Magnatilla electric set up

[Sabre Flyer]

Hi All,

I am thinking of converting my Magnatilla and would like to use 5s 3300ma lipos as I already have several packs.

I thought I might use one of the Turnigy easy match 46 motors but I am not sure which kv version to choose or if I will get reasonable flight times with a 3300 pack? The options are: 420, 550 or 670kv Or if you have other recommendations for a set up that will work with these lipos then I would be most grateful.

Many thanks

[Attilio Rausse]

Hi Sabre Flyer

Need to know weight of model (without power train) and intended prop size. 5S 3300 will be fine.

[Pete Collins]

Hi Sabre flyer

With a slow flying model like the Magnatilla you'd usually choose a low Kv so that you could use a larger prop. The only limitation is the length of the undercart and the ground clearance for the prop. So you need to know the prop sizes fot the three Kv options and work from there.

[ken anderson.]

one of the older members of our club BVRMC electrified his magnatilla....... he go's by the name of Pat Mcauley(Pat Mc)..send him a PM...he will keep you right......... he's good with electric's etc... have a look on this thread he's on there.... 

ken Anderson...ne....1 pat mc fan club dept.

 

Edited By ken anderson. on 13/05/2017 11:28:44

[Dwain Dibley.]

I used a 4 cell 3000Mah lipo and an 800KV motor for about 600W on a 12 X 5 wooden prop.

I fly for 7 mins on a timer, as I am cautious with my batteries, but it's good for more.

D.D.

[Sabre Flyer]

Hi all

Many thanks for your replies which are much appreciated. The model weighs 6lb including a four stroke engine and empty fuel tank. Therefore around 5lbs without the engine/fuel tank should be about right. So 2721 grams.

I have now found some data for the motors:

kv 420 18.5v 15x8 prop (2650g thrust) = 44 amps or 14x10 prop (315g thrust) = 40amp

kv 550 18.5v 12x6 prop 2450g (thrust)= 36.5 amp

kv 670 12x8 no other data

If I go for the 420kv then I can use the 14x10 prop and get around 10 mins flight time at approx at half throttle?

( about 7 mins is ok for me usually)

Does this sound right? I have a 12 " prop on at the moment and there is plenty room for up to a 15 " prop.

Many thanks for any comments/advice

[Sabre Flyer]

Hi Dwain Dibley, thanks for the suggestion, I would like to try to find something that will work with the 5s 3300 packs I have first but am interested in which make of motor you used?

[Trevor Crook]

Sabre Flyer

I haven't any models with a 5s setup, but from my experiences with 4s my gut feel is the 420kV setup would be fine. If a 14x10 prop does indeed pull 44A, that equates to over 800W, which for a 6lb model of that type is more than adequate. You could use a finer pitch prop which would suit the model better and would be less watty.

I fly a 3lb Atilla on a 3s 2200 setup and it is fine - flies better than one I had years ago with an OS25.

Someone in our club has an electrified Magnatilla. If I see him tomorrow I will get details and post an update.

[Attilio Rausse]

Hi Sabre flyer

I would go for the 550kv motor which will give about 8500~9500 RPM under load.

You are looking for about 500~700 watts so on 5S you will pull about 35A giving you 5 - 8 minutes flight time.

So a 550kv motor with a current rating of 40A or more should be just right 50~60A ESC for at least 23V (esc for up to 6S)

start with a 14 x 8 and measure current draw,

I would look at something like this

https://hobbyking.com/en_us/turnigy-aerodrive-sk3-4240-530kv-brushless-outrunner-motor.html

and this

https://hobbyking.com/en_us/turnigy-aerodrive-sk3-4240-620kv-brushless-outrunner-motor.html

and this (with a smaller prop)

https://hobbyking.com/en_us/turnigy-g32-brushless-outrunner-600kv.html

[Trevor Crook]

Oh dear, I hope our conflicting advice above hasn't confused you! To be honest, I think both the 420 and 550kV motors are going to be in the right parish. Attilio's power recommendations are spot on, and I would endorse his recommendation of starting with a 14x8 and a wattmeter, whichever motor you choose.

[PatMc]

Quoting myself from a previous thread - I'm using a Turnigy 3548/900KV, 4s 4000 lipos, 12x6 APC clone with a Hobbywing 60 esc in my Magnatilla. It was converted from ic so has turned out heavier, at just over 6lb, than if built for electric from scratch.

It takes 31A for 464W at WOT which is plenty of power for loops, rolls inverted etc. Average current per flight is 21A.

The 4s 4000 lipos used were only rated at 15C & 20C. Since I posted the above I've been using higher C rated 4s 2650 lipos which have actually noticeably increased the power available but due to using lower throttle settings hasn't reduced the duration by very much. Normal flight time is around 6 - 7 minutes, haven't bothered checking how much the 2650's take to re-charge with this model but there's always been plenty of life left when I've landed.

Your 5s 3300 have about the same watt-hour capacity as my original 4s 4000's so if a similar power is used duration should be about the same.
Converting the voltage/kv of my 4s/900kv to give the similar (460W) power using the same 12x6 prop gives 5s/720kv.
IMO an even lower kv to allow a bigger prop would be a better match for the model's flying style but it's not necessary to increase the power above 500W.

There are some pics of the conversion from ic to electric in this album.
BTW the alterations to the model are purely cosmetic - it's still a Magnatilla in an imaginary 1920's civilian Sopwith style.

[Sabre Flyer]

Thanks all for your replies, they all help.

I appreciate having a range of ideas/info to help me choose. I will think things over and report back on how things work out.

Patmc, your Maggie looks great!

[Trevor Crook]

I finally saw my clubmate with the electric Magnattila last night. He told me all the details but I didn't have anything to write them on. However, the set up is a lot different to your proposed 5S setup so it's probably irrelevant. What is interesting is the power and weight.

He originally built it some years ago and it flew with a brushed, geared Speed 700 and weighed 7lb. This power train used 12 nicads and produced under 300W. Its performance was limited on this, as you can imagine, but it took off and flew, although aerobatics needed careful planning.

It's now fitted with a 3S brushless setup and weighs 5lb. The powertrain pulls 360W. It now loops comfortably from level flight, and flies for much longer. It's flight is entirely in character with the type of model.

My friend's opinion is that around 500W would be just about perfect, which ties in with what has been said above. Good luck and keep us posted.

[Richard Wood]

Good luck with your Magnattila, it's a great design for conversion.
I flew a 6lb one quite a lot a few years ago on 550W or so, It was a 4S setup but a
slow turning 15" prop was ideal.

Hopefully the Magnattila & Attila kits will be available again sometime soon.
The Attila is particularly good.

[ken anderson.]

agree about the kits,i've had two magnatillas.... nice flyer's,hopefully someone will take the kits on board and start to sell them again..

ken Anderson...ne...1.... bring back the magnatilla's dept.

[Trevor Crook]

I built my electrified Attila from the plan I'd kept for ages. An easy build, luckily someone had given me a cowl.

[John Emms 1]

Posted by Richard Wood on 26/05/2017 09:45:14:

Hopefully the Magnattila & Attila kits will be available again sometime soon.

I am told by Flair that Magnatilla kits are being prepared for production right now, with the Hannibal due to be ready by the end of the year.

[ken anderson.]

thanks john...that's good news....roll on the return of the magnatilla...........

ken Anderson...ne..1..... Maggie fan club...

[Dwain Dibley.]

I agree Ken, it's excellent news.....Lets hope the other models are on the way too.

D.D.

[Trevor Crook]

Love my little Attila. Must try a Magnattila someday. Now, it can't be that hard to scale up my Attila plan......

[Richard Wood]

Posted by John Emms - Puffin Models on 26/05/2017 11:24:45:

Posted by Richard Wood on 26/05/2017 09:45:14:

Hopefully the Magnattila & Attila kits will be available again sometime soon.

I am told by Flair that Magnatilla kits are being prepared for production right now, with the Hannibal due to be ready by the end of the year.

That's great news.

[Rob Fairweather 1]

I ordered a Magnatilla kit through High Peak Models a couple of months ago, with a 10 week lead time. I'm told they will come with a 'bespoke' serial number now.

Also available are the wheels, decals etc.

As soon as mine arrives I'm putting in an order for a Brisfit.

[Sabre Flyer]

Hi all,

Thought I would update. I decided to make this the next project on the 'to do' list and removed the cowl, four stroke engine, fuel tank etc. Having measured up I then set about finding a motor that fitted the specs arrived at in this discussion but that would also fit in the cowl. I found the Purple power 5055-595 which should be a perfect fit once I have put a new bulkhead over where the recess for the f/stroke was.

Specs: 595 kv 58amp weight 303 grams prop 13x5 wood ( recommended size) I am thinking I may go with this combo from 4max? I would fit a 60 amp speed controller? Should I run the four futaba 3001 servos off the 5amp bec?

Many thanks for your ideas on this.

[PatMc]

IMO the motor's too big, too heavy & too expensive.
A 60A ESC is fine but make sure it has a switch mode BEC as this will handle more current per cell count than a linear mode one. 4 Futaba 3001's should be well within a 5A BEC's capabilities.

[Trevor Crook]

Agreed you could do it cheaper, that motor does seem a bit of an overkill. However, with its kV of 595 it's probably the most suitable of the Purple Power range, and will certainly do the job. A 5A bec should be fine.

The extra weight won't hurt with that short nose, and beefier construction should withstand unintentional abuse better!

If you are happy with your spend, then go for it. Hopefully after a few dozen successful flights you will have forgotten about saving a few quid. Also, 4-Max are an established UK distributor, so you should get good backup if you have any issues or queries.

Good luck and keep us posted. Just about to put my Atilla in the car and brave the heat!