HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 27, 2012, 04:34 AM
Registered User
Suomi, Espoo
Joined Sep 2011
155 Posts
Quote:
Originally Posted by rowdyjoe View Post
Hope the attached pics help explain the gear repair/modification. They're on good and strong now. ...
Joe,
I am not sure from the pictures, but important that your screws extend through to the inner ply plate, as the outer, thick ply is only glued to the foam on the sides, not underneath, making it possible to rip it out.

Details of the LG ply structure in my post 624 on http://www.rcgroups.com/forums/showp...&postcount=624

I am in Australia at the moment, with my planes left in Finland, so I immensely enjoy your and Don's conversations. Keep them reports coming!

P.S. In my experience, this MX2 will left wing stall violently at too low a speed (ask me how I know...), not with wings level. Therefore I recommend keeping speed up and "push" her gently to land, instead of stalling her to land as you would with a full-size plane/glider. D.S:

P.P.S. Already bought the power train for the PA AddictionX designed in Australia. Will be my first balsa plane. D.S.
Jstjern is offline Find More Posts by Jstjern
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 27, 2012, 10:21 AM
Registered User
rowdyjoe's Avatar
Arlington, TX
Joined Jul 2009
1,237 Posts
Quote:
Originally Posted by Jstjern View Post
Joe,
I am not sure from the pictures, but important that your screws extend through to the inner ply plate, as the outer, thick ply is only glued to the foam on the sides, not underneath, making it possible to rip it out.

Details of the LG ply structure in my post 624 on http://www.rcgroups.com/forums/showp...&postcount=624

I am in Australia at the moment, with my planes left in Finland, so I immensely enjoy your and Don's conversations. Keep them reports coming!

P.S. In my experience, this MX2 will left wing stall violently at too low a speed (ask me how I know...), not with wings level. Therefore I recommend keeping speed up and "push" her gently to land, instead of stalling her to land as you would with a full-size plane/glider. D.S:

P.P.S. Already bought the power train for the PA AddictionX designed in Australia. Will be my first balsa plane. D.S.
Thanks for the tip on the screws. I used screws that were approx. 1.5" to 1.75" long and should have penetrated far enough to go through both layers. They are firmly attached.
Sorry to hear your plane drops a wing. Mine does not drop a wing when stalled but, it does drop the nose rapidly.
Foam will warp in heat or under sustained stress. Here in Texas, we don't dare leave them in direct sunlight for long and certainly not in an inclosed area, such as a car, in the summer. Perhaps yours has more washout on one side than the other?

You'll like the balsa plane. They are more rigid but, tender. Damage that might be a dent in foam will probably break wood. Good luck with it.

RJ
rowdyjoe is offline Find More Posts by rowdyjoe
Last edited by rowdyjoe; Feb 27, 2012 at 10:46 AM.
Reply With Quote
Old Feb 27, 2012, 02:09 PM
Registered User
Joined Feb 2012
34 Posts
What are people recomending for the perfect replacement two blade prop with spinner and adapter from hobbyking with stock power setup? I would like everything shipped from the US and from one site.
cheynespub is offline Find More Posts by cheynespub
Reply With Quote
Old Feb 27, 2012, 04:32 PM
Registered User
rowdyjoe's Avatar
Arlington, TX
Joined Jul 2009
1,237 Posts
Quote:
Originally Posted by cheynespub View Post
What are people recomending for the perfect replacement two blade prop with spinner and adapter from hobbyking with stock power setup? I would like everything shipped from the US and from one site.
Try tower hobby
rowdyjoe is offline Find More Posts by rowdyjoe
Reply With Quote
Old Feb 27, 2012, 06:48 PM
Registered User
United States, FL, The Villages
Joined Oct 2010
3,994 Posts
Spinner is indeed from Tower Hobby, prop is 14x7. That seems to be the preferred prop. I got the 2 1/4 black nylon with aluminum back plate.
Don

Joe, didn't get to fly it today. Wind was fairly high and when it died down, the field was hogged by a new, young, talented boy. Gotta tell him to share!
dkrhardy is offline Find More Posts by dkrhardy
Reply With Quote
Old Feb 28, 2012, 12:30 AM
Registered User
rowdyjoe's Avatar
Arlington, TX
Joined Jul 2009
1,237 Posts
We had excellent conditions for flying today but, I didn't go. My wife wasn't feeling well and she asked me to stay home with her. How could I turn her down?
Tomorrow is forecast to be windy so, maybe I'll have another chance later in the week.

RJ
rowdyjoe is offline Find More Posts by rowdyjoe
Reply With Quote
Old Feb 28, 2012, 01:09 AM
A4Framie
alfiev's Avatar
New Zealand, Marlborough, Woodbourne
Joined Nov 2011
231 Posts
Hi all, I have AN mx2 from HK. I had an expert mate of mine to testfly it for me. We noticed that the wing tip tends to drop at slow speed meaning you have to fly it in with some speed on when landing. Another mate had a 3D extra ( balsa and a bit smaller wingspan) I noticed that it had winglets or shrouds on the wingtips.
Has anyone tried fitting winglets to the MX2? Does anyone think it would stop the tip-stalling that seems to happen at low speed?
alfiev is offline Find More Posts by alfiev
Reply With Quote
Old Feb 28, 2012, 01:14 AM
I need a bigger shed..
sammyc's Avatar
Australia, TAS, Launceston
Joined Nov 2011
1,498 Posts
Quote:
Originally Posted by alfiev View Post
Hi all, I have AN mx2 from HK. I had an expert mate of mine to testfly it for me. We noticed that the wing tip tends to drop at slow speed meaning you have to fly it in with some speed on when landing. Another mate had a 3D extra ( balsa and a bit smaller wingspan) I noticed that it had winglets or shrouds on the wingtips.
Has anyone tried fitting winglets to the MX2? Does anyone think it would stop the tip-stalling that seems to happen at low speed?
Search the thread, there is at least one person who has done it. There are pictures somewhere
sammyc is offline Find More Posts by sammyc
Reply With Quote
Old Feb 28, 2012, 01:25 AM
Just flitting about!!
bigroger's Avatar
Joined Aug 2011
2,637 Posts
I did it to mine, it did tend to improve the flight envelop a little and allowed the wingtip stall speed to be reduced a little before it dropped a wing and did the terminal landing.

They are called SFG's, (side force generators). Many proper 3D model planes use them to provide greater rudder authority and to improve the airfoil effect of the wing at slow speed.

There's lot written about this stuff all over this forum, but in a nut shell, when the wings stall, one side or another will tend to loose airflow before the other hence the wing drop, the SFG's help hold the air on the wings longer in stalled mode.

My EPO MX2 was a little improved but only marginally, still tip stalls badly at stall speed.

I have many 3D planes that I fly frequently these days, this EPO thing is not one of them, its sits in storage until I decide to sell it or dispose of it.

Let me be perfectly clear : THIS PLANE IS NOT A 3D PLANE AS ADVERTISED, IT IS A SPORT PLANE. SORRY FOR THE FALSE ADVERTISING FROM HK AND OTHERS.
bigroger is offline Find More Posts by bigroger
Reply With Quote
Old Feb 28, 2012, 11:15 AM
Registered User
United States, FL, The Villages
Joined Oct 2010
3,994 Posts
Hey Roger,
I have read every page of this thread and it is very clear in my mind that this is not a very good 3D plane. Having said that, and agreeing with you, it is pretty darned good at beginner aerobatics. I say beginner, but I do NOT mean it in the sense of 2nd or 3rd plane. I have had 14 or so planes and have 10 right now. Some were thinned from the herd via re-kitting! I had read all of the posts and decided to get it as a "trainer" for my fledgling aerobatics. Big, stable (in flight), easy to see, and CHEAP. So if I re-kitted it, not much lost. Your opinions, and others, didn't deter me, but gave me a good sense of what it would or would not do. And it was CHEAP. I never belly land planes (they are supposed to have wheels!) and I'm pretty darned good at landing planes with power on so this thing doesn't give me much concern. Yet? I'm glad you are still with us passing on your experiences with it.
Don
dkrhardy is offline Find More Posts by dkrhardy
Reply With Quote
Old Feb 28, 2012, 11:50 AM
A4Framie
alfiev's Avatar
New Zealand, Marlborough, Woodbourne
Joined Nov 2011
231 Posts
Thanks fellas,

Yeah I'm getting the picture. Of course you should always treat the advertising blurb and supporting video ( flown by an expert no doubt ) with extreme suspicion. This is not a 3D frame, more a neat looking, large, aerobatic model with a bit of a nasty tendency to tip stall at low speeds.
As Don says, it's a lot of bang for your buck, just beware this might not be as forgiving as your true 3D model would be.

Alf
alfiev is offline Find More Posts by alfiev
Reply With Quote
Old Feb 28, 2012, 12:44 PM
Registered User
rowdyjoe's Avatar
Arlington, TX
Joined Jul 2009
1,237 Posts
If your bird is consistently dropping the same wing at the stall, that wing tip is probably lacking correct washout (look up the definition). A correctly shaped wing should stall at the root first, not the tip, so that neither wing drops at the stall.
Engineers, in the early days, discovered that washout greatly reduced the hazardous tip stall that lead to the often times deadly "stall spin" crash. At low altitude it was/is impossible to recover.
The correction for lack of correct washout for a foamy is to heat up the foam (techniques vary) and twist it into shape. With a wooden airframe, heating the heat-shrink covering (eg. monokote) at and near the tip will do the same job.

If it alternates dropping a wing then adding leading edge cuffs to the outer 1/2 to 2/3 of the wing should slow the stall speed and reduce the tendency to drop a wing. Cuffs and washout seem to have a similar effect.

I have experienced the washout issue but, have never done the leading edge cuff mod. However, I have witnessed the effect on another fellas bird and they work very well. We have a few aeronautical engineers in our club who experiment with scratch built models.

It seems logical to me that lowering the stall speed (eg. cuffs) would help 3D performance.

RJ
rowdyjoe is offline Find More Posts by rowdyjoe
Reply With Quote
Old Feb 28, 2012, 03:01 PM
Registered User
United States, FL, The Villages
Joined Oct 2010
3,994 Posts
Joe - I just did a search for washout and everyone talks about it but never says what it is. I presume it is a slight twist in the wing near the tip, but is it (looking at the LE from front) the LE up a bit, or down a bit. I'd also bet that it is small, like a degree or two. Hmmm .... off to more checking.
Don

edit: I found something on wikipedia. It says the tip is lower incidence than the wing root. So that would be a slight twist down, at the tip, of the wing, yes?

edit again: More checking with a broad INTERNET search. Seems that an 1/8 to a 1/4 inch is the norm, but even too much is better than not enough. Too much only creates drag, while not a really good thing it makes the plane a bit slower. Seems that it is easy to check with a flat bottom wing, but may be a challenge for symetrical wings.
dkrhardy is offline Find More Posts by dkrhardy
Last edited by dkrhardy; Feb 28, 2012 at 08:37 PM.
Reply With Quote
Old Feb 28, 2012, 03:36 PM
I need a bigger shed..
sammyc's Avatar
Australia, TAS, Launceston
Joined Nov 2011
1,498 Posts
Im gonna look into putting some washout in, if anyone does it can you please report how you did it and how well it works.
sammyc is offline Find More Posts by sammyc
Reply With Quote
Old Feb 28, 2012, 04:48 PM
Just flitting about!!
bigroger's Avatar
Joined Aug 2011
2,637 Posts
Quote:
Originally Posted by dkrhardy View Post
Hey Roger,
I have read every page of this thread and it is very clear in my mind that this is not a very good 3D plane. Having said that, and agreeing with you, it is pretty darned good at beginner aerobatics. I say beginner, but I do NOT mean it in the sense of 2nd or 3rd plane. I have had 14 or so planes and have 10 right now. Some were thinned from the herd via re-kitting! I had read all of the posts and decided to get it as a "trainer" for my fledgling aerobatics. Big, stable (in flight), easy to see, and CHEAP. So if I re-kitted it, not much lost. Your opinions, and others, didn't deter me, but gave me a good sense of what it would or would not do. And it was CHEAP. I never belly land planes (they are supposed to have wheels!) and I'm pretty darned good at landing planes with power on so this thing doesn't give me much concern. Yet? I'm glad you are still with us passing on your experiences with it.
Don
Thanks Don, I hear you loud and clear but yet we still see posts from guys who buy this plane expecting a nice scale plane that they can learn to harrier and hover with in 3D mode.... sorry but from that perspective its just a waste of time. This plane is a big fat over weight pig of a plane. The only real positive I can see is that it is relatively scale looking for those that swing that way.

It will not handle slowed down post stalled flight with dropping a wing.

I've been through this argument with every tom.dick and harry on this thread claiming that its everything from my flying skill, setup skill etc that prevented this plane from performing.... then find out that the supported of this plane do not 3D the thing but just cruise around doing rolls and loops etc.

The things this plane can do are these: loops, rolls, KE pass, inverted flight, hover (if you are quick on the transition).

The things this plane will not do without crashing are: upright and inverted harrier, high AOA KE pass, post stall stable flight.

You can bend the washout, add sfg's till the cows come home. Slow it down and pull back on the elevator and it will stall and drop a wing. Poorly designed for 3D flight.
bigroger is offline Find More Posts by bigroger
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Anyone tried the BlitzRCWorks MX2 Pro 3D? HallaBalla Foamies (Kits) 2 Mar 26, 2012 08:16 AM
Discussion 4 CH BlitzRCWorks 2.4GHz Giant Air Zermatt EC-135 jblackwell Coaxial Helicopters 9 Sep 07, 2010 08:37 AM
Sold Texas Pickup: BlitzRCWorks GIANT F-117 RX ready w/light, bomb drop, retracts: $140 Roswalt Aircraft - Electric - Jets (FS/W) 4 Jun 13, 2010 04:59 AM
Question mx2 or multiplex acromaster and st model mx2: Unboxing vid? build vid? y info? jakerevs 3D Foamies 2 Mar 27, 2010 02:56 PM
Question MX2 von Hype and ST-model MX2? Thomas*rc Electric Plane Talk 4 Nov 17, 2009 02:42 AM