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Old Sep 13, 2012, 09:16 AM
WINS - Winch In Nose Sailplane
jaizon's Avatar
USA, NH
Joined Mar 2008
3,109 Posts
Don,

Do you have the 1107 with the new 6.7 gb in hand yet?

Preston
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Old Sep 13, 2012, 10:02 AM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
2,642 Posts
Quote:
Originally Posted by jaizon View Post
Don,

Do you have the 1107 with the new 6.7 gb in hand yet?

Preston
Preston,

Not yet. Maybe in two weeks. Waiting for the stator. Great motors. But a trial for the impatient. About 5 weeks total.

On the other hand, it appears that Reisenauer will be on vacation until October 12. I guess everything worthwhile is worth waiting for. We'll see.

Happy Landings,

Don
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Old Sep 13, 2012, 10:30 AM
WINS - Winch In Nose Sailplane
jaizon's Avatar
USA, NH
Joined Mar 2008
3,109 Posts
Just ordered mine. 4-5 weeks. Fingers crossed.
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Old Sep 13, 2012, 12:56 PM
Registered User
Stamford, CT
Joined Feb 2002
474 Posts
Don - You aren't going very far or very fast with a 17x8 or 17x9 prop on your 1107-2Y 6.7. I have a 17x11 on my Neu 1107-2Y with the Maxon 4.4 in my Supra. It is just enough to get me to altitude in 30 seconds. Watts are about 670 on a TP 1300 65C 3S battery, which is slightly over the motor recommended max. With 30 second runs, I haven't had any problems. With the small prop and big gearbox on your 1107, you'll be lucky to get 400 watts and 200 meter launches on a 3S battery. A 4S battery may solve the problem, but adds weight.

George
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Old Sep 13, 2012, 02:09 PM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
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Originally Posted by SaltyOne View Post
Don - You aren't going very far or very fast with a 17x8 or 17x9 prop on your 1107-2Y 6.7. I have a 17x11 on my Neu 1107-2Y with the Maxon 4.4 in my Supra. It is just enough to get me to altitude in 30 seconds. Watts are about 670 on a TP 1300 65C 3S battery, which is slightly over the motor recommended max. With 30 second runs, I haven't had any problems. With the small prop and big gearbox on your 1107, you'll be lucky to get 400 watts and 200 meter launches on a 3S battery. A 4S battery may solve the problem, but adds weight.

George
George,

I am using a TP 850 4S 65C battery pack. With an 11x8 on a Vladimir hub it should draw about 650 watts and have a pitch speed of about 44 mph. I used a similar setup with my Supra only using the 1110/6.7 with the 4S 1300 pack. It drew about 700 watts and would propel the Supra to 200 meters in 13 seconds. It was really more power than I needed and I wanted to save a little weight so I backed off to the 1107/6.7 and the 4S 850. Currently the Maxa has an 1105/4.4 drawing about 450 watts and it can get the plane to 200 meters in 24-25 seconds. I am just looking for a mellow 600 watt installation which will likely get me in the 18-20 second or so range.

Part of what is important here is to take our focus off of the power "draw" a little bit and look at the propeller. I don't know if the 11x8 will be right even if the power draw is in the range I am looking for. I have noted very wide differences in performance for plane and power system combinations even where the power draw is constant but the prop diameter/pitch combinations change. Most of my bigger planes have been powered in the 600 to 750 watt range and none has been as slow as you seem to be describing for yours and several have been much, much faster. I suspect that your propeller is not operating very efficiently. Maybe increasing the diameter and reducing the pitch will help.

As to the 4S packs, they are simply a matter of personal preference. A 4s 850 weighs slightly less than a 3S 1300 and has about 12 percent less capacity -- not a problem when you live on the top 60 percent of the battery anyway. They allow me to run at lower amperage for any given load and to either use a smaller ESC or to operate the ESC at a little lower load. I have had some bad experiences with ESC's and, frankly, like to give them a little room to breathe. In the Maxa installation I am using an older Phoenix 80 (which is rated to 120 Amp surge) for a maximum load of around 50 amps. I started using 4S packs on an application where a 3S load took me up to a 100 amp ESC. These bigger ESC's are not conducive to clean installations in skinny fuselages because of their size and especially because of their larger gauge wires.

Happy Landings,

Don

BTW-- It is important to understand that the ability to go from 3S to 4S without considering necessary changes to your gearbox and propeller choice can be hazardous to your motor.
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Last edited by dharban; Sep 13, 2012 at 05:38 PM.
Old Sep 13, 2012, 04:08 PM
W0X0F
IBWALT's Avatar
United States, CA, Los Angeles
Joined Nov 2005
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I currently have a Nue 1107 2Y with a 4.4:1 Maxon gb swinging a 18X10 prop powered by a TP 3S 1300mha 65C battery in my Maxa-e that climbs at 2300 fpm. It pulls roughly 47a and produces about 500w of power. Works for me.
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Old Sep 13, 2012, 04:34 PM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
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Quote:
Originally Posted by IBWALT View Post
I currently have a Nue 1107 2Y with a 4.4:1 Maxon gb swinging a 18X10 prop powered by a TP 3S 1300mha 65C battery in my Maxa-e that climbs at 2300 fpm. It pulls roughly 47a and produces about 500w of power. Works for me.
I've flown Walt's plane and you can take his power combination to the bank for Supras, Maxas, AVAs and such.

I wanted to come as close as I could to his combination, but with a beefier 6.7:1 gearbox. My 4S combination with the 6.7 gearbox will be very similar.

One thing worth noticing is the difference between observed power measurements and the predictions that the various programs predict for our three combinations. The truth on propellers and these computer programs is to use the program for a starting point and then work from there. The real performance will likely be very different from predicted performance.

On the other hand, finding someone who has worked out a combination and who has actually logged satisfactory performance can be a lot more useful. Just copy a successful setup.

Happy Landings,

Don
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Old Sep 13, 2012, 06:04 PM
WINS - Winch In Nose Sailplane
jaizon's Avatar
USA, NH
Joined Mar 2008
3,109 Posts
I switched to the 4.4 Maxon on my 1107 - before Walt posted () But I do trust what he has to say. Bottom line is the Maxon gives me more configuration options to get the wattage I want.
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Old Sep 14, 2012, 10:52 AM
Registered User
Stamford, CT
Joined Feb 2002
474 Posts
Don - I didn't realize you use 4S battery packs. The props you mention should be a good starting point for that configuration.

Your statement ... "They allow me to run at lower amperage for any given load..." ... seems counterintuitive to me. Since I=E/R, the higher voltage from 4S will result in a higher amperage draw than 3S, everything else being equal. I'm sure you can compensate with prop selection, but 4S inherently results in a higher current. Because of the laws of conservation of energy, if the "given load" and efficiency are about equal 3S and 4S should draw the same amount of power. I don't see how 4S gives you the same result at a lower amperage. Maybe you can explain. Thanks.

George
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Old Sep 14, 2012, 12:48 PM
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Modesto CA
Joined Nov 2009
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George:
I think you will find the answer to your question in the relationship
Watts = Amps x Volts.
For the same target wattage higher voltage results in lower amperage.
Mac
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Old Sep 14, 2012, 01:12 PM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
2,642 Posts
Quote:
Originally Posted by SaltyOne View Post
Don - I didn't realize you use 4S battery packs. The props you mention should be a good starting point for that configuration.

Your statement ... "They allow me to run at lower amperage for any given load..." ... seems counterintuitive to me. Since I=E/R, the higher voltage from 4S will result in a higher amperage draw than 3S, everything else being equal. I'm sure you can compensate with prop selection, but 4S inherently results in a higher current. Because of the laws of conservation of energy, if the "given load" and efficiency are about equal 3S and 4S should draw the same amount of power. I don't see how 4S gives you the same result at a lower amperage. Maybe you can explain. Thanks.

George
Trust me. It works. I've been doing it for years. Remember not everything else is equal. The difference between my set up and yours is that I am running a 6.7:1 gearbox to your 4.4:1. The increased voltage from the 4S increases the motor speed but because of the gearbox difference, the motor sees lower torque. Power = torque x speed.

What you can't do without a little caution is to simply slap a 4S on a rig that you've been running on 3S and not heat things up. If you increase the cell count under these circumstances, you normally reduce you prop size to get the load back down into a range that will not fry the motor.

Happy Landings,

Don
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Old Sep 19, 2012, 06:54 PM
W0X0F
IBWALT's Avatar
United States, CA, Los Angeles
Joined Nov 2005
1,003 Posts
hmmmmmmmm hmmmmmmmm good

Look what I got today.
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Old Sep 19, 2012, 07:04 PM
WINS - Winch In Nose Sailplane
jaizon's Avatar
USA, NH
Joined Mar 2008
3,109 Posts
Are you going 1110 for your Maxa?
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Old Sep 19, 2012, 08:48 PM
W0X0F
IBWALT's Avatar
United States, CA, Los Angeles
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Quote:
Originally Posted by jaizon View Post
Are you going 1110 for your Maxa?
No I'm staying with the 1107 ORKn in the Maxa. The 1110 is for the 4m Xploder.
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Old Sep 30, 2012, 04:38 AM
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Joined Feb 2011
57 Posts
I must say that this thread is E-Supra for ales - but then the motor would be the same for all similar models.
I have just completed a Pike Perfection SL ........... Converting an early Maxa (No 30) was a walk in the park in comparison.

I ended up getting the "1107/1.5Y - 6.7:1" or should I say Kv3850.

The Maxa is superb for light weather work - - Hang in the sky for as long as possible. The Hacker A20-6XL works fine for this as all I wanted it to do was get to 200m in less than 30 secs and weigh as little as possible.
The only other thing it needed to do was be able to do 2 rounds on the battery, in case you have to do 2 rounds, back to back.
So the Maxa now does everything and more - I am delighted.

For the next part I needed more speed / weight, to take over from the Maxa when the wind came up. The Pike seemed to fit the bill, except there is no E-fuz and when I got it, the task looked "difficult."
I actually flew the pike as an F3J model to get the feel and see if I really liked it. I did, it is really nice to fly, so I then had to figure out how to do it.
You cannot use under the wing and carving into parts of the tail just did not seem like options...........(I actually wanted to add weight to this plane) But, a very light, efficient motor was sourced, simply because I did not want to add weight to the tail and the momentum issues that would cause.

As F3J it weighed 1775g and as F5J it now weighs 1885g ......... An abject failure for its remit. That is with a 800-3S (65C) and no weight on the tail.
If I use an 1100-3S it would always be able to do 2 flights, but that needs 15g on the tail. The tailplane on this is extra light, so perhaps a standard / stronger one would be the solution.......... Wt then becomes 1930g.
Being the super light version, there are no ballast tubes, but the wing joiner could hold a substantial ammount. (Wrong solution - stronger / heavier wings being the right one)

And why post here ?

It is important to understand what you actually want. A light floater is just that - just get it up and float for as long as you can.
There comes a point where you need to move round the sky - efficiently. With the ability to get back after working a weak thermal.

My 3850 is on a 16 x 8 - and is very happy. I was told that there would be no problem with a 16 x 10......... I think it will get a 15 x 9.5 first, if I want it to get up wind faster.

Here, it is either very windy, windy with a lot of rain, very heavy rain or dark because it is night - so the important bits will come later.

After that lot, all I am trying to say is there are many different Supras and you must understand the strengths and weaknesses of your variety.
Light ones get a light setup and the heavy ones get a heavy setup. Light ones are meant to be light (and fragile) and heavy ones can get / need more power and they are stronger, to take it.
My Pike should have had a 1110/2Y and 4S and weighed in at 2200g - Perhaps I should look at an Xploder II next.
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