It's unfortunate that the mCX is the heli Great Wall chose to get their "design inspiration" from. Because of this, some technology advancements didn't make it over to the 9958 or 9998.
As we already mention, the Swashplate only has one ball position. The newer mCX2, mSR and Solo Pro has two ball position. A long one and a short one that you can switch between to modify the response of the heli would have been very helpful.
Another factor that I haven't seen mention yet is the body grommet. The 9958 chose to go with the rubber o-rings to mount the body onto the frame. It uses a total of 8 of these rubber o-rings to secure the body to the frame.
Newer helis have rubber grommets that is fixed into the body itself. I like this style better because the o-ring were really easy to lose during crashes. And during repair, they are easy to misplace.
So if you are ordering your heli from a place that happens to carry Nine Eagle parts, consider picking up a set of their body grommets.
- Once you have the Nine Eagles body grommets, use a 3/32" drill bit to enlarge the holes on the 9958 body. I like to use very light pressure to allow the drill bit to actually do the work. Pushing too hard will raise the plastic instead of cutting. A even better tool would be a body reamer. Make sure to clean up the hole with a xacto knife.
- With the holes on the 9958 body enlarged, fit in one of the Nine Eagle's rubber grommet. (I do this easily with a fine pair of tweezers. However, some find this process near impossible. There was a trick that was shared on a way to easily pop these in using dental floss or something like that. Search the Solo Pro thread)
- Now, remove all the rubber o-rings from the 9958. And then carefully slide on the modified 9958 body. (It'll be a tight fit. But once you figure it out. It actually goes on quite easily. If it's impossibly tight, then the hole was not enlarged enough. Also, a little Vaseline at the tip of the post will help.)
Enjoy this easy mod. It "upgrades" your new 9958 to be inline with "technological" advancements seen in the mCX2, mSR and Solo Pro.
Best of all, the body is now much more secure against the frame.