Josh's Lynx 180CFX Build

[jmtyndall]

Started off stock, going to be going all Lynx as they release parts that I want. So my first crash I pretty much destroyed the entire tail. I figured this was a good place to start. Ordered the complete Lynx tail, including boom, supports, torque tube, blades, tail box, grips, slider, pitch lever and tail shaft.

I heard some issues with binding with the Lynx tail setup. I did a dry setup of mine, and it had some tightness at the ends of throws, but nothing I was too concerned about. Pushing the lever by hand took very little force, and the servo moved everything easily.

I have no vibration issues in the tail at all, and the assembly went together easily with minimal slop. The tail feels better than stock, though I'm pretty sure most of the feel issues are from the AS3X gyro. It just has an odd feel in piro moves, and feels loose in hurricanes. This brings me to my next upgrade: The new MicroBrain. I haven't ordered it yet, but soon I'll post an update with that.

Long term, this heli will get completely Lynx upgraded. I suspect a 180mm stretch kit, and a Lynx motor are on the agenda. Perhaps a frame as it comes available, and a DFC or tri-blade head. We'll see what Luca has in store. I'll try to keep this thread updated as I get upgrades, and make some flight videos etc.

[jmtyndall]

Almost forgot, I started off by ordering 4 Lynx 460mah 35c batteries. I've flown them on another 180CFX and they offered much more power than stock. Also, the shorter power and balance leads give us more room under the canopy. Making it easier to install

I've been on a battery kick recently. So when I got these guys I did a break in on the charger. 5 nice gentle cycles.


I've started keeping track of things like cycle count and IR in an attempt to understand LiPo performance better, and just out of curiosity. It's apparent that manufacturer C ratings are at best inconsistent from manufacturer to manufacturer, and at worst, marketing lies. Some people have come up with a method of relating IR to C rating. That's what I use to compare packs. So...where were we?

So I tested my stock 30C batteries.
IR#1: Average IR of 56 milliohm
C rating: 15.5

IR#2: Average IR of 39 milliohm
C Rating: 18.5

Well..that's pretty piss poor, and explains the lackluster performance. That's somewhere between 7 and 8 amps continuous rating.

So I tested my Lynx batteries.
IR #1: 17
C Rating: 27.5

IR #2: 16
C Rating: 28.5

IR #3: 18
C Rating: 27

IR #4: 18
C Rating: 27

Well that's looking much better. That's right at 13a continuous rating, which closely matches the ESC. I'm sure after a couple cycles in the heli, they'll drop a bit more. I'll do some more testing and keep you all updated.

So here's what I'll be flying for now...at least until more batteries show up from Lynx. I ordered a few more

[RichKnapp]

Looks good.

[helirifick]

Hi, was wondering how you determined the actual C rating of the batteries? My iCharger 306B can measure IR.

Did you use an inline watt-meter?

Yeah, these "C" ratings are all hyped-up marketing BS for which we are charged more money.

Plus, what's the max power rating of that red JST wire & connector - 190 Watts or less?

Originally Posted by jmtyndall

So I tested my stock 30C batteries.
IR#1: Average IR of 56 milliohm
C rating: 15.5

IR#2: Average IR of 39 milliohm
C Rating: 18.5

Well..that's pretty piss poor, and explains the lackluster performance. That's somewhere between 7 and 8 amps continuous rating.

So I tested my Lynx batteries.
IR #1: 17
C Rating: 27.5

IR #2: 16
C Rating: 28.5

IR #3: 18
C Rating: 27

IR #4: 18
C Rating: 27

Well that's looking much better. That's right at 13a continuous rating, which closely matches the ESC. I'm sure after a couple cycles in the heli, they'll drop a bit more. I'll do some more testing and keep you all updated.

[jmtyndall]

I use the regular power formula, rearranged to solve for current.

I = (P / R)^1/2

We use 6 watts per 1000mah of capacity as the safe heat dissipation rate for a lipo. So then.
P=6watts/(capacity/1000)

Then some for I, which gives you the max safe amps. Divide this number by you capacity in Ah to determine C

I can't take the credit for it, but I can't post a link to my source. But a very smart guy named Nustin Pucci deserves the credit

[jmtyndall]

Finally got some new parts in. Stretch kit installed!

I have a new motor coming to hopefully alleviate the vibration issues I've been plagued with

[MinskUK]

How does your vibration issue manifest itself? Nothing seams amiss on mine yet I still have a visible vertical tail movement and a vibrating tail fin even though the tail assembly and all other bearings/shafts are fine/new. Suspect motor (nothing else really left) but so difficult to prove

[jmtyndall]

Mine is visible at the tail

Easy to prove a motor vibe. Remove main gear and spin up the motor. My heli will dance around the table if I do that