205 Stretch

[fwilly]

Align 205 blades sanded down at the roots. They don't track right. I'll have to make some adjustable links, or use align 250 grips or the entire head with unmodded blades.

Boom is an arrow shafts also sanded down a bit. 3mm solid carbon for the tt. Might need bigger tail blades. The align tail blades were too thin at the roots.

Tail servo relocated for balance and looks.

Canopy moved forward.

Still need to work out the batteries and motor. Might do stock motor with 2s 800, or a lower kv motor on a 3s 550. For now, I'll try some short hops with stock governed down and see what happens.

This is more than I wanted to sretch it, but I got bored and had all this stuff on hand. I'm confident that the drive train is stout enough, but less certain that the servos can handle blades this size. If I keep the head speed lower than stock, I think the grip/spindle assembly will handle it.

Indoor flying tomorow I'll have a better idea after that.

[Mojappa]

Agreed, it's a bit too out of proportion. When Lynx releases their stretch kit I assume it would likely run 180mm blades.

[Rahulgaba]

Are those blade grips and the feathering shaft screw / threads and the Jesús bolt up for the task of a blade 50mm longer ..?

[fwilly]

At the highest stock headspeed, I'm sure the head would explode. I've spun it up at the 25% headspeed, and it was still higher than I wanted. I'm gonna make an adapter for my castle link and lower the headspeed.

[fwilly]

Some 180 carbons would be perfect, and make it an honest heli :p

[soonglim]

Good to see others are stretching. Was hoping lynx would come out with a stretch kit faster, but no luck. So I'm also stretching. I'm also using trex 250 blades, but the plastic ones and cutting them down to 175mm, and same thing - sanded down the blade grip area of the blade to fit the 180cfx grips. Still in progress - working on the boom, using cf tube and using trex 250 torque tube. After that, expect to make cyclic gain adjustment. Hope to test them out soon.

[fwilly]

I got three flights in today. Mostly flips, and a few attempted tic tocs. Governed at 4200, I would guess the motor temp is around 130 after three minutes. Battery and esc are a bit above ambient. Cyclic servos weren't warm at all.

Heli flies great at this disc loading. I'm glad I stretched it so big. The whole heli seemed over built at the stock size. I fly at 5.5k' elevation, so heavy disc loading is very noticeable. The thin air probably helped keep my motor from smoking with the 205s.

I'd like to put 250 plus grips on the stock head, a smaller pinion on the motor, and swap in a ~550mah 3s pack. Bigger tail blades probably wouldn't hurt.

Appearance wise, a bigger canopy and skids would be cool.

I think a hybrid 180 250 head might be possible because both heads use 2.5mm id 6mm od bearings and 2.5mm feathering shafts. Gonna order some grips, links, and shims. The other option would be to drill out the head block on a 250 head to fit a 180 shaft, (Yup, the 180 has a larger main shsft) but I don't know I'd I could keep it square.

[vtown nick]

I want to see a video of this! Looks fun if it can hold up.

[fwilly]

Sorry, didn't get any video.

I think I have found a way to run align blades without sanding the roots...

The 130x head block is close in width to the 250 head block. use an aluminum 130x head block with align 250 dampners, non dfc fbl grips, and feathering shaft, plus a couple shims between the head block and grips.

The grips would accept 205 align blades and mount to a 4mm shaft.

[fwilly]

Finally got the hybrid head flying. I used a 130x titanium center hub, align 250 dfc grips and links and a 250 feathering shaft.

It's flying well on a 2s 950.

[gispos]

For me, a bit too much

[fwilly]

180cfx 205mm stretch (5 min 7 sec)

Not sure why it came out sideways. It was upright when I watched it before I uploaded.

[d12bn]

Nice job, shot some video