Rotax 912iS or 912ULS for Sling 2 ???

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TimTaylor
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby TimTaylor » Wed Mar 21, 2018 3:44 pm

How do you drive an auxiliary generator?
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby Wm.Ince » Wed Mar 21, 2018 4:07 pm

TimTaylor wrote:How do you drive an auxiliary generator?

With a Rotax 912iS.
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby TimTaylor » Wed Mar 21, 2018 4:27 pm

drseti wrote:The 912 ULS generator puts out 15 amps. For avionics systems that put a heavy load on it, most of us supplenent this with the 20 amp aux gen.
How do you drive an auxiliary generator?
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby 3Dreaming » Wed Mar 21, 2018 4:37 pm

TimTaylor wrote:
drseti wrote:The 912 ULS generator puts out 15 amps. For avionics systems that put a heavy load on it, most of us supplenent this with the 20 amp aux gen.
How do you drive an auxiliary generator?


Typically belt driven off a pulley added to the propeller flange. A small generator can also be added to the back of the gearbox on the accessory pad.

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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby drseti » Wed Mar 21, 2018 5:06 pm

My 20 amp aux mounts to the accy housing on the back of the gearbox.
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby TimTaylor » Wed Mar 21, 2018 5:18 pm

I was just curious how you could spin two generators.
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby drseti » Wed Mar 21, 2018 5:35 pm

At full current draw, the aux gen loads down the engine by 1/3 HP.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby FastEddieB » Wed Mar 21, 2018 5:46 pm

MrMorden wrote:[
We are on the same page. :)


...and...

Nomore767 wrote:Agreed!


Seriously guys, knock off all this Kumbaya stuff!

I came here for an argument!

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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby drseti » Wed Mar 21, 2018 5:58 pm

"No you didn't. "
"Yes I did!"
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS/PPC, iRMT
AvSport of Lock Haven
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby Nomore767 » Wed Mar 21, 2018 7:55 pm

FastEddieB wrote:
MrMorden wrote:[
We are on the same page. :)


...and...

Nomore767 wrote:Agreed!


Seriously guys, knock off all this Kumbaya stuff!

I came here for an argument!

Image


I can’t say anymore....I signed a Non Disclosure Agreement :wink:

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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby 3Dreaming » Wed Mar 21, 2018 10:11 pm

TimTaylor wrote:I was just curious how you could spin two generators.


The primary generator is built into the engine, leaving options for installing a secondary generator/alternator.

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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby drseti » Wed Mar 21, 2018 11:11 pm

The Rotax generator is really a cool design. (OK, I'll admit I'm a technology nerd.) They embed permanent magnets in the circumference of the flywheel. Thus, spinning magnetic field. Then, they place a total of seven stationary coils around the periphery of the flywheel housing. Since the coils are stationary, there's no need for slip rings or brushes.

The spinning magnetic field induces currents into the stationary coils. If you properly connect to a pair of coils spaced physically 180 degrees apart around the flywheel, you get a raw voltage. So, one pair of those coils generates power for one capacitive discharge ignition module. A second pair does the same for the other CDI module, and a third feeds the voltage regulator module that powers the main bus.

That leaves a single coil to produce a pulse of voltage each time the flywheel makes a revolution. And that pulse, students, drives the tachometer.

Pretty cool, no? Class dismissed.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS/PPC, iRMT
AvSport of Lock Haven
fly@AvSport.org
http://AvSport.org
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby cam737 » Thu Mar 22, 2018 12:02 am

Oh yeah. I knew that. :shock:

dr...my eyes are so glazed over I can barely type. But, I got through the first 2 sentences. :)
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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby cam737 » Thu Mar 22, 2018 12:12 am

Wm.Ince wrote:Regarding the choice between ULS and iS, something that should not be overlooked is the demand on the aircraft electrical system.
Besides wing strobes and position lights, I believe the Sling is equipped with 2 taxi lights and 2 landing lights. If the autopilot is engaged, will the ULS easily handle that load or will the limit be pushed?


Bill, I was concerned that my Sling 2 would need a really long extension cord for everything to work. Midwest Sky Sports has built Slings with higher electrical power requirements. The plan is to use a 40 amp external alternator.

Don't ask me any questions. I don't know the difference between 'positive' and 'negative', let alone the spinning magic things the dr talks about!

I just want everything to work great and last a long time!

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Re: Rotax 912iS or 912ULS for Sling 2 ???

Postby drseti » Thu Mar 22, 2018 12:24 am

cam737 wrote: I don't know the difference between 'positive' and 'negative', let alone the spinning magic things the dr talks about!


Not magic, Cam, magNETic!
;)
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS/PPC, iRMT
AvSport of Lock Haven
fly@AvSport.org
http://AvSport.org
http://facebook.com/SportFlying


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