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Old Jun 08, 2012, 08:33 PM
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Originally Posted by bigroger View Post
I thought hp had skylipo 40c6s3300 in stock?

I ordered 4 of these last week, hope that's what they actually send!
the sky 40c have been rock solid for me...good choice
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Old Jun 09, 2012, 12:51 AM
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United States, AK, Anchorage
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Originally Posted by bigroger View Post
I thought hp had skylipo 40c6s3300 in stock?

I ordered 4 of these last week, hope that's what they actually send!
They are too heavy for my heli application... The 40C they state 634g and the 30C 518g. I have a 600e converted to 12s and that would add to much weight to the front. (maybe time for a pro upgrade) What weight are you guys having good results with on the extra and edge 60" exp? I would like to be able to share packs. However the 6s 30C Sky 3300 mAh just came in stock.
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Old Jun 09, 2012, 10:37 AM
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Originally Posted by Aeroplayin View Post
Here it is... take a look and let me know what you think. I did some highlighting and it only means that I think the 9600 RPMs is probably a skewed value, and anything close to 0.360 is on the cusp with regard to angular momentum. The rest shows relative Static Thrust calculations using prop specs and RPMs, not actual measured thrust.

As you may know, when the popup appears, if you click on the window, the image will expand in a new browser.
Do any of you tester types out there have any way to quantify the difference on the dm 2820-683kv motor between the 14x7 apc and 14x7 xoar?
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Old Jun 09, 2012, 11:32 AM
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Originally Posted by -= GYRO =- View Post
Do any of you tester types out there have any way to quantify the difference on the dm 2820-683kv motor between the 14x7 apc and 14x7 xoar?
We are using the 14x7 APC because you don't need more power and a few less Amps means a little more flight time.
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Old Jun 09, 2012, 11:38 AM
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Could it be more efficient tho? Maybe give more time low and slow.
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Old Jun 09, 2012, 11:41 AM
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Personally (though I don't yet have the 683kv wind) I'd use the Xoar because it spins a bit slower and is much lighter so puts less structural load on the motor.
The Xoar want really an option on the 750kv version because the amps just got a bit crazy.

Steve
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Old Jun 09, 2012, 11:48 AM
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I think I'm gonna switch to the 14x7 Xoar... I don't have the ambient heat that many have to deal with. Also, I rarely fly WOT. Structural load on motor should be less. May look at endpoint limits also.
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Old Jun 09, 2012, 11:53 AM
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Originally Posted by bryansifsof44 View Post
Could it be more efficient tho? Maybe give more time low and slow.
Could very well be. It looks like the 14x7 is not going to be a problem on the 683 with 4S, and considering how much the Xoar seems to improve performance in all sizes, from 12 to 16 inch diameters, it's certainly worth a try.

I found out that I don't have a 13x7 Xoar in my prop box so I'm going to order a few today. One of the problems I have right now is that since we have some bigger toys to play with, the 48's with the 638 and 683 motors are on the rack with the 48 Extra and two 3DHS planes (Velox and SHP). The 3DHS airframes are just collecting dust at this point and I'm going to try to sell them at the next local swap meet so I can make some room. Anyway, I have to plan a day just for the 48's because they can't fit in the SUV when we bring the bigger planes out, and right now, we're kind of hooked on the bigger planes. When I get the 13x7 Xoar, I'l at least bring out the 638 to try the 13x7 Xoar and the 13x6.5 APC on 5S, but taking both 48 inch planes out on the same day may not be in the cards for a while.
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Old Jun 09, 2012, 08:05 PM
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Could very well be. It looks like the 14x7 is not going to be a problem on the 683 with 4S, and considering how much the Xoar seems to improve performance in all sizes, from 12 to 16 inch diameters, it's certainly worth a try.

I found out that I don't have a 13x7 Xoar in my prop box so I'm going to order a few today. One of the problems I have right now is that since we have some bigger toys to play with, the 48's with the 638 and 683 motors are on the rack with the 48 Extra and two 3DHS planes (Velox and SHP). The 3DHS airframes are just collecting dust at this point and I'm going to try to sell them at the next local swap meet so I can make some room. Anyway, I have to plan a day just for the 48's because they can't fit in the SUV when we bring the bigger planes out, and right now, we're kind of hooked on the bigger planes. When I get the 13x7 Xoar, I'l at least bring out the 638 to try the 13x7 Xoar and the 13x6.5 APC on 5S, but taking both 48 inch planes out on the same day may not be in the cards for a while.
I just want to get more out of my 683kv motor... Like I said earlier, I found that the 683kv on 14x7 APC was a tad anemic compared to the SunnySky 2820-800kv... but that motor can't take repeated 3d abuse on a 14x7. KE spins simply destroy it. It'd be nice if I could get Motrolfly durability at SunnySky performance. Need to find the right prop. Maybe 14x8 Xoar?
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Old Jun 09, 2012, 08:20 PM
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Originally Posted by -= GYRO =- View Post
I just want to get more out of my 683kv motor... Like I said earlier, I found that the 683kv on 14x7 APC was a tad anemic compared to the SunnySky 2820-800kv... but that motor can't take repeated 3d abuse on a 14x7. KE spins simply destroy it. It'd be nice if I could get Motrolfly durability at SunnySky performance. Need to find the right prop. Maybe 14x8 Xoar?
I had the 14x8 Xoar on my 638 before testing the 5S with the 13x6.5 APC, which I'm trying get to to field for an actual flight. It was better than the 14x7 and better than the 14x8.5 APC because it just couldn't turn the 14x8.5 fast enough. But the Xoar 14x8 had such a thick hub -- more so than the 14x8.5 APC -- that I had to bolt it on with no prop washer. But it worked fine.

If the 13x6.5 APC or the 13x7 Xoar on 5S doesn't live up to the 14 inch props, I'll probably put the 14x8 Xoar back on.
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Old Jun 09, 2012, 10:19 PM
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Originally Posted by bryansifsof44 View Post
They are too heavy for my heli application... The 40C they state 634g and the 30C 518g. I have a 600e converted to 12s and that would add to much weight to the front. (maybe time for a pro upgrade) What weight are you guys having good results with on the extra and edge 60" exp? I would like to be able to share packs. However the 6s 30C Sky 3300 mAh just came in stock.
That 634g is incorrect. There are reviews from guys on the web page that the weight is much closer to the 30C weight.
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Old Jun 09, 2012, 10:23 PM
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Gary,
why not just get a custom wind from Ken.
I'm sure the Motrolfly 750kV can handle the 14x7 prop if you just dial back the throttle end point to limit rpm to below 8500 at wot.

That's all it needs most likely.

Did you ever get rpm readings on the Sunnysky to compare?

By the way, I apologise for my absence of late. I've been flogging my 51" aj slick a heap in the park and I've fallen in love with its flying.

So much so that I'm thinking about bigger airframes at the moment.

Still have the 48" mxs and the 60" edge to build, but at the local flying field the 48's look a little toy like on that big runway strip.
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Old Jun 09, 2012, 11:26 PM
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Originally Posted by bigroger View Post
Gary,
why not just get a custom wind from Ken.
I'm sure the Motrolfly 750kV can handle the 14x7 prop if you just dial back the throttle end point to limit rpm to below 8500 at wot.

That's all it needs most likely.

Did you ever get rpm readings on the Sunnysky to compare?

By the way, I apologise for my absence of late. I've been flogging my 51" aj slick a heap in the park and I've fallen in love with its flying.

So much so that I'm thinking about bigger airframes at the moment.

Still have the 48" mxs and the 60" edge to build, but at the local flying field the 48's look a little toy like on that big runway strip.
When speaking to ken, he had a 683kv wind available, and thought it'd work nicely with the 14x7, in fact, I think he recommended it.
Its just a little below what I've been used to, however what I've been used to was destroying my sunny sky motors. So... I just need to find that happy middle place.
I've got a 14x8 Xoar, I'm going to try that next time I go fly.
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Old Jun 10, 2012, 01:22 AM
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I was thinking of maybe a 700-710kv on my next 2820... 683 may be plenty but then again I'm used to the power of the 750
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Old Jun 10, 2012, 01:50 AM
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If you avoided WOT KE spins the 14x7APC on the DM2820-750 (750kv) is almost certainly ok.. Even doing regular WOT KE spins mine lasted 6 months.

Steve
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