HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 31, 2012, 03:25 PM
Registered User
Canada
Joined Jul 2009
6,986 Posts
Quote:
Originally Posted by hklagges View Post
you can easily add a $25 gyro on your own after you bought it. It is no problem.
I think the stock gyro on mine is defective. It didn't work or I didn't know how to program it using the info given in the manual. I've bypassed it for the time being but may replace it with the tail gyro from an old Blade 400 helicopter. So far, I haven't even attempted to hover.

Quote:
Originally Posted by TheCure View Post
Has anyone reenforced the nose cone? I understand its a weak point for the plane.
I was thinking to afix to the plane using strong magnets, and reenforce the cone as well. The nose cone should pop off in teh case of any hard landings. The cone itself should have less of a chance of sustaining damage if its reenforced too.

Anyone have experience with this?
I glued mine on permanently and I've had a couple fairly hard landings but neither time did the nose come close to touching the ground. For me, the weakest part are those 2 plastic skids and the intakes. Cracked the heck out of one skid and cracked both intake foam. They do supply a second spare nose cone.
I did the magnet thing on my old SU-35 nose cone. In the end, the nose cone was the only thing not damaged.
xviper is offline Find More Posts by xviper
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 31, 2012, 03:50 PM
Registered User
hklagges's Avatar
Munich
Joined Dec 2008
1,174 Posts
Quote:
Originally Posted by xviper View Post
I think the stock gyro on mine is defective. It didn't work or I didn't know how to program it using the info given in the manual.
I thought so too, in the beginning. I got very angry with my supplier who ended up sending me a new gyro, which did behave exactly the same. So I re-read the manual and re-read the thread and it turned out that I had not understood the setup correctly. The standard stock gyro does not work properly in heading hold-mode, it has to be operated in normal mode. Also, it is normal that the tv rudder servo is shaking / jittering a bit.

After finding this out, I went flying the beast, and voila, it worked... I apologized to my supplier.

Cheers,
Henrik
hklagges is offline Find More Posts by hklagges
Reply With Quote
Old Oct 31, 2012, 06:19 PM
Registered User
Canada
Joined Jul 2009
6,986 Posts
Quote:
Originally Posted by hklagges View Post
I thought so too, in the beginning. I got very angry with my supplier who ended up sending me a new gyro, which did behave exactly the same. So I re-read the manual and re-read the thread and it turned out that I had not understood the setup correctly. The standard stock gyro does not work properly in heading hold-mode, it has to be operated in normal mode. Also, it is normal that the tv rudder servo is shaking / jittering a bit.

After finding this out, I went flying the beast, and voila, it worked... I apologized to my supplier.

Cheers,
Henrik
I have no idea what was wrong with mine. I guess I'm too stupid to program it.
When it was hooked up, just sitting on the table, there was absolutely no TV response to rudder stick input. Rudder TV worked normally when I took it out of the equation. I just gave up on it.
xviper is offline Find More Posts by xviper
Reply With Quote
Old Nov 01, 2012, 12:51 AM
Wats the worst that can happen
TheCure's Avatar
Canada, BC, Surrey
Joined Jan 2009
542 Posts
Motor Thrust Experience

I've just trialled the 3300kv Turnigy motors. Using a 4000ma 45-90 Nano pack I noticed the plane was able to hover while holding the nose. I'd say if I let go it was able to go vertical about 1ft/sec. Subsequent tries after the 15 second hover it was only able to maintain static height.

Has anyone tried this experient with the stock motors? I'm wondering if I'm down on thrust. I'd think based on what I've seen in the demo videos it should always be able to climb vertically.
TheCure is offline Find More Posts by TheCure
RCG Plus Member
Latest blog entry: My Mods to My RC Electronics
Reply With Quote
Old Nov 01, 2012, 01:09 AM
Registered User
Canada
Joined Jul 2009
6,986 Posts
Published weight to thrust ratio is 1:1.25, meaning it's supposed to have 1/4 as much more thrust than it has weight. At least at sea level, it should be able to go vertical at any time. I'm at 3500' elevation and when I first finished building it, just for kicks, I held it by it's nose in my basement, gave it full throttle and I could loosen my grip on it and it would begin to rise. I haven't attempted to do a vertical take-off yet. Haven't got up enough nerve to try it. 600 bucks is a lot of money to schmuck into the dirt as an experiment.
xviper is offline Find More Posts by xviper
Reply With Quote
Old Nov 01, 2012, 07:18 AM
Let the hating begin
evalith8's Avatar
HAMPTON VA
Joined Dec 2009
873 Posts
I hope it has some punch out from a hover.My normal rigs are 1700 watt 5.5 lb & 35/55 cc gassers which rocket out of hovers like slingshots.
evalith8 is offline Find More Posts by evalith8
Reply With Quote
Old Nov 01, 2012, 01:27 PM
Wats the worst that can happen
TheCure's Avatar
Canada, BC, Surrey
Joined Jan 2009
542 Posts
Quote:
Originally Posted by xviper View Post
Published weight to thrust ratio is 1:1.25, meaning it's supposed to have 1/4 as much more thrust than it has weight. At least at sea level, it should be able to go vertical at any time. I'm at 3500' elevation and when I first finished building it, just for kicks, I held it by it's nose in my basement, gave it full throttle and I could loosen my grip on it and it would begin to rise. I haven't attempted to do a vertical take-off yet. Haven't got up enough nerve to try it. 600 bucks is a lot of money to schmuck into the dirt as an experiment.
I would guess that even if the marketing drivel holds true a 125% power to weight you won't see the plane shoot to the stars from a standstill.
When you tried your hover experiment how fast did the Mig start to climb upwards?
I don't want to go chasing wild gooses by fooling around with timings, motors, etc if I know this behaviour is expected.
TheCure is offline Find More Posts by TheCure
RCG Plus Member
Latest blog entry: My Mods to My RC Electronics
Reply With Quote
Old Nov 01, 2012, 02:58 PM
Registered User
hklagges's Avatar
Munich
Joined Dec 2008
1,174 Posts
Quote:
Originally Posted by TheCure View Post
I've just trialled the 3300kv Turnigy motors. Using a 4000ma 45-90 Nano pack I noticed the plane was able to hover while holding the nose. I'd say if I let go it was able to go vertical about 1ft/sec. Subsequent tries after the 15 second hover it was only able to maintain static height.

Has anyone tried this experient with the stock motors? I'm wondering if I'm down on thrust. I'd think based on what I've seen in the demo videos it should always be able to climb vertically.
Thanks for sharing your experiment. I tried this several times, with a 462 gram 45C 4.000 mAh battery and at an elevation of 550 meters above MSL. The stock motors and fans are beasts, in particular, the motors have enormous headroom with respect to the maximum current per motor (60A +). The plane wants to go straight up energetically if you hold it by the nose and give WOT. If you launch it like that, you can go vertical for 100 meters without any problems - and I level out at that altitude just to conserve energy, the plane itself would go further.

I tried to improve the stock setup by going to Wemotecs and HET 2W20 motors. Maximum current per motor dropped to about 43A or so with a fresh battery. All I got was a plane that could roughly hold its altitude. So I built in the stock motors again.

So your experiment is like mine: It shows that it is hard to reach the level of the stock setup, and damn hard to improve on it.

Cheers,
Henrik

PS: In my opinion, the marketing statement of power to weight ratio of 1.25 : 1 sounds about true, especially if you use 3.600 mAh batteries as also written in the manual. Maybe it is only 1.15:1 or 1.20, but it certainly is comfortably above 1 : 1.
hklagges is offline Find More Posts by hklagges
Reply With Quote
Old Nov 01, 2012, 04:08 PM
Registered User
Canada
Joined Jul 2009
6,986 Posts
Quote:
Originally Posted by TheCure View Post
When you tried your hover experiment how fast did the Mig start to climb upwards?
Since I was in my basement, I never let it go altogether. The "lift-off" was not awe inspiring. If I had let off even a little bit on the throttle, it would have fallen. I think if you watch some of the hovering vids, you can get a pretty good idea of how well the thing climbs after a hover. It goes up but it ain't no rocket.
xviper is offline Find More Posts by xviper
Reply With Quote
Old Nov 01, 2012, 04:14 PM
Wats the worst that can happen
TheCure's Avatar
Canada, BC, Surrey
Joined Jan 2009
542 Posts
I get about 1250g thrust from each side measured from a hanging digital fish scale using these Turnigy SK3 3300kv motors. This is 30m above sea level.
I got the same thrust number from the one stock motor I bought.
The real-world upwards momentum difference I'm seeing between my jet and others with the stock configuration might be just a weight factor. I did use 2x100A speed controllers, heavier gauge wiring throughout, and yes, the 4000ma battery too. The motors themselves might be heavier than the stock. I will check this tonight. I am also going to look at ESC programming to see if I can improve on the thrust.
It will interest me if a few of you can weigh on a decently accurate scale their planes in flight form (with battery). I believe mine was 2.4kg with the 4000ma Nano.
I am sure the heavier battery has a significant bearing - the manual even suggests this as you state, HKLAGGES. From memory I think it suggests 4000ma for more of a non 3D flight.
I need to figure out a plan of action to get my jet air-ready. It's already been almost 10 months since I bought it! I will not re-wire it to save weight. It was too much work. I might consider to buy a smaller size battery pack, and/or replace the motors. Before I do this I'd like to compare AUW weight figures to see how far I'm off. The motor assembly with turnigy sk3 3300kv is 166grams. The AUW is 2.06kg with my 470g 4000ma battery.

Thanks!


Quote:
Originally Posted by hklagges View Post
Thanks for sharing your experiment. I tried this several times, with a 462 gram 45C 4.000 mAh battery and at an elevation of 550 meters above MSL. The stock motors and fans are beasts, in particular, the motors have enormous headroom with respect to the maximum current per motor (60A +). The plane wants to go straight up energetically if you hold it by the nose and give WOT. If you launch it like that, you can go vertical for 100 meters without any problems - and I level out at that altitude just to conserve energy, the plane itself would go further.

I tried to improve the stock setup by going to Wemotecs and HET 2W20 motors. Maximum current per motor dropped to about 43A or so with a fresh battery. All I got was a plane that could roughly hold its altitude. So I built in the stock motors again.

So your experiment is like mine: It shows that it is hard to reach the level of the stock setup, and damn hard to improve on it.

Cheers,
Henrik

PS: In my opinion, the marketing statement of power to weight ratio of 1.25 : 1 sounds about true, especially if you use 3.600 mAh batteries as also written in the manual. Maybe it is only 1.15:1 or 1.20, but it certainly is comfortably above 1 : 1.
TheCure is offline Find More Posts by TheCure
RCG Plus Member
Last edited by TheCure; Nov 02, 2012 at 02:38 AM.
Reply With Quote
Old Nov 02, 2012, 06:49 AM
Let the hating begin
evalith8's Avatar
HAMPTON VA
Joined Dec 2009
873 Posts
mine came last night.I got a DX8 & was wondering if anyone has the mix values & so forth for a DX8.Also mine has a vector 3 plug on it.I ordered the non gyro version & in the instructions only say to plug in v1 & v2 in aux 1 & aux 2.Any help setting up the mixes would be great(for the tv)
Thanks
evalith8 is offline Find More Posts by evalith8
Reply With Quote
Old Nov 02, 2012, 04:00 PM
Registered User
Bulgaria, Sofia-city, Sofia
Joined Aug 2012
178 Posts
Hello , planes flies very good without Gyro , as other guys say Gyro is needed for hoovering mainly. I disconnected mine since I had problems with programming . Look on prev page I think xviper posted DX8 setup file
cdmanbg is offline Find More Posts by cdmanbg
Reply With Quote
Old Nov 03, 2012, 06:06 PM
Let the hating begin
evalith8's Avatar
HAMPTON VA
Joined Dec 2009
873 Posts
well right before the 2nd flight the right motor stopped putting out full thrust above
half throttle,all the way up to about half its fine but anything over & its very weak.
tried a fresh battery & no change.Brand new plane & after 1 flight it's benched until I get this problem fixed.Im kinda baffled,seems like if it was the motor it would be conistent at any throttle setting.Possible esc maybe.Im hoping someone on here has seen this before.Looks like Ill be calling Hobby lobby on monday.Great way to spend the first weekend with a 500.00 plane
evalith8 is offline Find More Posts by evalith8
Reply With Quote
Old Nov 03, 2012, 06:37 PM
Registered User
fredmdbud's Avatar
USA, MD, Frederick
Joined Jan 2010
4,124 Posts
Did you try resetting your ESC throttle endpoints
fredmdbud is online now Find More Posts by fredmdbud
Reply With Quote
Old Nov 03, 2012, 08:52 PM
Let the hating begin
evalith8's Avatar
HAMPTON VA
Joined Dec 2009
873 Posts
Quote:
Originally Posted by fredmdbud View Post
Did you try resetting your ESC throttle endpoints
how?I did notice that each motor has the same output if one esc rx lead is unplugged & they are run 1 at a time,both together then the right side drops,how do you set the end poinst?same as a castle esc?
evalith8 is offline Find More Posts by evalith8
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
For Sale Phase 3 Squall Hp, thrust vector, plus new airframe redrsv Aircraft - Electric - Jets (FS/W) 10 Dec 28, 2010 10:07 AM
Wanted Seb-Art Miss Wind 110 E NIB, or Used RTF Aero12 Aircraft - Electric - Airplanes (FS/W) 0 Dec 26, 2010 01:11 AM
New Product NEW! MONSTER THRUST VECTOR EDF F22 buy the RTF get ARF kit free? rjp0325 Electric Ducted Fan Jet Talk 17 Sep 24, 2010 08:12 PM
Sold New Mig-29 Vectored Thrust Complete Kit Harv Aircraft - Electric - Airplanes (FS/W) 5 Feb 29, 2008 10:24 AM
Video Mig-29 with 2-Dimension Thrust-Vector-Control system bryan.chen Electric Plane Talk 0 Jun 25, 2006 09:21 AM