350 stretch kit, what's the recommended head speed?

[whaleboy]

I'm considering going 350 on my mini. I'm currently running 4s 2100mAh and 1630kv motor. What would the proper head speed be for basic 3d? What should I expect as far as flight time compared to what I get now, assuming the same flight style?

Thanks

-David

[rablett]

I have used the calculation of rotor tip speed to determine what I wanted my rotor speed to be when stratching mine. Since I knew what RPM I liked before I stretched it, I used the tip speed to calculate a new head speed with the longer blades. In other words, I reduced the rotor RPM to arrive at the same MPH of tip speed with the 350mm blades that I had with the 325mm blades. I am sure there are plenty of other ways to do this, but that has worked well for me. I am not a heavy 3D guys, preferring airplane style aerobatics, so my RPM overall is probably somewhat lower than other people use.

[Ecaf]

I probably fly the same way as Rablett, and using 4S power and a 2221-2010 KV motor, I fly at about 2700 RPM. I do like the 13.5 degrees of pitch that I have set up so its REALLY fast in the vertical axis

With that setup and a 16T, I was getting 5:30 flights to 75% pack usage. Now that I am running a 15T, I think I can bump that up.

I would think that running your power system harder on the 350's would shorten the flight time assuming you were running the same HS, but since you can lower it, then its not a problem.

[SidewaysLS4]

Sport flying here, and 2500 headspeed running 3S 2200 packs. Timer's set at 8 minutes for ~80% discharge with a 2010kv Scorp motor. Works for me

[rablett]

I am currently running my streched mini at 2700 rpm governed. On a 3S 2600 mAh pack w/ 2580 kVa motor I set the timer for 7 minutes. I also just got a couple of 3S 3300 mAh packs but haven't had time to test them yet.

[whaleboy]

Thanks, I'll shoot for 2700 and go from there.

-David

[Ride]

Originally Posted by rablett

I am currently running my streched mini at 2700 rpm governed. On a 3S 2600 mAh pack w/ 2580 kVa motor I set the timer for 7 minutes. I also just got a couple of 3S 3300 mAh packs but haven't had time to test them yet.

how does the 3s handle 2700 and stretch, 16t pinion? mine seems to bog on really fast tight turns with 325mm blades! and where are you getting the 2600mah 3s batts?

[exit44rc]

I also just got a couple of 3S 3300 mAh packs

where are you getting these?

[exit44rc]

Originally Posted by exit44rc

where are you getting these?

Looks like I just may have answered my own question:

• Thunder Power 3s 2600mAh: TP26003SPL2
• Hyperion 3s 2600mAh: HP35C26003S
• Turnigy 3s 3300mAh: T3300.3S.30
• Thunder Power 3s 3300mAh: THP33003SP30

[Ride]

where can I get the stretch kit in the US?

[exit44rc]

Originally Posted by Ride

where can I get the stretch kit in the US?

ReadyHeli.com has them (http://www.readyheli.com/MSH41106-St...s_p_38359.html).

[Ride]

Originally Posted by exit44rc

ReadyHeli.com has them (http://www.readyheli.com/MSH41106-St...s_p_38359.html).

Should I go for the kit with the sab blades or the stretch kit and radix 350 fbl blades for $3 less?

[rablett]

Guys,
Sorry for delay on responding about batteries as I have been away all weekend.

My 3S 2600 packs are Hyperion VX G3 packs, I believe I actually bought them in Japan while there on business but they should be available in the US through any of the places that carry Hyperion. I also have a couple ThunderPower Pro Lite V2 3S 2600 packs. They are smaller and lighter than the Hyperion packs.

The 3S 3300 packs are ProTek that I got from A Main Hobbies. They just fit under the canopy but should give even better flight times. I have a couple cycles on both packs so far and with my flying style haven't really noticed any difference in performance. It has been really windy so I can't really assess flight performance so far. The nice part is that with the timer set for 8 minutes I am only using 65% of the batter capacity.

Roger

[Thunder Fighter]

I am thinking about going with 4s 2100-2200mah packs with the 2050kv motor (if I remember the KV of the Scorpion) on the stretch when I get one. I think this will be a good comprimise of performance, weight and duration. I would go 6s (with the new motor) but the choice of batteries is more limitted.

I am guessing that if 3s 3300 fit under the canopy that the 4s I am looking at will fit ok.

//Dennis.

[exit44rc]

Originally Posted by Ride

Should I go for the kit with the sab blades or the stretch kit and radix 350 fbl blades for $3 less?

I would probably try to save the $3 and get the Radix. My flying skills aren't good enough to notice the difference in those blades brands.

[Ride]

got it up and flying with beastx and the stretch kit. I did two flights at 2800 with a 3s 2200 skylipo and after 5 minutes it was at 3.7v per cell, but the motor was a lot hotter than with the 325 blades.

[whaleboy]

Originally Posted by Ride

got it up and flying with beastx and the stretch kit. I did two flights at 2800 with a 3s 2200 skylipo and after 5 minutes it was at 3.7v per cell, but the motor was a lot hotter than with the 325 blades.

What speed on the 325's? Time comparison between 325 and 350?

Just curious...

-David

[Ride]

Same speed for 325's and 350's for my "normal mode" I didnt bother trying the idle up of 3000 with the 350's, I don't think my 3s set up would like that. After 5 minutes of 2800 on the 325's my batteries are usually closer to 3.8v per cell. I believe the stretch kit gave the heli more tail authority, slight spining on full inverted pitch pumps are gone!

[SidewaysLS4]

For even more authority, try those KBDD 62mm 450 'Pro' tail blades...probably the most powerful tail blades out there now