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Post by Ellis on Sept 22, 2008 22:59:33 GMT 1
Just got back from the maiden of the brushless mod. Oh man!... Oh man!... ;D Very cool to have power to spare. The thrust angle must be about perfect and after assembly with the lipo, the COG check out dead nuts on what it was stock - not sure how that happened.lol After a substantial amount of R rudder trim to get it going straight, I noticed when it was on the ground that the rudder was nice an lined up with the fuse. So I corrected that at the clevis. Hear are a couple of pics (I hope  )    |
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Post by admiralev on Sept 22, 2008 23:01:52 GMT 1
very nice mod! your battery bay is so clean....
do you have a vid of it yet?
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Post by Ellis on Sept 22, 2008 23:14:45 GMT 1
very nice mod! your battery bay is so clean.... do you have a vid of it yet? Not yet. The two choices I have are, the old hat cam (taping my camera to my head) or getting my wife to film it. I think she's willing, but not sure if she's able - soon though. I'll tell ya admiralev, I was thinking about you and your mishap the whole time. In fact I rebound it before I left the house and after I got back - probably wont make that a ritual though.lol |
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Post by admiralev on Sept 23, 2008 23:32:34 GMT 1
i was running a AR 6200 though...and you have the 6100. i was also running a cheap GWS ESC. fly shunned me on that one. i was alos using the cheap stock 7 cells which i think are running bad. my charging habits arent the best... read around RCU and RCgroups a little bit. there are some threads on this very problem. fly gave me some links if you want them btw, did you decide to go with the cellpro for you lipos? how do you like it? what are your flight times like with the 2100 mah? admiral |
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Post by Ellis on Sept 24, 2008 1:34:31 GMT 1
Thanks admiral, I feel a bit more confident now. As for flight times, I've only had it up once. I flew for about ten minutes - when I got home the resting charge was 65%, but I know fly says that's not accurate. I guess I have to find out how to test charge while under load ( anybody is welcome to give me pointers ). I'm still not sure about discharge amounts i.e. timer vs. auto ESC cutoff. The CellPro charger works like a dream and seems to have some nice features - my son is sending me his flaky heli batt to see if it will repair it.
The 450 was so nice, even at half throttle - also did my first loop and could of done several consecutives, but chickened out.
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Post by flydiver on Sept 24, 2008 3:07:27 GMT 1
If that resting charge was ON the Cellpro it is a reasonable reflection of the remaining capacity. It is not just acting as a voltmeter but doing a more sophisticated electrical test.
If it as with a simple voltmeter it is not. I think I've posted this before (NOFLYZONE'S BLOG) and it is a working approximation that is useful:
[http://www.rcgroups.com/forums/member.php?u=106813&page=2]
["Resting" Voltage per cell
4.20v = 100% of our battery's amp capacity remains.
4.03v = 76% of our battery's amp capacity remains.
3.86v = 52% of our battery's amp capacity remains. (A good voltage to store our Li-Pos at)
3.83v = 42% of our battery's amp capacity remains.
3.79v = 30% of our battery's capacity remains.
3.75v = 20% of our battery's amp capacity remains. (Where we want to take our Li-Pos to for long life)
3.70v = 11% of our battery's amp capacity remains. (Detrimental 'battery voltage dump' begins)
3.6?v = 0%
In line with the above, we do NOT want our Li-Po's resting voltage to be less than 3.75v per cell, which would mean we had used about 80% of their capacity.]
You need a wattmeter to test the voltage under load. It's a wonderful tool. Get one, learn how to use it and you'll wonder how you got along without it. Pays for itself in non-fried gear (motor, battery, ESC).
Very nice mod you've done there. Great workmanship.
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Post by admiralev on Sept 24, 2008 3:55:22 GMT 1
wow fly...nice info. layman's terms....i like it  |
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Post by Ellis on Sept 24, 2008 4:26:21 GMT 1
Thanks for the info fly.
I do have a volt meter and have actually used it several times.
Do you just read the power leads when the motors at say half throttle? Don't you get tired running along side it? - sorry couldn't help myself.
E
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Post by Ellis on Sept 24, 2008 4:28:02 GMT 1
Ah... but you said watt meter.
No gots
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Post by flydiver on Sept 24, 2008 4:55:43 GMT 1
What the h*** is a wattmeter, why do I want one, and what would I ever do with it? www.rcgroups.com/forums/showthread.php?t=311574Yes, it's small enough to mount and fly on a reasonable sized park flier. That alleviates the need to run alongside and jump up to read the screen. There are even more sophisticated test tools but this is adequate for most people. For RC if I had a choice between a good voltmeter and a wattmeter the wattmeter would win without question. fly |
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Post by Ellis on Sept 24, 2008 16:24:58 GMT 1
What the h*** is a wattmeter, why do I want one, and what would I ever do with it? www.rcgroups.com/forums/showthread.php?t=311574Yes, it's small enough to mount and fly on a reasonable sized park flier. That alleviates the need to run alongside and jump up to read the screen. There are even more sophisticated test tools but this is adequate for most people. For RC if I had a choice between a good voltmeter and a wattmeter the wattmeter would win without question. fly Great info! It's going to the top of my list. Time to spend some time looking the best deal. Ellis |
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Post by flydiver on Sept 24, 2008 16:58:53 GMT 1
There seldom is a best deal. They cost around $50. No one discounts them. Used one's at $40 disappear instantly. Never seen one below $35 ever. There are similar products that sometimes are a bit lower but not much.
There is almost never an outing that it doesn't get used and those without are always borrowing it. My buddy makes trips over just to check out prop combos.
Fer Instance - He got a new Dualsky, 15A motor, 1300KV. This is a nice looking mid-grade motor. Web site claimed 10x4.7 prop. That prop pulled 28A!!!!! It would have burned up the motor, fried the ESC, and croaked his lipo. Before it did he would have been AMAZED at the performance of the Dualsky and then wondered what he did wrong.
He did NOTHING wrong-Dualsky fed him bad info. I think the majority of motor specs are not accurate. Needless to say he had to prop WAY down.
If Tower Hobbies still does the $20 off of $50 when you join their email list (1x only deal), that's how I got mine.
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Post by duck9191 on Sept 24, 2008 18:11:13 GMT 1
tower has been doing a lot of 10 off 50 deals, the 20 off 50 is getting harder to get. but I have been getting a 10 off 50 after every order as a thank you so that's nice.
you can try to sign up on there mailing list, but some times it takes a while to get the cupon.
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Post by Ellis on Sept 26, 2008 3:18:49 GMT 1
what are your flight times like with the 2100 mah? admiral Just got back from a timed 15min flight. Wasn't going full-out all the time but wasn't holding back either. Did a loop and a stall and cut the throttle off and let it fall (that was cool) and a lot of power climbs. My charger said it had 25% when it stopped counting down from 45%  Anyway, so far it looks like 15min mixed flying and 20min half throttle cruisin'. Ellis |
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Post by admiralev on Sept 27, 2008 5:58:29 GMT 1
hey ellis just curious how is your landing gear mounted? did you modify the battery box at all or that little plastic inner thing?
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