Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Aug 06, 2014, 01:40 PM
Registered User
PeterF's Avatar
United Kingdom, England, North York
Joined Nov 2004
336 Posts
I started looking at the MythoS 50E but then considered the 125E. What I do not understand is the 50E requires around 1,100W on the recommended set up with a flying weight of 3.3kg (7.3lb) which gives 150W/lb, a respectable power level. The 125E weighs in at around 4.4kg (9.7lb) which is 33% heavier, but the recommended power set up delivers say 2,200W, giving 225W/lb, 50% higher than the 50E. From the videos posted by the OP both planes fly extremely well and with authority on the recommended set ups so I do not question this at all. The question is, is the 2,200W required for the 125E, do larger planes need disproportionately more power and if so why. I seek information as someone for someone who is thinking of going up to the size of the 125E (I currently have a 60inch / 1.5m glow powered pattern plane) and want to step up.
PeterF is offline Find More Posts by PeterF
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 06, 2014, 03:23 PM
Registered User
Sverige, Värmlands Län, Filipstad
Joined Jan 2009
1,141 Posts
Hi,

I can compare (almost) what You are thinking of, that I have:

1. Sebart Wind S 50E (not that different then the newer MythoS 50E).
2. Sebart MythoS 125E.
3. Sebart MythoS Pro (2M).

1. Sebart Wind S 50E:
I use Hacker A50-16S V2 (there is a slighly newer and better V3 nowadays).
With APC 17x10E and 6 cell 45C Gensace 5000 mAh I get on full throttle in the air 70 amp
that gives approx 6 x 3.7 volt x 70 amp = 1550 watt.
In reality this mean unlimited vertical performance and more then enough for most F3A manouvers, at least in Advanced Schedule.
I do not remember weight of my Wind S 50E ready to fly with battery.

2. Sebart MythoS 125E:
Here I have Hacker A60-7XS.
With Falcon Electric V2 carbon 19x12 prop and 8 cell ThunderPower G8 Prolite+ 25C 5000 mAh I get 77 amp on full throttle in the air that gives approx 8 x 3.7 volt x 77 amp = 2279 watt.
This gives also unlimited vertical performance and You can fly Advanced Schendule without problem.
You get better flying in higher winds with MythoS 125E then a smaller 50 seize plane.
Ready to fly weight on my MythoS 125E is 4670 gram.

3. Sebart MythoS Pro (2M):
Here I have Hacker Q80-14XS.
With Falcon Eelectric V2 carbon 20.5 x 14.5 prop (will switch to 21 x 14 soon) and 10 cell ThunderPower G8 Prolite+ 25C 5000 mAh I get 74 amp on full throttle in the air that gives approx 10 x 3.7 volt x 74 amp = 2738 watt.
This gives also unlimited vertical performance and You can fly Advanced or P15 and F15 without any problem. And it fly even better in more windy conditions then MythoS 125E.
Ready to fly weight on my MythoS Pro is 4930 gram.

One get little more watt when the battery packs are fully charged (4.15-4.20 volt) but as an average the nominal voltage 3.7 volt is good for comparison above.

/Bo
bossee is offline Find More Posts by bossee
Last edited by bossee; Aug 07, 2014 at 04:02 AM.
Reply With Quote
Old Aug 07, 2014, 01:02 AM
Registered User
PeterF's Avatar
United Kingdom, England, North York
Joined Nov 2004
336 Posts
Bo,

Thanks for the numbers, your 50E plane is being run above the recommended power for the Mythos 50E and at similar W/lb to the 125E plane. I have just looked at the APC performance data for my 60" (1.5m) glow powered plane and that generates the same static thrust as a 17x10E running at 7,000rpm which your set up will be doing. I should have done this calc first as this shows no difference between my smaller plane and a larger one, hence if I go for 50E size I should go for more power than the recommended set up to stay the same performance as my glow model.

Cheers,

Peter.
PeterF is offline Find More Posts by PeterF
Reply With Quote
Old Aug 07, 2014, 03:16 AM
F3A Team Finland
Finnspeed's Avatar
Järvenpää, Finland
Joined Nov 2005
898 Posts
Yes, Bo has it correct. 1100 W is enough to fly the Wind S50E or the new Mythos of the same size but for good F3A type performance you need 1300 W or more.

I have a Wind S50E with 3030 g AUW running from 5S 4600 mAh batteries with 1300 W input power. This is just enough to fly through the Nordic sequence without problems (other than what is between the sticks and ground).

BTW, I find it a bit weird that SebArt calls these planes "50" while in my opinion they are more like "70" class planes.
Finnspeed is offline Find More Posts by Finnspeed
Reply With Quote
Old Aug 07, 2014, 03:26 AM
Registered User
PeterF's Avatar
United Kingdom, England, North York
Joined Nov 2004
336 Posts
Quote:
Originally Posted by Finnspeed View Post
BTW, I find it a bit weird that SebArt calls these planes "50" while in my opinion they are more like "70" class planes.
Thanks for more confirmation, it backs up the thrust check on my glow powered 60" 70 size plane. I believe Sebart calls them 50 size because the Hacker 50 size motors fit rather than references to the glow motor size, which would of course be 70 size. See the Axiome 70 EP which is just a bit smaller than the Mythos 50E.
PeterF is offline Find More Posts by PeterF
Reply With Quote
Old Aug 07, 2014, 04:25 AM
Registered User
Sverige, Värmlands Län, Filipstad
Joined Jan 2009
1,141 Posts
And to confuse some more in the "50 size" (electric) model segment there is the new Galactik "90" that is in same seize (wingspan) as MythoS 50E. Again here it is a glow engine that is used for reference to the "90" seize (YS91, YS110, YS115), and for electric motor for the Galactik 90 they say "1650-1850W, 400-450g, 5060(Dualsky), A50(Hacker) brushless outrunner"

/Bo
bossee is offline Find More Posts by bossee
Reply With Quote
Old Aug 15, 2014, 11:07 AM
Registered User
Joined Aug 2014
2 Posts
Hello bosse.
Can you fly P15 whith your Mythos 125E configuration?
juandosm is offline Find More Posts by juandosm
Reply With Quote
Old Aug 15, 2014, 02:41 PM
Registered User
Sverige, Värmlands Län, Filipstad
Joined Jan 2009
1,141 Posts
Hi,
I have not tried but it flies Advanced schedule without problem.
My best guess is that it would fly P15 reasonably good with my setup, in hands of a good pilot. But it would be better with a MythoS Pro for example with the setup I use in my MythoS Pro. I have seen P15 and F15 flown with MythoS Pro with same setup as I have and it performs nicely. The Swedish F3A champion this year flies MythoS Pro with basically same setup as I have in mine (and I watched both his P15 and F15 flights this year - I was competing in Nordic/Advanced class with my MythoS Pro).

/Bo
bossee is offline Find More Posts by bossee
Last edited by bossee; Aug 15, 2014 at 02:53 PM.
Reply With Quote
Old Aug 16, 2014, 11:23 AM
Registered User
Joined Aug 2014
2 Posts
Thank you for your answer.
All the best.
juandosm is offline Find More Posts by juandosm
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log SebArt Sukhoi 29S 140E Build Thread... jfetter 3D Flying 438 Mar 31, 2014 11:31 PM
Mini-Review New Sebart KatanaS 30e - Build Thread/Mini-Review Bill K. 3D Flying 1067 Mar 11, 2014 12:03 AM
Build Log Turnigy (TECHone) Mythos Build Thread The_Mongrel Australia 13 Feb 13, 2013 07:59 PM
For Sale NEW SebArt Mytho S 125E FREE SHIPPING DiscountLipos Aircraft - Electric - Airplanes (FS/W) 9 Aug 29, 2012 05:00 PM
Mini-Review New SebArt KatanaS 50E - Build Thread/Mini Review Bill K. Sport Planes 334 Oct 04, 2010 03:44 AM