haasjj

This is just in a general sense but how can I tell if the specific motor or ESC will work with the battery and in a certain plane??? Is there a motor and esc calculator on the net somewhere.

Example I have a EDF L-39 from GP well I am planning on switchin to a 24-45-3790 motor and running as much as a 4 cell lipo will my 25 amp castle creations ESC do the job or burn out after the second time I hit full throttle???

I already e mailed GP about running that motor with the edf unit and a 4 cell lipo and they said it has been tested and works just fine, this is not a quote from the e mail just paraphrasing.

I know that the specs for the ESC should be Ok with the setup but its close and I don't want to burn up a $70 ESC to find out it was to close.


Please help if you can.

MrMulligan

My Feedback: (314)

CC Phoenix ESC's are only rated for up to 3 cell LiPo's. I emailed them about using a 4 cell A123 with a Phoenix 60 and they recommended a separate BEC. Also, I think you may be a bit light with your Phoenix 25. I think I'd go with a 35 or 45 ESC. You're looking at a high discharge in an EDF. It's always better to be higher With the ESC.

haasjj

Yes thats true if you don't use a separate BEC, but since I am planning on using a BEC I can use a 4 cell lipo.


I agree and that is why I asked the question about some kind of motor and or esc calculator, I guess I should have explained that what I want is some way of finding the correct combination for specific applications.

I don't want to buy another ESC if I don't need one and I don't want to burn this one up if it is to small.

MrMulligan

My Feedback: (314)

There are a couple of web sites out there that allow you to put in what you have and it will tell you if you are all right. Then there's Motorcalc or Motocalc. I'm having a senior moment. Anyway I looked through all my Favorites and can't find one of these sites. I know I marked a couple. Maybe someone else can help.

Time Pilot

Normally you start here: Decide how much power you need.
• 50-70 watts per pound; Minimum level of power for decent performance, good for lightly loaded slow flyer and park flyer models
• 70-90 watts per pound; Trainer and slow flying scale models
• 90-110 watts per pound; Sport aerobatic and fast flying scale models
• 110-130 watts per pound; Advanced aerobatic and high-speed models
• 130-150 watts per pound; Lightly loaded 3D models and ducted fans
• 150-200+ watts per pound; Unlimited performance 3D and aerobatic models

Then, choose a battery that will deliver that kind of power.

Eg. If you have a 1 pound plane that wants 100 watts, you will want a 1000-ish mAh 3S 10C-ish lipo.

Then, find a motor that will deliver the power (above example, look for a motor that will continuously put out 100 watts). Choose the motor's kv so it will spin the kind of prop you want. Typically lower kv for larger props (slower planes), high kv for smaller props (typically faster planes).

For the ESC: how many amps will the motor consume. You need an esc at least that size. Everyone has their own formula, but if the motor consumes 10 amps full throttle on a fresh pack, I'd go for at least an ESC rated at 12 amps. Go for 18 if you think you have the room, can spare the little bit of extra weight, and think it may go into another plane one day.

Time Pilot

One of these sites may help also help:

http://www.csd.net/~cgadd/eflight/calcs_gloconvert.htm

http://brantuas.com/ezcalc/dma1.asp

whitecrest

I like this one:

[link]http://flbeagle.rchomepage.com/software/webocalc_0.9.0/webocalc.html[/link]

It boils the process down to the essentials and is very user friendly. The amount of current you need to fly the plane you have in mind to the level of performance you desire will determine the ratings of the power train elements (battery, ESC, direct drive or geared motor/prop). It's very easy to do "what-if" scenarios with this program and to answer the question you have posed.

MrMulligan

My Feedback: (314)

Thanks for the web sites. These are what I have been looking for.

haasjj

Thanks for the info and web links. Sorry I haven't had time to check back in last few days I have been very busy. I will check them out and decide from there, well unless I have more questions.

Gtarling

Give Motocalc a try - it's FREE for 30 days and then very reasonable cost if you want to continue to use it. www.motocalc.com

haasjj

Thanks for the info but I have tried motorcalc and it doesn't work very well with EDF units.

haasjj

I guess that was a different one from what I have used before, and it did help a bit thanks for the link.