Bob Barrows and his Electric Ultralight Flying Machine

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Armilite

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needs a B&S v twin.....
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If you notice in this Video it must have been made before the FFA made the final Ruling that Battery Weight is Included in the total Empty Weight. Listen at 5:20 where he is talking about it probably coming in at 250 lbs without the batteries!

As Airframe sat, not done yet, he was at 120 lbs, Wings 25 lbs each equals 170 lbs and not done yet. Batteries for 45min of Flight he said was 75 Lbs and you still have Motor & Controller Weight. You still need a Reserve, so more like 35 min, with a 10min Reserve!

The Lazair MTOW 450 lbs with (2) Rotax 185's had an Empty weight: 210 lbs (95 kg). The 185UL 9.4hp each were around 28 lbs x 2 = 56 lbs. 210 lbs - 56 lbs = 154 lbs for Airframe. That left 100 lbs for Batteries, Controller & Motor & Brackets. When the Designer of the Lazair tried to convert it to Electric, 45min was all he could get with (2) 11hp Motors.

Lazair MTOW 450 lbs - 254 lbs = 196 lbs for Pilot & Bags.

A pair of 185UL's gave you 2hrs of Flight with a Reserve on 5 Gallons of Gas.
 

TLAR

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Sep 29, 2020
Messages
224
I have planted the Vtwin seed, hopefully it will take root!
I would like to see a Bob Barrows Vtwin!!!
 
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Armilite

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Joined
Sep 5, 2011
Messages
3,488
Location
AMES, IA USA
I have planted the Vtwin seed, hopefully it will take root!
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These Honda/Clone GX390+ Singles are lighter and go up to about 676cc today! A 420 can make 37hp with the Upgrades. A Harbor Freight 420 is $399.99 cheaper when on Sale. A Duromax 440 Electric Start on eBay & Amazon is the Best Bang for your dollar.
 

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TLAR

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Sep 29, 2020
Messages
224
I am having trouble deciding on what to build, Bob’s ultralight or the Sky Dog (a Sky Pup with a MTOW of #500), either one will have a 4stroke industrial engine
 

AJLiberatore

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Nov 27, 2011
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115
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Canton MI
Batteries, Carbon Fiber, bonding aluminum, Mmmmm
In a world gone mad, how can you not gravitate to Bob's common sense & simplicity utilized in his designs. He's so underrated as a designer imho, think Colin Chapman & Steve Wittman. If the EV experiment doesn't work, I wonder if the ZDZ 500 w/ the reduction drive would fit the bill. Chk out BD5 Pilot on YouTube as he is moving toward utilizing that engine.
 

TLAR

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Sep 29, 2020
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Oh believe me, I love the Bearhawk Ultralight, it’s just that I have a lot of time invested in the Sky Dog
Edit—maybe I should just build both
 

TLAR

Well-Known Member
Joined
Sep 29, 2020
Messages
224
In a world gone mad, how can you not gravitate to Bob's common sense & simplicity utilized in his designs. He's so underrated as a designer imho, think Colin Chapman & Steve Wittman. If the EV experiment doesn't work, I wonder if the ZDZ 500 w/ the reduction drive would fit the bill. Chk out BD5 Pilot on YouTube as he is moving toward utilizing that engine.
Call Bob and make make that suggestion
 

TLAR

Well-Known Member
Joined
Sep 29, 2020
Messages
224
In a world gone mad, how can you not gravitate to Bob's common sense & simplicity utilized in his designs. He's so underrated as a designer imho, think Colin Chapman & Steve Wittman. If the EV experiment doesn't work, I wonder if the ZDZ 500 w/ the reduction drive would fit the bill. Chk out BD5 Pilot on YouTube as he is moving toward utilizing that engine.
I found the video and will check out the ZDZ option, thanks
 
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