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Gas to Electric

Old 09-19-2003, 03:16 PM
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Default Gas to Electric

I have a Ranger 42 made by Goldberg. It calls for a .10 gas. I'd like to run it electric.
I also would like it to be direct drive due to space limitations. Plane weighs 30oz.
has 42" span, 31" lenght wing area.
based on some reading that I've done, I've chosen a Graupner 500 GR1799 swinging a 8x4.5 prop direct drive. My question is: how far off am I?

Old 09-19-2003, 03:47 PM
Greg Covey
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Default RE: Gas to Electric

Hi Carl,

Your Speed 500 motor is a good choice.

The key factor here is in the battery pack weight and your preference for flying style versus battery weight.

A Speed 400 motor will also work on the Goldberg Ranger 42 but it would likely work best geared. The 10amp draw would allow for a lighter battery pack.

If your Speed 500 motor doesn't last, you may wish to try either a Kyosho Magnetic Mayhem (MM) or a hybrid motor like the Permax Turbo 450. The MM is sold at Tower Hobbies and is a very robust Speed 600 motor for low cost. The Permax 450 Turbo motor is speed 400 size but has the power of a Speed 500 motor. Both motors are happy at about a 20amp max. current draw.

Planetary gearboxes exist for Speed 400, 480, and 500 motors if you decide that your prop is too small and you need more thrust. Hobby Lobby has several gearboxes [link=]here[/link].

A geared Speed 400 motor would draw only 10amps and allow you to use lighter cells like the HECELL (NiMH) or Kan 1000s (also NiMH). An 8-cell pack weighs about 6oz.

Keeping the plane light will require less power to keep it airborn and allow it to have softer landings.

Good luck!
Old 10-15-2003, 08:41 PM
Jim Finn
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Default RE: Gas to Electric

I had short life spans with my speed 500 motors. The magnetic Mayhem motort is a better choice I think. It is a bigger motor too.

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