Cloud Niner - Bill Winter design - K&B 65 to electric - RC Groups
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Jul 14, 2017, 07:54 PM
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Cloud Niner - Bill Winter design - K&B 65 to electric


A scratch build from RCM plans....I started this one with intention of putting the K&B 65 sportster glo engine in it.
After I read up on the issues with that engine I decided to go electric.

I'm relatively new to this electric thing...I've done four...all sailplanes and vintage oldtimers...an Oly 650 on a brush can motor and a Mega Pepper on a geared speed 400, a Skybench Big Bird sailplane with a direct drive Phasoar, and a Lanzo Bomber.

This will be my largest electric so far.

I've enjoyed flying the Eflite 480 on my Lanzo Bomber - so I decided on an Eflite 60 motor.

Question now, after reading past postings on the Eflite 60 ESC for the Eflite 60 motor - I'm considering ditching the EFlite 60 ESC and going for an 80 amp on the speed control.
I don't plan on doing aerobatics with this...just exploring the STOL features it was designed for - and thermaling.
So I'm not sure if I would be approaching the upper limit of the 60 A ESC....

Don't have an AUW on this yet...but specs on the Glo version said 7 - 8 lbs.

I'm interested in hearing from anyone that has had experience with the Efite 60 motor and what ESC you used....
- or anyone that has built and flown a Cloud Niner.
Last edited by AllThumbs; Jul 14, 2017 at 09:26 PM.
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Jul 14, 2017, 08:22 PM
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scirocco's Avatar
There are two Power 60 models. One has Kv=400rpm/V and the other has Kv=470 rpm/V. Which do you have?

What batteries are you intending to use?

What size prop is it?

Those answers are necessary to predict whether you are approaching the upper limit of the ESC.

My expectation is that a power system for a 71" 8lb non-aerobatic model using either Power 60 would use 5 or 6S batteries and will not need to draw more than about 45A so a 60A ESC should be more than adequate.
Jul 14, 2017, 09:21 PM
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AllThumbs's Avatar
Quote:
Originally Posted by scirocco
There are two Power 60 models. One has Kv=400rpm/V and the other has Kv=470 rpm/V. Which do you have?.
I've got the Kv 400

Quote:
Originally Posted by scirocco
What batteries are you intending to use?.
Motor Spec sheet suggests a 5-7S Li-Po

Quote:
Originally Posted by scirocco
What size prop is it?
Motor Spec sheet suggests a 16 x 10E....or a 14x8E - I have adequate clearance to go the 16 route, if it works well.

Quote:
Originally Posted by scirocco
Those answers are necessary to predict whether you are approaching the upper limit of the ESC.
My expectation is that a power system for a 71" 8lb non-aerobatic model using either Power 60 would use 5 or 6S batteries and will not need to draw more than about 45A so a 60A ESC should be more than adequate.
I noticed the motor spec sheet said Max burst current : 60A .....with footnotes on adequate cooling and maximum 30 seconds.
I read some horror stories on the forum about carbon cubs with Eflite power 60 burning up the Eflite 60 ESC....and guys going 80 A as a result.

I bought a used Eflite 60 amp Pro SB brushless ESC (V2) EFLA1060B 39007 indicates 3-6S Li-Po on it.

Thanks for your help......I'm a tad confused on the 80 amp thing on Eflite 60 motors......especially after I read this:
http://www.e-fliterc.com/ProdInfo/Fi...l_Addendum.pdf
Then I saw that was for the 470 Kv....

Still, after putting all this time and effort in this build - I'll do what is necessary to keep this thing proper.
I plan on using JR servos ...will have six analog servos for functions....R/E/T/two wing aileron/one flap drive
Jul 14, 2017, 10:30 PM
Registered User
scirocco's Avatar
With the 400rpm/V motor, I'd strongly suggest 6S. 5S will require you to use at least a 16" prop for decent performance and if you are limited to 16" by ground clearance you've got nowhere to go if you find you want more power.

Battery capacity you choose will depend on your weight budget and desired flight time but even 3000mAh should give you over 7 minutes for the flying you mentioned - plus thermalling time . Note that you won't need high C rated super expensive batteries in this application. Anything rated at or above 20C continuous will do the job fine.

Prop choice will depend on just how fast a climb you want, but if you prop for about 800W and it ends up at about 8lb, it will climb out at over 45 degrees. I'd suggest starting with an APC 15*8. That should draw about 37-40A for near 800W. Even propping to 16x10, which would give you near vertical climb, maximum current should still only be about 50A (for just over 1000W),

Note that the current drawn does not depend on the motor specification, but entirely on Kv, battery voltage and prop size. The motor and ESC specs are maximum limits we stay under by smart choice of the power system components. So for the 15x8 at about 40A up to the 16x10 at 50A that means comfortable margins for both the ESC 60A continuous/75A burst maximum and the motor 55A continuous/65A burst maximum.

Re the Carbon Cub. The stock motor @ 525 rpm/V has much higher Kv than your Power 60 and stock probably draws about 50-55A. Anyone going to a bigger prop is going to exceed the ESC limits quick smart.

All the above is planning and prediction using ECalc, which is sufficiently accurate to allow you to make informed component choices. The essential step before flight is real world verification, which requires a wattmeter, to confirm that indeed the current with the prop used is under the component maximums and that the battery is delivering healthy voltage under load.

But if you still feel uncomfortable about using your Eflite ESC, I can recommend the Turnigy Plush 60, Turnigy YEP 60, Castle Creations Talon 90 or Hobbywing Platinum 80. Of those maybe the best value is the Plush 60. Any will handle your 6 servos easily.
Jul 14, 2017, 11:52 PM
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AllThumbs's Avatar
Quote:
Originally Posted by scirocco
With the 400rpm/V motor, I'd strongly suggest 6S. 5S will require you to use at least a 16" prop for decent performance and if you are limited to 16" by ground clearance you've got nowhere to go if you find you want more power.

Battery capacity you choose will depend on your weight budget and desired flight time but even 3000mAh should give you over 7 minutes for the flying you mentioned - plus thermalling time . Note that you won't need high C rated super expensive batteries in this application. Anything rated at or above 20C continuous will do the job fine.

Prop choice will depend on just how fast a climb you want, but if you prop for about 800W and it ends up at about 8lb, it will climb out at over 45 degrees. I'd suggest starting with an APC 15*8. That should draw about 37-40A for near 800W. Even propping to 16x10, which would give you near vertical climb, maximum current should still only be about 50A (for just over 1000W),

Note that the current drawn does not depend on the motor specification, but entirely on Kv, battery voltage and prop size. The motor and ESC specs are maximum limits we stay under by smart choice of the power system components. So for the 15x8 at about 40A up to the 16x10 at 50A that means comfortable margins for both the ESC 60A continuous/75A burst maximum and the motor 55A continuous/65A burst maximum.

Re the Carbon Cub. The stock motor @ 525 rpm/V has much higher Kv than your Power 60 and stock probably draws about 50-55A. Anyone going to a bigger prop is going to exceed the ESC limits quick smart.

All the above is planning and prediction using ECalc, which is sufficiently accurate to allow you to make informed component choices. The essential step before flight is real world verification, which requires a wattmeter, to confirm that indeed the current with the prop used is under the component maximums and that the battery is delivering healthy voltage under load.

But if you still feel uncomfortable about using your Eflite ESC, I can recommend the Turnigy Plush 60, Turnigy YEP 60, Castle Creations Talon 90 or Hobbywing Platinum 80. Of those maybe the best value is the Plush 60. Any will handle your 6 servos easily.
Thank you ...very much.
Appreciate the suggestions.
Nov 27, 2017, 04:57 PM
Registered User

Finished?


Did you finish your Cloud Niner? I am considering building one for IC power.

My question is, did you happen to have the "Complete Construction Article" mentioned in the magazine article, as not much was actually talked about as far as construction goes. Is this still available anywhere, or does anyone have a copy of the construction article?
Dec 20, 2017, 08:10 PM
Registered User
Quote:
Originally Posted by ericemn
.....
My question is, did you happen to have the "Complete Construction Article" mentioned in the magazine article, as not much was actually talked about as far as construction goes. Is this still available anywhere, or does anyone have a copy of the construction article?
Scroll down to the bottom of the screen for "similar threads" hyperlinks..... one of which is "need construction article" wherein someone posted images of the 5 page magazine construction and flight article.

I don't think Cloud Niner was ever kitted and if so I doubt whether there is a longer/more detailed construction guide to this specific model.
Apart from the split flaps, the construction is fairly standard.

Is this your first kit/plan build?

Added: oops.... I see that you already should have that 5 page article and that you are a new to building from a kit or plans.
The conservative/more sensible advice would be to buy a kit of the same nature such as Sig LT-40 or a Great Planes PT-40/Pt-60, which have extensive construction guides that presume no or very little building experience.
If you have your heart set of building Cloud Niner from plans and the magazine article alone - and are patient, ask questions along the way - you can use the free downloadable construction guides for the above similar models and kits AND read the sticky notes at the building of various categories in this forum on LOTS of subjects/issues such as "what to use as building board", cutting/shaping ribs for a constant chord wing, etc.
There's nothing unusual in the construction of the Cloud Niner apart from the split flaps; for flaps you may want to substitute "regular" flaps although you can search out articles/build threads/ask questions regarding split flaps when you get to that point in the construction.


Michael in Ontario, Canada
Last edited by 2michaely; Dec 20, 2017 at 08:54 PM.
Jan 19, 2018, 06:00 PM
Registered User
Built Cloud 9ER mabe 25 years ago. never flown. Reading posts this thread , inspiration to get it into the air.
Power Astro geared 40, and was 20 x NiMh cells. Will go for 6 5000 Lipos .
Improvement in computer radios over the years should make flying this STOL model a pleasure.
My first major scratch build, not difficult, a short cut kit would have been great.
RC Modeler magazine Sep 91 and Oct 91 .original articles.
Plans were 2 sheets,fuse and stabs, wings on second sheet.
Not a lot of construction info magazine, Plans well detailed with with set up info.
Jan 21, 2018, 01:46 AM
Registered User
Power check using original Astro geared 40 (brushed motor). Specs.40 amps max.
Prop.APC 14/7 battery 6 5000 25c AUW 7.5 lb. 38 amps a tad over 800 watts.
Not over powered but should fly ok using design specs.


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