircraft you wont find a better starter than the Katana.
I might sell the Sukhoi 50 but that will be expensive because it has got some pretty specy JR gear in it.
The Katana has a Hacker 50- 14 425 kv 1250 watt motor running a 16 x 8 APC prop with a Turnigy 85 amp swichable ESC and Turnigy 959 coreless digital metal gear 12 kg servos that kick arse, communication is through a Spectrum AR 6200.
If your interested let me know.. I will make the price very respectable, will even throw in a 6S 5000 25C battery so you can bind'n'fly.
I have even done an structural upgrade on the landing gear mounting point so it can handle the odd landing that is a little on the hard side.
Over to you or anyone else who is thinking about upgrading to a Seb Art (don't need to say much else)
Gazz
gaz i sent you a text.. im interested but i need to buy all the rest of my hawk stuf so it depends if i have enough left over and im not sure what a seb art is worth..
RE: Viper Jet 70MM - gbanger - 30-11-2011
Thanks for the redirect Steve
Just had a brouse through the thread and noticed that you don't appear to have done anything with yours since July..... Whats happening with your Viper mate?
Must be all but ready for maiden???
RE: Viper Jet 70MM - samste - 30-11-2011
i Guess i need to get my act Together and finish my viper jet build as there will be a Squadron very soon
Quick Note i am going to install my servos differently to the std setup as i dont like the elevator setup as is, Too sloppy i feel.
Steve
RE: Viper Jet 70MM - gbanger - 30-11-2011
I have only just unpacked mine. Yipee another Jet.
I am probably going to put a 70 mm Wemo in it and run it on 6S, although the new 70mm 10 blade Extreme fan from Extreme RC does look very tempting. That will give me 2.5 kgs of thrust..... YEEEEEHAAAAAA !!!
I am planning on bungy launching mine..... langing gear adds a lot of drag to jets and who needs that crap.
Are you using slim wing or standard mini servos Steve???
RE: Viper Jet 70MM - paulj - 30-11-2011
Hey Gaz,
I've just bought 2 of those 10blade 70mm fans from china.
Going to swap them over from the plastic Change Sun housings to
something like a wemo housing.
Lots of reading on RC Groups about them with interesting articles about which motors
to use etc.
Mark at Extreme is to dear with this offerings although the alloy housing would be nice.
I intend on using them on my B737 model.
RE: Viper Jet 70MM - gbanger - 30-11-2011
Thanks for the heads up Paul,
What is wrong with the Change Sun housings? I wouldn't use one but am a little curious.
I have a bit more research to do yet, but I dont mind dropping a few grams of thrust to get that lovely turbine whir.....
RE: Viper Jet 70MM - samste - 01-12-2011
(30-11-2011, 09:45 PM)gbanger Wrote: I have only just unpacked mine. Yipee another Jet.
I am probably going to put a 70 mm Wemo in it and run it on 6S, although the new 70mm 10 blade Extreme fan from Extreme RC does look very tempting. That will give me 2.5 kgs of thrust..... YEEEEEHAAAAAA !!!
I am planning on bungy launching mine..... langing gear adds a lot of drag to jets and who needs that crap.
Are you using slim wing or standard mini servos Steve???
Have Std 939 metal gear from Hobbyking to put in. The Elevator i was planning on doing something similar to this below, Which i found someone had the same Idea on Rcgroups Already.
http://www.rcgroups.com/forums/showpost.php?p=17948398&postcount=153
RE: Viper Jet 70MM - robair - 01-12-2011
G'day fellow Vipernauts
My first thought in regards to the elevators was to mount the servos up near the fan. Then use goldnrod routed up the fuse outside the duct tube to connect to the elevators. This magic little aircraft does not deserve to have stuff hanging off the sides. Will use mg939 digitals all round.
I need to check if any of our nearby LHS's have goldnrod in stock. I am pretty sure my visa has expired for a trip to kellets.
Cheers
Rob B
RE: Viper Jet 70MM - samste - 01-12-2011
Ok i finally got my lipos for my viperjet build and did a test run to make sure all is good before i continue on with my viperjet project.
As Power is most importantant
It got quite windy in the office doing the test, just spent 10 minutes picking up all the papers that flew everywhere.
Test Results
7s lipo setup, 70 amps, 1750 watts,
I think plenty of thrust coming out so its been as rob says ?
My other thoughts was to rod connect the elevator either side and then one rod back to servo, and yes i think the 939 or 929 metal gear will be fine.
Steve
RE: Viper Jet 70MM - gbanger - 01-12-2011
I've already got half a dozen MG 939's on the shelf so its good that we are all on the same wavelength with our servos.
I have not had a really good look at the placement of things yet but I too am thinking about mounting one servo further up the airframe to run both elevators but that is only a preliminary thought.
Steve have you put the servos for the ailerons and flaps under or on top of the wing.
I know it doesn't look as nice on the ground but because it has such a low wing I thought of running them on the top of the wing to stop them fouling on the ground during landings just like we do on our skyfun's.... (your thoughts????)
I suppose I should have asked if you are running landing gear. I won't be, I want to keep the little sucker as light and slippery as possible and landing gear will just generate to much drag and or weight.... and I'm not a big fan of weight, especially in an aircraft I hope will fly at around 240 plus kph.
Gazz
RE: Viper Jet 70MM - samste - 01-12-2011
Gazz, i guess the reason why i have taken so long with this build is because i have been yessing and noing myself about lots of things in regards to the build.
As Simple as it looks it reality there are a lot of decisions i guess in the way you build it, which you and rob will realize, unless I'm just looking too deeply into the build and should just throw it together as is.
But with a lot of reading up on it, main Issues was COG, Tip Stalling, elevator controls failing,
1.
I had concerns with weight, cog etc as lot of people say keep it light or you will have grief as it will tip stall very very easy.
So motor weight and lipo weight was a consideration i had to work on.
This is the reason you see on my Viper belly opening is longer than standard. as i pushed my motor to the rear 4 inches more so the lipo weight will balance out the cog a lot better with the lipos I'm using.
which i hope i have worked out OK and give me good flight time.
2.
My other issue which stop my build basically was i could not decide to fit retracts and Flaps or just maiden without and see how it flies First and then add them in later. Will it be easy to add later ? but if i install all of it will it add extra weight that isn't wanted ? and affect flight ?
Are Flaps really necessary to use on the viper as you have to come in hot any way, is going to help a whole lot ?
With all the discussions i read there is no mention of any one using flaps on landing, a couple have mentioned they use it for take off but doesn't really need it. especially if you bun geeing.
and the weight of the flaps, 50gms including wiring, fixins etc is not much but adds up in the whole scheme of things
Retracts could be good in help slowing down viper on the grass and good for area 51 and take off from grass, but extra weight which would be approx 250gms installed is a bit considering thats half my lipo weight.
But in saying all this should i just throw all the bells and whistles in the build and just fly it ?
Has that confused you all or am i just confusing the matter
Steve
RE: Viper Jet 70MM - ~KevJ~ - 01-12-2011
steve..man..seriously..get that bad boy finished and text me when your maidening please!
i just got my nanos for a sapac hawk about the same size, im only running 4s in her to start as it has retracts and im worried about the weight but i cant wait to see you push it through the skies on 7s
ps i also cant wait to see you belly land it on 7s :P
RE: Viper Jet 70MM - robair - 01-12-2011
G'day Steve
I know what you mean, I work at the speed of dark building aircraft due to the excessive planning/ do I or don't I phase.
Beer is consumed during this process.
Having said that once I have a plan build progresses reasonably.
I am not thinking about weight at all yet. The sapac fan that's going in has one position, butted up against the end of the inlet ducting. I think you were quite brave moving the motor back. Servo positions are set as per the wing cutouts, esc will be poking its heatsink into the end of the inlet ducting. Flaps will be fitted because they can be. Air retracts are partially installed already.
So most of my weight distribution is set in stone.
I am hoping that just moving the battery, rcvr, air tank and bec etc forward or back to get the c of g correct. Still you may be right re the motor shift as she does look very light up the back.
Looks like I will have the fast food eating version of this aircraft once we are all done.
6s nano is the battery plan, the c of g issue could dictate the mAh's thus battery weight.
I intend to leave the elevators split, I am not sure I would trust a single 939 servo, or any mini servo handling the entire load over what is a quite large control surface overall.
Kev's right though, just build the bugger. Bear in mind that Kev builds a really nice aircraft very quickly but doesn't even slow down to take the barcode stickers off his props.
It's great 3 of us are building the same aircraft almost concurrently!
Cheers
Rob B