# Electric Belite!

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#### Farfle

##### Well-Known Member
you painted the Oratex?
Yup! There is a list of paints that work, and paints to avoid. Nothing can be used that has plasticizers or agressive solvent bases. In this case I used Acrolon 100, which is an awesome rough duty 2 part waterbased urethane/acrylic paint thats designed to be a marine coating on oil rigs and locomotives.

Its pretty friendly VOC content wise and I tested a sample on the oratex earlier in the month. It did not affect the strength of it, and stretched with the fabric almost to the fabrics failure strength before starting to crack.

#### proppastie

##### Well-Known Member
Log Member
You could have used Dacron for a lot less money.....why?

#### Farfle

##### Well-Known Member
You could have used Dacron for a lot less money.....why?
Because the oratex covering and shrinking process was so easy even with the extra paint step (which was just a single stage paint, so mask and spray one coat and done)

Saved a load of time over a traditional system, plus its a good deal lighter.

#### Farfle

##### Well-Known Member
How much weight did the paint add?
All in all, I mixed about 1200ml of paint, thats thinned about 10% with water that evaps out. So at about 1.1g/L for the paint, I would say i have added about two pounds of paint total to the fuse.

#### pictsidhe

##### Well-Known Member
How many sq ft of paint?

#### Farfle

##### Well-Known Member
How many sq ft of paint?
Not much paint, The black is only the bottom ~8" of each side and the red is the top of the cabin/empennage and the whole vertical stabilizer + 1/2 of the rudder. Maybe .75'x13'x2= 19.5 sq/ft for the black and 2'x14' =28 sq ft for the Red paint. 1200 grams of paint for 47.5 sq/ft leaves about 25 grams per square foot for the acrolon 100.

#### pictsidhe

##### Well-Known Member
The lightweight oratex is around 3oz/yd^2, so the paint at 8oz/yd^2 is heavier than the fabric...
Anyone have numbers for painted dacron?

#### Farfle

##### Well-Known Member
The lightweight oratex is around 3oz/yd^2, so the paint at 8oz/yd^2 is heavier than the fabric...
Anyone have numbers for painted dacron?
Hah! I would not have guessed that.

However, take those numbers with a grain of salt, as it was 1200ml of mixed material going into the spray gun, I sprayed several test panels with that material, plus while spraying a WAG of 70% of it makes it onto the airplane with the rest becoming overspray, then some amount after that flashes off as the paint cures. at least 15% evaporates off because thats the water its thinned with, and then the solvent in the acrylic side flashes off some unknown percent. then whatever is left in the spray gun got poured into the trash and cleaned out of the gun.

At the end, there is a good amount of that 1200ml that did not become part of an airplane. I might even say as far as half of it does not make it to the airplane. Either way, I dont think my corner scales are accurate enough to see the weight difference from the amount of paint that went on.

#### Farfle

##### Well-Known Member
Awesome. I will have a much better shot at weighing the paint application to the wings, as the fuse is too heavy for my sensitive scales, but I have a 20kg fish scale that can do single digit grams, so I should be able to get before and after weights after painting on each wing. will also be good to see how asymmetrical the paint loading is by hand spraying it just as a data point for entertainment.

#### proppastie

##### Well-Known Member
Log Member
2 gram......4.18 oz/sq yard
3 gram.... 6.28 oz/sq yard

I found a sample of the 2.7 oz it weighed 2 gm but the resolution is only to 1 gram so I calculated for 3 gram also. I think it rounds off so could be any where from 1.5-2.5 gram. That does not count glue, tapes, rib stiching, rivets etc..... just raw finished fabric the Poly Fiber Ultra-lite process as per appendix A.

One coat of Poly Brush...Three Coats of Poly Tone 318M Piper Trainer Blue which already has the silver in it.

That was for my seat, but the plane will be covered in 1.8 oz bleed cloth un-certified Dacron.

#### Armilite

##### Well-Known Member
Hello all, I purchased a Belite Ultracub in Feb of this year, and now that I have some progress, I am posting up some pictures, Enjoy!

Specs:
Motor: Zero ZF75-5
Hp: 41hp cont, 54hp 5min
Tq: 78 ft/lbs
Base speed; 5808 RPM
Reduction: 65-30 8mm toothed belt drive (2.2:1)
Controller: Sevcon Gen4 size 4
Battery: Farasis 29Ah pouch in 28S4P configuration for 12.0 Kwhr of storage

===============================================================
Nice Project!

Do you have some Photos of your Battery Packs, Controller Setup?

What Size Cells does it use to make up the Packs?

Do you assemble your own Packs?

Most Electric Motors I have looked at show Continuous use at 50% of Max Power = 27hp.

If 54hp for 5 min, and then 41hp Continuous, what is your total Flight Time and what Reserve Time do you use?

#### Farfle

##### Well-Known Member
The Powertrain (Battery, Motor, Controller and DC-DC converter) are all factory components from a Zero Motorcycle. Specifically the motor from a 2016 Zero FX, and the controller and battery modules from a 2017 Zero DS.

The battery modules are 56 29amp-hour cells each, arranged 28 series 2 paralell for a total of 103V nominal at 58 amp hours. There are two modules in paralell for 116AH at 103V giving just under 12 Kwhr of usable energy.

The motor is agressively air cooled vs the motorcycle mounting where it is tucked behind bodywork, this plus the ventilated case about doubles the continuous output power. Mainly the burst power is limited by saturation, but this motor can handle another few hundred amps hefore really saturating, but the DS controller can only do 420 phase amps max.

There is the bigger controller that can do 660 phase amps and would raise the horsepower from mid fifties to mid 60s, but at the expense of more weight (9lbs vs 6lbs).

As far as reserve energy and flight time, nobody has good numbers on how much horsepower it takes to keep this plane in the air. The Polini motor makes 38hp on its best day, and the belite cruises at half throttle with that setup. Making the BOLD assumption that half throttle is half horsepower, that would be ~14kw of output power. At 12 Kw/hr that would be roughly 51 mins of flight tine between charges. With the average charge time off of a 220 welder plug being one hour, thats not a bad amount of flight hours per day.

#### Armilite

##### Well-Known Member
The Powertrain (Battery, Motor, Controller and DC-DC converter) are all factory components from a Zero Motorcycle. Specifically the motor from a 2016 Zero FX, and the controller and battery modules from a 2017 Zero DS.

The battery modules are 56 29amp-hour cells each, arranged 28 series 2 paralell for a total of 103V nominal at 58 amp hours. There are two modules in paralell for 116AH at 103V giving just under 12 Kwhr of usable energy.

The motor is agressively air cooled vs the motorcycle mounting where it is tucked behind bodywork, this plus the ventilated case about doubles the continuous output power. Mainly the burst power is limited by saturation, but this motor can handle another few hundred amps hefore really saturating, but the DS controller can only do 420 phase amps max.

There is the bigger controller that can do 660 phase amps and would raise the horsepower from mid fifties to mid 60s, but at the expense of more weight (9lbs vs 6lbs).

As far as reserve energy and flight time, nobody has good numbers on how much horsepower it takes to keep this plane in the air. The Polini motor makes 38hp on its best day, and the belite cruises at half throttle with that setup. Making the BOLD assumption that half throttle is half horsepower, that would be ~14kw of output power. At 12 Kw/hr that would be roughly 51 mins of flight tine between charges. With the average charge time off of a 220 welder plug being one hour, thats not a bad amount of flight hours per day.
====================================================================

Thanks for the Reply! I'm kind of challenged in all this Amps, Volts, Watts, KW, etc., stuff, but I'm learning.

Yes, many People know their Planes Max Speed and Engines Max HP, but never really pay attention to it's lowest Speed and HP@Rpm used for just maintaining Level Flight. Most of the Electric Motors that state their 50% Continuous HP use, don't really state in how their mounted, like on Bikes, Carts, etc., which are mounted Inline, so very little Cooling Air goes through them at those low Speeds, or are even mounted Rigid Stationary.

I would think a Simple Spreadsheet could be made up for each Type/HP of Engine and each Type of Battery Pack once you knew the Numbers. You will always have a +/- even with Gas Engines, since each Plane and Pilot Weigh different and as the Weather is always different.

If we use your, "54hp for 5 min, and then 41hp Continuous," and I asked what is your total Flight Time and what Reserve Time do you use?

54hp = 40.3kw for 5 min = How many Amps/Volts/Watts of Battery use does that take?

41hp = 30.6kw for Continuous use for what's left of the battery? That 41hp Continuous draws so much Amps/Volts/Watts per minute.

If I figured correctly, "For example say 90 minutes of discharge time at 25kw/33.5hp you would need (25kw * 1.5 hours) 37.5 kw-hours.
Since watts = amps * volts, and if the motor was 120v, then you would need 37,500/120 = 312 amp hours.
1 Kilowatt = 1000 watts.
If, Lithium Ion Cell is 4.2v, and Lithium Ion Phosphate Cell 3.7v."

All depends on what Size & Type of Cells used. On Belite's web page, they show a Battery Pack that looks to be 10 x 8 Cells = 80 Cells. But don't say what Type & Size. If I had to guess, one of these Lithium Cells from Headway. S means Threaded Stud I believe.
38120S 3.7v 10Ah
40152S 3.7v 15Ah
40160S 3.7v 16Ah

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#### pictsidhe

##### Well-Known Member
If you can find the minimum sink rate, required power can be estimated using an approximate prop efficiency. Will get you in the ballpark, anyway.

#### Armilite

##### Well-Known Member
If you can find the minimum sink rate, required power can be estimated using an approximate prop efficiency. Will get you in the ballpark, anyway.
============================================

The problem is, all Planes, and all Pilots, Weigh different, with different Size and Weight Electric Motors making different HP, at different Rpms, with different Props being used. That's why I left the RPM Column Blank. I'm betting 18-20hp on Average for Part 103's.

Like this REB 30 - 30kw Motor. (7) different Models to choose from. Most are 120v and look to be 4000rpm, 30kw/40.2hp and says Continuous at 15kw/20.1hp! But they only give you Max Hp@rpm.
http://www.rotexelectric.eu/products/bldc-motors/reb-series/

We should be able to put some HP/KW@rpm Numbers to a Chart. As we ought to be able to put some Battery Time in Minutes for each rpm used. Once you Build the Battery Pack it doesn't change, only HP@rpm used changes.

30kw@4000rpm
29kw@????rpm
28kw@????rpm
27kw@????rpm
26kw@????rpm
etc.

If I figured correctly, "For example, say 90 minutes of discharge time at 30kw/40.2hp you would need (30kw * 1.5 hours) 45.0 kw-hours.
Since watts = amps * volts, and if the motor is 120v, then you would need 45,000/120 = 375 amp hours.

1 Kilowatt = 1000 watts.
1hp = 1.341022kw
Lithium-Ion Cell is 4.2v, and Lithium Ion Phosphate Cell 3.7v.
So depending on what Type and Size of Cells used to make battery pack for 1:30min, for 375 amp hours, probably (102) 3.7v Cells or (90) 4.2v Cells. Cells prices seem to vary greatly, so it Pays to Shop around, but they aren't Cheap.

38120S 3.7v 10Ah = $16ea. 40152S 3.7v 15Ah =$24ea.
40160S 3.7v 16Ah = $32ea. Some way we should be able to put some Numbers to each HP @ Rpm Setting in Minutes of use. Say for Takeoff Full Power 30kw/40.2hp for 5 min Max = ????watts used. Then use say 75% 30.2hp = ????watts, and also 50% 20.1hp = ????watts used. Interesting Electric Go Cart Build. https://www.instructables.com/id/Gas-Beating-Electric-Race-Kart/ Using a popular High Output, smallish electric motor is the Motenergy (previously Mars) brushless motors. We thought they were about the best electric equivalent to Rotax, so we selected the ME1114 which will deliver over 20kW (27hp) on 78V, a peak torque of 98Nm at ????rpm, weighs 16kg (22lb) and costs around$900. A cheaper option is the ME1117 with 20kW peak weighing 10kg and costing about \$600.

#### Farfle

##### Well-Known Member
Made some serious progress over the last week! Got a bunch of things checked off the to-do list:

Finished the paint on the fuse! Red/Black/white is an easy color scheme, and it looks good! Paint on the wings next!

Replaced the last of the temporary hardware store bolts with AN hardware.

Repaired the tailwheel (wrong rod on the 1095 tailwheel spring made it crack and fail. Replaced it with a bolted joint.)

I also took it to the local EAA chapter#1395 and the folks there did an awesome job going over it and looking for things to fix. Found a few obvious ones, and some not so obvious ones! (thats the blue tape in the pictures, they correspond to numbers on a squawk sheet)

20180912_180335 by Jackson Edwards, on Flickr

20180915_161118 by Jackson Edwards, on Flickr

20180915_160934 by Jackson Edwards, on Flickr

20180915_160816 by Jackson Edwards, on Flickr

image-20180915_162535 by Jackson Edwards, on Flickr

20180915_174248 by Jackson Edwards, on Flickr

20180915_175015 by Jackson Edwards, on Flickr

20180915_175304 by Jackson Edwards, on Flickr

#### Victor Bravo

##### Well-Known Member
Farfle CONGRATULATIONS on a great looking project ! You are going to have a blast with that !

When you get to the point of flying, and if you find that are interested in a slight improvement in the climb rate and max L/D, let me know. There is a small but worthwhile chunk of aerodynamic efficiency and drag reduction available at the outboard ends of your wings.

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