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Section 40 Change

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yankee-flyer

Well Known Member
Does anyone know the reason for the addition of the blast tube and cooling shroud over the rectifier added in the new Page 40-14 revision? 143WM is basic, no lights, no Skyview-- do I need to order those parts and cool the rectifier?

Wayne 120142/143WM
 
Section 40

Section 40 is for the lighting kit. My interpretation is that additional cooling is not needed for the voltage regulator unless the lighting kit is installed. Heat shortens the life of electronics. The voltage regulator will get hotter with the lights turned on. Even without lights, keeping the voltage regulator cool will prolong its life. But it might not be worth the time and expense and weight to install the cooling kit if the lighting kit is not installed.
Joe Gores
 
yankee-flyer said:
Does anyone know the reason for the addition of the blast tube and cooling shroud over the rectifier added in the new Page 40-14 revision? 143WM is basic, no lights, no Skyview-- do I need to order those parts and cool the rectifier?

Wayne 120142/143WM
Click to expand...

This came with the first light kit and we assume it is to prevent the rectifier from over heating at higher load levels that may occur with the added draw of the lights.

It would be a good idea for any RV-12 as keeping the rectifier cool is always a good idea.

We have found one small issue with Van's design of this modification, the ridges on the blast tube are to small for the thickness of the fiberglass where you cut the hole to install the blast tube. We have modified several with a small aluminum plate riveted to the inside of the engine cooling shroud with a hole that fits the smaller diameter of the blast tube and then cut the hole in the fiberglass just larger than the larger diameter of the blast tube. with the hole centered in the hole of the fiberglass the plastic blast tube fits nicely and holds as it is designed to. The plate was made from scrap 0.0020 or 0.0025 material, we used three or four standard pulled rivets with a little RTV under the plate and then added RTV around the outside of the blast tube.

Good luck with yours.

Best regards,
Vern
 
Lighting kit changes

My lights are not yet installed, but I will be doing that job soon. Does anyone know if Vans has an upgrade kit available, or at least a revised parts list to go with the updated plans?
 
DonFromTX said:
SN461 lighting kit did not come with that stuff, probably with the engine or avionics kits?
Click to expand...

mine came with the lighting kit.
perhaps it was a later addition?

Anyone know why cars don't have to do this?
I'm always interested to know the "why".
I know the point is to keep it cool.
But this is not a nuclear power plant !
cars have a 12V electrical system and plenty of headlights etc.
perhaps it's the size of the regulator? small and light for the aircraft and much larger and heavier in a car?
 
Dynamo vs Alternator

The Rotax has a permanent magnet alternator also known as a dynamo. The magnetic field of the dynamo is fixed by the properties of the permanent magnets. The magnetic field of a car alternator can be changed as required by varying the current going to the field winding. The output of the Rotax dynamo is controlled by the regulator turning the output on and off at a fast rate. Doing that makes heat. The output of the car alternator is controlled by varying the field current. Since that field current is a small percentage of the car alternator output, not as much heat is produced.
A analogy is a furnace. One type of furnace is turned on and off to control building temperature. Another type of furnace varies the flame size to control building temperature.
Even though the Rotax regulator is prone to fail if overheated, the dynamo does not have much to go wrong. The only moving parts are the magnets. And they are part of the flywheel. If the flywheel stops turning, you won't need the dynamo anyway.
Joe Gores
 
Of course if you want automotive type dependability and function, you MIGHT be in the market for a Viking! :D
tim walter said:
Anyone know why cars don't have to do this?
I'm always interested to know the "why".
I know the point is to keep it cool.
But this is not a nuclear power plant !
cars have a 12V electrical system and plenty of headlights etc.
perhaps it's the size of the regulator? small and light for the aircraft and much larger and heavier in a car?
Click to expand...
 
Note to self...

rgmwa said:
My lights are not yet installed, but I will be doing that job soon. Does anyone know if Vans has an upgrade kit available, or at least a revised parts list to go with the updated plans?
Click to expand...

Just had an email from Ken at Vans saying that the new connectors for the lighting kit will be shipped with the avionics kit.
 
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