speed 400 duration
10-11-2004, 11:03 AM
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speed 400 duration
My daughter needed a science fair project. I needed to learn about electrics and to find the most efficient for my 2 meter sailplane for longest flights. I suggested we do a comparison on several different motors and measure their watt usage with the same prop at the same RPM. I will need a ammeter (need suggestion) and several types of speed 400 motors from the least efficient (I would guess ferrite) to the most efficient (need suggestion) I would like input on which motors to select and from where, or get or borrow used motors from a fellow r/c flyer and some suggestions on how to run the experiment. Our project investigation plan is due Nov. 8 and results and final project due in Dec. How bout some input?
Its raining in MO, and time for the indoor projects to start!
thanks,
Patternman
Its raining in MO, and time for the indoor projects to start!
thanks,
Patternman
10-11-2004, 11:48 AM
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RE: speed 400 duration
I guess it would have to be a comparison between Watts-in, because if you're spinning the same prop at the same RPM, the Watts out will be the same across the board 
It gets a little complicated, because "400" is a bit of an arbitrary term.
400 could mean a motor that's the same physical size as a 400, like Mega 16/15 series motors. However, there is no comparison; a Mega 16/15 can handle twice as much power as any can 400, and far more of that power finds its way to the prop.
400 could also mean a motor that has similar power output to a can 400. These are usually physically smaller than can 400s because they're far more efficient. Eflite's Park 400 motor comes to mind.
To make your comparisons as proposed, you need to be prepared with many different gear ratios and a variable voltage power source.
It gets a little complicated, because "400" is a bit of an arbitrary term.
400 could mean a motor that's the same physical size as a 400, like Mega 16/15 series motors. However, there is no comparison; a Mega 16/15 can handle twice as much power as any can 400, and far more of that power finds its way to the prop.
400 could also mean a motor that has similar power output to a can 400. These are usually physically smaller than can 400s because they're far more efficient. Eflite's Park 400 motor comes to mind.
To make your comparisons as proposed, you need to be prepared with many different gear ratios and a variable voltage power source.
10-11-2004, 01:00 PM
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RE: speed 400 duration
Thanks matt, I knew it would be complicated. Our project is on motor efficiency, comparing motors giving the same output, and finding the differences in design in the motor that gives the greatest efficiency. If necessary, we may build a thrust meter so different props and gearboxes may be run. There is a thrust tester in Model Airplane News I wold use. The thrust output requirement I would have to figure. I figure I would have to buy the proper speed controls for the motors as well. However, I am wanting in the end to power a sailplane that has been just sitting for 2 years.
