Originally Posted by GoneFlyin74
I have ran into a little bit of an issue with my motor installation. This is my first electric, so bare with me. So I decided to get a different motor than the one that was specified. I decided to get the Hacker A50-12S. The mounting pattern for the motor was slightly off so I redrilled some mounting holes using the center as a base for re-mounting the motor. The problem came in when I mounted the cowl with the predrilled mounting holes. The prop adapter is not centered within the cowl. So after trying to figure everything out, I think the problem has to do with the length of the motor mount and motor. The instructions say for a glow motor to the back of the motor should be 146 mm. So the mounting spacers that come with the plane are 62mm. The original e-flite motor is 62mm and lets say 2mm for the mounting plate and maybe 5mm to the back of the collet adapter, that is 131mm. By comparison the hacker is 62mm for the spacers and 71mm to the back of the prop adapter, this equals 133mm. With this setup the back of the prop adapter is recessed within the cowl. So I added a 5mm spacer, with this setup, the back of the prop adapter just barley clears the cowl but it is on right side of cowl (looking from the back). So what I was thinking was just re-mounting the cowl, this way I could center the prop and give some additional clearance for the cowl. I tried to find longer machine screws, but the maximum length I could find was only 3" which is what was supplied with the plane.
Should I just re-mount the cowl and call it good or do you guys have any other suggestions?
Thanks for the help.
Are you in the USA???
If so, take a run to your local hardware store, and buy a hand full of small flat washers with the proper inside diameter for your screws. If your 3 inch screws are to short, pick up four 3 1/2 inch screws and corresponding locking type nuts with the nylon inserts.
Then, by trial and error, put in a few flat washers on all four corners to bring your prop spinner forward. If the spinner is off center, put an extra set (or two) on one side to center it. Make certain the flat washers are equal, you don't want to twist the back side of the motor.
I'm assuming your model has some long spacers that are used to space the backside of the Hacker motor from the firewall? If so, I'd be a little reluctant to space the motor more than an inch or two from the firewall. That Hacker motor represents one and a half horsepower, and if its mount is not solid, you could have vibration problems if your prop is even slightly off balance. What I've done in this situation is to fabricate some hardwood spacers out of rectangular 1/2 or 3/4 inch stock, stacking them up to the proper height. One set for each side. When they fit, then glue them all together, and epoxy them to the firewall. To secure them run screws all the way from the Hacker motor mount, through the stacked hardwood stocks and through the firewall. Again, you can tweak the exact centering by a pile of flat washers. Doesn't weigh much, and is stronger than heck. Plus, its cheap. You can also buy commercial motor mounts, but they are not as cheap.
Also, since this is your first electric model, be
careful with that motor. That is, do ALL
setting up and stuff with the propeller removed from that motor. That motor looks pretty small compared to a glow 70 sized engine, but believe me, you do not want to get in the propellers way.
If you can locate them, pick up an APC-E electric prop, not a prop for a glow engine. They simply work better. If you're running a 5S Lipo pack, a good prop is a 15X10 APC-E.
If you have any other questions on your Hacker motor, let us know. FYI, I've got 8 Hackers, including two A50-12S and one A50-16S motor. Along with two A60 series motors. Those A50 motors will haul their respective 8 pound airplanes straight up, out of sight.