Well any king 2 owner probably knows about the weakness and flexibility of the motor mount on the king 2 stock plastic frame. Well there are several ways to fix this, including the extreme frame stiffener, the problem with that is that its expensive and adds considerable weight. This product is a nice alternative http://www.cy-model.com/product_info...b592ab89c79252 I bought this product a couple weeks ago and boy am i glad i did, so i just wanted to share with you some of my findings because i couldn't find anyone who has used this product yet. First off it comes at an incredible price of five bucks and free shipping, i thought "what the hey i'll give it a go" This stiffener only weighs in at 3.5 grams which i personally confirmed. This stiffener comes in two pieces, the smaller piece does not require any screw mounting, it sits right in the grooves of the motor mount. The bottom piece comes with two screws and a couple holes for mounting to the frame. Mind you, it says five minute fix but it took a good couple hours for me. In order to mount the bottom piece, you need to drill into the frame Around the area of the pulley, the screws a very small so finding an adequate drill bit is a bear. I was not able to find a bit this small so i had to put the screw against the frame and turn it until it was in a bit for both screws (luckily they're sharp screws), then took it off lined up the holes with the stiffener and screwed it in as much as i could. I then had to use pliers to to manually twist it in all the way until it was tight. When you mount this piece obviously you are going to have to remove the bottom part of the frame by removing the four screws and then popping the legs off. Be sure that when you mount the bottom piece that its not as far as it can go towards the front of the heli otherwise the front two legs of the frame will not fit back on. You'll notice in one of the pictures that i had to slightly file the two legs to get them to fit on, no big deal. After you get the bottom piece on, slip the top piece on the motor mount tray, it should fit quite nicely with no modifications. (again from the pictures you'll notice that i originally had to mod the frame to make the 3800 motor fit, but since the motor sits on top of the plate, it requires no modding). Now even though they give you motor mount screws with the package, they are unfortunately too short (not sure why?) So you will need to find some longer screws, but make sure they aren't too long, otherwise they could touch the motor windings and cause a short which could fry your esc. If they do touch, (you can see by looking in the side of the motor) Then use a dremel cutting disc to shorten the screws. Be sure to use washers when mounting the motor if your screws are on the narrow side. Be sure that every screw is very tight and your done! I must say, what a difference this makes, there is absolutely no flex in the motor mount area and the pinion runs much straighter to the main gear so that the mesh is truer and smooth Only problem is you might have to adjust where the pinion sits on the motor shaft, mine ended having half the width of the gear on the pinion, is this okay? Anyways for 5 bucks its an absolute must have and weighing in at only 3.5 grams its perfect. Mine came in a yellow white color instead of the black shown by the pictures on the website. If you are battling frame weakness get this, its just five bucks and free shipping you have nothing to lose. Only downside is the wait. Just wanted to let everyone know that there is a much cheaper and lighter solution than the extreme frame stiffener.

I have been using this since I got my king and my frame is still perfect after all this time. I colored mine with a magic marker to blend it in a bit.

The probl I see with this is that its to short. I see it cracking where it stops.. Personally I think the Xtreme Stiffener is better because it is longer so it distributes the stresses over a wider area and away from the problem areas around the motor and main shaft areas... MHO

happy fly'n

Yeah of course the extreme one is better, but this works pretty darn good. The benefits of this one is that its cheap and light, neither of which are characteristics of the xtreme. Oh and this stiffener isn't meant to prevent the frame from breaking in a crash, this one is solely to prevent it flexing during flight. I don't think that the frame will crack in flight.

That's not where the frame breaks DD. It breaks right behind the motor mount, not inside of the frame.

Thought you might like to see this. It is the original of what you have. I bought it from a guy that came up with the idea early last year. I bought the original from him, usedf it for a long time and still have it in my toolbox. Not a good picture but you can see its a prototype (vise grip marks and all). It was designed to be either screwed in with small screws or tie wrapped in or JB weld in. I found that the small screws used for it tore out of the frame when it flexed on a hard landing (but prevented the frame from breaking at the expense of the main gear). Worked best when screws were used to postion it and the whole thing JB welded in place. Used it till the Extreme stiffener came out.
There was another one like yours that was made from cast epoxy resin but it was longer and didnt include the spacer to put under the motor. I use a Align motor mount under my motor (alumn and all ready drilled).