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Old Jul 18, 2015, 05:13 AM
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Jack,

Flying the schedule I consume around 3200 mA on an 8S set-up which can get to around 3500mA if it's very windy (which it mostly is !!). This is with a 2200-2300W setup
If I flew with 6S 5000 batteries I would run out of capacity.
Also heat produced by an electrical system is proportional to resistance & time but the square of current - so to reduce heat (motor, ESC) it's better to run at a lower current & higher voltage, maintaining the same watts.
And then there's the battery to consider - I run 25C batteries, maximum just under 80A peak, for 6S you would be around 106A - so a higher C battery would be required...
Like I said previously I just don't understand why 6S is the recommended set-up, yes it can be done but why would you considering the issues it creates .

Steve
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Old Jul 18, 2015, 08:16 PM
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I am not suggesting the 8S option is a bad idea, more Voltage is always better for efficiency, I am simply showing Seba's recommended setup works fine. I fly with a 6S x 6,600 mAh pack now because I do prefer more capacity but it fly's well on 6S...

Jack
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Old Jul 19, 2015, 05:10 AM
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Jack,

I know you have had success with 6S but you use 6600mA packs - which have almost the same energy density as a 5000mA 8S pack. This is also the size of pack I would need to fly a schedule on 6S.
I see you run TP 65C packs - these cost (in the UK) 5X what 2 packs of Zippy Compact 4S 5000's cost which, to me at least, illustrates my point of not understanding why 6S was the suggested route i.e. you then need High C High Capacity batteries.
I assume a significant number of Mythos 125 owners moved from a Sebart 50 sized plane such as a Angel 50/Wind 50 - well the size of 6S battery for these planes is too small for the Mythos 125 - then there are those (like me) that ran the wind 110 - which was 8S !!

Steve
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Old Jul 19, 2015, 07:41 AM
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Seba wanted a 2M Pattern Plane (the look, feel and flight characteristics) that most people can afford. By trimming down the size a bit, he saved manufacturing costs, by spec'ing it out to fly on 6S, he now saves the pilot money on electronics, mainly the ESC, which 6S has always been the delimiter for low and high Voltage systems, and a fair price difference too.

All the video's I posted are 6S x 5,000 mAh, the proof is in the video...

Jack
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Old Jul 19, 2015, 08:32 AM
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Jack, I really think you're missing the point that Steve is making. For what it's worth I completely agree with Steve, that's not to say that I disagree with you! I just don't think your fully understanding his points.
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Old Jul 19, 2015, 03:58 PM
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Hi,
When Sebart released MythoS 125E it was only Hacker A60-5XS (and 6XS) motors and they are intended for 6 cells LiPo. Later Hacker A60-7XS came out that is for 8 cell LiPo. It was when A60-7XS came I jumped on the train and bought a MythoS 125E with A60-7XS.
It has really not been a problem in rather windy conditions with my plane (with Falcon 19x12 electric carbon V2 prop) - of course very windy conditions it will strugle but so do the 2M MythoS Pro also in very windy conditions. I have MythoS Pro also and have flown it in competition in 11 meter per sec wind and it really struggeled in the headwind. Another person at that competition had also a MythoS Pro and he switch to his second model Wind S Pro since it fly better in very hard winds.
I doubt many buy a MythoS 125E today and run it on 6 cells since it is so much advantages to use 8 cells (and Hacker A60-7XS) instead.
Of course 6 cell will work but it will be higher amp draw and need for ESC that can cope with the higher current.
Some even run MythoS 125E on 10 cell with suitable motor but in my opinion 8 cell (25C 5000 mAh in my case) works just fine with the A60-7XS.

/Bo
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Old Jul 20, 2015, 06:23 AM
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Jack,

First let me say thanks for this build thread, it was the inspiration for me to buy a Mythos 125.

Now I do not understand why you are defending the 6S power system so much and your arguments for it being lower cost make no sense.
Your ESC is more expensive than mine & the batteries are so much more expensive (TP 65C 6600mA) - I would need a small mortgage to buy them !!
I know your video's are with 5000mA packs but in your own words you replaced them with 6600mA to increase duration.
I could not fly a schedule with 5000mA 6S packs.
Even if people flying a Mythos 125 don't compete I suspect a significant proportion have the aspiration to compete one day & therefore still fly schedules. It will be a big disappointment to them if they try & do it with 5000mA 6S packs !!

Mouldy Bo, thanks.

Steve
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Old Jul 20, 2015, 07:45 PM
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You guys are stuck on competition use I feel, a LOT of folks bought this plane and never compete! No way to build it is wrong but I stand by my point on total price being a major consideration and it was to attract a lot more folks with the OPTION of flying it on 6S (if that says it in a better way) ;-) The point about expensive batteries, you don't need expensive packs, 6S x 5,000 mAh that can push 22 - 24C max will do just fine. No matter how you slice it, this plane is a great trainer/competition entry level F3A that can fly on 6S through 10S, a winner for sure...

Jack
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Old Jul 20, 2015, 09:01 PM
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I thought that when this plane was first introduced (F3Aunlimited) the price was in the $ 800 range. At that price point, I am not sure that people should be fretting too much over the cost of the batteries. Fully equiped, depending on the choice of electronics, the plane is probably in the $1500 range. It would not make sense to spend that much on the airframe and not try to get the best performance out of it. I think that there has been a similar discussion going on about the Great Planes Sequence 120.

At any rate, SebArt planes are really nice and I am sure this one fits the bill.

Teo
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Old Aug 19, 2015, 02:28 PM
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Hello everyone,

For those located in North America (and South America if you have a freight forwarder here in the US), through the end of this month (or while supplies last!) we're including a FREE Hacker A60-6XS V2 or A60-7XS V2 motor (a $210 value!) with all Mytho S 125E orders! Best of all we currently have both models of motors and both color versions of the airplanes in stock and ready to ship:

SEBM125-WB; Mytho S 125E 71" F3A ARF, White/Blue = $799.99 (plus shipping)
SEBM125-YB; Mytho S 125E 71" F3A ARF, Yellow/Black = $799.99 (plus shipping)

And please email (sales@sebartrcusa.com) or call (702-724-0555, M-F from 11A-6P PST) us to order.

Jason M.
SebArt RC USA
www.SebArtRC.com
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Old Aug 19, 2015, 02:34 PM
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Holy crap!!! Awesome deal!!!

Jack
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Old Aug 25, 2015, 07:49 PM
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Has anyone perhaps tried alternative landing gear from f3aLorenz for the Mythos 125? If so, which set of landing gear would be most appropriate?

Chris
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Old Yesterday, 12:47 AM
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Bo Edström, Sweden
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Chris,
The stock carbon or glass landing gear for MythoS 125E works fine but it might be some lighter landing gear out there perhaps. Or was You thinking of a landing gear that has fences built in on them like the gear for MythoS Pro (and Wind S Pro) has?
Or do You just need a spare landing gear?

/Bo
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Old Yesterday, 07:40 PM
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Hi Bo,
Had an incident with the stock gear! Broke the carbon against an anthill. Don't ask!
I replaced it with the moulded gear for the Mythos 2m / Wind S Pro, but this is not ideal. It may just be that drilling the gear was not well done, but the fit of the built in fences is not great against the fuse.
So looking at alternatives.
Cheers, Chris
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