Hi All.
So got a Teksumo as my first wing. Decided I really like wings and built a Versa blunt nose to use as a medium range FPV plane.
So the Teksumo is easy to launch flys great had a blast with it. Just not big enough and easy enough to house all the FPV gear well. I really like it all internal leaving a totally clean wing. Must be more efficient than bits hanging out all over the place.
The Versa which is bigger and has some internal space due to construction with the foam board worked ok. Just found it a little hard to launch. I think because the thing flys at what feels like double the speed of the teksumo even with the same motor. Just running on 4s instead of 3s. I think its just too much an aerobatic wing to really be good for a FPV wing. Well for me anyway.
So looking around came across lots of good suggestions mostly from here. Just about all ruled out as I am living in China at the moment just cant get easily. So decided I want to have something I can build myself. After all that is half the fun for me.
So found this design on you tube with enough info to easily do a build. Looks good and seems to fly ok. Fair big bigger again but all good :-)
https://www.youtube.com/watch?v=_tm0y-ygJU8 (https://www.youtube.com/watch?v=_tm0y-ygJU8)
So looking at the designs as to why the Teksumo might be so much more mellow than the Versa. Measured up and this is what I found. See attached info.
Looks like the tapper on the versa wing is a fair big more. Having a much smaller wing tip is maybe what helps increase the speed / agility. But with a higher flying speed also makes launching harder and its almost just too lively. The build I am looking at looks most of the way back towards the Teksumo in numbers so maybe fly similar to that? No idea about the foil shapes which obviously has a lot to do with it. Only have the real shape for the proposed wing not the others.
What do you guys think? Is there a better wing section I should be looking at?
Cheers
If you're flying a versa wing with the same motor you used on a tek sumo your versa is bound to be under powered- no wonder you found it hard to launch.
The versa is supposed to be a very reasonable flyer- if it's stall speed is really that high you either
1) have it too heavy.
2) have built it poorly and it's not generating the lift its supposed to be generating
Wing design is really complex I'm not going to pretend to know what I'm talking about- but IMO you're making life far more complex than it needs to be by looking into it.
I appreciate being in China narrows your options- but there must be somewhere you can buy a decent 50-60" wing from over there?! Built it light with a fairly powerful motor and it will be fine.
If you're really convinced about the scratch built lark- find a source of some EPP foam and scale the tek sumo up to 50-55" and clone it's shape from EPP. Strengthen the EPP with carbon rods and then Laminate it and you will probably have a fairly nice wing.
Or save yourself a shed load of hassle and email the guys at flying wings and buy a Venturi and have it posted to you. Put a 1400kv 4s motor kicking out 500W and it will be lovely.
Motor is a 2212 1400. Rated at 230w max. I had it on 4s at full throttle was drawing 24 amps so 400w.... Opps. Seemed to be ok for the few seconds of full throttle it was getting.
Have ordered one with about 50% more power and only 16g heavier. Meant to have a max 1500g thrust.
Versa with a 2200 4s and 900mah 3s for the FPV gear is AUW 1080g. So 1500g of thrust should kill it :-) not sure what it should weigh?
I think I have done a fairly reasnoble job on the build. It does fly very good just very speedy. Maybe I just need a slightly bigger motor and some more launch practice.
You are right scaling up the Teksumo would be the most sensible thing. Just need to work out the wing profile. Can try and make a patten off it I guess. The one I found online had plans for the profile and I can just plot at work. So very easy to replicate.
Kinda keen on the scratch build thing. Another reason is to up the quality of parts. Im ok with using foam, hard to go past really. But really dont like the standard aileron connections, Hot glue holding everything together etc etc. While a lot of these wings available are super cheap If Im going to be putting $4-500 worth of electronics in it I would be not happy if something stupid failed and I lost everything. Maybe Balsa Ailerons with proper hinges things like that.
for the Foam the EPP is good but very flexi. Haven't seen the blue board XPS foam but think its fairly rigid. Maybe the result might be more like the foam board. O must say I was impressed on how stiff the versa came out.
Cheers
If all that 400W was going towards thrust you would be ok. But if it's going as heat because you're over stressing the motor there's no benefit. Also experiment with prop size- you may find a bigger prop with less pitch makes launching easier.
1kg is light for a versa! Having said that I'm surprised it's only a 1m wingspan I thought it was bigger.
You don't need to work on the wing profile for the tek sumo. Trace it onto paper, measure all its dimensions- and then increase everything by 50%.
Have you seen the monkey blunt tek sumo? Very popular. You could add something similar to your scaled up tek sumo.
Most people who buy existing pre made planes upgrade the elevons and rods and other minor things. That's no reason not to buy an existing off the shelf plane.
Yes EPP is flexi as standard. But the most famous fpv plane in the world- the zephyr- was made from EPP. All it needs is some sparring and lamination and it's rock solid.
So, to conclude
1) buy a flying wings Venturi!
2) on the versa Try a bigger prop with smaller pitch and see how the plane launches. I launch all my wings full throttle overhead by gripping the nose. Dead reliable.
3) look at existing wings, £50 for an airframe isn't much to spend when you have £££ of electronics in there. What's going to happen to the versa when it gets wet?
4) if you must build yourself- look at the monkey blunt. Introduce this to the tek sumo having scaled it up to 120-150cm.
Or for £50 from the international warehouse- which is local to you- you can save a load of dicking about and, as it's the kit- you can use high quality parts and fit them yourself. Build it light and the stall speed will be low.
http://www.hobbyking.co.uk/hobbyking/store/__53815__Phantom_FPV_Flying_Wing_EPO_Airplane_1550mm_V2_KIT_.html?strSearch=Phantom (http://www.hobbyking.co.uk/hobbyking/store/__53815__Phantom_FPV_Flying_Wing_EPO_Airplane_1550mm_V2_KIT_.html?strSearch=Phantom)
Check builds on other forums for recommended motors etc.
Surely if anything being in China is an advantage, FPVModel.com are presumably in China and sell all the Skywalker planes and wings.
If you want to build one from scratch get some Depron. I've built an FPV40 which flies great but there's also the FPV49 which looks to fly amazing.
Video from my FPV40 flying low: https://youtu.be/NbmkHX99VbY (https://youtu.be/NbmkHX99VbY)
Quote from: Billy_boy_2010 on May 06, 2015, 07:58:39 PM
If all that 400W was going towards thrust you would be ok. But if it's going as heat because you're over stressing the motor there's no benefit. Also experiment with prop size- you may find a bigger prop with less pitch makes launching easier.
1kg is light for a versa! Having said that I'm surprised it's only a 1m wingspan I thought it was bigger.
You don't need to work on the wing profile for the tek sumo. Trace it onto paper, measure all its dimensions- and then increase everything by 50%.
Have you seen the monkey blunt tek sumo? Very popular. You could add something similar to your scaled up tek sumo.
Most people who buy existing pre made planes upgrade the elevons and rods and other minor things. That's no reason not to buy an existing off the shelf plane.
Yes EPP is flexi as standard. But the most famous fpv plane in the world- the zephyr- was made from EPP. All it needs is some sparring and lamination and it's rock solid.
So, to conclude
1) buy a flying wings Venturi!
2) on the versa Try a bigger prop with smaller pitch and see how the plane launches. I launch all my wings full throttle overhead by gripping the nose. Dead reliable.
3) look at existing wings, £50 for an airframe isn't much to spend when you have £££ of electronics in there. What's going to happen to the versa when it gets wet?
4) if you must build yourself- look at the monkey blunt. Introduce this to the tek sumo having scaled it up to 120-150cm.
Thanks all good info.
The Versa is actually 1180.
Yes living in China generally makes for buying cheap RC stuff easy and plenty full. That said just because stuff is made here doesn't mean you can buy it. A lot of companies that set up for 100% export only and go out of there way not to let stuff get sold locally in fear of it getting copied. Up until recently I couldn't even get Hobby king delivered here. This has recently changed.
That said yes all the Skywalkers are readily available. I just had a bad experience with them so a little shy. My first plane (after flying helis for a few years) was a Skywalker 1900 I set up for FPV. Longest flight was about 30 sec. Combination of trying to fly it like a heli, Build video I watch had the CG way aft. and crapy build using the bits that came with it. Really liked the X8 for a while but seen some videos that have turned me off.
So then brought a bixler which was super easy to fly and I had a lot of success with. Just not enough room inside bit small / slow and so floppy / flexi looks like a kids toy. Been good but want something better.
So looking around can get the Zeta FX-61 at a bargin for an empty shell. About 30 Quid. Half tempted to just go that way for now. Has a decent amount of room in the middle so should be able to lay stuff out ok. I have my sunnysky 2814 1100kv motor from the skywalker so that should be plenty. ? Up to 2.5kg thrust.
http://item.taobao.com/item.htm?spm=a1z0d.6639537.1997196601.24.GesfOt&id=22027824223 (http://item.taobao.com/item.htm?spm=a1z0d.6639537.1997196601.24.GesfOt&id=22027824223)
Will have a think about that and see where I end up.
Cheers
Do it. The cockpit isn't huge but plenty of room for a 3-4000 4s lipo and full autopilot system. That motor will be fine.
Do plenty of research on the CG and enjoy the easy flight.
Quote from: Billy_boy_2010 on May 07, 2015, 06:46:52 PM
Do it. The cockpit isn't huge but plenty of room for a 3-4000 4s lipo and full autopilot system. That motor will be fine.
Do plenty of research on the CG and enjoy the easy flight.
Ok if you insist :-)
I thought the space inside looked massive. Keep in mind comparing to a Bixler and Versa. The Versa I had to cut a whole in the front lid to get 1 x 4s 2200 inside. It sat about flush with the outside of the wing.
I have 2 x 2200 mah 4s lipos I was planning on using in parallel. So would need a space at least 110 x 35 x 70. Looks like people are using similar sorts of packs.
Other Gear I need to get in.
40 Amp ESC
Tornado OSD / Autopilot.
600mw 5.8g mini VTX
L9R Frsky RX.
Sony Board Camera
Mobius.
900mah 3s lipos for video gear and to power the Tornado.
One other reason for doing a scratch build was to draw the whole plane with all components in cad to get the perfect fit and layout. Maybe a longer term project.
The Versa now has the nose a bit softened from failed Launches and is all a bit delaminated. Shape is still ok and in one bit just getting very soft in the front sections. Might just use it for launching practice and try some different techniques. Can go in the bin at the end.
Just found this story. 2:37 flight time and 114km traveled. Wow thats impressive.
http://diydrones.com/profiles/blogs/phantom-fx-61-flying-wing-110-km-flight (http://diydrones.com/profiles/blogs/phantom-fx-61-flying-wing-110-km-flight)
Cheers
It's massive compared to the bixler , and will handle your two smaller batteries I'm sure- it's just a much smaller plane to its bigger brother the x8.