SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Nov 17, 2009, 02:10 PM
Registered User
ender707's Avatar
Sacramento, CA
Joined May 2009
718 Posts
Gryphon,

Thanks for the advice, the motor was heating up, so I only did the two tests spaced apart.

I dont have any way to measure rpms, and my numbers are very approximate, as I really only test it to make sure I am not going to melt anything! and get a general idea.

I will also heed your advice about the 7x8, which is fine really, this 7x7 setup is a pretty good bump in performance from my previous setups.
ender707 is offline Find More Posts by ender707
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 17, 2009, 04:17 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by johnnyrocco123 View Post
What is this about a new mount in the making?? Mopar?
I can NOT confirm or deny anything on new mounts....................
HOWEVER, there are some very easy ways to strengthen the stock mount and include a HUGE heatsink
moparmyway is offline Find More Posts by moparmyway
Last edited by moparmyway; Nov 17, 2009 at 05:43 PM.
Reply With Quote
Old Nov 17, 2009, 08:05 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by GryphonRCU View Post
My guess is that at max speed, the ARC may have just a little more RPMs but suck enough extra AMPs for those few RPMs to not be worth it.

The MEGA is under propped big time.....Mopar's test gets as close to stacking the deck in favor of ARC as it gets in a Stryker.

A better comparison would have been to see which one could get to higher speeds with appropriate props....ARC does have its of its best 3S prop for a Stryker....not the case for the MEGA.

That test was just a baseline.....which is the right way of doing it before moving up to the next stage.

Watch the MEGA pull 1100W or more (at reduced efficiency as compared to now, of course)....way higher than ARC at 1100W....wait a minute, we don’t want the ARC burning down.
Gryphon
OK, well here is to your good guess.....................

APC 6x4 sport prop
4s-5000 (30/60c)
CC 125 Phoenix (all power settings @ default)
Stock Stryker with NO CF, NO glass, stock elevons, HS65mg's

MEGA 16/25/2..............................................ARC 28/48/1.5

1 second into launch

32,467 RPM............................................... ...32,608 RPM
15.21 volts............................................. ......14.61 volts
86.22 amps.............................................. .....102.68 amps
1311 watts............................................. ......1500 watts
27 mAH out of battery.....................................37 mAH out of battery


Vertical climb

30,120 RPM............................................... .....30,487 RPM
13.94 volts............................................. ........13.91 volts
73.39 amps.............................................. .......88.23 amps
1023 watts............................................. ........1227 watts
2164 mAH out of battery...................................2160 mAH out of battery

Static test at end of session

30,487 RPM............................................... ......31,779 RPM
14.09 volts............................................. .........13.99 volts
80.38 amps.............................................. .......92.82 amps
1133 watts............................................. ........1299 watts
2306 mAH out of battery....................................2390 mAH out of battery

**NOTE**
Both of these flights (MEGA and ARC) required me to hit the stops on the right stick. The stock elevons and NO carbon fiber caused this Stryker to corkscrew and flutter. There wasnt enough stiffness to get to top speeds and see about unloading. I would need wooden trailing edge, elevons, and some CF before I try the same test again.

Draw your own conclusions
Here is mine...................
1. The ARC (135 f) was heating up ALOT more than the MEGA (80 f) (FLUKE IR temp gun)
2. I believe (based on motor temps and rpm performance) that the ARC was at its limit. There is no way to prop up to a 6x5.5 E without worrying about motor failure. Not the same case with the MEGA
3. MEGA was louder
4. Both motors flew just about identically, I couldnt really see much of a difference, except that the MEGA spooled up faster when nailed compared to the ARC spooling up when nailed, and the ARC had to land much sooner than the MEGA did.
moparmyway is offline Find More Posts by moparmyway
Last edited by moparmyway; Nov 17, 2009 at 08:14 PM.
Reply With Quote
Old Nov 17, 2009, 09:19 PM
You down with EPP?
johnnyrocco123's Avatar
Houston, Tx
Joined May 2009
6,787 Posts
Quote:
Originally Posted by moparmyway View Post
I can NOT confirm or deny anything on new mounts....................
HOWEVER, there are some very easy ways to strengthen the stock mount and include a HUGE heatsink
Cool, thanks for the pics. What is that on top of the stock mount in pic 737?
johnnyrocco123 is offline Find More Posts by johnnyrocco123
Reply With Quote
Old Nov 17, 2009, 09:23 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by johnnyrocco123 View Post
Cool, thanks for the pics. What is that on top of the stock mount in pic 737?
Thats Gorilla tape to keep the mount from breaking off at the base. It gets wrapped under the mount as well
moparmyway is offline Find More Posts by moparmyway
Reply With Quote
Old Nov 17, 2009, 10:55 PM
What's that button do?
Shpook's Avatar
Hollywood, FL
Joined Feb 2008
1,347 Posts
I don't think I've ever seen a 5.5x8 prop before...that's gotta scream in a pylon or low drag delta. With the right power system, of course.
Shpook is offline Find More Posts by Shpook
Reply With Quote
Old Nov 17, 2009, 11:02 PM
Registered User
GryphonRCU's Avatar
United States, CA, SF
Joined Mar 2008
3,838 Posts
Here is how I analyze the data;

At 1 second mark:
To get MPH pitch speed difference; The ARC draws 19% more AMPs.

_______________________

Vertical Climb:
20% more AMPS gets the ARC extra 1.4 MPH pitch speed, which means well under 1 MPH speed difference during vertical climbing.

________________________

Static test at end of session:

15% more AMPs will get extra 3-4 MPH actual flight speed (4.9 MPH pitch speed difference).


***Oh My God “OMG” , need I say more?
ARC 28-48-1.5 draws extra 15%, 19%, or 20% more AMPs and people get next to nothing in return!!!!!!!!!!!!

A big waste; Huge reduction in flight duration without needed performance gain.

The MEGA 16/25/2 is not even running its best prop yet.

Obviously the ARC is just done/toast/inefficient/finito (spelling?) at those power levels.
Surely as the prop unloads a little, it does not look as bad as it looks above.
As it unloads and/or as battery gets weaker its efficiency will not look as bad.

Is that ARC potent? Yes
Is it as awesome as people on RCGRoups make it out to be? Hell no
Is it better than the MEGA 16/25/2 as it has been getting whispered in some dark corners? My answer is that those (2) motors should rarely be spoken of in the same sentence.

____________________

Moparmyway: Thank you for your great efforts.
You helped shed the light by testing on 3S and 4S….you made the test as fair towards the ARC as possible.
Your test was definitely unbiased.

Now, I can show you what a unfair test would look like….forget it; let’s not burn out that ARC as it flies slower


Gryphon
GryphonRCU is offline Find More Posts by GryphonRCU
Reply With Quote
Old Nov 17, 2009, 11:06 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by Shpook View Post
I don't think I've ever seen a 5.5x8 prop before...that's gotta scream in a pylon or low drag delta. With the right power system, of course.
Sorry 'bout that................it is a 6.5x8 prop, the sharpie took a turn when I was writing on the prop cuz I sneezed.
moparmyway is offline Find More Posts by moparmyway
Reply With Quote
Old Nov 17, 2009, 11:09 PM
Registered User
GryphonRCU's Avatar
United States, CA, SF
Joined Mar 2008
3,838 Posts
Shpook,

That is a cutdown APC Sport prop....Tips were re-shaped similar to original, and then balanced.

Next he flew to see if there was improvement given his particular setup that day.


Edit; woops, looks like we were typing at same time. (sorry mopar).

Gryphon
GryphonRCU is offline Find More Posts by GryphonRCU
Reply With Quote
Old Nov 17, 2009, 11:10 PM
zoom zoom
gotboostedvr6's Avatar
USA, NJ, Mt Laurel
Joined Oct 2007
3,691 Posts
Mopar,

I have a feeling your ARC motor is on its way out... those numbers are very far off from almost every other test i have seen.

I have never seen that high an amp draw on that setup. Even using 4s 10,000 lipos.. i have a strong feeling that ether the motor is toasted or the high timing has to be the culprit.

lmk what you think

Edit:
I have 54 flights on one of those setups using good 5200 mah 40/90c lipos.
It draws 74 amps on deans and 84-90 amps on 6mm connectors. I also get 32900 ish rpm static
gotboostedvr6 is offline Find More Posts by gotboostedvr6
Last edited by gotboostedvr6; Nov 17, 2009 at 11:16 PM.
Reply With Quote
Old Nov 17, 2009, 11:12 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by GryphonRCU View Post
Here is how I analyze the data;

ARC 28-48-1.5 draws extra 15%, 19%, or 20% more AMPs and people get next to nothing in return!!!!!!!!!!!!

A big waste; Huge reduction in flight duration without needed performance gain.

.you made the test as fair towards the ARC as possible.
Your test was definitely unbiased.



Gryphon
Thanks Dude !!
I went prop vs prop............not really fair to the lower kv MEGA

I know the MEGA will handle 6.5x6.5 on 4s in MY Stryker, and I also know the ARC will NOT handle 6x5.5 E prop on 4s........................kind of a "no brainer" if you are looking for performance............................
and versatility, that makes the MEGA able to run 8 inch on 3s and possibly 6x4 sport on 5s
moparmyway is offline Find More Posts by moparmyway
Reply With Quote
Old Nov 17, 2009, 11:18 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by gotboostedvr6 View Post
Mopar,

I have a feeling your ARC motor is on its way out... those numbers are very far off from almost every other test i have seen.

I have never seen that high an amp draw on that setup. Even using 4s 10,000 lipos.. i have a strong feeling that ether the motor is toasted or the high timing has to be the culprit.

lmk what you think
Same amp draws as I got when she was new, and she still has the same resistance.

High timing????????????? Its set to default (normal)

If this motor is on its way out, then NOBODY should ever buy one again !! I have babied this motor compared to the Medusas and MEGAs. Even the NEU motors have gotten way more abuse (high power) than this ARC.
To date, max prop on 3s was 6.5x6.5 and max prop on 4s was 6x4 sport. If it burned from those flights and the few ground tests...........you can have it for free, after I make sure to fry it on video in the air with a 6x5.5 E prop on 4s5000 in King Lymey. (King Lymey is the current speed record holder @ 176 mph)

**NOTE**
It has been suggested to re-run the tests with settings optomized for each motor. That might be nice to do, but I already am on borrowed time with this bone stock airframe. I should have crashed several times yesterday and today, but my height was way up there, and I had time to recover. I could do a series of static tests to see what difference is made on each motor, but that might come as the snow gets deeper and flying becomes very unconfortably cold.

Boosted, did you get a chance to doppler those passes on my latest video ?? (especially 1:40 knifedge pass)
Playing around with a FAST Stryker (2 min 49 sec)
moparmyway is offline Find More Posts by moparmyway
Last edited by moparmyway; Nov 17, 2009 at 11:27 PM.
Reply With Quote
Old Nov 17, 2009, 11:40 PM
zoom zoom
gotboostedvr6's Avatar
USA, NJ, Mt Laurel
Joined Oct 2007
3,691 Posts
Im going to bed now .. gotta get up at 5am but i will tomorrow around 10pm est.


I still think the timing may have something to do with it.... maybe a low timing static test would shed some light..

Btw i came across some new adhesive for glassing thats better then 3m90 and is slightly stiffer and alot lighter weight. I have to run it by you as it needs an addition to be 100%
gotboostedvr6 is offline Find More Posts by gotboostedvr6
Reply With Quote
Old Nov 17, 2009, 11:41 PM
Registered User
GryphonRCU's Avatar
United States, CA, SF
Joined Mar 2008
3,838 Posts
ender707,

If I were you, I would do some OCCASIONAL 7X8 flights.


Keep the flight on shorter side and use throttle control......keep your battery happy.

Consider doing some level flight passes (starting from far away) over a sound recorder for Doppler analysis by your friends on this thread.

See the difference of 7X6, 7X7, and 7X8.

Have some fun with APC E 7X5 for good climbing and good speed....barely more AMP draw than 7X7 sport.

LOW Low pitch 8" diameter prop will get you max climbing. (lots of unloading in flight).

Graupner does make a 7.5X5.0 incase you wanted to know.



Gryphon
GryphonRCU is offline Find More Posts by GryphonRCU
Reply With Quote
Old Nov 17, 2009, 11:55 PM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,991 Posts
Quote:
Originally Posted by gotboostedvr6 View Post
Im going to bed now .. gotta get up at 5am but i will tomorrow around 10pm est.


I still think the timing may have something to do with it.... maybe a low timing static test would shed some light..

I have 54 flights on one of those setups using good 5200 mah 40/90c lipos.
It draws 74 amps on deans and 84-90 amps on 6mm connectors. I also get 32900 ish rpm static

Btw i came across some new adhesive for glassing thats better then 3m90 and is slightly stiffer and alot lighter weight. I have to run it by you as it needs an addition to be 100%
Timing could speak for the 10 amps difference. I also run 6.5mm bullets, so there is some more right there.

RPM's.....................I used Eagletree brushless sensor and Medusa Oracle brushless sensor as well....................what did you use ??

I will be in my office tomorrow between 11:00 and 12:00, or before 07:00 if you want to run it by.
moparmyway is offline Find More Posts by moparmyway
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Parkzone F-27C Stryker That can fly?!? Parkflyers 109 Sep 26, 2012 10:54 PM
Discussion Parkzone's New F-27C Stryker itspat Parkflyers 1 Nov 08, 2011 07:56 PM
Mini-Review F-27C Stryker Review That can fly?!? Parkflyers 27 Jul 29, 2010 08:25 PM
Discussion Parkzone F-27C Stryker 3S 11.1 V Balance Plug WDP Batteries and Chargers 12 Oct 26, 2009 08:44 AM
Discussion Coming soon! F-27C Stryker RTF with lipo and brushless Solcat Electric Plane Talk 0 May 31, 2006 12:34 PM