300X - motor and ESC alternatives?

[kpod]

I flew a couple packs and the wicked/cool33a combo does great. I'm not a 3d pilot so I didn't do anything more than sport flying with some loops, rolls, flips, and rainbows. When it came down at 4 minutes, the battery was slightly warm, the motor was barely warm, and I couldn't tell if the esc was any warmer than it was before the flight.

The 300x was quieter than normal and I didn't notice any significant vibes.

The soft start works great.

The flights were at 75% TC.

On a side note: by my calculations, a 4800kv motor on 3s with 10t pinion/140t main and an efficiency of 90%, the headspeed should be around 3,425 ungoverened. The 75% tc should bring it down to 2,550 rpm. With the same calculation, the stock 4,500kv motor at 3s voltage on 9t/140t ungoverend would be 2,890 rpm head speed. Are my calculations wrong? I would need to govern the headspeed around 82% to match the stock 100% headspeed. The 4800kv of the wicked vs 4500kv stock should give around a 7% bump in headspeed and the gearing of the 10t vs 9t should add around 11% to the head speed.

[DoubleCH]

HS is not directly proportional to throttle percentage (unless you're talking about governed HS for the throttle signal value) . You should get more than 2500rpm at 75% throttle (in throttle mode not governor mode) with your Wicked setup. To govern at 2900rpm with 10T you need 74% throttle according to BLHeliSetup

[kpod]

Originally Posted by DoubleCH

HS is not directly proportional to throttle percentage (unless you're talking about governed HS for the throttle signal value) . You should get more than 2500rpm at 75% throttle (in throttle mode not governor mode) with your Wicked setup. To govern at 2900rpm with 10T you need 74% throttle according to BLHeliSetup

So would my attached file be correct for 74% flat tc for a similar to stock head speed and 82% for a 3,400 rpm headspeed?

I'm also thinking about trying a 1000mah 4s battery that I have that's a little lighter than the stock eflight. I was looking at using the 9t pinion and 85% tc or 10t at 80% which looks to be a 3,200 rpm headspeed. What do you think? I don't want to burn anything up but the esc and motor both say they are ok for 4s. I wonder if it would be more or less efficient.

4s/10t shows almost 4,000 rpm for 90%tc. That would be fun if the 300x would hold together.

[DoubleCH]

Originally Posted by kpod

So would my attached file be correct for 74% flat tc for a similar to stock head speed and 82% for a 3,400 rpm headspeed?

Looks good. Don't forget to calibrate PPM min/max values or else all these throttle values won't correspond to target HSes.

I'm also thinking about trying a 1000mah 4s battery that I have that's a little lighter than the stock eflight. I was looking at using the 9t pinion and 85% tc or 10t at 80% which looks to be a 3,200 rpm headspeed. What do you think? I don't want to burn anything up but the esc and motor both say they are ok for 4s. I wonder if it would be more or less efficient.

To target at efficiency, 15% HS headroom is optimal. This setup seem to have much more than 15%. From 3S->4S you get 1/3rd voltage, but from 10T->9T you only reduce 1/10th HS. That means motor

4s/10t shows almost 4,000 rpm for 90%tc. That would be fun if the 300x would hold together.

You better have the frame super-stiffened.

[Dylwad]

All good points, I don't bother calibrating the throttle end points on the cool ( what do you really gain in the end?), just set the throttle to your liking, and don't ever assume or try to calculate rpm, you have to measure it to know what it is with any accuracy. Add in the fact that some transmitters vary, and the motor Kv can also vary...

The AR 7200 is a pain to calibrate esc end points with since it outputs a 0 throttle signal for too long during initialization, so you never get the chance to teach the esc full throttle. HH has an addendum all about how to work around this "feature"



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[Dylwad]

Also, using Mr mels headspeed calc, I get around 4000 rpm at full throttle on a 10 tooth and 85%eff.

using yge gov store option, 3400 rpm would be at 85%throttle, which is just about right.

I have data logs with this setup in the New Motors thread...

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[kpod]

Originally Posted by Dylwad

Also, using Mr mels headspeed calc, I get around 4000 rpm at full throttle on a 10 tooth and 85%eff.

using yge gov store option, 3400 rpm would be at 85%throttle, which is just about right.

I have data logs with this setup in the New Motors thread...

Sent from tapatalk

I was confused by the 75% tc from an earlier post. I saw that and the video with 3400 head speed and thought that hs went with the 75% tc.

I bumped my tc up to 82% and at 4 minutes of sport flight the batteries came down at 3.79v and barely warm. The motor is the same. The ESC is cool to the touch.

I want to get a tach to see what mine is doing. It sounds slower than stock but it is definitely faster and has more power. I believe its just running that much smoother.

What batteries are you guys using? I'm using the stock e-flights with e-flight carbon blades.

[kpod]

I also downloaded that hs calculator and it gives me a 4100+ hs at 60%tc with my 4s battery. I don't think I'll try that any time soon.

[Dylwad]

Originally Posted by kpod

I also downloaded that hs calculator and it gives me a 4100+ hs at 60%tc with my 4s battery. I don't think I'll try that any time soon.

Don has a 4000KV version of the motor too.... Looks like 4000KV/9 tooth 4S is in the same RPM range as 3S 4800KV/10 tooth.

[Dylwad]

Originally Posted by kpod

I was confused by the 75% tc from an earlier post. I saw that and the video with 3400 head speed and thought that hs went with the 75% tc.

I bumped my tc up to 82% and at 4 minutes of sport flight the batteries came down at 3.79v and barely warm. The motor is the same. The ESC is cool to the touch.

I want to get a tach to see what mine is doing. It sounds slower than stock but it is definitely faster and has more power. I believe its just running that much smoother.

What batteries are you guys using? I'm using the stock e-flights with e-flight carbon blades.

I'm running Billowy 1300 3S 30C and Gens Ace 1300 3S 25C, both are better than the stock batteries.

The flight in the video the batteries were at about the same voltage as yours after 4 minutes, and everything was just warm.

I am running 75% flat throttle in the TX, but have never done any calibrating in Blheli, or during startup. I could have a slightly higher KV motor too.

[DoubleCH]

Originally Posted by Dylwad

All good points, I don't bother calibrating the throttle end points on the cool ( what do you really gain in the end?), just set the throttle to your liking, and don't ever assume or try to calculate rpm, you have to measure it to know what it is with any accuracy. Add in the fact that some transmitters vary, and the motor Kv can also vary...

The AR 7200 is a pain to calibrate esc end points with since it outputs a 0 throttle signal for too long during initialization, so you never get the chance to teach the esc full throttle. HH has an addendum all about how to work around this "feature"

I don't have a tach (yet) so that's why I calibrate PPM for BLHeli on my 130X so that I have good idea what kind of HS I'm running and what HS a particular motor tops out at regardless of TX. Agree that it's not worth calculating rpm from throttle percent in throttle mode.

[lemaster]

why arent more people running these with 4s?
seems most of the motors available are slightly lower kv for the 450 size birds and running 4s would bring the head speed up on the lower kv motors
and as i understand it the more cells a battery has the more efficient they are

[Dylwad]

Originally Posted by lemaster

why arent more people running these with 4s?
seems most of the motors available are slightly lower kv for the 450 size birds and running 4s would bring the head speed up on the lower kv motors
and as i understand it the more cells a battery has the more efficient they are

4S 1000 packs aren't too easy to find, most 450 size motors are in the 80+ gram range, the smaller offerings from Scorpion are expensive and you would have to run a bigger than ideal pinion on them to get you to the 3400 RPM governed point.

Going up in voltage and down in KV does not always mean higher efficiency, especially if the 3S setup makes tons of power and nothing gets hot.

I went to 6S on my stretched Mini Protos so I could get some horsepower in it that couldn't be achieved with a 3S system without adding a bunch of weight. The 6S motor is actually less efficient on paper than the 3S motor for the Mini P, but as a whole system 6S makes sense at the power levels I need on it.

Higher KV motors have lower internal resistances than lower KV motors of the same style/weight too, and that plays a part in motor efficiency.

[SHYguy]

Is a 4S battery plug and play? (coldn't find the 4S tread)

A bit frustrated with the 300X right now... there seems to be way too much bind in the driveline! First when we can have some proper CNC'ed gears this thing will be a really good heli. As it is now it sounds horrible and you can actually see the main geir being "broken in" with the pinon... No way I'm spending a fortune trying to find a "good" main gear...

I know LYNX is right around the corner with a slanted CNC'ed main gear, and a pinion to suit. This should be the ticket!

With my new MH head I also have some wobble at the top (new main shaft, runs 100% true). Dissapointing...

Tail seems smooth now though, with alu grips and carbon blades.

LYNX dampeners received today!

[DoubleCH]

Originally Posted by lemaster

why arent more people running these with 4s?
seems most of the motors available are slightly lower kv for the 450 size birds and running 4s would bring the head speed up on the lower kv motors
and as i understand it the more cells a battery has the more efficient they are

Agree with Dylan about 4S being not common and 3S is not inefficient as it is so no gain to go 4S. I like 3S 1300 that wIth a good size ESC for the 300X for now, the battery/ESC combo can go to 450 in the future as a 6S setup. Just run 2 3S 1300 in series.

[SHYguy]

DoubleCH, did you find any tricks to free up the drive train? On your teaser vid it looked to be spinning rather free... or did you remove the motor?

[kpod]

If I could get an aftermarket cf frame and a bullet proof main shaft, I'd go 4s in a heart beat to see what 4k head speed would do. I do agree that in it's current form, 3s with the blheli esc and the wicked motor is a wicked combo. Efficient and low running temps.

I went through the beast settings last night and made some tweaks. I hovered under the street light and tried some pitch pumps and the difference was amazing. Next step is to cut weight and add 255 sab blades.

I really enjoy trying new things as much as flying though so overkill or not, 4s is definitely coming. I haven't been able to get the batteries I want yet though. So far, I have a zippy compact 1300mah 35c 4s and a nanotech 1000mah 25c 4s. The nanotech says it's a few grams lighter than the stock batteries but I've lost my scale so I haven't had a chance to weigh them yet. My thoughts on the zippy were to have a cheap battery that I could sport fly for 8 minutes on a charge.

[DoubleCH]

Originally Posted by SHYguy

DoubleCH, did you find any tricks to free up the drive train? On your teaser vid it looked to be spinning rather free... or did you remove the motor?

That is my one-way-bearing mod. It's up to version 2 now and spins much smoother. That and shimming my main gear that's wobbly out of the box make a big difference in how smooth the drivetrain is. Oh, and dynamic balance the tail rotor as well. I find that my tail shaft is sloppy on the tail shaft bearings like the motor on the motor bearings. Once I get replacement for my main motor that's wobbly out of the box (I've balanced it as best as I can) I'll be able to run up to higher HS and see if I need to do something more with the sloppy tail shaft like loctite it to the bearings.

[SHYguy]

Custom made with a lathe?

[DoubleCH]

Originally Posted by SHYguy

Custom made with a lathe?

Drill press. Here's the thread if you've missed.
https://www.helifreak.com/showthread.php?t=503141