How many teeth in Swift 16 main gear?

[ghopper]

I'm interested in this heli. I did a search but turned nothing even after downloading the manual. How many teeth are in the main gear? I'm trying to get a feel for headspeeds with different pinions and KV motors.

Dan

[kaan.gok]

This may be helpful :)

http://www.swift-tuning.com/motors.php

[ghopper]

Thanks Kann,
But where does the gearing come into play there? Different helis have different main gears with different teeth counts and some like the hurri have multiple gear ratios you have to plug in.

Dan

[kaan.gok]

That calculator has the gear ratio of stock Swift built in.
I think that Swift's main gear is 96t, but I'm not sure.

[ghopper]

thanks Kaan,

That should help me.

Dan

[JustPlaneChris]

Dan, check out this online calculator. It has a Swift profile built-in:

http://dhrc.rchomepage.com/calc.htm

[ghopper]

Thanks JPC,
It is your thread on RCgroups that even has me considering this heli. I've been waffling on this one and the hurri. What's your opinion on the non driven tail? I've not seen any vids yet of anything but low level autos.

Dan

[RAV50]

A non driven tail leaves a lot more energy in the rotor for the auto then does the driven tail. We did autos with non-driven tails for many years (I still finish most all my flights with my Swift and Hawk Pro - both with non driven tails) with 360 or 180 degree autos. In an auto, the motor is not driving the main rotor, so there is no torque for the tail rotor to have to counter. Consequently it does not have to turn. So the heli will automatically weather-vane in the same direction that you fly the heli...specially if you use a standard sized vertical tail fin. They work a lot better then do the perforated 3D type of tail fins.

The reason for the driven tail coming on scene a few years ago, was to allow us to perform aerobatic autos (e.g. backwards autos, inverted autos and pirouetting autos where you did not want the tail to weather-vane.)

At the bottom, when you are landing, there is no forward speed to weather-vane the tail on heading, as the heli is now stopped, so if you bleed off too much rotor speed, the tail can yaw a bit on landing. With a driven tail, one can control this better.

[JustPlaneChris]

Thanks JPC,
It is your thread on RCgroups that even has me considering this heli. I've been waffling on this one and the hurri. What's your opinion on the non driven tail? I've not seen any vids yet of anything but low level autos.

DanDan, I'm only just venturing into autos, but so far I haven't missed yaw control at all. As RAV50 says, it weathervanes, and I plan to install a "real" vertical fin soon on my Swift since I'm not into hard 3D and find the tiny fin on the Swift to be really silly looking. :)

Here's a video of mine with a couple of autos at the end (my first two auto attempts, in fact).

http://www.youtube.com/watch?v=XX9_FpadC7o

[ghopper]

Hi Rav,
I finally caught up to the discussion on JPC's thread that got into the auto's. At 120 some pages long, I'm still reading on it as I get time. I think I actually like the thought of the undriven tail on this heli thinking about it. I'm aways from doing any autos, I'd just like to be able to perform them in the case of emergency. I've seen some vids that show the way the swift really can hang there a bit before losing that energy. I just got 3 DS821's so my first purchase is now complete :thumbup: The swift shall be my new bigger bird, no more waffling. The price is right, the weight is right, the repair costs look good. My only lingering concern is the availability of replacement parts.

Dan

[ghopper]

Hi Chris,
Yep you beat me to it, I caught up to the discussion somewhere about page 50 in your other thread. I'm sold.

Dan

[JustPlaneChris]

You'll love it, Dan! As for replacement parts, I get mine from either Ron's Heliproz South or Heli-World, but there's also Tower Hobbies. Heck, I've even found Century parts on Amazon.com! (No kidding, do a search some time!)

[ghopper]

Thanks Chris,
I've bought some parts from Ron's before, so I"m sure I will again. I"ll have to catch the vid you pointed to tomorrow as I'm on dial up at home and it sucks. I'm pretty sure that is the one I saw you do from your first flight, don't remember how high you were when you ckicked into TH, but that heli just floats. Of course some of you pilots make it look pretty easy, my 450 has been anything but easy for me. I"m checking into some larger lipos, and watching ebay for the A123's, but those things have really gotten expensive as well now that folks are using them. Is Dewalt the only brand that has the A123 cells in them? And how do you know what Mah those batteries have? I've not seen that posted that I can remember. I've got a Cellpro 4s, so it will work with upto a 4 cell pack. I'd have to hook 2 in series for flight, unless there is an other option to charge a bigger pack without spending too much money.

Dan

[JustPlaneChris]

Dan, I'm far from an expert... the Swift makes me look better than I am. ;) The video is one we shot Saturday-before-last, so it's pretty new. If you haven't made it to the end of my thread you probably haven't seen it.

You can buy the loose A123 cells from a couple of vendors now, for around $15 per cell. With the way eBay prices on Dewalt packs is creeping up, pretty soon it'll be just as cheap to buy the loose cells! As far as I know, Dewalt 36v packs are the only non-hobby way to obtain the cells at the moment. They are 2300 mah, so that's why I went high voltage; more volts = less amps and longer flight times.

[ghopper]

Chris,
I hear where your coming from on the HV. I"ve been looking at what ESC to go with this machine and the HV one's start running some bucks. I'll keep looking in case I can get a deal on a used one. Have you seen where anyone is using the new century HV ESC they have listed, at $130 for a 85/110 with 12s capability one of the more reasonable ones I've seen?

Dan

P.S. I'll check the vid tomorrow.

[JustPlaneChris]

Yeah, HV controllers are a bit pricey. I lucked into a used (but new in package) HV45 Phoenix for $100. I was happy with that deal. :)

[ghopper]

Chris,
I'd love to get my hands on a HV for that kind of price. I'll keep looking and maybe get lucky sometime before I need it. Here is a thought for you. Do you know of anyone who has hooked three 2200 3s in series? If I can get it mounted, the voltage, weight, and Mah would be very similar to your 10s setup. I'd probably have higher voltage actually (meaning lipo) If I remember right your NEU is a pretty heavy motor. I didn't realize it was less than 700 KV thou. Finding the right motor to keep headspeed in check without cripling the ESC will be key I suspect. I don't recall seeing, are you using gov mode on your CC45HV? I'd like to eventually do the kind of flying your vids show, no hardcore 3D for me. That other stuff is just hard on nerves, equipment, wallet, and significant others tolerance level.

Dan

[JustPlaneChris]

Dan, 8S lipo will provide about the same voltage under load (~28v) as 10S A123. Along those lines, I have contemplated two 4S packs in series. The problem with using 2200s is that to be safe you should only deplete them to about 80% of their capacity. That means about 1750 mah, which is going to give you pretty short flights (5-ish minutes). Weight-wise, a pair of 4S 4000's would be about what my A123 pack weighs (775g) and would give longer flights. TrueRC has some reasonably priced packs that I intend to try someday.

The Neu weighs 285g, so it's not a lightweight. Sure does crank out the power though. :)

[ghopper]

Hi Chris,
I just got to the page on your thread where you asked the same question I posed about running 3 3s in series. So far I haven't seen where anyone actually tried it. Someone said it was possible. I checked into the TrueRc bats and will probably pick up a couple of 4s to use in series, but with about 4000 Mah capacity. I plugged the 9s into the DH calc this morning and it looks like flight times might be somewhere around 8 minutes. I'm sure I don't have the weights and some other factors to put in setup correctly. The only reason I mentioned the 3 3s in series as that would give me an already on hand pack that I could use after making a harness and trying to get a CG figured out. With the prices of A123's I think the 2 4s in series is the way I will try to setup the power train for now. Not too many less than 800 KV motors to choose from that I've found so far.
I also got to the part where you were considering selling the Swift in an effort to get more power..... I see you are either resatisfied or at least still on the Swift bandwagon. My servos for the cyclic will ship either tonight or tomorrow. If you see any bargains you think I should check into, keep me in mind. I'm in no rush, just gives me more time to sort thru things and keep practicing on the sim and with my little Rex.

Thanks,
Dan

[JustPlaneChris]

I also got to the part where you were considering selling the Swift in an effort to get more power..... I see you are either resatisfied or at least still on the Swift bandwagon. My servos for the cyclic will ship either tonight or tomorrow. If you see any bargains you think I should check into, keep me in mind. I'm in no rush, just gives me more time to sort thru things and keep practicing on the sim and with my little Rex. Yeah, a swap to a 10T pinion and 550 blades really woke it up, at the expense of about 1.5 minutes less flight time. I'll keep an eye out for bargains! :)

[ghopper]

Thanks Chris,
I'm gonna take my time with this one. So far the motors I'm considering are the NEU, Orbit, and Z-Power. If anyone can think of some others I need to keep in mind, please feel free to chime in.

Dan

[RAV50]

I run this motor in both of my Swifts (16 & 550SE):

http://www.heli-world.com/detail.aspx?ID=9145

The 16 has over 100 flights with 5 cell 18.5V lipos packs doing some pretty demanding 3D geared for 1920 head speed and another about 150 flights with 6 cell 22.2V Lipo packs flying harder 3D - And the motor has been a trooper. That is why I got it also for my 550SE.

The 16 with the 5 cell uses this 55A controller:

http://www.heli-world.com/detail.aspx?ID=9021

The 550SE only has about 60 flights on it and uses this 80A controller (as did the 16 with the 6 cell configuration)

http://www.heli-world.com/detail.aspx?ID=8014

Even after a hard flight the motor and ESC's are always barely warm (almost body temp).

And setting them up has been "bundy" easy :-))

[ghopper]

Hi Rav,
I had looked at that motor, but if I go HV 8s, I'm gonna need a motor that is less than 800 KV. I'm looking for low amps and long flight times. Just circuits, stall turns, a few rolls and loops. With the 96 tooth main gear, it is gonna be hard to keep HS low without getting too small on the pinion. Do you like the century ESC, I was considering it's HV brother if I could find some folks that like how it performs?

Dan

[ghopper]

How does this look.

Dark Horse - Helicopter Power & Setup Calculator
Setup Report No. 1
=====================================
Generated: Thu, 10 Apr 2008 13:45:16 UTC
=====================================
Motor RPM/V: 800
Main Gear: 96
Motor Pinion: 13
Gear ratio: 7.3846

Efficiency: 100 %
Motor RPM: 17760
Rotor RPM: 2405

Efficiency: 85 %
Motor RPM: 15096
Rotor RPM: 2044

Battery Pack: Six cell (6S) - 22.2 v
No. of cells: 6
Nominal Cell V: 3.7
Nominal Pack V: 22.2
Actual Pack V: 22.20
mAh capacity: 4000
Amps average: 20.00
Watts average: 444.00
Runtime avg.: 12.00

Rotor size mm: 1100
Tip speed MPH: 263.5
Max FF MPH: 79.0
Tip speed KMH: 424.0
Max FF KMH: 127.2
AUWeight g: 2150
Watts/kg of mass: 206.51
Disk loading kg/m²: 2.26


The weight is a pure guess on my part, maybe you guys can help me fine tune it if I can get comparable part weight for what I'm thinking. I dropped the main rotor diametor to 1100 (Is this correct for 500mm blades?) If I can get something close to this then maybe I can forgo HV at least for now. The TrueRc packs I'm looking at 3s 4000mah are 256 grams apiece. The Z30a 800KV motor weighs 277 g, so pretty much a wash with your NEU Chris.

Dan

[JustPlaneChris]

Dan, my Swift tips the scales at 6lbs 2oz (2778g) including non-stock landing gear (Hirobo Scedeau) which is slightly heavier than stock. I think 1160mm would be closer for the rotor diameter on 500's. Stock blades are 520mm. Other than that, you probably would have a nice flying setup there, and the motor could then handle HV later if you choose to do so.