I am taking a quick look at the ESC settings. Timing is a bit of an experiment as while the higher the timing gives more power the duration is somewhat less. The reverse is true with a lower advance in timing adds duration, but with less power. It is also kinder on the motor. In the end I settled for +5 degrees and see what happens. Start up force was set quite high. The rest of the settings I left at default numbers.
More later in the week.

What size gas engine is your electric motor equal too.. 100-120cc ? Im just curious

When I ran a Hacker A200-8 in a H9 Sukhoi 40% on four 7s I found I needed a lot more pitch to get horizontal airspeed and the right amp draw. I ended up with a 32x16 Biela. A 10 pitch may not pull hard enough. Just a thought.

3DJP, the motor is listed as being equivalent to a 100cc gasser. Having experimented with it on an old 35% airframe (and a heavy one at that) it certainly seems to be capable of driving that size airframe and definitely a lighter one such as the EF.

I take your point Deckeriv, the 28x10 is only a starting point and I accept I may have to go larger to get enough pull. When I flight test eventually I will report back.

As with all my 12S setups I use AS150 Anti-Spark connectors for my power packs using 8 AWG wire which seems to work well.

The ailerons are connected to the MicroMatch units and these are paired up so I only need to use 2 RX channels.

The main wings are attached to the fuselage using two separate methods. Each with a nylon bolt and metal bolt as follows.

I am using 30% Expo on the ailerons and 20% on the elevators as a starting point. All end points will be set to to 100 on my Futaba T14SG TX, but I may need to dial back a bit on that depending on how it all goes.

All we want now is for some decent weather here in the U.K. so I can do the maiden. Gales, rain more gales and more rain .......

Will take head cam video clip and post here when it's acheived.

Looking forward to seeing how it all works out.

Good luck with your maiden.. alot of rain here across the pond also.. i hope it clears up soon!

Cheers, thanks for you thoughts gents will let you know.

Just found this build thread. Very nice! What is your final weight with batteries?



I just completed a similar conversion on my 104" Extra 300 V2. We had a break in the weather on Sunday, February 23, so I did my maiden already. I posted the details, and a link to the build, on my blog on RCGroups. Plane flew well, but there are a couple issues to work out. LiPos do not like cold weather! 50F is really the lowest temp for decent performance, although I have flown my electric 95" Extra at 45F and they did OK. Just keep the batteries warm before taking off.


Someone mentioned using a higher pitch prop. That is good advice. I started out with a Falcon 24x10CFE on my 95" Extra and ended up with 21.5x13CFE. My 104" has a Falcon 28x13CFE on it. AUW is 29 lbs.



Best wishes for the maiden flight!

Originally Posted by Flybye Steve

I don't think there has ever been any doubt that there are a number of electric options for the plane you have. Practically speaking, if you can be satisfied with 6 minute flights, your good to go.

When my LiPo packs were in their prime I could get 10 minute flights doing IMAC aerobatics on my 95" Extra. That is time to do two complete Intermediate sequences with time left over to practice additional maneuvers.


According to eCalc I should get close to that with my 104" Extra EV2.

Thank rclad. Sadly no maiden yet as we are still under the jet stream in the UK and weather is rubbish. Might be a window of opportunity next week on Wednesday fingers crossed.
Sounds good to get 10 minutes although I must admit I will be surprised to get that. I am using Overlander lipos. Which brand of Lipo are you using?
As to your question about weight, I haven't assessed it as all EF airframes are as light as they can be for their size. I know that's a cop out! I think if I need to shed weight I will save myself at least 1/2 kg by ditching the Turnigy CA motor and replacing it with a Hacker Q100-7M beastie. Will see how it goes though. I will have a look at your blog to view your maiden. Good one!

Congrats on the great project superleccy68 and good luck on the maiden.
I know that project is complete but have you already seen Jim Kitt's StinGR belt gear system for giant electrics? This is what rclad is using, StinGR's advantage is based on the increased efficiency (from 80% to over 90%) to either extend flight times or provide more power for the same flight time.
Check this post on Jim's blog. The StinGR is the only power system that would make me go electric on a 100cc class.
Jim is one of the most knowledgeable guys when it comes to power systems for aerobatic aircraft, not to mention an awesome guy to deal with.
Ronaldo

rclad, I saw the EF Extra build log on your blog, what a fantastic and well documented project, congrats!
Ronaldo