Upgrading to the Lynx Stretch Kit

[3D Dave]

So, now that I've stripped all three cyclic servos & broke the skids, I want to try the Lynx stretch kit that I bought.

For the stretch kit, it says "

"Increased rotor disk will change heli behaviors, adjust your FBL Gyro Cyclic Gain P.I.D and F in order to get your favorite feeling.
Use advance 180CFX FBL set up menu to know how to change your cyclic gain."

I might have an issue with programming though (I'm using the original DX7, not the DX7s) so I'm not sure if I can/should even try to get to those settings and mess with them. Something tells me I can't get to them.

Since it does not appear I can get to those parameters with my radio, I was only going to put the 9t pinion on and reprogram the ESC for a slightly lower HS.

Can anyone confirm that the stretched 180 flies ok with the original PID and F settings?

John?
Jon?
Anyone else?

PS: I think I messed up one of the servos trying to take it apart (too far) and removed the motor, tape, etc. I was trying to see how it went together.

Are those little nylon gears available as replacements?

PPS: I will do the servo saver mod to the replacement servos I ordered unless I use the Lynx servos savers that I previously bought. I thought I'd read that the lengths were different from stock though so adjustments would need to be made.

If I do my own saver mod, I do not have the rubber O-rings to keep them tight.

Does anyone have 3 they could spare?


Sorry for the long post.

[farquward]

You got instructions?

[JonJet]

I've done the stretch on several 180CFX's...and every one turned out great...

Previous tail wag - GONE...

Pinion change - nah...no worries I can adjust the headspeed easily enough (but have not)

PID adjustments - I haven't even bothered trying

Keep in mind that I was doing stretch when doing stretch was considered uncool...but now everybody including some of the mfgr's are jumping on the bandwagon

[FR4-Pilot]

I haven't messed with any of the PIDs on my helis - they're whatever they were set at the factory.

As far as the o-rings for the DIY servo saver - I don't have them either and the servos have been saved a few times already during some ground-contact maneuvers

I might try the stretch thing this spring/summer though ....

[Freeskiken]

I have mine stretched but I am getting up and down tail movements. I put the Lynx head dampers in last year and it flew better. I didn't fly it all summer. I am going to change the dampers back to the original one and try it. I didn't change the cyclic gain.

Edit: Took it apart and fixed it tonight. Replaced the hard Lynx dampers with the stock dampers and now it flies perfect. No more up and down oscillation.

[3D Dave]

Thanks guys!

So I used a Castle Link to program my 2nd 180 in Castle gov. high mode w/9t pinion and 104t main gear. I set the HS to 3700/4100/4600

Hopefully my pinion puller will fit/work on that small of a shaft/motor to swap the pinion to the 9t

I did not, however, change the KV or pole count that was in the software. Can someone confirm that the stock motor is 5800kv 6 pole?

As for the servos, I'm not sure if I should use the Lynx servo savers I have (I thought they were too long) or, use the stock ones. If I use the Lynx arms, I assume I'll have to try to adjust the links to make them fit.


Thoughts?

[JonJet]

I'd fly it with the stock pinion...someone reported lots of bogging with the 9T...

And since you have the ESC programmed for gov high...you can set the headspeed in your TC

[Thickfog]

Originally Posted by JonJet

I'd fly it with the stock pinion...someone reported lots of bogging with the 9T...

And since you have the ESC programmed for gov high...you can set the headspeed in your TC

That doesn't make sense as the stock in 10t pinion. You wouldn't get bogging going to a lower tooth count pinion.

[JonJet]

Originally Posted by Thickfog

That doesn't make sense as the stock in 10t pinion. You wouldn't get bogging going to a lower tooth count pinion.

Really?

Lower pinion tooth count = lower headspeed...

I expect it would be more than 400 RPM loss by reducing the pinion tooth count by 10%

[3D Dave]

So I flew the stretch 180 tonight, back to back with my stock 180.

It definitely is floatier and surprisingly a little quieter with the Lynx stretch Blades.

HS programmed is 4000/4300/4600 (Castle gov. High)

10t pinion.

4600 just feels too high and unnecessary on the stretch.

4000 felt just a tad weak and had me wishing for a little more pop so I'd say 4300 seemed just about perfect.

I did add some expo so I'm at 28% there and 75 D/R.

Funny though, I'm getting a tiny sporadic squeal (when I rotate the head by hand back and forth) as if a bearing is going out. Not sure if it's the motor bearing(s) or main shaft bearing(s).

I'll have to investigate further to see what exactly is causing it. Other than that and a little spool up and spool down vibes, she's pretty smooth.

The stretch does feel like it needs more room to fly in so I'm not sure it's ideal for the indoor space where I fly. We'll see in a week when I get back there.

One other annoying thing is the holes (or slots) on the stretch tail boom seem to be drilled-cut slightly off. It makes the tail fin (and tail, obviously) slightly skewed and looking goofy.

Did anyone else get a mis-drilled/mis-cut boom?

Maybe I can get a replacement.

[vertico]

Originally Posted by JonJet

Really?

Lower pinion tooth count = lower headspeed...

I expect it would be more than 400 RPM loss by reducing the pinion tooth count by 10%

Your motor is working less with the 9t and thus less likely to bog. More torque

[JonJet]

Originally Posted by vertico

Your motor is working less with the 9t and thus less likely too bog. More torque

Course...I don't fly hard 3D by any means...

My pitch servo travel is 75 pos/neg so nearly impossible to bog the motor no matter how hard I pump the collective

[JonJet]

At the Red River R/C Club indoor event...

Dylan Hudock discovered his 180CFX had a stripped tail pinion gear shaft...after we had finished installing the stretch kit to his 180CFX...

Dismayed that it wouldn't fly...I walked to the car and brought in the case of 180CFX's I had...

Dylan flew the stretch version...without the 9t pinion at full-tilt headspeed...

"Amazing tail lock" and "flies much bigger" were his impressions within 15 seconds

[Dylan Hudock]

Will agree here, the 180 felt great with the bigger blades. I have the tail drive gear ordered and will toss it around a bit once it is fixed and report back on how it flies with it. Expecting it to feel much better in 3d.

[hookedonflying]

I like it stretched, but only blades available are the Lynx black ones, which almost makes me want to go back to standard. I don't like flying with black blades, so I paint the tips. The 9t pinion is a must, I think, the motor gets too hot with the 10t. I like the way it used to run cool as a standard setup, but it just doesn't feel so heavy stretched.

[Bhujang]

It's just a pity lynx won't be doing a stretch version of the belt tail. I just put the belt tail on and wow it's sweet. Don't think I could go back to a tt just for stretch.

[Epoweredrc]

old thread but I just got a new to me blade 180 cfx its got the long boom on it but ive not tried the bigger blades that came with it cause i don't want to try changing the pinion.. I have slowed down the HS i don't need all out crazy speed.

So some have used the longer blades and boom with stock pinion w/o issues?

[hookedonflying]

Originally Posted by Epoweredrc

old thread but I just got a new to me blade 180 cfx its got the long boom on it but ive not tried the bigger blades that came with it cause i don't want to try changing the pinion.. I have slowed down the HS i don't need all out crazy speed.

So some have used the longer blades and boom with stock pinion w/o issues?

It's actually been a while since I did this, but I believe the problem with not going down a tooth on the pinion is that the motor heats up too much swinging bigger blades. Please look into it further, though, because I'm just going by memory.

[Epoweredrc]

Originally Posted by hookedonflying

It's actually been a while since I did this, but I believe the problem with not going down a tooth on the pinion is that the motor heats up too much swinging bigger blades. Please look into it further, though, because I'm just going by memory.

That is what I thought, but wasn't sure. I might try them and just temp the esc/motor.

[JonJet]

The majority of My previous 180CFX's flew much better with the stretch kit and the stock blades...

No motor heating...added tail authority...no bogging

Win...Win...Win...without the risk of damage trying to replace the pinion

Those I sold went out with the 9T pinion and stretch blades still in the sealed bags...and a recommendation to try it first with the stock blades and 10T