Electric newbie - sorry for asking such basic questions
04-15-2012, 10:02 AM
#1
Thread Starter
Electric newbie - sorry for asking such basic questions
I’m finalizing a decision for my next build. What I’m looking at is a 15-18lb (hopfully closer to 14lbs), twin engine, 92”ws, A-20 Havoc/Boston (Dan Palmer) rated for two, 0.91 glow engines.The plane will be a scale project rather than an everyday flyer.I have no experience with electrics, but they seem to be the most reliable and least “fussy” set up. Over the course of the build I’ll educate myself to the world of electrics.My questions are:
1. Are there electric engines that can match the power a 0.91 glow?
2. How does the physical size of the electric motor compare to the glow?
3. How will total weight of the electric setup (motor, speed controller, battery) compare to the weight of a 0.91 glow engine (muffler, gas tank, servo)?
4. Would an electric setup cost more, less, or about the same as glow?
5. Idon't see a significant downside to going electric here, are there additional considerations Ishould be aware of?
5. Idon't see a significant downside to going electric here, are there additional considerations Ishould be aware of?
04-15-2012, 11:33 AM
#2
RE: Electric newbie - sorry for asking such basic questions
Yes, yes, yes, yes, yes, and maybe.
Yes the electric motor will match a 91fs engine with ease. On the plus side, you could run scale 3 or 4 blade props with the "E" power.
I have attached 2 pictures of a 60 sized electric motor. It has a little bit more power then a 60 2s, so about or just a touch more then a 91fs engine. The plane it is on is my glider tug. I use it to lift our glider up. It is a 60 sized low wing plane. Tons of power and 10 to 15 minutes flights are the norm.
You could make the electric setup lighter by going with smaller batteries. Yet that would limit the flight times. I would say they are about the same or just a little heaver for the "E" powered. But nothing like the old days when you had 4 pounds of NICD's for a 3 minute flight.
Depends on the electric setup. If you went with only the high end name brands, it would be a lot more then the glow engines. Yet I have had great luck with several brands that or in the budget realms.
Each setup will give about 11 pounds of thrust per motor, so that should be around 22 pounds of thrust for the twin setup. That is using a 18X6 3 blade prop. If you run a 16X8 4 blade prop, that puts it right at the rated limits with 12 pounds of thrust. So if you did not use full throttle all the time, you should be safe.
To get an idea of what a motor prop combo may do, I use this [link=http://www.s4a.ch/eflight/motorcalc_e.htm]This online calc program[/link]
Hope this gets you started in the right direction. Looking
Here is a setup to look at.
Some of the items are out of stock right now. But it will give you something to research.
ESC without BEC. You will need to power the radio with another battery or a UBEC?
http://www.hobbypartz.com/07e07-proton-60a-opto.html
https://www.leaderhobby.com/product....=9394001220254
Motor
http://www.hobbypartz.com/96m606-big...030-400kv.html
https://www.leaderhobby.com/product....=9394001223792
Battery
http://www.hobbypartz.com/98p-25c-5500-6s1p.html
Buzz.
ETA: Pictures did not make it the first time.
Yes the electric motor will match a 91fs engine with ease. On the plus side, you could run scale 3 or 4 blade props with the "E" power.
I have attached 2 pictures of a 60 sized electric motor. It has a little bit more power then a 60 2s, so about or just a touch more then a 91fs engine. The plane it is on is my glider tug. I use it to lift our glider up. It is a 60 sized low wing plane. Tons of power and 10 to 15 minutes flights are the norm.
You could make the electric setup lighter by going with smaller batteries. Yet that would limit the flight times. I would say they are about the same or just a little heaver for the "E" powered. But nothing like the old days when you had 4 pounds of NICD's for a 3 minute flight.
Depends on the electric setup. If you went with only the high end name brands, it would be a lot more then the glow engines. Yet I have had great luck with several brands that or in the budget realms.
Each setup will give about 11 pounds of thrust per motor, so that should be around 22 pounds of thrust for the twin setup. That is using a 18X6 3 blade prop. If you run a 16X8 4 blade prop, that puts it right at the rated limits with 12 pounds of thrust. So if you did not use full throttle all the time, you should be safe.
To get an idea of what a motor prop combo may do, I use this [link=http://www.s4a.ch/eflight/motorcalc_e.htm]This online calc program[/link]
Hope this gets you started in the right direction. Looking
Here is a setup to look at.
Some of the items are out of stock right now. But it will give you something to research.
ESC without BEC. You will need to power the radio with another battery or a UBEC?
http://www.hobbypartz.com/07e07-proton-60a-opto.html
https://www.leaderhobby.com/product....=9394001220254
Motor
http://www.hobbypartz.com/96m606-big...030-400kv.html
https://www.leaderhobby.com/product....=9394001223792
Battery
http://www.hobbypartz.com/98p-25c-5500-6s1p.html
Buzz.
ETA: Pictures did not make it the first time.
04-15-2012, 11:42 AM
#3
Thread Starter
RE: Electric newbie - sorry for asking such basic questions
Thanks for getting me started. It seems the power is there- Iforgot about shorter flight times. How much battery do I need for the motor/controller to give me a 8-10 minute flight? It looks like weight may rear its ugly head here...
04-17-2012, 04:53 PM
#4
RE: Electric newbie - sorry for asking such basic questions
Well the setup I have in the glider tug, I have done over 20 minute flights with it. That is with a lot of floating around. Cruising around with as little throttle as I can to hold altitude. You should get 8 to 10 minutes easy with a 6s 5000mah battery per motor.
Just get (4) batteries, fly, land, pull batteries, put on charger, install second set of batteries, fly, land shoot the fertilizer with the guys, batteries are all charged up
Buzz.
Just get (4) batteries, fly, land, pull batteries, put on charger, install second set of batteries, fly, land shoot the fertilizer with the guys, batteries are all charged up
Buzz.
04-17-2012, 05:41 PM
#5
Thread Starter
RE: Electric newbie - sorry for asking such basic questions
Thanks for the reply, I'll be learnign a lot about electircs in the next year (during the build). Any things that are easliely overlooked Ishould check out?
04-18-2012, 04:35 PM
#6
RE: Electric newbie - sorry for asking such basic questions
I think it would be better to have the batteries, ESC, motors, mounts,props on hand so you can arrange them for a better balance. Might be better to mount each motor, ESC and battery in the nacelle then putting both batteries in the fuse, or it may turn out to be better the other way around? hard to tell until you place them.
You can save a lot of weight from the 4s engines with just changing or not using some of the plywood and see where you can cut the weight without reducing the strength.
Buzz.
You can save a lot of weight from the 4s engines with just changing or not using some of the plywood and see where you can cut the weight without reducing the strength.
Buzz.
04-18-2012, 05:03 PM
#7
Thread Starter
RE: Electric newbie - sorry for asking such basic questions
I went to the hobby store to ask some basic questions, looked at the eflite 90 outrunner - seems very easy to mount. I tried to compare weights of electric vs glow, and they come out about the same. Electric cost more. The guy was steering me toward 8s 10,000 mah batteries, they seemed expensive.
04-19-2012, 05:18 PM
#8
RE: Electric newbie - sorry for asking such basic questions
That would be about the right size of battery. Yes it does cost a lot. That is why I showed you (2) batteries. Plus, if you do not abuse the batteries, you should get a couple years worth of flying and glow fuel is costing more and more.
If you have a real long battery leads, you will run into other issues with the speed control. if the leads are to long it will cause problems. So if you mount the battery in the belly of the fuse, how long will the leads have to be to reach the ESC in the nacelle? These are the question you will need to research to see the best way to setup your plane.
You can use (2) of these wired with a "Y" cable to make 8s
http://www.hobbypartz.com/98p-25c-5500-4s1p.html
I helped a friend put this into hon 8s.
https://www.leaderhobby.com/product....=9394001224337
It does a real good job of pulling his 110 sized pattern plane around on two of the batteries listed above.
Buzz.
If you have a real long battery leads, you will run into other issues with the speed control. if the leads are to long it will cause problems. So if you mount the battery in the belly of the fuse, how long will the leads have to be to reach the ESC in the nacelle? These are the question you will need to research to see the best way to setup your plane.
You can use (2) of these wired with a "Y" cable to make 8s
http://www.hobbypartz.com/98p-25c-5500-4s1p.html
I helped a friend put this into hon 8s.
https://www.leaderhobby.com/product....=9394001224337
It does a real good job of pulling his 110 sized pattern plane around on two of the batteries listed above.
Buzz.
