SonexBuilders.net

We have picked the project back up and made some progress the past few months. I am going to try to keep this page updated as the project progresses. Currently I am working on a mount for the Yamaha apex and I am considering panel layout options. I am planning to order the dual stick kit soon.

Very cool! Keep on building!

Thanks Bryan!

The Skytrax gearbox is on the way. The gear tower will be welded up this weekend and I am working on a jig to connect the gear tower to the engine support tubes so I can fabricate the rest of the engine mount. I may change this some as it comes together but here is what I am going for:

I received the skytrax gearbox and got the gear tower welded over the past few weeks. I am working on wrapping up the engine mount and hope to have the engine hung before too much longer.

I finished the majority of the engine mount and I hung it on the plane for the first time today. It fits perfectly under the top cowling, but the bottom will require some slight trimming and reshaping to clear the water pump. Next step getting the cowl on and the radiators and exhaust mounted.

I am planning to paint the engine mount red. I am considering using a quality high temp rattle can paint, although I do have the tools to mix and spray. Anyone have any suggestions for painting 4130 Steel parts?

When I was restoring a C140, I pretty much painted all the 4310 with epoxy primer. I think it is the gold standard. But I think rattle can would be fine too. Definitely a rattle can would be fine for an aerovee, they have a great corrosion inhibitor system.

Thanks! Hopefully I don't end up with the built in oil corrosion protection. If I have oil leaks, I have big problems. I will look some more at a 2-part epoxy primer. Is there a particular brand you would recommend?

I think I used Stits white:
https://www.aircraftspruce.com/catalog/ ... ckkey=5223

Probably they are all good.

Is powder coating an option? I've done many parts at a local shop here. Always a very nice finish, and durable. Though a bit costlier than rattle can.

How much does that engine/gearbox weigh?

Thanks for the suggestions! I too love powder coat and I have a great local shop I have used in the past. I considered powder coat for this, but ultimately decided against it because it loves to hide cracks. I was leaning towards painting it a light color so I will see any cracks if they do develop. Another plus is that I can patch paint or epoxy a lot easier than powder coat.

The engine with gearbox weighs 137 pounds. That does not include the radiators, airbox, exhaust, oil tank, and other misc. items. It is slightly heavier than a rotax 912, but makes 1.5x the power. With a fixed pitch prop it is within the 200 pound limit sonex gives. I am thinking about biting the bullet on an airmaster propeller, which is heavy. If I do, I will be really really close to the 200 pound limit sonex gives.