Bee & Sure Start Mounts

Hi Roddie,

I think I understand what you mean but I think you are viewing the mounts as mounts that have independant fastenings to the firewall.

I always like to simplify things and be able to make adjustments on the fly.

The fastenings I used for the pictures were intended to show the mounts fastened to the engine. So I can see that looking at the nuts you would appreciate the difficulty using these to mount the assembly.

However, in the forewall, I use captive T nuts and epoxy them in. They are positionsed to match the engin mounts. A bit like this, except in this example I didn't think that the firewall was thick (or strong) enough so I spread the load.



Then the motor is mounted and bolted straight through.



I also use spring washers and threadlock where necessary.

This one is more deceiving



This plane was intended for a .39 IC engine and so shows four additional fastenings (also T nutted) - they were intended to take the engine bearers for the IC engine and so I built the mount to uses these as well as the straight through fastening. A bit of overkill - eight M3.5 fastenings!
This was also locked in place with threadlock, spring washers and lock nuts using threaded rod.

So, I tend to set the firewall so that it can take the engine directly and then use the mount to extend the engine using the same holes (with T nuts behind).

The mount is then the same size as the backplate and not larger - no ears. Otherwise the firewall may have to be enlarged.

I hope all this makes sense.

Yes, that makes perfect sense Ian. Seeing the mounts set-up on your models, makes it a lot more clear. They look really good.