An Electric Lazair

Share your thoughts, photos and general help to all builders

Postby Chappy » Fri Jan 06, 2006 11:28 pm

Clipped from the Lazair 4 thread:

"I am however working this winter on an electric Lazair conversion. 20 minute flights once a week are all I need and bye bye engine hassles. Expensive outlay though but hope to get costs including battery replacement to about $20/hr and that will come down."

Dale Kramer

Hi Dale,

Since I purchased the series IIIEC, I've been contemplating converting my early series 1 back to it's original condition (minus most of the heavy mods I thought were such a great idea way back then) and removing the engines (and associated stuff) so I could fly it at the Hang Glider field where my daughter and her boyfriend fly. They have a couple fat UL tugs there that could easily tow me. They have one of the late model Super Floaters there that flies fairly ofter. A striped down series 1 Lazair has to be superior to the heavy Dacron covered Super Floater, especially if you fitted the Lazair with a small nosecone and reclined the seat a little more.

Anyway, it turns out that I have a friend that has been into electric powered model planes now for 5-6 years. He's the local expert, having built SEVERAL hundred electrics over the years. A couple weeks ago I stopped by the hobby shop that he now works at since he retired. I told him about our 6000 mile trip this fall to pick up the EC, and he asked if I still had the Series 1. I told him about my thoughts on turning it into a glider (with those old Pioneers, it's been a "glider" many times) and he got excited about converting it to electric. He said there were some large electric motors available now that he thought (a pair) would be adequate to get me up. I had to postpone getting back to him since then, but maybe next week I'll stop by again.

I did came across a motor just the other night that's used in an electric bike that looks pretty awesome. The motor is made by Briggs and Stratton of all people. It's the E-Tek, and it's rated at 12 HP peak, 2.7 HP continuous and weighs 21 pounds. Fancy electronic controllers are available for them off the shelf. Batteries to power them would be serious money, I'm afraid, but then we only need a thousand feet or so per charge. I haven't done any number crunching as to what would be required in the way of motors and battery capacity. I'm not sure I could get all that close anyway. I would be very interested to hear what you think would be required.

I hadn't planned on discussing this conversion on this forum, as many members get a little bent (to say the least) when you start talking about modifications to Lazairs. Since you brought up the subject, and in a way you are sanctioning it, I think I'm safe talking about it now!


E-Tek motor link: ... _motor.htm
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Postby Dale Kramer » Sat Jan 07, 2006 9:41 am


Send me an e-mail and we'll talk.

Dale Kramer Member
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Postby darkhorse » Fri Apr 07, 2006 9:03 am

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Postby yankeflyer » Tue Apr 11, 2006 4:14 pm

There is one Briggs Stratton Etek DC motor for sale on eBay. Obviously one motor is not enough to do Lazair people any good and there is a caveat at the Briggs Stratton web site that the motor is only available for export? I'm not sure if I had a US web site or European web site.

Very interesting guys -- electric motors can be run in series or parallel for more efficient operation at low speeds and then after the momentum has built up transition can be made to series or parallel set up.

I'm embarrassed to admit that after 20 years of running locomotives I can't remember which one is which -- series or parallel -- but one definitely has its advantages when used in starting the loads moving.

I just bought a new Milwaukee cordless drill that uses 28 volt lithium-ion batteries -- very impressive performance.

I will certainly be researching this motor and the possibilities for use with my airplane, it would be nice to avoid the use of a redrive B)
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Postby rayjb60 » Tue Apr 11, 2006 5:19 pm

Check out this full size electric glider for ideas on the power system.

Apis Motor glider

Very cool, but the cost is still high.

I guess brand new Zenoahs at $1,800 with CDI are looking pretty cheap at this point.

Even a pair of AMT Jets for $10K looks good.

<H5>Nothing is impossible...Even the word tells you Im-Possible!!!</ H5>
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Postby yankeflyer » Wed Apr 12, 2006 12:42 am

This guy has put the etek motor through some test on his boats and has documented some interesting numbers.

and the guy in Italy that won`t sell to directly to Americans- has a new engine with some great numbers-

Displacement cm³ 164
Bore mm 62
Stroke mm 54.5
Compression Ratio 11:1
Power Hp 22
kW 16.18
RPM 7.200
Weight of the engine Kg 9
Weight of the propeller kg 3

But the Swedish made engine still looks to be the best buy for the money-
not that there is anything wrong with the tried and true engines that are on most Lazairs, I read about.

Raket 120 Aero Es-Rd
Partno: 3201-4
Retail price: 864,89 € ( about $900.00 or so ) <_<

Raket 120 Aero ES-RD complete engine with a built-in reduction drive.

Raket 120 ES-RD is developed for paramotors and it is prepared for propeller mounting.

The engine has a built-in electrical start and the engine starts with a simple click on the start button.

The weight of the engine complete with reduction drive is only 8,1 kg (without battery and exhaust)The engine is delivered complete with carburettor, exhaust system, reductiondrive and user manual.

Technical data

type of engine one cylinder two-stroke engine, piston control of inlet
cylinder volume 118,8
stroke 42 mm
bore 60 mm
piston ring 1 st 1,5mm
cooling fan cooled
ignition transistor
power 10 kw 9000rpm
max rpm 13000 rpm
weight 6,8 kg
carburettor Walbro
clutch centrifugal
starter built-in electric start
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Postby Chappy » Wed Apr 12, 2006 8:31 pm


Thanks for the link (Apis Motor glider)! I see he is planning on upgrading to much lighter and more efficient brushless motors for the production version. I'm just wondering where he's going to find 20HP motors, and controllers for them. Maybe he's planning on building them?

Good thing a Lazair doesn't need two 20HP motors to fly. I don't think it will be too much longer before we see Lazair's fitted with electric motors.

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Postby yankeflyer » Thu Apr 13, 2006 1:32 am

I'm collecting some very interesting about electric motors. Ray is right about the cost, however there are many options, that the resourceful and enterprising Lazair owner could consider.

The electric motor on ebay sold for $650 and the top-of-the-line equivalent is now made in Europe cost almost $1900.

An electric motor can be wired to be a generator -- using the weight and momentum of the vehicle -- windmilling propellers while descending could theoretically recharge a battery.

I sure like the idea of not needing gasoline to fly. <_<
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Postby yankeflyer » Tue May 02, 2006 2:22 pm

Here are some pictures of my series 1 as it presents itself after an unknown amount of time in the trailer. After months of reading about and looking at the pictures of other lazair owners airplanes and their efforts, I think that putting out some before pictures of my plane, will help me focus on the most necessary changes to ensure airworthiness and reliable performance.

Not that the cosmetics are unimportant to me -- the sooner I'm flying the better. One more thing, I'm posting to this thread because I hope to have electric motors as an option for the future.
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Postby yankeflyer » Tue May 02, 2006 2:28 pm

hanging from the rafters of my almost finished shop/pole barn/studio/hanger
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