SonexBuilders.net

I was watching the Aerovee assembly video and it looks very easy to heat and install the gears and prop hub. For those that have done it. Is it that easy? Or is it better to get the pre assembled crank?

I assembled mine with no trouble.... Have not yet flown

Bruce Johnson
N593SX

I did mine. If I had it to do over, I would have refroze the crank after I put the gears on. When I put the heated gears on the crank it warmed up the crank enough to cause some difficulty getting the prop hub on the last 1/8 inch. I took it to my brother who has a 20 ton press. When I pressed it on I could see that it had a very good fit against the oil slinger, so there was a silver lining. Nothing ventured, nothing lost.

Tom

I had the factory do the first one but when I did the rebuild i did it my self. It was just as easy as the video showed. My oven was set at 500 and is right across from the kitchen island. My wife and son held the frozen crank while I put the prop hub on and smacked it home with a heavy hammer. I wouldn't pay to have it done again now that I know how easy it is to do.

It really is pretty easy. It is even easier now that they re-designed the crank for the 2.1 motor and you no longer have to put a few of the other pieces that used to act as spacers on an aerovee. As suggested above the easiest way to do this is in two steps. Freeze the crank and heat the timing gear and install those together first. After that is done go re-freeze the crank for a few hours and then heat the prop hub. If you try to put the prop hub on at the same time as the timing gear you run a good chance of the crank warming back up from the heat of the gear and the hub getting stuck half way installed. It isn't the end of the world but if it goes on far enough you will need a press to get it back apart. Call sonex if this happens to get proper directions on how to press it back off if needed as the crank will need to be supported correctly.

It also helps to have a second person helping you so one person can grab the crank from the freezer and hold it while the other grabs the hub from the oven and installs it. Have everything ready to go and do this installation on the kitchen floor right between the freezer and the oven. Don't heat things up or freeze them and then walk them out to the shop or down to the basement. They will loose too much heat or cold by the time you get there. Also, turn your oven up to 500 degrees and put an oven thermometer in there to make sure it actually is getting that warm. Finally, don't forget to put the bearing on there before installing the hub. You wouldn't be the first person to assemble the whole crank and find it laying on the ground next to where you were working.

Don't let this intimidate you. It really is an easy process. Just make sure you have everything lined up and ready to go and take your time doing it in two steps. If you do that I guarantee that they will slide right together and you will be wondering what the fuss was all about.

Keith
#554

If you any experience doing this sort of thing it is pretty straight forward, however if you have doubts I say let Sonex do it. I made a simple jig to hold the crank on my bench. As my shop is not so close to my house I did not freeze my crank . I did drag my propane B.B. Q. out there, fired up both burners and " cooked " my parts for about a hour. They slid right on. Be certain all parts are clean, no oil or grease allowed. Do not hammer directly on the flange, use a piece of wood as a buffer between hammer and flange. A pair of oven gloves is highly recommended. Good luck and keep at it, it is SO worth it

I assembled my own crank as well. Not too much of a problem. I want to know the results y'all get when you install the cam. When you have it together and rotate the crank how does your cam gear mesh with the timing gear? Is there any degradation of the aluminum cam gear by the steel timing gear? I'm having some problems with this. If you had/have this problem what was your solution.

I bought the crank assembled. I am afraid to do it. Mostly because my wife would KILL me if I put airplane parts in the oven and freezer. Back in NY where I was chapter president, we had a clubhouse with an oven which was sometimes the EAA thermoplastic forming facility. I made landing light lenses for the C140 leading edges there. Surely the spouse factor was the reason Sonex offers them assembled.

Thank you for the replies! They are very helpful! With all this in mind I am going to do it my self. I don't have any issues with the wife and the kitchen (she hates the kitchen). I will be ordering the engine next month and will report back on my results.

The secret to easy crank assembly is to make sure you get the gears and/or hub hot enough. let it heat soak for a while in the oven. Don't be in a hurry! The timing gear will turn a nice shade of deep blue when it's hot enough. It will then slip right on the crank with no problem. For the hub, you shouldn't even need a hammer. If it's hot enough it will slip right on to it's full seating with hand pressure and the bolt will seat it nicely. (The hub will not change color, but it needs to be good and hot.) No muss, no fuss!