ESM 74" Corsair On-board battery cap
 

I asked this question in the Q&A forum, but only received one response. I am not well versed in the electonic requirements of fuel planes and I am building this plane in anticipation of flying it in a year or so, as my flying skills develope. The Corsair is outfitted with digital servos on all control surfaces, and one for the throttle -seven in all.Oneadditional pneumatic gearanalog servo.I have a Saito 170 radial for power, but may go to the 200 if AUW dictates it. An on-board glow with a 4.8V battery is to be also used. Considering that I would like to keep the weight down, what type and capacity of a mainbattery would be suggested. I favor the 6.6V LIFE style battery for power and weight factors. That being said, what mAh capacity is suggested for this plane. I am now at the point of needing power to adjust the servo installations. Thanks for you input.
Keith

RE: ESM 74
 

If you are going to need weight up front put the biggest pack you can fit to make up the weight needed. If not a 3300 Mah pack would be plenty. Hope you have a programer for those servos. Why you ask, because there is a good chance they will be off center and humming. With the programer you would set the center with all surfaces at neutral that way the servos stop hunting trying to find the center point. Saves you from having a premature dead battery. 2.4 Rx along with digital servos are energy hogs. They are not like the analog servos and 72mhz Rx. Bottom line is when your radio is on, your plane should be silent when everything is at neutral. If not you better fix it, or one day it may catch up with you. If you don`t have a programer , get one if you will be on the digital band wagon.

BTW. most guys using digital servo don`t know that they SHOULD be using the programer. They fly with the servos humming because they think it is normal for the servos to hum. Wrong.. It is not. It is the same like the buzzing in the analog servos when there is binding somewhere. But it is up to you. Just keep checking the RX battery after 3 flights to make sure all is good.

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1)great advice on the batterys and weight , its what I practice 100%
2) excellant advice on the servos , I did not know that on the digitals !!! I have to get a programer

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Zulu:Thanks for your info. I checked on Servo City for a programmer for my HT HS5625MG servos. There are plenty to choose from - any recommendations?
Re: 3300 battery consideration as ballast. I doubt that I will be needing any nose weight with the use of a 170r3 or 200r3 radial andglow driver and separatebattery up front. My main battery choice will be driven by the anticipated capacity needof the primary battery. Considering that the LIFE style appeals to me, I am looking to keep any extra weight to a minimum, especially if I use the smaller radial engine, which I currently have. If the battery need dictates using a 3300 or greater size, so be it, and I may have to go to a larger engine to cope with the increasedAUW. A twin NiMH redundancy system is also under consideration, but I will have to look at available space, asit is limited. I believe that I will be somewhere between 16.5 and 18 pounds when done.
Your suggestion of the programmer seems to be well founded. I will get one. Looking forward to more information.
Thanks, Keith

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Keith: I use LiFe batteries in my planes. Good choice. You might want to consider two 2200s, each with their own switch, and wiring. This provides two current paths to you RX (or power expander). If the servos happen to call for it, a LiFe can put out each amperage to melt connectors and switches. Multiply 3300 mah time the LiFe C rating. Two paths reduce that possibility.<div>
</div><div>Brian</div>

RE: ESM 74
 

You don`t have to , but you should. That humming that you hear from the servos is the sound of it hunting for the center, You could stop the humming by programing the band width of the center point and also to relocate the center point. In other words if your linkages are as best as you could get it, you could relocate the neutral points by using the programer or adjust the band width. Your servos should not be humming at neutral.


A 2 battery set up is also a good way to go. Two 2200s will give you 4400 Mah which is even better. The Hitec programer is the one to get, you could do a lot more with it including testing your set ups with out using your radio.

http://servocity.com/html/hfp-25_servo_programmer.html

Having this gadget will make things a lot easier.

RE: ESM 74
 

I know this thread is about batteries but it's the only 74" ESM Corsair post I can find. So here goes. Does anyone out there know what the color name, code, scheme is on the rudder and tail? Had to do a repair on the rudder and recover it but can't seem to get the color to match.

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Sawtooth: Don't know the answer to your question, but here are a couple of threads on the ESM 74" corsair.

<span style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); ">KMP Corsair - same plane, earlier seller</span><br style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); " />http://www.rcuniverse.com/forum/m_7626632/tm.htm<br style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); " /><br style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); " /><span style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); ">ESM F4U Build</span><br style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); " /><a target="_blank" href="http://www.rcuniverse.com/forum/m_9664536/mpage_1/key_/tm.htm" style="color: rgb(0, 38, 94); font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); ">http://www.rcuniverse.com/forum/m_96..._1/key_/tm.htm
</a>
Brian<br style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); " />

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Sawtooth: The sites suggested by Aghost are filled with tips and suggestions in the building and flying of this plane. I gained alot from the reads. I had Home Depot custom mix 4 oz jars of each ofthe 3 colors. The medium blue is spot on. I simply brought in two flap sections and they read the colors off of their spectrometer.Let me know if you need their formula.
Keith

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Stoneke: Awesome information............. I really appreciate it. I recovered the rudder with ligh blue SolarTex and it looks pretty bad. The company was out of neutrual and I wanted to get this plane in the air sometime in the near future. TBM lists a rudder replacement for only $19 but it's out of stock so I will give Home Depot a try. Have you guys used the recommended C.G. with success?

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I started out with the CG at 120mm (4.7 in), measured at the point on the wing shown in the manual. By about flight 40, I had moved the CG backwards to 127mm (5.0 in). Got about 70 flights on my ESM Corsair now.

If I remember right, there are folks on those two threads that set CG's from 4" to 5.1". Most of them seem to be happy with the results.

Brian

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RE: ESM 74
 

I am still in the build phase with my Corsair and will be anxiously considering the correct COG this spring. I am planning to install the air tank (or tanks) in the wing saddle area to save room in the forward fuse area. I will be running my Saito 170 or a Saito 200 radial and thus will need a glow driver set up, which is another item to occupy the forward area. I will be mostly flying at 4500 ft and above, so I'm concerned that the 170 will be marginal power for the anticipated 18 to 19 pound final weight of this bird. Any thoughts on required power at higher elevations? I would gladly replace my 170 if needed, as these two are the same physicalsize.

If anyone is looking for a full sized pilot, VQ Warbirds has a 1/6 size that is a dead ringer for Ira Kepford. I will post some pictures when I get my computer (and photo folders) back from the shop.
Keith

RE: ESM 74
 

Factory suggests 130mm so I'm glad they are pretty close and people are having good results with that general area. It's been very helpful..........thanks alot.

RE: ESM 74
 

Stoneke:<span style="font-family: Arial; ">I fly at 3700 ft or so, using a G-38 with a 17 x 10 Zinger prop. The plane weighs about 18.5 lbs. Powerwise, its OK (kind of scale), but not extra fast or unlimited vertical.</span><div style="font-family: Arial; "></div><div style="font-family: Arial; ">I have no experience with either radial, so based on looking at the prop size and some quick prop calcs, the 170 performance (speed and thrust) look similar to the G-38. The 200 with a little more speed and thrust would be nice.</div><div style="font-family: Arial; "></div><div style="font-family: Arial; ">Brian</div>

RE: ESM 74
 

Just one more question on CG. You all set C.G. with the gear up, right?

RE: ESM 74
 

yes, gear up.

RE: ESM 74
 

In a previous message, I referenced a full body pilot that is offered by VQ Warbirds. The likeness of this figure to the WWII piot of VF-17 #29, Ike Kepford, is remarkable. A perfect compliment to a scaled cockpit. Also pictured is the plane with the "island wing weathering". I plan to also weather the fuse when I complete the build. I hope these photos install - I haven't had great success before.

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Well, this has taken quite an effort!