LX Models Mig29 issues

[ddsjoseph]

I have been working on an LX Models Mig29 KIT for the past three weeks. I have been having several major issues with their design and was wondering if anyone has dealt with these issues. This jet does not come with wing spars. To add the wing spars would be great, but the landing gears are in the Fuselage, and occupy the space adjacent to the wing mounts. As the landing gears are in retracted position, there is no room for the spars to enter the fuse without hitting the LG. I have seen videos of this Mig29 on YouTube, where the wing snaps off during flight due to lack of a wing spar. I also wanted to know if anyone has had CG issues because of battery placement. The manufacturer recommends to use two 3S 4000 mah batteries in Series. The plane has two separate compartments for the batteries, one being near the nose of the plane and the other just behind the canopy. I have seen some Youtube Videos where the pilots have used just one 6S 4000 mah battery in the rear compartment. I would prefer to use the latter, with just one battery, however I am not sure if it would cause CG issues. The stock LX twin 70mm EDF motors are nice and light, but are garbage. Instead I am planning to use twin FMS 1850KV 2860 inrunner motors that are slightly heavier. One of the major flaws of this model is that the fuselage comes in two halves. The top half, which the LG is mounted on and the bottom half, that incorporates all the servo and esc wires. Once you glue the two halves together, there is no way to do any modification. So it's important to check all systems before permanently gluing the two surfaces together. I will post photos of the build shortly.
Thanks

[bradl4648]

Hi yes LX models have great looking frames but everything about them electronically and in finish really lacks bad. I have seen this time and time again and not having a spar on that big of a jet is just plane stupid. You really do not want to go with a single battery at all. What will happen for some reason as the battery drains the right motor will die out first. This will put this in a right spin and if you are not ready for it its over. Also you will have to add some nose weight more in likely to cg with only 1 lipo in it . Its to bad about how bad LX truly is and Banana does not even care at all. They should be addressing them telling them to get their act together and get this stuff fixed. Their is only a hand few that said they had no problems all the rest is negative. I hope all goes well for you and no more issues happy flying!

[Arcangel]

I fully understand where you are coming from ddsjoseph, I have been working off and on a LX Mig-29 for the past year. I love the looks of the aircraft so I have been taking my time to learn all the mods and make it a good aircraft for me. It can be done but there is soo much re-engineering and structural reinforcement that needs to be done to that model. It's good that you chose to start with the kit and not the ARF as all the most important mods are damn near impossible to do when the model is all glued together.

Your choice in fans sounds like a winner, :Cool: I have a set of Freewing 70mm high-performance in-runners with the metal anodized housings and a pair of Gecko 125A ESCs for mine. I have not had the opportunity to check out the FMS power plants yet, and the newer v2 of the Freewing 70mm 12 blade fans run great ( I have one a DuraFly Vampire ) but they are never in stock at MRC.

I will offer up some helpful info that I have found trolling Youtube for the LX Mig-29.

) There are videos from a guy who has installed carbon fiber tubes into the wings of the model and believe me; it's not easy to do but well worth it if you want to keep the plane flying. ( the guy who posted the videos is Brandon Moon and he has several mods on the model worth watching )

) He also replaced the Landing gear with some custom made gear from another Chinese company, I don't feel you have to go that far, but definitely replace the stock plastic gear with something more reliable and sturdy. I plan to mod my Mig to use the gear from the Freewing SU-35 running smaller tires.

) I plan to " try " and run the Mig with a single battery but will use 2 if it can't be helped. My idea is to redo the nose landing gear to operate in the correct manner ( the model has the nose gear retracting forward like the F-18, while the real aircraft's nose gear retracts backwards toward the intakes and main body ). If this works out for me, I'll have all the forward nose section to use as a battery compartment.

) There are several hatch mods that were done by various people who have built the model and posted to Youtube, I highly recommend you look into these and do one the suits you. As you have noticed, once the model is glued together, there is no way to get at the electronics without the mods.

) Check Youtube for videos on the C.G. placement for the Mig-29. The general consensus of everyone who has owned one, have flown it, and not crashed it, is that the recommended C.G. in the manual is way off.

) If you have not already glued the T V nozzles together, there is a mod that shows you how to add some foam and a suggested thrust tube diameter to optimize the power output from the motors and fans. Apparently the openness of the vector ball joints steal quite a bit of the available thrust and let it leak out of the airframe.

) To help improve the performance of the model, I plan to add some cheater holes near the fans; and guess what, the smaller, grey, plastic, grill covers for the cheater holes on the Freewing 90mm Super Scale F-16C are a perfect form fit to the nacelles on the Mig-29. So I will be adding them on mine to the inboard side so no one will really notice. :Don't-tell-Anyone:


I hope this will help you out and get you pointed in the right direction for your build. As a foot note, I do NOT plan on using the crappy designed plastic plug-in pin system for the elevators. I want to use the Freewing style system used on all their big models but I have yet to find readily available parts that can be easily fitted to the Mig-29's body. I might end up having to print my own pieces and go from there once I have my 3D printer back up and running. If it comes to this, I'll post some pics for you in the future.

Good luck on your build.

[crxmanpat]

All good info guys. I have a kit version (that I bought from Brandon Moon) and will be working on it soon. I plan to use the Freewing Me-262 fans (the older 6-blade version, wish I had known about the upgraded version before buying them), and mostly Freewing MG servos. I too will be looking for a way to add wing spars and a better elevator setup.

[ddsjoseph]

Thank you Gentlemen for all the helpful hints and suggestions. I took your advice and came up with these results. I was able to place the HSD Viper 90 LG, which sat higher than the Stock LG, allowing the wing spar to go through. Notice one of the photos showing the wing spar and the separate carbon fiber rod being inserted into the wing. Plywood was used to reinforce either side of the LG well to support the wing spar. The entire Fuselage was reinforced with 1/64 plywood. I opened the hutch for the electronics and placed magnets for retention. The only thing left to do is to address the TV nozzles. I was not aware of the loss of power due to lack of a good seal. Here are photos of my 16 hour build in one day.

[ddsjoseph]

Here are some more photos of the build

[ddsjoseph]

ArcAngel
Could you please post the link for the Thrust Vector Mod ?

[Arcangel]

Wow,

Nice work, you definitely got a lot of work done on the mods. I noticed in your pics that you had a fun time putting in the carbon spars in those thin wings. ;)

Here's the link for the TV ball joint mods. https://www.youtube.com/watch?v=KOyC_9PKcLs

It was done by Brandon Moon and he goes into detail about the glue joints and seams in the plastic TV balls could be poorly fitted / glued, cracked, or split allowing thrust leakage. He also addresses the open area inside the ball joints themselves end up creating a decent amount of internal turbulence reducing the thrust out put. He mentions the use of a wallmart coffee cup towards the end of the video that appears to be the perfect diameter for the TV thrust tube, but I couldn't find any videos that show the specific mod or that particular coffee cup he used. :Nerd:

I still have a ways to go with my Mig-29 as I am currently learning how to refinish and repaint a YF-23 also from LX / Banana Hobbies. The paint they used on that plane is horrible and I'm now testing out the Polycrylic method with fewer coats / layers. I'm still on the look out for a paint remover that works decent and doesn't scald or melt the foam.

[ddsjoseph]

Found the link on youtube

[ddsjoseph]

I stripped the paint off of my LX Models F4 phantom by using WD40 and after that used Mineral spirits from HOME DEPOT to clean up the oily residue. You can use Rubbing Alcohol instead of Mineral spirits as well.
Check out my F4 twin 70mm to single 90mm conversion POST on Hobby Squawk for photos showing the paint process in detail..

[ddsjoseph]

Here is the link for the F4 Phantom build

[ddsjoseph]

I am finally done building the Mig29. I tried using two separate Batteries of 3S 4000mah 70C and ended up being nose heavy. Instead I decided to use a single 6S 5000mah Admiral. The battery ended up sitting in the middle of the canopy where the pilot's seat was. So the Pilot had to be ejected. I also had to modify the canopy and added 1/64 plywood from the outside, since the foam was getting too thin to carve from inside the canopy. I will update the flight characteristics as soon as the weather permits.

[crxmanpat]

Mig looks great! I need to get mine out and build it.

[Alpha]

I really liked my LX MiG-29 a few years back, before I lost a wing. The second one I installed two rectangular spars, but still lost a wing when the surrounding foam buckled, taking the spar and foam and my hopes for the airplane with it. By the sounds of things, yours is better reinforced so I wish you many enjoyable years with this rare EDF!

[ddsjoseph]

I was able to fly the Mig29 today, and I must say that I was surprised how well and easy it was to fly it. Is is a very comfortable plane to fly with no bad habits. The flaps and slats work together and needed no elevator input to compensate. I am so happy that all my efforts paid off and it outperformed all my expectations. It is powered by twin 70mm FMS inrunner EDFs. I flew with Admiral 6S 5000Mah battery for 2.5 minutes and had 35% left after the flight. Hope these videos do justice to this amazing plane.

[ddsjoseph]

Short Landing Video of this MIG

[crxmanpat]

Congrats on the maiden! I will be building mine soon.

[ddsjoseph]

Nice!!

I would love to see your build photos

[crxmanpat]

Finally got around to getting my Mig completely built. All I have left to do is finish painting and add decals and finishing touches. I got the Star demo scheme, but repainting into an East German bird based on the scheme posted in the pics below. I plan to maiden this weekend, even if the paint is not finished. Here's a list of stats and the mods I did (and some Brandon Moon had already done when I bought it from him):

All Freewing servos
Freewing Me-262 power system (new 12bl setup)
2x RoaringTop 3S 6250 35C lipos
RCLander Mig-29 custom retracts (the mains rotate about 47°), Freewing steering servo
Freewing F-14 cheater grates
Wing spars, 3mm rod through to near the wing tips, which then keyed into tubes with a 3mm ID that were installed in the body (you can see them in the LG pics)
Elevator connections reinforced with steel pins
Removable turtle deck hatch
The bottoms of the LEFs have plastic covers to cover up those huge gaps between the wing
TV system completely removed and exhausts glued solid
Drag chute tail cone held on with magnets

I tested the drag chute system today in the road and it works fine.

[ddsjoseph]

Looks great! Just watch your timer when it comes to freewing 12Bladed 70mm EDFs, I could never fly more than 2.5 minutes before the battery drains to 20%.
Good luck, Pat
Joe