SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Dec 21, 2012, 11:50 AM
Flirtin With Disaster !!
D.B. Hooper's Avatar
United States, OR, Mt Angel
Joined Jan 2008
1,435 Posts
Wonder how long this would last in the Demon on 6s 6x4 prop?

http://www.hobbyking.com/hobbyking/s...ion_29mm_.html
D.B. Hooper is offline Find More Posts by D.B. Hooper
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 21, 2012, 03:44 PM
never mind the boll⁣⁣⁣ocks
brosius85's Avatar
Australia, NSW
Joined Dec 2010
1,256 Posts
only one way to find out!

its such a shame about the 3mm shaft....
brosius85 is offline Find More Posts by brosius85
Reply With Quote
Old Dec 21, 2012, 04:34 PM
Registered User
Peter M's Avatar
Newcastle, New South Wales, Australia
Joined Sep 2007
2,366 Posts
Quote:
Originally Posted by D.B. Hooper View Post
Wonder how long this would last in the Demon on 6s 6x4 prop?

http://www.hobbyking.com/hobbyking/s...ion_29mm_.html
About half a flight I would think!
kV too high for 6 cells on that prop.


I honestly think you would be better investing that 35 bucks towards a better motor as you will end up buying one anyway.
Peter M is offline Find More Posts by Peter M
Reply With Quote
Old Dec 21, 2012, 11:10 PM
Some call me the other guy!
DoctorAudio's Avatar
Milwaukie , Oregon
Joined Feb 2003
4,471 Posts
Hooper, your right.
I been to get some fudge at the church.
I want to fly that valley behind there. Now that would be an epic flight.
I actually plan on it as part of my bucket list!
I am getting ready, for a very interesting year coming up!

Quote:
Originally Posted by D.B. Hooper View Post
Good idea! I'll do that for the maiden flight then check the flight log.

Dr Audio . I see your not far from me. Nice flying weather we are having! Hard to believe they are having a dust storm in Texas. Almost makes me want to move back there.

Thanks again to Murd and Mopar for the number crunching and advise.
DoctorAudio is offline Find More Posts by DoctorAudio
Reply With Quote
Old Dec 22, 2012, 09:41 AM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,997 Posts
Quote:
Originally Posted by D.B. Hooper View Post
Thanks again to Murd and Mopar for the number crunching and advise.
OK, since I only gave a smidgeon of advice ............................ want some more ?
moparmyway is offline Find More Posts by moparmyway
Reply With Quote
Old Dec 22, 2012, 09:45 AM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,997 Posts
Quote:
Originally Posted by moparmyway View Post
OK, since I only gave a smidgeon of advice ............................ want some more ?
Quote:
Originally Posted by D.B. Hooper View Post
Got the Mega installed in the Demon
3 day shipping from Gary at EffluxRC.com
WOT for 5sec.bench test.
7s 4000 6x5 carbon prop
120amps
2675watts
35,820RPM
Hope to fly this weekend.
Your gunna burn it
moparmyway is offline Find More Posts by moparmyway
Reply With Quote
Old Dec 22, 2012, 10:00 AM
Flirtin With Disaster !!
D.B. Hooper's Avatar
United States, OR, Mt Angel
Joined Jan 2008
1,435 Posts
Quote:
Originally Posted by moparmyway View Post
Your gunna burn it
Even with the 6x4 sport prop
D.B. Hooper is offline Find More Posts by D.B. Hooper
Reply With Quote
Old Dec 22, 2012, 10:20 AM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,997 Posts
Quote:
Originally Posted by D.B. Hooper View Post
Even with the 6x4 sport prop
If you fly WOT the entire flight .................. yup, than one too might cook her.

IMHO, Put her up with the 6x4 Sport, make 1 or 2 passes, then land and review the inflight log.

Need to see where the 6x4 Sport wants to run at speed

Or

Fly her how u want, but limit your throttle duration untill you can review the log. If your flying batts deliver more than 3.2 volts per cell, you are gunna want to see the numbers before you throw her
moparmyway is offline Find More Posts by moparmyway
Reply With Quote
Old Dec 22, 2012, 02:45 PM
Victim of C.D.O.
murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
4,081 Posts
Thanks for jumping in with additional info, Mopar.
Always good to help out when something doesn't look quite right.

DB's setup may very well be on the edge. Predicting how a motor will respond to 3 minutes of WOT is a little tough, given that the majority of my data and experience is with max-speed, throttle-controlled flying.

Much of my recommendation was based on my flying with the 16/35/2C motor on 7S and 6x5 prop. It got:
90A
2200W
39,300 RPM

This motor did alright with 2-minute WOT flights in summer while preparing for a pylon race.

The static test that DB did on his 16/40/1.5SCE is a little surprising on the watts and RPM. Seems high, like the motor's KV came out a little high. I'm checking into it a little more...
murdnunoc is offline Find More Posts by murdnunoc
Reply With Quote
Old Dec 22, 2012, 03:02 PM
Victim of C.D.O.
murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
4,081 Posts
DB, any chance you can post a screen shot of your static test data from the ICE data log?
murdnunoc is offline Find More Posts by murdnunoc
Reply With Quote
Old Dec 22, 2012, 03:15 PM
Flirtin With Disaster !!
D.B. Hooper's Avatar
United States, OR, Mt Angel
Joined Jan 2008
1,435 Posts
Quote:
Originally Posted by murdnunoc View Post
DB, any chance you can post a screen shot of your static test data from the ICE data log?
oops
D.B. Hooper is offline Find More Posts by D.B. Hooper
Last edited by D.B. Hooper; Dec 22, 2012 at 03:42 PM.
Reply With Quote
Old Dec 22, 2012, 04:12 PM
Flirtin With Disaster !!
D.B. Hooper's Avatar
United States, OR, Mt Angel
Joined Jan 2008
1,435 Posts
Quote:
Originally Posted by murdnunoc View Post
DB, any chance you can post a screen shot of your static test data from the ICE data log?
First is with the 6x4 on 7s
Second graph 6x5 carbon on 7s
D.B. Hooper is offline Find More Posts by D.B. Hooper
Last edited by D.B. Hooper; Dec 22, 2012 at 04:56 PM.
Reply With Quote
Old Dec 22, 2012, 06:15 PM
Victim of C.D.O.
murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
4,081 Posts
Can't really tell anything from the 6x5 static test. Needs to be 2-3 seconds to see what the motor is really doing.

Based on the data you posted for 6x5 prop on 7S, the motor is pulling more power and more RPM than I expected. I did a static test just now on a 16/40/2EC motor (same size, same performance) and got an identical 35,820 RPM, but only 2399W.

Your motor will be safe for sure on 6x4 Sport with some gliding to cool off in between WOT at 30 second intervals or so.
Take it easy at first like Mopar suggested until you get a feel for motor temps. It should never come down over 140F.

So fly it easy on 6x4 first. If that's OK...
WOT flight on 6x4. If that's OK...
Limited throttle on 6x5. If that's OK...
WOT flight on 6x5 like you planned.

You'll have to repeat this process any time you step up the power system. Like when your new batteries get here.

If at any point the motor is hot when you land, do NOT go on to the next step.
If it turns out you can only run 6x4 in limited throttle, and it's just not fun, you can always switch to 6S and run 6.5" diameter pylon props. They're not as noisy-fun, but the performance-fun is still there. Great speed!
murdnunoc is offline Find More Posts by murdnunoc
Reply With Quote
Old Dec 22, 2012, 09:01 PM
Flirtin With Disaster !!
D.B. Hooper's Avatar
United States, OR, Mt Angel
Joined Jan 2008
1,435 Posts
Quote:
Originally Posted by murdnunoc View Post
Can't really tell anything from the 6x5 static test. Needs to be 2-3 seconds to see what the motor is really doing.

Based on the data you posted for 6x5 prop on 7S, the motor is pulling more power and more RPM than I expected. I did a static test just now on a 16/40/2EC motor (same size, same performance) and got an identical 35,820 RPM, but only 2399W.

Your motor will be safe for sure on 6x4 Sport with some gliding to cool off in between WOT at 30 second intervals or so.
Take it easy at first like Mopar suggested until you get a feel for motor temps. It should never come down over 140F.

So fly it easy on 6x4 first. If that's OK...
WOT flight on 6x4. If that's OK...
Limited throttle on 6x5. If that's OK...
WOT flight on 6x5 like you planned.

You'll have to repeat this process any time you step up the power system. Like when your new batteries get here.

If at any point the motor is hot when you land, do NOT go on to the next step.
If it turns out you can only run 6x4 in limited throttle, and it's just not fun, you can always switch to 6S and run 6.5" diameter pylon props. They're not as noisy-fun, but the performance-fun is still there. Great speed!
Ok, sounds like a good idea. I'll run the 6x4 first and take it easy
I've installed the MPI heat sink and the clam shell so that should help. Temp here is in the low 40's so that will help too.
Got my new 45-90c 4000mAh Nano's 4s & 3s today!
No more driveway tests after dirty looks I got from the neighbor lady across the street today Tomorrow I'll give it a good test at my friends shop with both props and the new batteries. Monday the weather looks good for a test flight.
D.B. Hooper is offline Find More Posts by D.B. Hooper
Reply With Quote
Old Dec 23, 2012, 12:54 AM
Registered User
GryphonRCU's Avatar
United States, CA, SF
Joined Mar 2008
3,848 Posts
Static tests should be 3 seconds.....not 5.
Longer tests than nessasery will just heat/beat/abuse the motor.

I bet the motor was pretty hot after that 5 second static test mentoned before.

A motor that gets overheated will have weaker magnets....KV rises, efficiancy goes down.

10 samples per second logging rate is best for testing.
Zoom in on the results, find peak AMP spike after initial full throttle....pluck/read the data from 1.0 seconds or 1.5 seconds after that initial peak AMP spike.

Might as well start with low ESC timing advance incase it barely drops power level. Sometimes it makes no difference because castle selects its own timing advance within each range. There can be overlap between low and medium timing advance ranges and that is why there "maybe" no difference in power between them.

Maybe Stick with older packs at first.....when switching to newer and more capable packs step back down on prop size and duration and increase stress incrementally all over again.

Some ICE ESCs are not as accurate as others.
I got lucky with mine and it reads close enough to my Eagle Tree logger.


Gryphon
GryphonRCU is offline Find More Posts by GryphonRCU
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
I got some Fan Fold what to build thread part II started by emoone!!! Don Sims Foamies (Kits) 188 Jan 23, 2010 08:28 PM
Build Log RiteWing 48-FT build thread theclaw Slope 46 Dec 09, 2007 08:53 AM
Mountain Models Tantrum Partial Build Thread.. Tram Parkflyers 142 Apr 03, 2004 10:41 PM
My Bobolink Build Thread (very Colibri like) Jim Poor Hand Launch 65 Dec 10, 2003 04:48 PM
Switchback re-build thread (or What the $#*& was that!) Biggles604 Parkflyers 17 Jun 23, 2003 09:34 PM