I'm on the way to completing a pull-apart Yatsenko Classic (home built copy with some changes to thrust lines) and will be installing one of my EL set-ups.

I've found in my previous models and when using the cheaper Arrowind 2832 motors that when the motor is mounted at the rear the whole 'can' tends to 'flex' a little which sometimes results in the stator rubbing internally on the magnets inside the 'can'.

With this in mind I thought I'd try something different and mount the motor at the front (still rear of the motor really - the drive shaft is just pushed through the stator and bearings so that it exits out the back end).

I found some 'right angle' annodised aluminium - about 2.5mm thick and quite sturdy - unable to flex it easily and have adapted it to take the motor.  Attached are photos of the motor now mounted on the aluminium bracket which I intend to mount flat up against the top section of the fuselage on a  1/4" plywood mount.  I thought that by using this method I'd be more certain of getting a zero degree thrust line from the motor as trying to mount a plywood former exactly vertical can sometimes be a little difficult and that it would perhaps be a little easier to 'flare' the nose of the model down to a spinner.

Attached are a couple of photos of the motor in-situ in the bracket/mount - at this stage I haven't any mount holes drilled in the bracket for where it will be attached to the model.

What I'm wondering is whether the aluminium is going to be susceptible to 'work' hardening and cracking during continued use/flying - particularly where the right angle section is.  I'd expect that when it was manufactured it was 'extruded' - not bent; as mentioned, it feels quite sturdy so I don't think that 'strength' will be an issue.

Any useful comments welcomed!

Thanks, Bruce

Hi Bruce,
 I'd go along with what Tim said, I think any form of mount where the fuselage anchor point(s) are not in line with the motor is asking for trouble, there is a lot of gyroscopic force coming from a prop turning at 9000+ rpm without the inertia of the motor itself. I too use aluminium right angles for mounting my motors but I use two attached each side of the centre line of the motor, doing it this way also keeps the motor itself in the air flow rather than partially hidden behind a plate. I would think you would actually see quite a variation in effective thrust line during some hard square corners for example.

TTFN
John.

Instead of the angle, I would use an aluminum U-shaped channel of the right size that your motor would just fit inside. 
Design fuse nose structure to provide hard attach points for both the top and bottom legs of the U-channel.   

     You are probably right. It does have scaring that runs length wise and the out side corner is nice and sharp just like the extruded ones I see at the hardware. It felt soft and when I was working with it in a vice it bent which I kind of liked thinking I might run it in the ground some day and would prefer that it gave some. One thing it wont do is bend at or close to the corner. I've noticed that my planes are a little noisier using this type of mounting.

I suspect that your mount as pictured would suffer from fatigue failure after a reasonably short time, maybe less than 100 flights. Extruded 6063 (one of the more common) is not friends with fatigue and that's a pretty thin section. You might have significantly more luck with that piece if you had triangular gussets welded into the corners.

The apparent obstruction of the cooling vents may also be something to worry about.