

Dec 18, 2005, 09:39 PM  

Does that mean you are now on it fast and furious?
You will undoubtedly finish before me. I have not as of yet recieved mine. Well actually I did recieve it, but it was the wrong color for my tastes so I sold it and ordered another. I hope to have it in hand by early this week. It has good reviews and everyone seems to love it here in RCG. I really Cant wait I told Carlos I would not have time until after the new year to start, but i think now I will find it Complete Review: http://www.winnerrc.com/Arfairplane/...0MOTH%2030.pdf 
Dec 18, 2005, 09:43 PM  
Joined Oct 2002
35,016 Posts

Quote:
That review has some neat pic's and yes, I am on it as much as tonight will allow since I have to go back to work on Monday as I don't have any leave to take for these holidays...I may take some sick leave to finish this wonderful and graceful model. My Camera ran out of batteries so, they are charging as I work on my (formerly yours ) all "Yellow" Tiger! Later! Carlos 

Dec 19, 2005, 05:41 AM  
Joined Oct 2002
35,016 Posts

Quote:
HC3528800 has Io=1.7, Ra=.031, Kv=800 HA3630780 has Io=0.70, Ra=.085, Kv=780 Using the formula: P(out)=(Volts(in)  [Ra*Amps]) X (AmpsIo) You will noticed that for a given AMP draw the Outrunner you have selected has a better efficiency at 35 AMPs and Volts(in)= 12.5Volts, therefore, provides much more Watts Out (Transfers most of the energy into mechanical power). Given: Volts(in)=12.5Volts to the motor assuming 4S (I took off a little for internal resistance of battery). AMPs = 35 AMPs @ Wide Open Power(In)= Volts(In) X AMPs = (12.5)X(35)=437.5 Watts Therefore, Power(OutOutrunner) = 380.12 Watts Power(InRunner) = 326 Watts Motor Efficiency = Power(Out) / Power(In) Without doing the calculations, it is obvious which wins here......your Outrunner. However, both have almost the same RPM/Volt (Kv) such that to get any respectable RPM at the Propeller you would need at least 4S type of LiPOLY??? ImagesView all Images in thread


Dec 19, 2005, 05:54 AM  
Joined Oct 2002
35,016 Posts

2. This leads to my question on your item (2.), what LiPOLY arrangement were you thinking for this power system, a 4S? I noticed you indicated a 3S pack but, would that be pretty low RPM's at the Propeller....?
Lets see..... RPM = (Volts(in)  [Ra*Amps]) X Kv Recall your Himax HC3528800 has Ra=.031 3S equates to 10 Volts at the Motor for calculations purposes. Using the AMPs obtained from the HA3630 motor...so, perhaps a little error here... With the 3S, the PCalc indicates that you will have 10 Volts to Motor and about 24 AMPs @ Wide open. Therefore, RPM = (10[.031*24])X800= 7,404 RPM This might be enough assuming a 4lbs model and biplane. If you look at the PCalc, just a little over 3 lbs. of static thrust....it will fly but, very scale like, IMO. Again, the above is an approximation and using AMP values from a different motor so, perhaps you will be okay with 3S LiPOLYs...I would certainly measure the Prop RPMs. I used the following Web Site to come up with the dirty and quick calculations: http://members.aol.com/kmyersefo/page17.htm Carlos 
Dec 19, 2005, 11:37 AM  

You guys are on the way, cool!
Did you see this offering from Hobby Lobby? http://www.hobbylobby.com/tigermoth.htm John and Christo 
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