LATEST MODS

Here’s an easy mod for those of you who fly with the tail fin removed because it requires heatshrink where the tail fin normally sits. The goal is to prevent the tail motor holder from sliding up the boom and severing your tail motor wires. Securing the tail motor holder is important on the 9958 because the tab molded into the tail motor mount isn’t very strong. On hard impact, this stopper tab will break away and the motor holder will slide up the tail boom and nick or severe the motor wires. It is one of the biggest weakness to the 9958. The resulting cut wire is obvious, but when it’s only nicked through the insulation, the bare wires can short and cause the RX to reboot or weird tail behavior during flight. It can be hard to see the nick wires.

This is one of the first things I do to my 9958. Desolder the tail motor wires so I can remove the boom. Then slip on a 3/16″ heatshrink tube in my choice of color. On one end of the heatshrink tube, I use a pair of tweezer to prestretch the heatshink tube to the max it will allow without tearing. This allows me to fit over the plastic motor mount.

Then slide the heatshrink tube as far as you can get it on and use a hair dryer on high settings to shrink the tube. You can put a tinsy amount of glue at one end of the heatshrink tube if you so desire to strengthen this mod even more. The final result is a highly decrease risk of nicking or cutting the tail motor wire while still allowing easy future repair should the boom become damage.

Heat shrink used to keep the tail motor holder in place

WL Toy’s v911 is a fun micro RC helicopter. But because of it’s unique battery connection, you are limited to the factory 120mAh LiPo or recently released 130mAh LiPo. Here’s a mod that takes the battery connector part and turn it into a battery tray so that you can use the popular 1s LiPo with the Parkzone/E-Flite ultra micro connectors.

First, use a wire cutter or nail clippers to cut along the yellow line. Use a file to get everything smoothed out. It should look like the piece on the right when you are done.

Use a pair of wire cutters to cut where indicated. It should look like the piece on the right when done.

Then you can slip into the existing battery slot on the v911 skids. You will also need to solder on some ultra micro plugs.

The new adapter fits right in to form a battery tray. Solder on some ultra micro leads.

For those concern with the stock center of gravity. The fit is tight enough that you can position the battery where you like.

Here, you can see the battery position at about the stock location. Personally, I prefer the Solo Pro location. Fully forward, and into the canopy. :)

Battery seated at about the location of the stock LiPo.

You can make the battery tray more secure if you glue it to the skid. I have tested and found that ThunderPower 160, Hyperion 160, E-Flite 120 fits perfectly. I can also fit Turnigy 160 battery as well. Though I have had one where it was too thick to fit. The NanoTech 160 are definitely too thick for this mod. I recommend getting a Solo Pro skids if the battery you run are the NanoTech 160.

Here’s a couple of comparision photos showing the weight difference between the Bravo SX and v911 RX. Some of you want to be able to use the v911 RX in your Nine Eagles Bravo SX and Solo Pro.

Without servo linkages.

With servo linkages.

Here’s a video I made of the Xieda 9958 with Bravo SX head. The Bravo SX and Solo Pro head are the same. You can use either one. See this post: http://www.hacksmods.com/2011/12/xieda-9958-with-solo-pro-head/

I was asked the following:

Would the holes for BSX match up with holes for V911 main shaft. I plan to get this jig to make main shafts for 9958, V911, Bravo SX from 120SR tail boom.

Well, the jig does a good job of keeping your drill bit straight and true. And if you know what you’re doing, you can definitely use the 9958 jig to drill out holes for other helicopter’s main shaft.

The unique thing about the v911 is that they did a very good job of cloning the Solo Pro. I believe the Solo Pro stock main shaft is a direct bolt on. And because it’s already made of carbon fiber, buying the Solo Pro main shaft and fitting it on the v911 is probably the easiest way to go about it.

For those who like to hack and mod their stuff. Or those who can get hollow 3mm CF tubes, or even those who wants to make their main shaft out of a solid CF rod, then the following photos should help.

I took apart my Solo Pro so I can put it’s main shaft on the jig for comparison. You should be able to use the jig in two steps to fabricate a Solo Pro/v911 main shaft. As you can see, the top two holes of the Solo Pro lines up this way.

That means, from the front…line up the top of your carbon fiber tube to the BSX line. Secure with some tape.

Flip over and drill the top two holes. (Top two “ALL” position)

Once the first two holes are drilled, flip the whole thing back to the front. Remove the tape. And move the CF tube up to line up with the bottom of the word: MSR.

Again, secure with tape. Flip the jig over. Drill the hole, then cut the CF tube using the bottom of the jig as a guideline. Take extra care not to splinter you CF tube.

That’s all there is to it. It’s pretty easy once you do one.

I just wanted to share a drilling jig that Jim Stoll made for us Xieda 9958 modders and hacker. I came across his jig on one of the forum. As a hobbiest, he created a drilling jig so he can make new main shaft for the mCPX helis. I guess going CP means more likeliness to break main shafts. Well, soon enough, he was making jigs for friends and forum members.

So I approached him, hoping he can do something similar for us Xieda 9958. That way, we have something that takes the guesswork out of making carbon fiber main shafts for the 9958. The photos below are the result of that collaboration. It’s really a labor of love for Jim and a way to pay it forward. At least that’s the feeling I get from collaborating with him over the holiday break.

The CNC machined aluminum jig will help help you drill your holes at the appropriate locations while keeping the bit straight and perpendicular. The bottom edge serves as a guide as to where to cut. It really simplifies the whole process for those of you who want to experiment with the various heads on your 9958. Switching from a metal main shaft to a CF one shaves about 0.8g. That’s pretty significant.

The best part is, the jig itself is pretty inexpensive. Go to http://stollstuff.com and email Jim to get one of your own.

Here’s a mod to try if you happen to have some broken 9958 blades you want to resurrect. Use MicroHeli mSR aluminum balls. Drill a hole were the ball broke off and screw on one of the MicroHeli ball to resurrect your 9958 blades.

How many of you are breaking off the link guides like I am prone to doing during hard crashes? I put some 9958 canopy grommets on them and hopefully they reduce the breakage rates. Give it a try and let me know if works out for you.

I use tweezers to open up the o ring so they easily slip over the link guides.

Left: Example of the link guides breaking off on the rotor head. Right: Using tweezers to open up the o ring so it easily go onto the link guides.

Adjust the o ring so they don’t rub against the linkage.

Get the o ring as close to the linkage as possible, but don't allow them to rub.

I am searching for the best performing 1s LiPo for the money. Here’s the discharge curve for some of the cells I had on hand. Keep in mind that the Hyperion is brand new. The NanoTech are relatively new as well as the 9958’s stock cells. Only the Turnigy 160 has been well used. I am pleasantly surprise to find they still perform pretty well. It hard to see but the Hyperion 160mAh being new, and also has great chemistry, stayed flat at 3.8v until about 172s. Good performance and I can see why it’s one of the most popular 1s LiPo for the micro helis. I am waiting to get some new ThunderPower 160 to put to the test against the Hyperion 160.

I intend on updating this post with better data as soon as I get new cells from each of the manufacturers to test.

This test is to check discharge to 3.8v. Usually I fly my heli to about 3.7v or so.