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#1 Ortho10 Oct 18, 2012 04:59 PM

Top Flite Spitfire Electric Conversion
 
9 Attachment(s)
I can't find much info from anyone who has electrified a Top Flite Spitfire.
Am far from an expert when it comes to building, so gonna need some help with this one.
I'm two evenings in to the build and no major problems so far.
Have ordered some Hobbyking electric retracts, gonna need some Oleos.
The Turnigy G60 Brushless Outrunner seem good value, but are available in a number of different KV options(help needed here)
Am planning to run a 6s Lipo pack.

#2 TTRotary Oct 18, 2012 06:14 PM

TG 60 in 400Kv will work fine if you plan on using 6S or 7S. I run a 14x14 APC pattern prop on a Efl Power60 and 6S and it's a rocket. My plane is a WM .60 Spit, so it is probably lighter than your TF Spit will turn out, however. You may want to consider a Power90 as well or the Turnigy equivalent. Hobbyking's Plush 60 or 80 controllers are bulletproof and would work will with that motor. I personally use HK's 700MaH 2S LIFE packs for my RXs, rather than the BEC.

Try to build the tail as light as you possibly can and set up your cowl area so that the batteries will be as close to the motor as possible: if they are not almost completely inside the cowl area, you will need to add nose weight. Spitfires are notorious for building tail heavy. Keep in mind the TF kits are designed to withstand glo vibrations, so try to find areas where you can lighten up the build for electric. If it's like my TF P-51, it calls for flexy and heavy 2/56 rod inside guide tubes. Ditch that heavy setup in favor of carbon tube with 2/56 threaded pieces epoxied in. Much lighter and stiffer.

Try to set up your build so you do not have to remove the wing to change batteries. Consider adding a hatch to the top of the cowl, just behind the motor, so you can insert the 6S 5000 pack vertically. It should just fit in there. I started out at 25% MAC CG and just left it there. No bad habits and flies like it's on rails.

Because of this, make sure your wheels will be as far forward as possible. Consider moving the retract rails forward, angling the rails, or both. These planes are also known for nosing over quite easily when at the correct CG if you try to use scale landing gear location / configuration. Scale is nice but breaking props and worse is no fun.

Not sure I would rely on those HK retracts for this nice plane at this weight. I'd get the.60-120 Eflite electrics, which are much beefier, and mate them to the excellent RcSkylite oleo struts that hobbyking now sells.

Good luck with the build.

#3 Doug Bartley Oct 18, 2012 08:06 PM

If you intend to run a 3 blade prop, \i just completed some testing on a SK3 5055-320. It makes 1100watts on a Master 16/10 and 1265 using a Graupner Gsonic 16/12, both on 6S.
Your G60 would likely handle a 15/10/3 bladed prop, but testing with a wattmeter is important, along with proper esc setup. fwiw Doug B

#4 Ortho10 Oct 19, 2012 05:39 AM

Thanks Guys, some really useful information there.
Would love the E-Flite retracts, but the hobby fundís say no.
I know the margins are a little thin on the HK retracts; hope Iím not going to get an ďI told you soĒ at the end of this.
Retracts are in transit at the moment, will have a good look when they turn up.
Top Flite seem to have done a bit of work lightening the kit since the instruction were printed certainly in the tail area.
Still undecided about battery position, my initial thought was to build a ply battery compartment within the cowl and make an access hatch in the firewall, but of course this would involve removing the wing every time to remove the battery.
The idea of a hatch just in front of the canopy also doesnít appeal, gonna have to put the thinking cap on.
Very much like the look of the SK3 5055-320, seems to be a step up in quality.
Will stick with a standard prop, to be strictly scale the MKIX Spitfire has a four blade prop.
Thanks again.

#5 Electrofish Oct 19, 2012 05:18 PM

As per the retracts: I wouldn't be surpried if both brands were made at the same facility in China.

Same with electric motors. And batteries. And ESCs
And............................................... ........you name it.

To pay over twice the money for the same thing doesn't work for me.

Only my opinion.

#6 KOMET 44 Oct 21, 2012 07:18 PM

Ortho10,Taking the wing off isn't as bad as you think.If you look at my blog you will see picture of my Focke Wulf Fw 190.Yes it's conciderd "OLD SCHOOL". Making a top hatch you'll need to get it rite the first time.Good luck.
stefanP

#7 Ortho10 Oct 22, 2012 07:57 AM

Komet, Did your FW190 balance out ok, or did you need to add some lead up front?

#8 KOMET 44 Oct 22, 2012 04:47 PM

motor/flight pack.
 
I put my motor as far foward as possible then I mounted my receiver battery in the cowel area too.Yes I still use receiver battereis.My flight pack lies on a flat tray/ board.I can slide the pack forward or back if needed.I'll post some up close pictures of the planes power system.
stefanP

#9 Ortho10 Oct 22, 2012 05:01 PM

1 Attachment(s)
Getting on with it, will be a while before I get to the Electric bit though!

#10 Ortho10 Oct 23, 2012 05:06 PM

1 Attachment(s)
Big sanding job ahead, yes that is filler!

#11 Pilatuspc12 Oct 26, 2012 07:31 PM

Be careful, these are extremely tail heavy built as stock.

#12 Ortho10 Nov 14, 2012 04:17 PM

3 Attachment(s)
Things are progressing slowly.
Good to see the retracts are the correct size for the rails.

#13 Dereck Nov 14, 2012 05:15 PM

Hi Ortho
Bristol - nice place, poked around it a little, used to drive past it plenty in my RAF days near Weston Super Mare and Newquay.

Can't help on this kit, unless some electronic drooling helps, but the one thing I've found with 'electrocuting' any wet power model is to think ahead. You're going to fit a completely different drivetrain in there. Shape, weight, weight distribution, cooling, 'fuel lines', how to 'refuel' - anything else you can imagine, it'll be different.

Realizing this when looking at a finished model on your bench is not good :eek:

Will give you that this is not as much fun as gluing bits of wood into a Spitfire shaped object. Tough. Get your fuselage plan out and your motor, ESC and battery. Figure a way to mount your much shorter motor - firmly, too. A new, correctly located 'firewall' is far better than hanging your motor off the kit firewall than a cobbled together extension,, for starters.

Battery security and access comes next. A solid battery mount tray, Velcro's as good as it gets for security and if you're thinking of charging a big lipo in your model, go read throe sticky on lipo fires in the battery forum. The 'record' used to be shared by a guy's garage and a Lexus Landcruiser truck, both destroyed. So look up similar models to your Spitfire and figure out a battery hatch that let's you swap packs with the model right way up in the pits. Do not even think of taking the wing off to get at the battery :eek:

Added light weight is still the cheapest performance upgrade going. Two aspects. One, overall flying weight - lighter is always better. Two - avoid tail-heaviness, as it costs in dead weight ballast and hence higher RTF weight.

Structure. You are being smart and fitting a vibration free motor. A lot of your kit's structure is there to cope with a slimer thumping away.

Good luck. Am only slightly jealous...

D

#14 Ortho10 Nov 15, 2012 05:31 PM

Hi Dereck

You must have been based at RAF Locking in Weston Super Mare.
My Dad was involved in decommissioning some of the equipment when the base closed.
Newquay is now the number one destination for Stag Weekends in the UK!

As far as the model goes, youíre absolutely right; Iím not going to be charging the Battery while itís in the model.

Iím leaning towards the idea of making a hatch/making part of the cowl removable, and retaining with magnets. Still have to purchase my motor/Batteries combination so no decision will be made until these are in place.

I have a couple of electric conversions under my belt (see my blog), and I have mounted the motor using the threaded rod/bolt technique. I think this model does deserve a bit more; extending the firewall is probably a bit beyond my skill set though!

Am really enjoying the building so far, thanks for you advice.

#15 jdlfreedom Nov 20, 2012 03:14 PM

subscribed!

I just started to build my top flite spit today. Going to power it with a e flite power 90.

Looking forward to your updates!


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