SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Mar 02, 2012, 08:08 AM
Registered User
Joined Oct 2011
152 Posts
Quote:
Originally Posted by manuel v View Post
That's right, very interesting question.
On a forum asked Dr. kiwi, if, when selecting the engine weight, included the Xmount and adapter or just the engine.

Not if my answer is correct.
but I think in any application, any metallic material that is touching the engine helps to dissipate the heat.
If we add air flow, then increase heat dissipation.
That I be the reason why an engine used in 3D applications only pays 2.5 to 4 watts per gram of weight, while EDF pays a facilmete 8 watts per gram.
In a metal DF engine must be able to be enforced more.
I think in the case of two engines of the same weight, one inruner vs a outruner as CP-480, the outruner has more ability to dissipate heat.
But it is difficult to measure because it also features efficiency.
Het motors and the like are very efficient, while CP-480 are not so (I think, but I have not measured), so in like circumstances will produce less heat het that the CP-480 matching the stage.

EDF have some additional air inlets at the front to give better ventilation to the engine.

Of course, an EDF without proper ventilation with no holes Inruner front backwards, has little chance of performing .

Manuel V.
Thanks Manuel! I thought I might find a way to normalize the scale and take efficiency into account via the g/w (Grams of thrust per Watt) calculation for the motors. This also does not hold true when I compare actual run temps of the various motors.

Example: The XK2850-B-3000kv has a better G/W efficiency, actually equal to the Het in our testing sample here so not bad for a ~$30usd motor but is also more efficient biased on that calculation than the CP-3300kv. The CP runs cooler and provides more thrust on 4S as measured compared to the XK2850-B-3000kv. I would run the CP-3300kv on 4s as a performance minded setup.

The rating scale seems to be a proxy for motor temp and I guess without controlled and measured motor temps there does not seem to be an accurate way to account for the discrepancies in the rating scale. I would agree that the scale is directionally correct but not correct in all cases ( too many variables). So be careful, it is just a data point.

I will add it as is and maybe we should also try and come up with a recommendation biased on our testing knowledge and categorize by each xS as an efficiency and performance motor recommendation?

...
901racer is offline Find More Posts by 901racer
Last edited by 901racer; Mar 02, 2012 at 08:29 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 02, 2012, 09:06 AM
Kamikaze Ace
Glacier Girl's Avatar
USA, FL, Lakeland
Joined Jan 2010
2,386 Posts
901, sorry that was Manuel's chart I was looking at with the colors.
A preference would be really nice. Like looking at a "How fast do you want to go and how big is your wallet" menu.

Top of the line for each S rating, with a list below in ascending order of preferences.

As for temps, you probably already know this but, an ambient temp and final temp should be considered when stating the rise. Like said a lot a variables to consider.

A disclaimer too is a must. You never know, I test a set up at 70 degrees in the shop and it gets listed.
Someone uses it in the summer, where it's 100 degrees out and it fries.
Glacier Girl is online now Find More Posts by Glacier Girl
Reply With Quote
Old Mar 02, 2012, 09:10 AM
Kamikaze Ace
Glacier Girl's Avatar
USA, FL, Lakeland
Joined Jan 2010
2,386 Posts
flylow, Mega 16/25/4, 6S, 7x7 prop. 61 amps, 1350 watts. NEVER burnt out one.
Glacier Girl is online now Find More Posts by Glacier Girl
Reply With Quote
Old Mar 02, 2012, 12:56 PM
Registered User
Joined Nov 2011
1,141 Posts
Quote:
Originally Posted by Glacier Girl View Post
flylow, Mega 16/25/4, 6S, 7x7 prop. 61 amps, 1350 watts. NEVER burnt out one.

Wow, thanks for great info.
I think I had the motor I want to use on this CS 10 blade :-)
Low KV motor, high torque, high cell count, low amps, high volt ... :-)

BTW, is there a good way to do "anti spark" when you use high cell count
such as 8S or 10S on the power???

THx.
flylow2011 is offline Find More Posts by flylow2011
Reply With Quote
Old Mar 02, 2012, 01:08 PM
Registered User
manuel v's Avatar
Mexico, BC, Mexicali
Joined Aug 2004
5,336 Posts
If you forgot,
must consider the variable temperature and altitude.
warmer and less altitude does not help much.
I live at sea level and normal summer is 120 degrees F.
In these conditions it is better to use the engines up to 8-9 grams per watt.

Manuel V.
manuel v is online now Find More Posts by manuel v
Reply With Quote
Old Mar 02, 2012, 01:18 PM
Registered User
Joined Nov 2011
1,141 Posts
Quote:
Originally Posted by manuel v View Post
If you forgot,
must consider the variable temperature and altitude.
warmer and less altitude does not help much.
I live at sea level and normal summer is 120 degrees F.
In these conditions it is better to use the engines up to 8-9 grams per watt.

Manuel V.

8-9 g/watt ...
you meant Full throttle all the time right???


.
flylow2011 is offline Find More Posts by flylow2011
Reply With Quote
Old Mar 02, 2012, 01:25 PM
I make bad look so good.
SteveC68's Avatar
League City, Texas
Joined Sep 2006
2,552 Posts
What were the settled watts on the Turnigy L2855 -2300kv on 5S?
SteveC68 is offline Find More Posts by SteveC68
Reply With Quote
Old Mar 02, 2012, 01:44 PM
Registered User
manuel v's Avatar
Mexico, BC, Mexicali
Joined Aug 2004
5,336 Posts
With respect to colors,
I believe there is any problem with the blue and yellow.
Possibly not the red.
The problem is with orange markings, which will have to be handled with caution and the results of longevity, viavilidad will be determined by each.
What if it should be noted is that the tests of these engines have different number of cells, does not mean that they can be used, they safely.

Put a drawing of another example of an attempt to make the engines. this engine is 63mm for DF.

Manuel V.
manuel v is online now Find More Posts by manuel v
Reply With Quote
Old Mar 02, 2012, 01:47 PM
Registered User
manuel v's Avatar
Mexico, BC, Mexicali
Joined Aug 2004
5,336 Posts
Quote:
Originally Posted by flylow2011 View Post
8-9 g/watt ...
you meant Full throttle all the time right???


.
Possibly if
But no flying at full speed.
You have to consider the battery, but it resists the motor, battery no.
manuel v is online now Find More Posts by manuel v
Reply With Quote
Old Mar 02, 2012, 02:19 PM
there is no spoon...
Cap232ac's Avatar
Pueblo, Colorado
Joined Jul 2005
602 Posts
mine showed up today..anyone know what size screws are used to mount the L2855motor?
Cap232ac is offline Find More Posts by Cap232ac
Reply With Quote
Old Mar 02, 2012, 02:23 PM
Registered User
United States, TX, Grand Prairie
Joined Nov 2005
5,773 Posts
Hey guys has anyone strengthened a fans shrouds motor mount and can holder with fiberglass and epoxy for smaller and larger fans?

Thx
erh7771 is online now Find More Posts by erh7771
RCG Plus Member
Reply With Quote
Old Mar 02, 2012, 02:50 PM
I make bad look so good.
SteveC68's Avatar
League City, Texas
Joined Sep 2006
2,552 Posts
Quote:
Originally Posted by erh7771 View Post
Hey guys has anyone strengthened a fans shrouds motor mount and can holder with fiberglass and epoxy for smaller and larger fans?

Thx
I have not done it but yes it has been done.

http://www.rcgroups.com/forums/attac...mentid=3628122
SteveC68 is offline Find More Posts by SteveC68
Reply With Quote
Old Mar 02, 2012, 03:22 PM
Registered User
United States, TX, Grand Prairie
Joined Nov 2005
5,773 Posts
Quote:
Originally Posted by SteveC68 View Post
What were the settled watts on the Turnigy L2855 -2300kv on 5S?
19.1v\55a\56-60 oz thrust

No heat to speak off, seems like the perfect 5s motor, on 6s the room started to stank
erh7771 is online now Find More Posts by erh7771
RCG Plus Member
Reply With Quote
Old Mar 03, 2012, 09:55 AM
Kamikaze Ace
Glacier Girl's Avatar
USA, FL, Lakeland
Joined Jan 2010
2,386 Posts
flylow, here you go, anti spark device.
http://www.rcgroups.com/forums/showthread.php?t=1229558
Glacier Girl is online now Find More Posts by Glacier Girl
Reply With Quote
Old Mar 03, 2012, 11:05 AM
Registered User
Joined Feb 2006
2,405 Posts
I have a anti spark cable I bought from xps I can sell you

$5 bucks shipped. LET Me know.
sherlockshah is online now Find More Posts by sherlockshah
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product Change Sun 12 blade 90mm Flip Flop Electric Ducted Fan Jet Talk 7102 Nov 21, 2014 06:33 PM
New Product Change Sun 120mm and new 10 blade 70mm fans Flip Flop Electric Ducted Fan Jet Talk 131 Apr 27, 2012 08:07 PM
Sold Change Sun electric retracts Flip Flop Aircraft - Electric - Jets (FS/W) 3 May 23, 2011 07:20 AM
Sold Change Sun Electronic retracts w/Lander struts hole digger Aircraft - Electric - Jets (FS/W) 2 May 06, 2011 02:27 PM
Sold Change Sun Electric retracts NIB 75.00 jzuniga Aircraft - Electric - Jets (FS/W) 2 Sep 03, 2010 10:36 AM