I recently received a Top Flite AT-6 Texan complete with Saito FA-82 four-stroke glow engine and servos. After a thorough safety inspection and cleaning I've started the conversion process. I ordered a new cowl from tower hobbies as the old cowl had holes in it for the muffler and glow plug. I removed the dummy motor from the old cowl and cleaned it using borax and a brush to cut the oil and grease. Cleaned up nicely.
The biggest issue when doing an electric conversion, I have found, is the appropriate power setup. I fly scale and one of the goals I shoot for is scale RPM. This in turn leads to issues with motor selection as you need the right KV motor and battery selection with a prop to actually pull the plane. The scale RPM is 2250 which is really out of the question to get speed. I decided on a 4S setup and the NTM 42-48 650 KV motor. Without a prop this will swing at about 11K RPM. I chose a 15X10 APC-E prop that will put the draw close to the max of 1300W on the bench but will unload in the air. An 85 A ESC that has a 5A BEC built in will do the job nicely. I've used this ESC in my L-4 Grasshopper with the same number of servos with no issues.
So, the other issue you face with these conversions is that the firewall is typically very far back from the prop location. Now you can spend the $ for a fancy adjustable mount or you can do what I did. Spent 5$ on some bolts, screws, and aluminum stock and make your own! The aluminum is 0.75" wide and 3/8" thick. I simply placed the stock in my vise and bent it to shape measuring the distance the mount needed to be. The manual states a total of 145mm from firewall to the back of the prop. My motor with mounting plate is 59mm so measuring carefully I made the mount 86mm. I drilled out the mounting holes and secured the motor to the bent aluminum with hex head bolts and nylon lock nuts. CA on the back threads to make sure they do not go anywhere. The firewall was drilled with new holes and T-nuts were installed. The motor was secured with more hex head bolts into the T-nuts. Pictures show where I am now.
The biggest issue when doing an electric conversion, I have found, is the appropriate power setup. I fly scale and one of the goals I shoot for is scale RPM. This in turn leads to issues with motor selection as you need the right KV motor and battery selection with a prop to actually pull the plane. The scale RPM is 2250 which is really out of the question to get speed. I decided on a 4S setup and the NTM 42-48 650 KV motor. Without a prop this will swing at about 11K RPM. I chose a 15X10 APC-E prop that will put the draw close to the max of 1300W on the bench but will unload in the air. An 85 A ESC that has a 5A BEC built in will do the job nicely. I've used this ESC in my L-4 Grasshopper with the same number of servos with no issues.
So, the other issue you face with these conversions is that the firewall is typically very far back from the prop location. Now you can spend the $ for a fancy adjustable mount or you can do what I did. Spent 5$ on some bolts, screws, and aluminum stock and make your own! The aluminum is 0.75" wide and 3/8" thick. I simply placed the stock in my vise and bent it to shape measuring the distance the mount needed to be. The manual states a total of 145mm from firewall to the back of the prop. My motor with mounting plate is 59mm so measuring carefully I made the mount 86mm. I drilled out the mounting holes and secured the motor to the bent aluminum with hex head bolts and nylon lock nuts. CA on the back threads to make sure they do not go anywhere. The firewall was drilled with new holes and T-nuts were installed. The motor was secured with more hex head bolts into the T-nuts. Pictures show where I am now.
