HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 16, 2012, 08:50 AM
Registered User
Joined Nov 2004
1,144 Posts
Reccomend using motocalc to work out battery, ecs and prop combs. A few years ago a high KV inrunner and gearbox was common place. I have a mega 22/20/2 and 3.5:1 ratio gearbox and 17x11 prop on a larger glider. It has about 4.5Kg of thrust
AUSELECTRIC is offline Find More Posts by AUSELECTRIC
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 16, 2012, 10:46 AM
Registered User
feefo's Avatar
Staffs, UK
Joined Apr 2009
3,111 Posts
Quote:
Originally Posted by AUSELECTRIC View Post
Reccomend using motocalc to work out battery, ecs and prop combs. A few years ago a high KV inrunner and gearbox was common place. I have a mega 22/20/2 and 3.5:1 ratio gearbox and 17x11 prop on a larger glider. It has about 4.5Kg of thrust
Yes I've used a calc, results look ok but I don't trust them too much. Maybe Motorcalc is better and more accurate, but I don't have it.

Not many tend to use a Mega, most opt for Hacker, Neu, etc, so I'm not sure how far past the specs the 16/15/3 will take. Mine's the newer 2800kv version, rated at 35a according to Mega

16/15/3 with a 5:1 GB, 14x14 prop on 3s gives 43a, 109oz of static thrust, 71mph pitch speed. But I don't know what the constants for the prop are, and are using the APC's at 1.11 when I'll probabaly use a different make. On 4s, with a 10x16 (think I've seen it mentioned?), 29a, 98oz thrust, 120mph pitch.

Both these and other prop sizes/cell counts seem to suggest it'll work as a motor/GB combo, just wondering what people who are more familiar with GB's think?
feefo is offline Find More Posts by feefo
Reply With Quote
Old Aug 16, 2012, 01:53 PM
Registered User
United Kingdom, Wales, Monmouthshire
Joined Aug 2011
176 Posts
Feefo - personally, I wouldn't bother running that setup on 3S for the Swift/Reverb The Kv is quite low and would be more suitable for F5J/thermal use.

4S (or higher if your willing to split the packs) would be better. I would have thought the Mega should be OK for around 50amp burst if it's rated for 35amps .Anybody with some experience?? 50amps on a small 4S would make it shift, and would be a nice light and efficient setup.

If you're going to the expense of using a Reisenaur GB, it does seem a bit of a waste to use it around 500W on a plyon/hotliner as you'd be able to get similar performance from a cheap 35mm outrunner, albeit with a small weight and efficiency penalty. Just my opinion tho.
TimR74 is offline Find More Posts by TimR74
Reply With Quote
Old Aug 16, 2012, 02:31 PM
Livin it UP when Im goin DOWN
Arcteryxxx's Avatar
Norway, Telemark, Skien
Joined Feb 2010
4,118 Posts
Recently the HotHawk went down in flames The CC ICE100L caught fire and took out the AR7000 rx also. Luckily it happened over a wheat field with meter high crops, so the impact left the plane unharmed except for the burnt electronics ....and the stench
The LHS (Elefun.no) was very kind to replace the ICE, and the Hottie is ready for the skies once more. To increase the airflow to the ESC I opened the fuselage under the wing and placed a (dunno what it's called) to scoop up some fresh air.
I also decided to prop down and a friend and contributer in this thread offered some assistance. So I picked up a couple of new props today (Thanks a bunch, Rolf) and have just done some static testing on the Scorpion 2221-6, KPG 5.2, 4S:

RFM 12x17: 122A, 12.8V, 1565W, 8610rpm (138mph pitch speed)

RFM 10x17: 85A, 13.3V, 1130W, 9990rpm (160mph pitch speed)

For reference the 13x16 (cut down RFM15x16) on static test showed 148A, 13.8V, 2040W, 8594rpm. (Notice: ESC BURN)

All data above from CC log files.

Here's a video of the burn:
CC_ICE100Lite burn (1 min 40 sec)


Notice the difference in V under load in the static tests above. The 12x17 and 10x17 were run with a fresh and new Turnigy 4S1800 40/50C and the 13x16 with a almost new Turnigy Nano 4S1800 65/130C. Sure looks like the Nano is worth the extra pennies!

Really looking forward to testing these new props, and I have a feeling the 10x17 is going to be a VERY nice prop for hot goofing with decent motor-on time
Arcteryxxx is offline Find More Posts by Arcteryxxx
Last edited by Arcteryxxx; Aug 16, 2012 at 03:09 PM.
Reply With Quote
Old Aug 16, 2012, 03:09 PM
What is Highspeed ?
Rolf D.'s Avatar
Germany, BY, Bergen
Joined Feb 2011
508 Posts
Quote:
Originally Posted by Arcteryxxx View Post
Recently the HotHawk went down in flames The CC ICE100L caught fire and took out the AR7000 rx also. Luckily it happened over a wheat field with meter high crops, so the impact left the plane unharmed except for the burnt electronics ....and the stench
The LHS (Elefun.no) was very kind to replace the ICE, and the Hottie is ready for the skies once more. To increase the airflow to the ESC I opened the fuselage under the wing and placed a (dunno what it's called) to scoop up some fresh air.
I also decided to prop down and a friend and contributer in this thread offered some assistance. So I picked up a couple of new props today (Thanks a bunch, Rolf) and have just done some static testing on the Scorpion 2221-6, KPG 5.2, 4S:

RFM 12x17: 122A, 12.8V, 1565W, 8610rpm (138mph pitch speed)

RFM 10x17: 85A, 13.3V, 1130W, 9990rpm (160mph pitch speed)

For reference the 13x16 (cut down RFM15x16) on static test showed 148A, 13.8V, 2040W, 8594rpm. (Notice: ESC BURN)
Here's a video of the burn:
http://www.youtube.com/watch?v=mjBd3...&feature=g-upl

Notice the difference in V under load in the static tests above. The 12x17 and 10x17 were run with a fresh and new Turnigy 4S1800 40/50C and the 13x16 with a almost new Turnigy Nano 4S1800 65/130C. Sure looks like the Nano is worth the extra pennies!

Really looking forward to testing these new props, and I have a feeling the 10x17 is going to be a VERY nice prop for hot goofing with decent motor-on time
better would be to use a 2200 mAh 4S Lipo, they hold better the current Volts.
Test I did with the 12x17 I have had all time around 140 Amps in peak.
wich middlepeace do you use ??? the 41 ?

also too in future I bring own folding props in this sizes on market
Rolf D. is offline Find More Posts by Rolf D.
Reply With Quote
Old Aug 16, 2012, 03:14 PM
Livin it UP when Im goin DOWN
Arcteryxxx's Avatar
Norway, Telemark, Skien
Joined Feb 2010
4,118 Posts
I had to use the AeroNaut spinner which has the same spacing as the Reisenauers. This is because I have a KPG25 which of course has a 5mm shaft.

I agree about the battery size, but remember that you used a Reisenauer 5.0:1 and I a KPG 5.2:1. I'm sure the 0.2 difference in reduction rate will have an effect on the Amps too.
Arcteryxxx is offline Find More Posts by Arcteryxxx
Reply With Quote
Old Aug 16, 2012, 04:49 PM
"RC ADDICT" in Toronto!
wollins's Avatar
Toronto Canada
Joined Aug 2004
1,670 Posts
Quote:
Originally Posted by stanordave View Post
If you want a great motor choice for the Reverb, try a HET 2w-23 with a 5.25x6.25 prop and a 4s, 65C battery.

What capacity was the pack?
wollins is online now Find More Posts by wollins
Reply With Quote
Old Aug 16, 2012, 05:02 PM
Registered User
FlyLT's Avatar
Earth
Joined Oct 2009
343 Posts
Today I tried my Scorpion 2221-8 with out the gear box
With 4.75X4.75 APC prop.
I pushed it a bit too far
1400W , ~ 90A on 4S and motor was hot ( 80'C )



Mini Hawk hotliner speed pass (0 min 54 sec)
FlyLT is offline Find More Posts by FlyLT
Reply With Quote
Old Aug 16, 2012, 05:18 PM
Registered User
feefo's Avatar
Staffs, UK
Joined Apr 2009
3,111 Posts
Quote:
Originally Posted by TimR74 View Post
Feefo - personally, I wouldn't bother running that setup on 3S for the Swift/Reverb The Kv is quite low and would be more suitable for F5J/thermal use.

4S (or higher if your willing to split the packs) would be better. I would have thought the Mega should be OK for around 50amp burst if it's rated for 35amps .Anybody with some experience?? 50amps on a small 4S would make it shift, and would be a nice light and efficient setup.

If you're going to the expense of using a Reisenaur GB, it does seem a bit of a waste to use it around 500W on a plyon/hotliner as you'd be able to get similar performance from a cheap 35mm outrunner, albeit with a small weight and efficiency penalty. Just my opinion tho.
Cheers TimR.

I was figuring 45a burst would be ok, up to 50a might push it a bit. As you've said, anyone with any experience with Mega?, Seems not many, most favour different motors over the Mega.

At this point I'll admit to not putting this in a Wasp/Swift/Reverb, I'm looking to fit out a Bird E 60", but you guys were talking motor/GB's so it saved starting a thread. I was considering using the motor because I have it, but I did think it wouldn't be powerful enough anyway. I need to read up more before I make a decision, cheers for your advice.

Arcteryxxx....wow that shifts, that motor must be close to it's limits, did I count right with 2 sec motor runs? Maybe last run was 3 secs? Cool your LHS shop replaced your esc, even cooler is they stock them! And even cooler you didn't damage your plane!!

I think your esc cooling holes are 'Snake Rod Exits' or a 'Control Rod Exit', depends on the make.
feefo is offline Find More Posts by feefo
Reply With Quote
Old Aug 16, 2012, 05:29 PM
Livin it UP when Im goin DOWN
Arcteryxxx's Avatar
Norway, Telemark, Skien
Joined Feb 2010
4,118 Posts
Thanks Feefo
BTW: I absolutely love MEGA motors! I just don't have any experience whatsoever with the size you were posting about so I'm not comfortable with giving advice. I have a 16/25/2EC in my other miniHawk fuselage doing mid 260 kph with a 6x5.5. (Waiting for some 5.25x6.25s and have a special 6x8 just in case I get the itches). Jacko is running the same size Mega with a KPG 5.2 on 6S and a slightly trimmed 14.5x14. Just ask him if he likes it
On a side note: I have 4 other Megas - all are specials, firsts and not what you find in your LHS shelf - and all are outstanding in quality and performance!
Arcteryxxx is offline Find More Posts by Arcteryxxx
Reply With Quote
Old Aug 16, 2012, 06:00 PM
Registered User
Joined Nov 2004
1,144 Posts
My mega is rated at 70A and draws about 100A for about 2 secconds so does not even have time to warm up.

With a 2800KV motor On 3s I think you need to reduce the GB ratio to arround 3:1 or 2.5:1 this in turn will allow you to reduce prop pitch and be more efficient.

My personal opinion is that Watts are not the only indication on performance and often high current outrunners lose power to heat generated.
AUSELECTRIC is offline Find More Posts by AUSELECTRIC
Reply With Quote
Old Aug 16, 2012, 06:15 PM
RC Farmer
Farmer_Joe's Avatar
Joined Aug 2011
413 Posts
Arcteryxxx - sorry to hear that, good that your plane was ok.

FlyLT - that must be over 300km/h you should do one good pass for doppler.
Farmer_Joe is offline Find More Posts by Farmer_Joe
Reply With Quote
Old Aug 16, 2012, 07:13 PM
Registered User
feefo's Avatar
Staffs, UK
Joined Apr 2009
3,111 Posts
Quote:
Originally Posted by Arcteryxxx View Post
Thanks Feefo
BTW: I absolutely love MEGA motors! I just don't have any experience whatsoever with the size you were posting about so I'm not comfortable with giving advice. I have a 16/25/2EC in my other miniHawk fuselage doing mid 260 kph with a 6x5.5. (Waiting for some 5.25x6.25s and have a special 6x8 just in case I get the itches). Jacko is running the same size Mega with a KPG 5.2 on 6S and a slightly trimmed 14.5x14. Just ask him if he likes it
On a side note: I have 4 other Megas - all are specials, firsts and not what you find in your LHS shelf - and all are outstanding in quality and performance!
I've recently become a fan of Mega, thanks to Gryph. He sorted me a special 16/25/2CE F5D motor out for my FJU. No prob you don't want to advise if your not familiar with the motor. I'll do some reading and see what I think.
feefo is offline Find More Posts by feefo
Reply With Quote
Old Aug 16, 2012, 07:19 PM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
6,972 Posts
feefo, ive never tried a 16/15 on a gearbox before, have been tempted to many times though


16/15/3 will handle 60-70A LMR fine, Id suggest 4S too and see what you can come up with. Start with small props and work up
jackosmeister is online now Find More Posts by jackosmeister
Reply With Quote
Old Aug 16, 2012, 07:23 PM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
6,972 Posts
Quote:
Originally Posted by Demon 6 View Post
Whats a "KPG25" is that a Gearbox?

I looked it up... Espiritmodels has them in stock... Which ratio?
So would the Mega and the KPG25 be a hot setup with the folder?
Espirit also has the Aeronaut 36mm spinners...
Its resonably hot, this is flying in as tight a box as possible to keep it in view of the camera. Much faster passes are possible, its a nice reliable setup thatll make you grin.

Mibo Wasp/Launchmodel Swift +5 degree halfpipe (3 min 21 sec)
jackosmeister is online now Find More Posts by jackosmeister
Last edited by jackosmeister; Aug 16, 2012 at 07:30 PM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Will Wasp V4/Belt 250 parts fit on Wasp V3? cfanto Skyartec 8 Mar 24, 2010 04:02 PM
Wanted Spirit E by mibo FASTBEN Aircraft - Sailplanes (FS/W) 3 Dec 07, 2009 01:36 AM
anybody know Mibo Modeli "spirit e"??? trashmanf High Performance 3 Jul 23, 2005 08:33 PM
Mibo Modeli Spirit e 207 Electric Sailplanes 15 Jul 23, 2005 07:26 AM
Any info about Mibo Spirit E? AndrésMtnez High Performance 27 Jun 20, 2005 09:21 AM