TF Cessna 310 Electric conversion help needed

[skripo]

I purchased a Top Flite Cessna 310 at Toledo. Full specs can be found here:

http://www.top-flite.com/airplanes/topa0910.html

It is a 17-19 pound model with an 81" wingspan that requires 2X .46 glow engines but I want electric. I want to use my heli 6S 5000 Mah, one in each nacelle and am thinking of getting the Hacker A50 12L and X-70 pro ESC. I am looking at going Hyerion because of the value.

What electric motor and ESCs do you recommend? What 3 Blade scale prop would work well? Please list your brand preference as well as why you recommend them.

Thanks!

[Michael in Toronto]

Esprit Hobbies has some suggestions:

http://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=5768

[bruff]

I'm working on one now. Using Hacker A50-12L outrunner motors, 48 AMP Optp ESC, 6S LiPo per side. Using Vario 3 bladed props for the motor. Once I get full time on the project I'll post some pictures.
Bob

[Coastwatcher]

For me

I'm planning one too for late summer build. Working on a plane now , and theres one to do after it.......then the Cessna 310.

Mine will use a pair of Eflite Power 60 outrunners , Jeti Spin 66 's , MAS 3 blade props maybe 13/8, tru-turn spinners and 6S4500mah Thunder Power extreme series for each nacelle. And will upgrade to DX9 before I fly it.

Fred

[P-51C]

I was looking at using the e-flite power 60s, two Castle 85 HV controllers (slready have one). I haven't decided on battery or location yet.

[skripo]

Esprit Hobbies has some suggestions

Great link, thanks!

[LaxLife]

Follow Bruff and Esprit Models and you won't go astray. Prop diameter is the first critical measurement needed to select a motor. How big a prop can be accomodated within the ground clearance, fuselage clearance tolerances? On twins the collective wisdom I've gathered from these pages over the past 6 months is to have only one central lipo pack (so both Motors/ESC's "see" the same exact power source) to protect against single engineout flying mishaps. Oh and disable the ESCs' low voltage cuttoffs and fly your plane on the clock again to avoid flying a twin with one motor.

[Coastwatcher]

Also saw a killer build ( totally scale) of this on RC WORLD. He used RIM FIRE 50-55-650 motors and 13-8 MAS props . The guy went nuts with detailed extras.

[hermperez]

very careful with a single battery in the center, the long wires to the nacelles require special precautions.. I would use a pack in each nacelle and a timer to land before the battery runs out.

[feathermerchant]

Skripo - Castle creations has a great paper on how to configure twins. I have one I did and I set up both scontrollers like this:
Fixed throttle
Brake off
Soft cutoff
Low advance timing (because they are outrunners)
Everything else is default.
If you are considering 4130's which will certainly be more power than you need, then on 6S the APCE 15X10 2blade is what most of us use. A 14X10 3 blade should work about the same. I use a Phx80 controller but a 60 should work also. I would put the batteries in the nacelles to keep them close to the speed controllers. I would not interconnect them. No need to IMO as long as you obey the timer. From experience the above should give you >10min flight time.
Maiden for 5min so you can practice stalls, flaps gear, etc then land and recharge. Based on how much you have to put back in, you can calc a safe flight time.
If you ever do lose a motor/prop/whatever, the safest is probably power off and try to make the runway.

[jrb]

Here are some of the photos included in the update to the original conversion article; recent AXI & Varioprop experience: http://www.rcgroups.com/links/index.php?id=4788 .

[skripo]

I am definitely going with 2X 6s 5000's because I use those cells in my T-Rex 600 and I don't like the idea of one pack. Esprit calculated everything and came up with a 3 bladed prop combo that I wanted for scale effect and ground clearance.

Esprit recommended a Hacker 12S A-50 combined with Jeti 55 to turn a Graupner 14 X 7 X 3 prop. I prefer the Hackers and plan to use 2 Hacker X-70-Opto Pro controllers. Any comments?

Thanks for the help!

[bruff]

After talking to Kyna at Hacker USA I changed my motor selection from A50-12S on 5S LiPo to A50-12L on 6S LiPo. I'll be using a 48 AMP Master Opto ESC. Going with 3 bladed 15" dia. Vario props so I can dial in the prop load. Vario props allow you to change the pitch of the blades. Batteries are going in the behind each motor.
Bob

[skripo]

After looking at the http://www.hackerbrushless.com/motors_a50.shtml I have done the same and changed to the 12L. I wonder why Esprit recommended the 12S with a 6 cell pack? More RPM?

[m898]

Hi

Can anyone please help me ?

I am very interested in the Cessna 310 but want to convert it to electric.
I am wondering why it is so heavy.
This is the only issue that is putting me off from buying the kit.
I have read on the forums about a lead shot in the nose and would like to know if this is removable?
How much does this lead shot weigh?
I am still puzzled about the heaviness of the plane compared to similarly sized or even larger kits.

I hope to hear from someone soon

Regards


Michael

[bruff]

It weighs no more then most scale airplanes this size. The KMP Tigercat which about the same size.is coming in at 20 to 23 lbs. This plane was designed for glow motors so it is beefier than most electrics. I don't see a problem with the weight of this plane. Most of my large scale electrics are in the 15 to 18 lb ranged.
Bob

[andres.c]

I have a A50-12L on my heli it has 5 flights on it works great but the high temps concern me

I am using 14sp1 a123 packs with a CC85HV ESC

[m898]

It weighs no more then most scale airplanes this size. The KMP Tigercat which about the same size.is coming in at 20 to 23 lbs. This plane was designed for glow motors so it is beefier than most electrics. I don't see a problem with the weight of this plane. Most of my large scale electrics are in the 15 to 18 lb ranged.
Bob

I agree with the logic. Unfortunately at my club i am limited to 7.5 kg for electric models including batteries. i really want the Cessna 310 and I may have to modify the front to remove the dead weight if the 'bug' eats into me enough eg cut it out and make a new nose.

[bruff]

The lead in the nose is required to maintain correct CG of the model.
Bob

[m898]

The lead in the nose is required to maintain correct CG of the model.
Bob

Thats correct Bruff. With electrics one has the advantage of shifting the batteries to balance the model. My expectation was to put the batteries in the nose to do this and remove the lead shot as its dead weight.

[wrenwright]

I agree with Michael on this one.

I don't see any reason that this plane should be so heavy. I think one would be better scratch building one to get the weight down. Doubtless if the model were designed for glow power, some weight savings could be had from eliminating the extra reinforcement that a glow engine's vibration demands.

[Coastwatcher]

Just how much lead is required to balance the conversion bruff.
Fred

[bruff]

Coastwatcher,
Not sure. I'm putting the batteries in the nacelle right behind the motors. Trying to keep the installation simple. There is a guy on RCU that has already flown this plane electric with a pair of Rimfire motors. Did very well.
Bob

[Coastwatcher]

Bob,

Yep I read that thread to the point where he about finished it , but never went back to see how it flew. , where he had CG or weight that was added. HEck ....it may have not flown yet for all I know.

I have mostly put my batteries in the nose.......but on this Cessna it seems best to put one in each nacelle . It looks really straight forward on his thread, and I'm planning on cutting the access like he did too , that seemed like a good plan.

I was wondering if that fellow that used the rimfires added any weight myself.

Good luck with yours .
Fred

[bruff]

Fred,
Thanks, once I go hot and heavy on it I'll be doing a build thread.
Bob

[m898]

Got the weight down alot on this one !. AUW is under 7.0 kg and converted to electric. Still too heavy for my liking but much better than what i first expected. I hope it flys well.