As the title says, I’m looking to build up a power system to equal a Rotax 447. I’ve read through the posts in this section looking for a power system I’m wanting. Seems most power systems discussed are either in the PPG or 28-30 HP range, or Rotax 912 and larger equivalent.
I’ve had an idea for this design for a few years, but didn’t think that the technology was where I wanted it. More importantly, I didn’t have the money to do the project. But this week we sold a house that we’d inherited a few years ago, and now I can use a small portion of the proceeds to work on this project.
The idea’s based on a plane I built back in 1996. It’s a kit that was popular at the time. The plane is a two place plane with a nice, large wing for good wing loading numbers. For example, one day I was trying to fly it across the Pacific range to fly the coast, but as I approached the mountain range I was getting thrown all over. I turned back and parked the plane in the hangar. I’d had enough bouncing around. When I got home I calculated the wing loading at 3.9 pounds per square foot. The plane is sometimes registered as a motor glider, so it has a fair L/D ratio. I want a 447 equivalent because the plane was originally designed for that engine. Seems to me that it'd be a good plane as a single place e-machine.
Preliminary numbers. The plane had an empty weight of 375 pounds with a Rotax 503 and a BRS. If I remove the BRS, 503 and accessories, the plumbing and accessories, I figure I lose another 135 pounds. So, starting weight is 240 pounds. The gross weight per the manufacturer is 960 pounds. So 720 pounds to work with. Call it 700 pounds. Subtracting 250 pounds for the pilot and accessories leaves 450 pounds for the electric propulsion system.
Rotax says the 447 is 42HP/31 kW for power and 35 ft. lb./47 Nm for torque max 1 minute. I’ve looked at a few motor manufacturer websites for equivalent motors, but everything I found is either over or under that power/torque range. Once I find the motor that meets my needs, I’ll pick a controller, prop setup, and lastly batteries.
So, I’m new to actually researching motors and was hoping someone has good ideas about motor possibilities.
Mark
I’ve had an idea for this design for a few years, but didn’t think that the technology was where I wanted it. More importantly, I didn’t have the money to do the project. But this week we sold a house that we’d inherited a few years ago, and now I can use a small portion of the proceeds to work on this project.
The idea’s based on a plane I built back in 1996. It’s a kit that was popular at the time. The plane is a two place plane with a nice, large wing for good wing loading numbers. For example, one day I was trying to fly it across the Pacific range to fly the coast, but as I approached the mountain range I was getting thrown all over. I turned back and parked the plane in the hangar. I’d had enough bouncing around. When I got home I calculated the wing loading at 3.9 pounds per square foot. The plane is sometimes registered as a motor glider, so it has a fair L/D ratio. I want a 447 equivalent because the plane was originally designed for that engine. Seems to me that it'd be a good plane as a single place e-machine.
Preliminary numbers. The plane had an empty weight of 375 pounds with a Rotax 503 and a BRS. If I remove the BRS, 503 and accessories, the plumbing and accessories, I figure I lose another 135 pounds. So, starting weight is 240 pounds. The gross weight per the manufacturer is 960 pounds. So 720 pounds to work with. Call it 700 pounds. Subtracting 250 pounds for the pilot and accessories leaves 450 pounds for the electric propulsion system.
Rotax says the 447 is 42HP/31 kW for power and 35 ft. lb./47 Nm for torque max 1 minute. I’ve looked at a few motor manufacturer websites for equivalent motors, but everything I found is either over or under that power/torque range. Once I find the motor that meets my needs, I’ll pick a controller, prop setup, and lastly batteries.
So, I’m new to actually researching motors and was hoping someone has good ideas about motor possibilities.
Mark
