Fun, Learning, Friendship and Mutual Respect START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopters > Low Head Speed Helicopters


Low Head Speed Helicopters Low Head Speed Helicopter Setups and Flying info


Like Tree2Likes
Reply
 
LinkBack Thread Tools Display Modes
Old 04-24-2018, 11:27 PM   #21 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: May 2012
Location: usa, az, phoenix
Default

TONY,
I think the old setup ( 120A and 10s) was better regard the motor power out!!

I think it's better to go back to 10s setup , I will pull more AMPS which was 41A but I can get better power out!!
Since my watts not going more than 1800watt it's maybe like you said the insensitive instead of medium for the motor page,

I will also check for lower pitch setup
I had 10+ pitch but will try 6+ just to see with lower rpm and lower pitch what the motor will result to!?

I will do another test flight with my old setup and report here

Thanks alot
Oz
flyingdragon is offline        Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 04-25-2018, 12:57 AM   #22 (permalink)
Registered Users
 
Posts: 1,230
 

Join Date: Mar 2016
Location: Essex, UK
Default

Quote:
Originally Posted by flyingdragon View Post
TONY,
I think the old setup ( 120A and 10s) was better regard the motor power out!!

I think it's better to go back to 10s setup , I will pull more AMPS which was 41A but I can get better power out!!
Since my watts not going more than 1800watt it's maybe like you said the insensitive instead of medium for the motor page,

I will also check for lower pitch setup
I had 10+ pitch but will try 6+ just to see with lower rpm and lower pitch what the motor will result to!?

I will do another test flight with my old setup and report here

Thanks alot
Oz
The current limiting feature of the ESC is dealing with high start up currents and spikes, it doesn't worry about the normal running currents as long as they are within the max capability of the ESC. For heli's, you always set it to insensitive or off to stop it current limiting when it sees the inevitable spikes, the likes of which you just don't get with fixed wing models.

I don't think that lowering your pitch more is going to help because you are already running the electronics near the bottom end of their capability and your power out numbers will probably reduce even more. I would think that going much below 10 degrees will make the heli pretty docile and probably not very nice to fly.

If you can't re-gear, maybe dropping to 7 or 8S would give you the head speed and power out figures you need. It would get you a bit nearer the 70-80% levels you ideally want. It would be worth doing the calcs to see if this would work better.
__________________
Mark

So many heli's, so little time.
Crashalotjoe is offline        Reply With Quote Quick reply to this message
Old 04-25-2018, 08:23 AM   #23 (permalink)
Registered Users
 
Posts: 9,421
 

Join Date: Sep 2008
Location: Atlanta, GA
Default

Quote:
Originally Posted by flyingdragon View Post
TONY,
I think the old setup ( 120A and 10s) was better regard the motor power out!!

I think it's better to go back to 10s setup , I will pull more AMPS which was 41A but I can get better power out!!
Since my watts not going more than 1800watt it's maybe like you said the insensitive instead of medium for the motor page,

I will also check for lower pitch setup
I had 10+ pitch but will try 6+ just to see with lower rpm and lower pitch what the motor will result to!?

I will do another test flight with my old setup and report here

Thanks alot
Oz
Good start. Your motor is already seeing near 40A now despite what the logs say. At 50% power out, the ESC is pulsing on half the time and off half the time.

This means your input battery voltage being seen by the motor is halved and the current is doubled despite what the input values in the log shows.

You are getting away with it because of your low rpm and current draw so the values are still within your electronics rating.

The input values more closely match what the motor is seeing the closest to 100% power out, so this is why proper gearing is so important. This why you can see a decrease in electronics heat by spinning the motor faster with a higher PWM value which is counter intuitive to many.

Low head speed guys can get away with things not being so perfect, however this becomes a serious problem for normal 3D models when the rpm or load is such that the current values are much higher.

A log may say one is averaging 50A for example which most will think is fine, but at 50% PWM the motor is actually seeing 100A continuous which it may not be rated for and will cook itself.

I agree with the above post that maybe 7-8 S would be an option too and it would also save some weight to help even more. My Protos 700 flew great on one 7S pack at 1200 rpm and shaved a couple pounds weight doing away with the second pack which also reduces the current needed fly.
__________________
Tony
Synergy 516, Gaui R-5 Speed, Spirit FBL, Hobbywing and Scorpion Tribunus ESC, Xnova motors

Last edited by Xrayted; 04-25-2018 at 08:37 AM..
Xrayted is offline        Reply With Quote Quick reply to this message
Old 04-26-2018, 01:25 AM   #24 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: May 2012
Location: usa, az, phoenix
Default

Hey Toney
What you suggest regard the Pwm and the motor timing ?

Today I put back my old 120A and the 10s 5000mah

What your recommendation regard the PWM and the motor timing

I have had reading the lowest timing of 8khz is good for low rpm setup!!

And the pwm set to low (0)(*) is good for keeping the motor cool!!

But some other people saying the lower pwm will make the motor drew amps in different slower rates causing the motor to lose its efficiency !!!

So what is your suggestion ?
The goal is to get more flying minutes in cooler electronics !

Thank you
Oz
flyingdragon is offline        Reply With Quote Quick reply to this message
Old 04-26-2018, 11:13 AM   #25 (permalink)
Registered Users
 
Posts: 9,421
 

Join Date: Sep 2008
Location: Atlanta, GA
Default

Quote:
Originally Posted by flyingdragon View Post
Hey Toney
What you suggest regard the Pwm and the motor timing ?

Today I put back my old 120A and the 10s 5000mah

What your recommendation regard the PWM and the motor timing

I have had reading the lowest timing of 8khz is good for low rpm setup!!

And the pwm set to low (0)(*) is good for keeping the motor cool!!

But some other people saying the lower pwm will make the motor drew amps in different slower rates causing the motor to lose its efficiency !!!

So what is your suggestion ?
The goal is to get more flying minutes in cooler electronics !

Thank you
Oz
Your terms above are backward

Timing affects motor power and efficiency. Lower timing = cooler motor but possibly less power, so this is fine for low HS flight. The timing numbers in Castle ESCs are not in actual degrees. They are arbitrary values that represent a dynamic "range" of timing in degrees that adjust themselves within that range in the background, so use the "low" range

PWM will affect the ESC. Higher PWM will increase the temps of the ESC but may allow the motor to run smoother and more efficiently. With that being said 8-12 kHz is fine for just about any motor and flight style, so I would start with 8, especially in the hot climate you live in and adjust up to 12 as long as the ESC isn't getting too hot. Up to 175F or so is normal and thermal shutdown will occur at 100C/212F.
__________________
Tony
Synergy 516, Gaui R-5 Speed, Spirit FBL, Hobbywing and Scorpion Tribunus ESC, Xnova motors

Last edited by Xrayted; 04-26-2018 at 11:29 AM..
Xrayted is offline        Reply With Quote Quick reply to this message
Old 04-28-2018, 04:02 AM   #26 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: May 2012
Location: usa, az, phoenix
Default new test flight 120A 10s low timing and 8khz

hey guys,
I flew it today for about 7min 2~3 min and land to check the heat!!
as I don't have telemetry for now!
l have 19.2V left in my 10s !! 3.84V per s

here is the data I have attached it here ...

the new setting is : motor timing low (0)
PWM 8khz

was flying most on Idelup 1; 1060 RPM

the motor is still burn if keep my hand for more than one 2 second ~

my bad ;( forget my Temp gun at home ! )

the ESC was very worm to hot !

so I think I am getting there but I only need to cool down my motor!!

by the way today outside Temp was 93F (arizona

I scared to fly it without landing it and check the motor, and told myself will not fly higher than 1F above ground in case if cut off happen, don't want to damage my new second skids!

just like what Crashalotjoe suggested; I may get 8S lipos and try them out !!

thank you
Oz
Attached Thumbnails
Click image for larger version

Name:	cutoff.png
Views:	21
Size:	67.1 KB
ID:	744405   Click image for larger version

Name:	motor.png
Views:	21
Size:	67.3 KB
ID:	744406   Click image for larger version

Name:	setup.png
Views:	20
Size:	77.9 KB
ID:	744407   Click image for larger version

Name:	A hour.jpg
Views:	20
Size:	65.7 KB
ID:	744408   Click image for larger version

Name:	current.jpg
Views:	21
Size:	72.2 KB
ID:	744409  

Click image for larger version

Name:	log data 2.jpg
Views:	21
Size:	101.8 KB
ID:	744410   Click image for larger version

Name:	log data.jpg
Views:	21
Size:	100.3 KB
ID:	744411   Click image for larger version

Name:	power out.jpg
Views:	21
Size:	68.4 KB
ID:	744412   Click image for larger version

Name:	ripple.jpg
Views:	19
Size:	67.8 KB
ID:	744413   Click image for larger version

Name:	temp.jpg
Views:	8
Size:	67.1 KB
ID:	744414  

Click image for larger version

Name:	thro.jpg
Views:	8
Size:	67.5 KB
ID:	744415   Click image for larger version

Name:	watt.jpg
Views:	7
Size:	75.5 KB
ID:	744416  
flyingdragon is offline        Reply With Quote Quick reply to this message
Old 04-28-2018, 04:49 AM   #27 (permalink)
Registered Users
 
Posts: 1,230
 

Join Date: Mar 2016
Location: Essex, UK
Default

Just remember the temperature gun next time you fly.

Motors are typically ok up to around 170 - 180 degrees C. (340-360 F). Fingers hurt around 60C (140F) so you have a long way to go from the finger pain point to the motor failure point.
__________________
Mark

So many heli's, so little time.
Crashalotjoe is offline        Reply With Quote Quick reply to this message
Old 04-28-2018, 07:52 AM   #28 (permalink)
Registered Users
 
Posts: 9,421
 

Join Date: Sep 2008
Location: Atlanta, GA
Default

Everything looks good! Motors get hot in use, especially in near 100F ambient temps. Please understand that 140-150F for a motor is COLD, yet it will still burn your hand. There is likely nothing at all for you "to cool down" as you claim.

It's like complaining that something must be wrong with your electric stove because its uncomfortable to touch it after cooking, or that your car motor must be bad because it burned you when you touched it after driving. Things that generate power get hot, so stop obsessing over it

Your ESC is averaging only 120F which is very low, especially in a 93F ambient climate. It's barely heating much above the air temp so there is absolutely nothing wrong with your ESC temps despite what you think by touching it.

The power out does look better creeping up to an average of 67.

Bottom line is everything looks perfectly fine. There is nothing wrong with your model or its temps and you could continue to fly exactly as is with no further changes if you want to assuming you can let go of this OCD with temp you seem to have

Your model did not shut down due to over temp. Your logs simply do not support that.
Freeskiken likes this.
__________________
Tony
Synergy 516, Gaui R-5 Speed, Spirit FBL, Hobbywing and Scorpion Tribunus ESC, Xnova motors

Last edited by Xrayted; 04-28-2018 at 08:18 AM..
Xrayted is offline        Reply With Quote Quick reply to this message
Old 04-30-2018, 11:16 AM   #29 (permalink)
Registered Users
 
Posts: 693
 

Join Date: May 2006
Location: Champaign Il
Default

everything looks fine in those logs. I've spent a LOT of time with motor/esc/gearing experimentation and low headspeed setups, and I've seen numbers all over the place. Yours look fine.

As for Joe's Temp comments,.. his numbers are correct, However,.. once you pass a point around 210~220 the temp will runaway, and you'll hit the 360 limit in a matter of seconds and demag the motor.it's really interesting to see this happen in a log, and with no exceptions I've seen, it's always in the 210~220 range when they runaway and they're gone in literally a second or two.

You're numbers aren't even in the neighborhood of being worried. Always take temp gun with you to the field. It's just kewl to play with for one,.. plus it provides the most valuable data possible. If you can't shoot the actual windings due to the construction of your motor, try to get the end of the shaft up top of the can. I'm a total wimp and can't touch something more than a fraction of a second if it's 130F, and that's so far below any danger point that I MUST use a temp gun to have any meaningful data.

It's always good to keep things as cool as possible. All of the heat you feel is simply wasted energy so I try to gear and configure for the lowest temps possible. My 700 (E5 stretched) generally doesn't go over 115 on ESC or 120 on motor (log image attached)

Lower PWM will allow the ESC to run cooler,.. higher PWM will help the motor, but possibly at the expense of a warmer ESC. Timing too low can cause commutation synchronization issues on some controllers, which can result in a chattering sound, or the motor stopping completely, but it's rare on helis an generally indicates you have the setup overgeared, like having too large a prop on an airplane motor. .
Attached Thumbnails
Click image for larger version

Name:	E5SSbham.jpg
Views:	11
Size:	102.8 KB
ID:	744652  
__________________
Gary Wright
Helifreak user # 7001

Last edited by gwright; 04-30-2018 at 12:27 PM..
gwright is offline        Reply With Quote Quick reply to this message
Old 05-01-2018, 01:12 AM   #30 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: May 2012
Location: usa, az, phoenix
Default Low rpm with heavy machine

Gary, Thank you very much for the great info!
The temp gun is must have in the flying site,

My problem with the gearing issue started when I was looking for more than 118t slant main gear but couldn't find !

The 10s will get me to the range of 1300 rpm with 80% thro I will have 1050 to 1100

Last time when I was flying my bird at 1050 was not controllable when I want to pull it up,

For example; I came from 10 feet down to 3 feet flying slope not vertical
The bird wanted to hit the ground hard I put full pitch and the bird took another 2 feets till it lift itself up!!

Was very bad experience I almost broken the skids!!
My pitch range is +8 ~+9

Feel like very havey to fly !!

It's 15 lb and low rpm !!

Anyway, I just received my pixhawk today from the mail
Will start learn about it till I have full autopilot with telemetry setup

In the main while thinking to order castle telemetry link to use it for now to give me live data...

The only problem with the castle telemetry and futaba 14sg is that there is no voice only on screen so good look if I can put my eyes down while flying 15lb machine

Thanks
Oz
flyingdragon is offline        Reply With Quote Quick reply to this message
Old 05-01-2018, 08:08 AM   #31 (permalink)
Registered Users
 
Posts: 693
 

Join Date: May 2006
Location: Champaign Il
Default

don't compute based on "80%" throttle,.. or anything less than 100,..i.e. the "efficiency percentage" some calculators erroneously insert. KV times voltage, divided by gear ratio. That should be your target max headspeed. Use 3.7/cell for the batteries, and you should still have enough overhead, as modern batteries maintain a bit more than that unless they've been treated poorly. For example,.. one of my previous setups in the E5SS was regularly flown at 1750. It governed well there, and did not load . It was 400KV, 12S and 12/121 gearing, so the math would say (400*44.4*12)/121=1761 rpms possible. Running without governer at 100% throttle at zero pitch it would spin 1780, indicating the voltage was just a tiny bit higher than the 3.7 used in calculations. What I've seen with all the overgeared setups that have used some sort of "efficiency factor" in the calculations, or some lower percent of throttle,.. is that although they work, they get warmer, and are less efficient.


Quote:
Originally Posted by flyingdragon View Post

The 10s will get me to the range of 1300 rpm with 80% thro I will have 1050 to 1100

Last time when I was flying my bird at 1050 was not controllable when I want to pull it up,

Oz
__________________
Gary Wright
Helifreak user # 7001
gwright is offline        Reply With Quote Quick reply to this message
Old 05-01-2018, 08:36 AM   #32 (permalink)
Registered Users
 
Posts: 9,421
 

Join Date: Sep 2008
Location: Atlanta, GA
Default

Quote:
Originally Posted by gwright View Post
don't compute based on "80%" throttle,.. or anything less than 100,..i.e. the "efficiency percentage" some calculators erroneously insert. KV times voltage, divided by gear ratio. That should be your target max headspeed. Use 3.7/cell for the batteries, and you should still have enough overhead, as modern batteries maintain a bit more than that unless they've been treated poorly. For example,.. one of my previous setups in the E5SS was regularly flown at 1750. It governed well there, and did not load . It was 400KV, 12S and 12/121 gearing, so the math would say (400*44.4*12)/121=1761 rpms possible. Running without governer at 100% throttle at zero pitch it would spin 1780, indicating the voltage was just a tiny bit higher than the 3.7 used in calculations. What I've seen with all the overgeared setups that have used some sort of "efficiency factor" in the calculations, or some lower percent of throttle,.. is that although they work, they get warmer, and are less efficient.
That is one of the problems that is difficult for him to solve Gary. This is a homemade 800 and he doesnt have any better gearing options at this point other than lowering the motorKV or using less cells. There are no other pinion options, so he is running about 67% motor power out with the current 10S setup, and was down as low as 50% with 12S which was a terrible setup. He mentioned the 80% because we suggested he try and get things at least up into the 70-80% PWM range if possible back when he was running the 12S setup.

I think a 7-8S setup would do the trick and shave some weight by potentially losing one of the packs as a bonus. I flew my Protos 700 with one 7S pack 1200rpm low head speed at 100% flat and it worked well, but it wasnt quite as heavy as his model is either. He has those big 800 blades too which should perform better at low RPM than my much smaller 696s. He is averaging a measly 20A or so with a 15lb 800, so I think it would be fine with a few less cells and the weight reduction will help cancel some of the current increase out.

Bottom line is his numbers are way low as we both stated, so the model should be fine as is despite not being the best setup possible if he were to decided to keep things the way they are. His temps aren't indicating any stress despite the less than ideal gearing.
__________________
Tony
Synergy 516, Gaui R-5 Speed, Spirit FBL, Hobbywing and Scorpion Tribunus ESC, Xnova motors

Last edited by Xrayted; 05-01-2018 at 08:49 AM..
Xrayted is offline        Reply With Quote Quick reply to this message
Old 05-01-2018, 11:03 AM   #33 (permalink)
Registered Users
 
Posts: 693
 

Join Date: May 2006
Location: Champaign Il
Default

agreed as stated before on the temps, they're cool, so nothing should be hurt,.. it's just terribly innefficient. There are lots of lower KV motors available.

Needs a much lower KV motor, and something in the 450~600 gram range. I just skimmed some things in this thread, and also watched a bit of the video. Just hovering around and gentle forward flight,.. doesn't need a lot of power, but shouldn't be so overgeared. It's like you're trying to drive a car up a steep mountain at 20mph in 5th gear. Ran some numbers, and 12S on a 300KV motor with the 10/118 gearing should be in the ballpark. I think xnova has a 300kv in the size needed. I'm totally confused as to where anyone has published you need 250 watts per pound to fly a heli. My 700 does smooth low headspeed 3D averaging 76 watts per pound (telemetry logs and a calculator ).Peaks are of course over 200 watts/lb but that's pulling 16 degrees pitch. I;d suggest going back to 12S, and this motor http://www.xnovamotors.com/xnova-4035-300kv/ , and spinning at 1050-1100. It's still a touch overgeared for that, but pretty close and that motor is available. Haven't found another that's 300kv, but I'm sure something else is out there. I think there's a KDE at 295 but it's one of those big heavy slugs and the xnova should be more than needed, plus a heck of a lot more efficient
jonnyflox likes this.
__________________
Gary Wright
Helifreak user # 7001
gwright is offline        Reply With Quote Quick reply to this message
Old 05-20-2018, 01:03 AM   #34 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: May 2012
Location: usa, az, phoenix
Default

Another crash!! 😞

After changing all the connectors to rcprosupra and install the Futaba telemetry

I flow it for about 3 min and just fail of the sky! Smashing the landing skids and twist them again!!!

All my current were under 80A the esc temp was 37. The voltage is was 39.1 v

Then the damn thing fail of to hit the ground !!!

I don’t know if that because it got only +8-9 pitch and 1170 rpm is not good !!!

Also why when I Spin on normal I get faster sound of rpm than idle 1 or 2 !!

I have flat 30% on idle 1 and 70% idle 2
It’s very unstable regard the pitch

When I want to recover from going down I had to pull the pitch all the way up and the heli took more to recover !!!

Don’t know why this thing is not going well


I may go back to 6s setup and change th main gear and the pinion

Oh oh what a time killer !!
flyingdragon is offline        Reply With Quote Quick reply to this message
Old 05-25-2018, 08:07 AM   #35 (permalink)
Registered Users
 

Join Date: Dec 2015
Location: Seattle
Default

take a look at the telemetry fbl and esc logs. there should be useful information there.

or post them here and we can take a look.
etherbatxx is offline        Reply With Quote Quick reply to this message
Old 05-31-2018, 12:19 AM   #36 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: May 2012
Location: usa, az, phoenix
Default

Yeap, going to fly it first the weather get better and download all the esc logs again 🙂
Thank you
Oz
flyingdragon is offline        Reply With Quote Quick reply to this message
Reply




Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Location
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On




Copyright © Website Acquisitions Inc. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1