themanimal

My Feedback: (1)

what started out as a good enough idea.. build a 1/2 shrike, use my existing batteries, esc, and radio gear and buy an inexpensive BL motor for it.

Now the fusion starts. I have posts on 4 different forums and have got motor suggestions ranging from a 300 watt monster motor and big prop down to a $10 Tower pro.

I have spent HOURS pouring through posts with discussions of watts to weight ratios, amps, volts, thrust, pitch speed, etc, etc, etc.

I guess the bottom line is that I don't know how to effectively evaluate the motors
I am looking at and I have the feeling that most of the manufacturers don't supply the right info either. So in the absence of a suitable knowledge base can someone, for the love of all things fast and made of balsa, tell me what motor to put in my plane...

PLEASE!!!!!
Here are the details...

1/2 lanier shrike
BL motor under $25
AUW is 17 oz
I have a 25 amp BL esc
I have three 3-cell 2000k 15 c batteries
I also have two 2-cell 1500 12C batts.

Looking to fly this thing around 70mph... at least.

Mohillbilly

ELE Brushless Outrunner Motor EA460FX(KV2950) @ http://www.xushobby.com/servlet/Detail?no=189 $40 --- I did the test runs on this motor on rcgroups it will spin a small prop at a high prop speed and still give lots of thrust @ around 20A. On the two cell.

HY-01 Brushless Motor - KV: 2100 @ http://www.xushobby.com/servlet/Detail?no=110 $15 --- for a light build prop small, high speed max 15A.

I just read your other thread that said you wanted light and cheap, I would then go with the Hy-01 for speed on a 5X5 on 3 cells, high speed at cost of thrust.

If you want good and easy performance I would go with the TP-21 its pulls around 18oz thrust on 7X6 and has a good prop speed. You would e happy with the power and speed of this motor on 3 cells and max of 16A thats 177watts.

Also a good cheap go is http://64.33.154.92/blackdogrc/brush...ies.jsp#EC28PM with either the 28PM of for speed up to a 6X4 prop or the 28PL for thrust you can also prop this one down a little for more speed.

Mo.

themanimal

My Feedback: (1)

10,000 thank you's !!!

order made, sanity restored.

Mohillbilly

Glad I could help. What one did you deside to go with?

Mo.

themanimal

My Feedback: (1)

I went with the uber cheap TP.... http://cgi.ebay.com/2409-12T-Outrunn...QQcmdZViewItem

I figured the light weight of this motor will help offset the heavy weight of my 3-cell 2000k batteries.

I think at this point I am just worried that I can hand launch it fast enough that it won't crash due to lack of thrust. I'm going to put a 7x5 or 7x4 prop on it.

cptcrusty1

Mohillbilly,

I'm having the same issue with a zagi 400xs. The stock motor is a speed 400, 2000mah 2/3 9.6v NiMh. I have a 35amp electrifly brushless esc w/BEC and want a kick-fanny motor for it. Unfortunaltey, I'm limited to the Ammo line of inrunner motors since I have only a gift certificate to spend on tower hobbies. They recommended the 28-35-3900kv which I purchased. The motor is now toast after 4 flights with something rattling inside. I called Tower, really pissed off that they recommended a motor which then tanked on me. They still think its the right motor, just defective. Any ideas?

packyj

If it's admittedly defective they should offer a free replacement... which will tell you if it's defective or if they told you the wrong one. I would push for a replacement or at least a credit.

Mohillbilly

Well sounds like a defective motor unless..... What prop are you running on it? Do you know how many amps you were pulling? 3900kv is pretty high for a direct drive unless its a TINY prop. If it was geared it would work good. How about cooling? Ever check the temp after a flight? unfortuitly I can't get to towers site on this PC while deployed so full motor spec would help a ton as well as how it flew with that motor before it died. Ammo motors are actually pretty good from what I have seen in the past. I personaly have never had one. Sounds like a loose mag in the motor, I would send it back and tell them all was fine till the 4th flight and then this, ask for a replacement.

Mo.

Mohillbilly

BTW I actually got towers page to load today and it says they have a 2 yr warrenty, I would use it to get a new motor, When you get a new one I would hook up a watt metter to it, or at least do short flights and check the motor temp etc.

Mo.

cptcrusty1

Ok... so here's the skinny. I talked to Tower who said they'd replace it. Just for grins, I hooked it up to the esc before I took it out to be shipped. Amazingly, the dumb thing worked. So, when I got home from work that evening, I traced the problem to one of the leads coming out of the motor. The stupid thing fell off in my hand. Well, a soldering gun and solder later, it works great. No replacement needed.!!!! WOOOHOOOOO