HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 08, 2012, 04:52 AM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Quote:
Originally Posted by Mike F View Post
The swifts all have anhedral. The wing is designed to fly with this and creates stability.

Mike F
Okay thank you for the clarification!

You'd think this piece of info would be part of the instructions sheet, along with suggested amount of elevon travel..
Pouncer is offline Find More Posts by Pouncer
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 11, 2012, 05:33 PM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Ready for maiden

Hooked up the servos to the moving surfaces, one servo gave up on me, luckily I had a long throw spare. Looking back I might have selected the HK orange 1.7 g servos but that would have meant switching plugs, which I can do only with difficulty having no crimper.

The wing became quite flexible what with gouging out control rod channels and bays so I added a 2 mm carbon spar, found a region that was quite flat span wise so carved out a small recess and covered with glass fiber reinforced tape.

All up weight with a 14 g MiniAviation 210 mAh cell is 59 grams, if the maiden this weekend goes well I'll add some colour.
I heard here that you can dilute UHU Por with Ronson lighter fluid, so I got a small bottle of petrol (Benzinum). The idea is to dilute the glue, apply to surface and lay down the Solar film and not use the heating iron.
The film is light and opaque and without heating I needn't worry about shrinking.

Wish me luck come saturday!
Pouncer is offline Find More Posts by Pouncer
Reply With Quote
Old Oct 13, 2012, 09:47 AM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Second maiden (strykerized Swift)

Partially clouded with a ~3 m/s breeze with gusts, not ideal but could be worse.

First flight was hairy as I needed full down trim to even begin to keep her level, had very control in little pitch and roll but managed to bring her down with throttle and rudder (still had to do the walk of shame..)

Put a coin on the nose, pressed the U-bends for down trim and she behaved better but still very little control by elevons.
Took her down to examine more closely and saw that the servos barely moved!
The servo covers were the cause so off they came, much better.

Centre of gravity needs to be no further back than 95 mm and even then it needs an ever so slight down trim.
Tracks well, better than the original Micro Swift, rudders are pretty effective and puts the plane in yaw first, followed by rudder roll (on the Stryker rudders pretty much act like a second set of ailerons).
Pitch authority is good but roll rate leaves a bit to be desired, although this is due to a DX6i peculiarity which doesn't allow for full deflection when in elevon mode. On the Stryker this isn't a real problem but on the Swift there's a lot of surface area induced inertia to overcome at the wing tips.
This made low speed handling difficult to judge as well.
I'll see if I can't increase the max throws on the ailerons.

So how does it compare to the Stryker?

It's a bit early to tell before I've found a way to increase the throws but as it stands it doesn't penetrate wind nearly as effortlessly, has a lower top speed, couldn't be put it in a boomerang, low speed handling a bit dicey.
The first two can be improved with a smoother covering (but by how much I don't know), and the last two by increasing throws so there's hope still!

Update: found the trick to maximize throws on a DX6i and wow what a difference!
The Stryker/Swift has come to life! Quick rolls and crisp elevator movements.
Low speed handling similarly improved.
Lower top speed (I don't mind) and excellent vertical.
Still no boomerang but I got good rudder authority, wing overs are possible, also nice flat turns if I hold a little opposite aileron.
Had a servo lock while trying for a boomerang and pile drived into ground, exactly the kind of crash that killed my Stryker. The Swift was unscathed, so very durable and that's kind of the whole point of this conversion.
So I'll reduce the servo travel a bit and all should be good!

The CoG really shouldn't be any further than 95 mm back, tried the 100 mm and while I got exceptionnally fast elevator responce it'd randomly show a tendency to tuck under, at first I thought it was because of the down trim I put in but it was stable at speed, with the tucking under showing mostly at low speeds, weird.

Here's a link to the elevon fix on a DX6i, but essentially you just use your two mixes:
Mix 1: ELEV ->ELEV 125% TRIM ACT
Mix 2: AILE -> AILE 125% TRIM ACT
Pouncer is offline Find More Posts by Pouncer
Last edited by Pouncer; Oct 14, 2012 at 07:47 AM.
Reply With Quote
Old Oct 25, 2012, 06:42 AM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Split elevons?

Ok so now that the stock Micro Swift is boring compared to the strykerized one I'm thinking I could add split elevons ("duckerons" to some, but it is a silly word) to get some yaw action going.

So, to do this mechanically or by programming?

Programming elegance with a hacked Turnigy 9X transmitter, with air brakes to boot.
This is out of my league, for starters I have a DX6i and not about to get a new transmitter for this one project.

Speaking of DX6i's this guy and this guy are using a combination of transmitter mix with a couple of V-Tail mixers on a DX6i.

I hurt my brain trying to figure this out and the closest I can get is this (see schematic). It should work, save for one thing: when using rudder the servos opposite of the splitting pair will try to clamp the elevon beyond its closed position, not good.
Also I suppose I could skip the Y Harness and plug the second rudder servo in the CH6 port and use a RUDD->GEAR 100% mix. Not sure what that would accomplish though?

As for a mechanical solution it's entirely possible, with a spring to close the elevons and pulling a wire to separate them and uses one servo only, but something so simple in concept in usually harder than it looks to implement.

To be continued..

Luke Warm, RCPowers.com forum moderator explains how he did it:http://www.rcpowers.com/community/th...5/#post-145568
Seems I wasn't that far off, he used the gear and flap channels with 2 mixes and avoided clamping.
Pouncer is offline Find More Posts by Pouncer
Last edited by Pouncer; Oct 25, 2012 at 07:59 AM. Reason: Added link.
Reply With Quote
Old Oct 31, 2012, 09:47 AM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Made a proof of concept split elevon and although the idea is basically sound there's a couple of things that need rectifying and that would lead to a solution probably too complex for this application.

One problem is that the two surfaces, due to not sharing a hinge and to minute play in the assembly can skew when returning to closed position, leading to either up or down deflection even though the elevon horn is centered, not good.

The other problem is the difficulty in overcoming the initial geometrical inertia since when collapsed the hinges are almost all in the same plane (no leverage).

I'm going to think about it some more, but it looks like I'm going for the 4 servo solution after all!
Pouncer is offline Find More Posts by Pouncer
Last edited by Pouncer; Oct 31, 2012 at 09:52 AM.
Reply With Quote
Old Oct 31, 2012, 09:56 AM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
In other news the little strykerized Swift has earned its colours!
Pouncer is offline Find More Posts by Pouncer
Reply With Quote
Old Oct 31, 2012, 03:38 PM
Crashomatic
CrashMeUp's Avatar
United States, CA, SF
Joined May 2010
2,043 Posts
cute
im split between the radjet 420 and another um stryker (or just a new airframe, mines pretty dead) to add to my collection
CrashMeUp is offline Find More Posts by CrashMeUp
Reply With Quote
Old Oct 31, 2012, 04:38 PM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Quote:
Originally Posted by CrashMeUp View Post
cute
im split between the radjet 420 and another um stryker (or just a new airframe, mines pretty dead) to add to my collection
I have the parts for a RadJet 420 and honestly it looks even more fragile than the Stryker. But it can take 3S, there's a Youtube comparison vid of the two, the Styker is slightly faster on 2S but is left in the dust when the Radjet is on 3S.

Me, I'm thinking of putting Beast3D guts in it and add canards. Horizon gave us this wonderful stabilisation system, time to get playing with it.
Pouncer is offline Find More Posts by Pouncer
Reply With Quote
Old Oct 31, 2012, 04:53 PM
Crashomatic
CrashMeUp's Avatar
United States, CA, SF
Joined May 2010
2,043 Posts
Ive seen your video
I'm supposing the Stryker on 3S (different brick) would also be a speed daemon.. not that it would be slow to start with anyway.

I like your canards idea tho!

I mainly need a tiny bird that flies fast, straight, handles strong winds decently, and flies decently long, like, say, 10min+. The stryker actually provides all that. My micro switch does ok, but not nearly as good as the stryker (even thus its heavier, and uhm, indestructible)
Does the radjet more or less compare to it? (on 2 or 3S)
CrashMeUp is offline Find More Posts by CrashMeUp
Reply With Quote
Old Oct 31, 2012, 07:04 PM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Quote:
Originally Posted by CrashMeUp View Post
Ive seen your video
I'm supposing the Stryker on 3S (different brick) would also be a speed daemon.. not that it would be slow to start with anyway.

I like your canards idea tho!

I mainly need a tiny bird that flies fast, straight, handles strong winds decently, and flies decently long, like, say, 10min+. The stryker actually provides all that. My micro switch does ok, but not nearly as good as the stryker (even thus its heavier, and uhm, indestructible)
Does the radjet more or less compare to it? (on 2 or 3S)
I don't have the Radjet, just the foam parts to assemble one, and the video isn't mine, so can't answer your question.
But it sure sounds the UM Stryker would fit your bill, perhaps the Radjet would too.

BTW the Stryker/Swift isn't cute, it's pugnacious..
Pouncer is offline Find More Posts by Pouncer
Reply With Quote
Old Oct 31, 2012, 07:20 PM
Crashomatic
CrashMeUp's Avatar
United States, CA, SF
Joined May 2010
2,043 Posts
The Swift is like puss in boots Tiny, so looks cute, even thus it has teeth hehe

I'll keep on wondering for a while as I don't currently have time to build/play with a radjet (i think i'd want to try 2 and 3s and probably stabilization and canards too.. stealing ideas, yes. if you do *must* post video ! )
CrashMeUp is offline Find More Posts by CrashMeUp
Reply With Quote
Old Nov 01, 2012, 02:40 PM
Never trust laughing dolphins
Joined Feb 2011
2,085 Posts
Quote:
Originally Posted by Pouncer View Post
Made a proof of concept split elevon and although the idea is basically sound there's a couple of things that need rectifying and that would lead to a solution probably too complex for this application.

One problem is that the two surfaces, due to not sharing a hinge and to minute play in the assembly can skew when returning to closed position, leading to either up or down deflection even though the elevon horn is centered, not good.

The other problem is the difficulty in overcoming the initial geometrical inertia since when collapsed the hinges are almost all in the same plane (no leverage).

I'm going to think about it some more, but it looks like I'm going for the 4 servo solution after all!

You could probably do something like that with a push rod on a guiding rail, but its not useful for aileron movements. I do think you will always need four servos for that, regardless of the mechanical approach. :-)
PHMX is offline Find More Posts by PHMX
Reply With Quote
Old Nov 02, 2012, 06:25 PM
Wanton construction
Pouncer's Avatar
Stockholm Sweden
Joined Sep 2006
954 Posts
Quote:
Originally Posted by PHMX View Post
You could probably do something like that with a push rod on a guiding rail, but its not useful for aileron movements. I do think you will always need four servos for that, regardless of the mechanical approach. :-)
Yes I've more or less abandoned the mechanical route, too finnicky plus I'd need a bigger servo so securely operate it, so not even any weight gain.
Not that I'd know where to put it, there's not exactly acres of space on a Micro Swift..

On the other hand I'm too keen on ordering a pair of mixers either so kept thinking; what if I use the transmitter mix described above and put small linear servos in between the split elevons?
That would greatly simplify the mechanical aspect.
But the whole assembly would add quite a bit of weight in the back of an already borderline tail heavy plane.

I could also keep it simple-stupid and add spoilers..
A couple of rods with bent ends, a small piece of cardboard and a 1.7 g HK servo would be enough.
Pouncer is offline Find More Posts by Pouncer
Reply With Quote
Old Nov 06, 2012, 12:43 AM
Never trust laughing dolphins
Joined Feb 2011
2,085 Posts
Quote:
Originally Posted by Pouncer View Post
Yes I've more or less abandoned the mechanical route, too finnicky plus I'd need a bigger servo so securely operate it, so not even any weight gain.
Not that I'd know where to put it, there's not exactly acres of space on a Micro Swift..

On the other hand I'm too keen on ordering a pair of mixers either so kept thinking; what if I use the transmitter mix described above and put small linear servos in between the split elevons?
That would greatly simplify the mechanical aspect.
But the whole assembly would add quite a bit of weight in the back of an already borderline tail heavy plane.

I could also keep it simple-stupid and add spoilers..
A couple of rods with bent ends, a small piece of cardboard and a 1.7 g HK servo would be enough.
You'd be the first to put duckerons on a mini swift. I think it's interesting to see how far you can get with this. There's almost no space, but push rods can be longer for a different servo placement.
PHMX is offline Find More Posts by PHMX
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Looking for MS Swift or similar epp wing HomeDaddy Atlanta Area RC 3 Jul 01, 2012 11:48 PM
Sold MS Composit Swift II flying wing michelh Aircraft - Electric - Airplanes (FS/W) 0 Jun 25, 2012 07:10 AM
Sold MS Composit Swift II NIB! blue7.62 Aircraft - Electric - Airplanes (FS/W) 4 Apr 06, 2012 12:13 AM
Wanted MS Composite Swift 2 wanted Davidpe Aircraft - Electric - Airplanes (FS/W) 3 Mar 31, 2012 10:31 AM