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Old Mar 26, 2012, 05:09 PM
I use EXPO and Senior Rates
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United States, MI, Custer
Joined Jan 2010
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Originally Posted by bostomper View Post
Been able to fly the sensei for the 1st time this spring. Went out on 3 different days, and I really enjoy the relaxed flying with this model. However my landing skills really suck, and I have apparently bent he landing gear wire back about 15 degrees from where it was straight down before. ( Did this on another model also due to panic attacks when landing.LOL) Anywho, it still taxis great and takes off and lands as good as ever, so rather than take the cowl off and try to repair I am going to leave it as is. Any thoughts?--Bo
If it taxis ok I would't worry about it. I did the same thing to mine on the 4th or 5th landing and did'nt think it was worth the effort to straighten. Glad to hear the flights were ok.

That's my thoughts.

Roger
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Old Mar 26, 2012, 05:18 PM
That's a funny word
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I did the same thing on my first few flights. Then the nose wheel started swiveling in the breeze for many flights after that. I can't taxi or take off on my lot so I didn't care.

I don't know how many flights I have on mine , but just a few days ago I landed short of my lot in the field and bumped down hard enough to bend the main gear back into the foam. I think it hit a rut in the field and stopped dead.

Upon dissasembly I decided to put together another one instead of fixing it. It's ready to go now. Hey, this one even steers.

It's ugly on one side where someone cut a square hole in the fuse , the drop bay and servo is gone so I taped it up. The cowl has been cut off and re-glued. I'm still using my 3sx3500 pack and a rearward COG and my old wing,tails,motor,esc, ect. I also switched to my 9x TX for this one, we'll see how it goes. It weighs 1490 grams.
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Old Mar 26, 2012, 08:18 PM
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In case anyone is wondering, the lvc went off on me at 8.89 volts, as measured by my little voltmeter. I went out a few days ago with 2 fully charged packs, landed after about 12 minutes a usual and packed it up due to the increasing winds. Yesterday I grabbed the other pack and went out for a quick flight. As it turns out, you guessed it, I grabbed the already discharged pack by mistake. It wasn't discharged enough to notice and I also was taking it easy with low power flying, after about 9 minutes, I hit the throttle to overshoot an approach and all I got was short weak bursts of power, so the overshoot turned into a landing. Good thing it happened there. Now I just hope i didn't damage the pack, it was a new one.
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Old Mar 26, 2012, 09:00 PM
Right Rudder
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Originally Posted by Kawi View Post
In case anyone is wondering, the lvc went off on me at 8.89 volts, as measured by my little voltmeter. I went out a few days ago with 2 fully charged packs, landed after about 12 minutes a usual and packed it up due to the increasing winds. Yesterday I grabbed the other pack and went out for a quick flight. As it turns out, you guessed it, I grabbed the already discharged pack by mistake. It wasn't discharged enough to notice and I also was taking it easy with low power flying, after about 9 minutes, I hit the throttle to overshoot an approach and all I got was short weak bursts of power, so the overshoot turned into a landing. Good thing it happened there. Now I just hope i didn't damage the pack, it was a new one.
Kawi,

I am sure that the Voltage has gone up and I would charge this pack under slow charge and nothing more than 1/2 an AMP rate. I always check the Voltage of the Battery Pack prior to inserting it into a model just to double check.

The Li-POLY chemistry type really do not like lower end of their Voltage values and I am sure they puffed up as going this low will at times puff the packs, especially the middle cell. Li-POLYs do not like over charging over discharging such that if this continues, the cycle life will be reduced to 50%.

Recommend to check the pack's voltage level before selecting them for flight.

Carlos
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Old Mar 26, 2012, 11:49 PM
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I noticed i wrote 8.89, i meant to say 2.89. That was cell #3. The other 2 cells were at 3.3, which i found weird. Still close to 8.89 actually. (9.5)

There didnt appear to be any puffing. It was the first thing I checked. Im going to keep an eye on it. I usually check my batteries. Just goes to show you, even when you're so so sure, check anyway.
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Old Mar 27, 2012, 04:15 AM
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United States, CA, San Diego
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Bo,
I'm with Gulio and Rightfly. I too bent my nose gear back about the same amount a couple of weeks ago. Took it apart then and straightened it, but then managed to bend it again last Friday on that one tough landing. It taxied and steered okay even after that, so this time I'm leaving it alone. I did check to make sure my rudder still had full throw in both directions since the two are tied together on that same servo.
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Old Mar 27, 2012, 04:32 AM
Right Rudder
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Originally Posted by Kawi View Post
I noticed i wrote 8.89, i meant to say 2.89. That was cell #3. The other 2 cells were at 3.3, which i found weird. Still close to 8.89 actually. (9.5)

There didnt appear to be any puffing. It was the first thing I checked. Im going to keep an eye on it. I usually check my batteries. Just goes to show you, even when you're so so sure, check anyway.
Yes, 2.89 Volts for one Cell is very boarder-line and again Charge with a balancer and at a very low (0.5 AMP) rate and keep an eye on charging!

Best of luck!
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Old Mar 27, 2012, 05:00 AM
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United States, CA, San Diego
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Originally Posted by Kawi View Post
I noticed i wrote 8.89, i meant to say 2.89. That was cell #3. The other 2 cells were at 3.3, which i found weird.
Kawi,
Actually, that's not weird at all with a battery that has three little cells hooked up in series. If you draw three boxes (representing the three cells) and put a positive and negative symbol in the left corners of each you have your three cells.

Cell #1 the positive terminal has a wire that leads to your Deans plug positive terminal. The negative of #1 hooks to the positive of #2 cell, the negative of #2 hooks to the positive of #3 cell and the negative of #3 loops back to your Deans negative terminal.

Although we always think of "positive" as the hot wire, in actuality batteries flow current from negative to positive. Batteries are DC (direct current) and this is called electron current flow. A really great and simple explanation of all this electrical theory is condensed into a couple of simple paragraphs (with diagram) here:

http://www.sciencelobby.com/dc-theor...c-current.html

With that understanding then, you realize that cell #3 is actually the first cell feeding the current through it's negative lead to the motor and unused current is fed back to the battery's cell #1 via the positive lead.

I'm guessing (since I don't know LiPo chemistry) that you drew the cells down so far that #1 and #2 could not overcome their own internal resistance to flow any more electrons to #3, so #3 began bleeding down by itself. Hence, it had a lower voltage than the other two cells.

Okay, I'm done expounding for the evening. But hope that clears up the confusion a little bit.
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Old Mar 27, 2012, 12:23 PM
Right Rudder
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Quote:
Originally Posted by Kawi View Post
I noticed i wrote 8.89, i meant to say 2.89. That was cell #3. The other 2 cells were at 3.3, which i found weird. Still close to 8.89 actually. (9.5)
Kawi,

I almost forgot!

The middle Cell on a 3-Cell Li-POLY taken it to an extreme of really low Voltage state will certainly Puff the middle cell due to the heat generated due to the depletion of the cells to their minimum levels.

In you case perhaps it was a short flight and the cells did not have enough time to build the heat.

Again, be careful with this batteries.
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Old Mar 27, 2012, 08:22 PM
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Nose gear is a bit of a weak spot .... I've seen 3 guys bend them back with less than perfect landings. Hoping my rebuild comes up with some better system than stock.

Kawi excuse me if I'm repeating something you know or was said in a previous post but you want to aim for approx. 3.8V on each cell after a flight. Fly, land and test, keep doing that till you know how long a fully charged battery lasts with your flying style. 4.2V is the starting voltage. I used to have a good link for this battery info but can't find it right now.

I have 3 of these, they are a very good tool at the field, on the bench etc. :

http://www.hobbyking.com/hobbyking/s...itor_2_6S.html


flashes the reading for all 3 cells plus total V
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Old Mar 28, 2012, 12:57 AM
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Thanks for the input to everyone, but like i said, i mistakingly used a used pack, i do know all about proper lipo use, and that tool is exactly what i have and use. Its a cool tool, but im not sure how accurate it is though, my balance charger tends to show a higher number at times. Still pretty accurate though.
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Old Mar 29, 2012, 02:29 PM
Right Rudder
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SENSEI FOR sale

http://www.rcgroups.com/forums/showthread.php?t=1622555

Hurry!
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Old Apr 01, 2012, 01:34 AM
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Bad day Friday: I fly, I bank, I stall, I crash. Ugly.

Bent motor mount, broken prop, cowl broke, fuse cracked in half, main landing gear ripped away from fuse, bent nose gear really bent now. Wings and tail feathers all okay, though.

Amazingly, going back together okay. Only the landing gear left to glue back in place. What's helped is a spare motor mount and nose gear. Quick swap-out there. Going right back out to the field on Monday or Tuesday, soon as the rain clears again. (Ain't no sissy plane gonna beat the hell out of me!!)
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Old Apr 01, 2012, 06:49 AM
Right Rudder
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Originally Posted by Sykon View Post
Bad day Friday: I fly, I bank, I stall, I crash. Ugly.

Bent motor mount, broken prop, cowl broke, fuse cracked in half, main landing gear ripped away from fuse, bent nose gear really bent now. Wings and tail feathers all okay, though.

Amazingly, going back together okay. Only the landing gear left to glue back in place. What's helped is a spare motor mount and nose gear. Quick swap-out there. Going right back out to the field on Monday or Tuesday, soon as the rain clears again. (Ain't no sissy plane gonna beat the hell out of me!!)
Skyon,

This "is" exactly why this model was designed for!

If this was made out of traditional Balsa and Light Plywood, you be perhaps in the Hobby Shop buying a new model.

You got the Spirit and better luck next time!

Happy landings!
Carlos
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Old Apr 01, 2012, 09:59 AM
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We got a couple flights yesterday, all went well. Brad is going to check the balance, it
took a lot of left aileron trim. It was a little gusty so it was hard to get an exact fix on it.
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