ORIGINAL: squeakalong
You did a fine job with lots of info to get these old grey cells going. One question: why use an outrunner type motor (remember I'm new at this..
)? Thanks for the help my friend!
Soft landings.
Joe
We are going to talk in general terms here.
Inrunners, like most motors you would think of, have the spinning part inside the can. These are usually high kV motors meaning high RPMs per volt applied. When turning propellers they can turn small props very fast. However for sailplanes, we are not looking for speed we are looking for steep climb. So we prefer big propellers. IN order to use an inruner you typically need a gearbox to step down the speed and multiply hte torque to handle the big prop.
NOTHING WRONG WITH AN INRUNNER AND A GEARBOX. They work extremely well. They also avoid any moving parts outside the casings. Finally, if you use the right gearbox, they can be quite slim and fit into narrow spaces.
Outrunners have the spinning part on the outside. They tend to be lower kV motors that can spin big props without a gearbox. Because there is not gearbox they also tend to be a bit quieter. So we eliminate the need for a gearbox, but we have to deal with the spinning can.
I prefer to do away with the gearbox and deal with the spinning can. Just a personal preference.